01697nas a2200181 4500008004100000245006900041210006800110300001200178490000700190520114100197100002301338700001801361700001801379700001901397700001801416700001901434856006201453 2021 eng d00aFire frequency, state change and hysteresis in tallgrass prairie0 aFire frequency state change and hysteresis in tallgrass prairie a636-6470 v243 a

Hysteresis is a fundamental characteristic of alternative stable state theory, yet evidence of hysteresis is rare. In mesic grasslands, fire frequency regulates transition from grass‐ to shrub‐dominated system states. It is uncertain, however, if increasing fire frequency can reverse shrub expansion, or if grass‐shrub dynamics exhibit hysteresis. We implemented annual burning in two infrequently burned grasslands and ceased burning in two grasslands burned annually. With annual fires, grassland composition converged on that of long‐term annually burned vegetation due to rapid recovery of grass cover, although shrubs persisted. When annual burning ceased, shrub cover increased, but community composition did not converge with a long‐term infrequently burned reference site because of stochastic and lagged dispersal by shrubs, reflecting hysteresis. Our results demonstrated that annual burning can slow, but not reverse, shrub encroachment. In addition, reversing fire frequencies resulted in hysteresis because vegetation trajectories from grassland to shrubland differed from those of shrubland to grassland.

1 aCollins, Scott, L.1 aNippert, J.B.1 aBlair, J., M.1 aBriggs, J., M.1 aBlackmore, P.1 aRatajczak, Zak uhttps://onlinelibrary.wiley.com/doi/abs/10.1111/ele.1367602414nas a2200157 4500008004100000245010000041210006900141300001400210490000600224520187700230100002302107700002502130700001902155700001902174856006302193 2017 eng d00aComplex variation in habitat selection strategies among individuals driven by extrinsic factors0 aComplex variation in habitat selection strategies among individu a1802-18220 v73 a

Understanding behavioral strategies employed by animals to maximize fitness in the face of environmental heterogeneity, variability, and uncertainty is a central aim of animal ecology. Flexibility in behavior may be key to how animals respond to climate and environmental change. Using a mechanistic modeling framework for simultaneously quantifying the effects of habitat preference and intrinsic movement on space use at the landscape scale, we investigate how movement and habitat selection vary among individuals and years in response to forage quality–quantity tradeoffs, environmental conditions, and variable annual climate. We evaluated the association of dynamic, biotic forage resources and static, abiotic landscape features with large grazer movement decisions in an experimental landscape, where forage resources vary in response to prescribed burning, grazing by a native herbivore, the plains bison (Bison bison bison), and a continental climate. Our goal was to determine how biotic and abiotic factors mediate bison movement decisions in a nutritionally heterogeneous grassland. We integrated spatially explicit relocations of GPS-collared bison and extensive vegetation surveys to relate movement paths to grassland attributes over a time period spanning a regionwide drought and average weather conditions. Movement decisions were affected by foliar crude content and low stature forage biomass across years with substantial interannual variation in the magnitude of selection for forage quality and quantity. These differences were associated with interannual differences in climate and growing conditions from the previous year. Our results provide experimental evidence for understanding how the forage quality–quantity tradeoff and fine-scale topography drives fine-scale movement decisions under varying environmental conditions.

1 aRaynor, Edward, J.1 aBeyer, Hawthorne, L.1 aBriggs, J., M.1 aJoern, Anthony uhttps://onlinelibrary.wiley.com/doi/full/10.1002/ece3.276401176nas a2200181 4500008004100000245008000041210006900121300001200190490000700202520057000209100002100779700002500800700002000825700002400845700001900869700002300888856008300911 2017 eng d00aJuniper invasions in grasslands: research needs and intervention strategies0 aJuniper invasions in grasslands research needs and intervention  a64 - 720 v393 a• Despite prescribed fire programs, invasive juniper trees are increasing in the Great Plains. • Continued encroachment of junipers in the Great Plains, especially eastern redcedar and Ashe’s juniper, is degrading grasslands and increasing health concerns through pollen production. • Biological and ecological research needs include effects on soil and water as well as restoration potential after a mature invasion is treated. • The interface of social science, ecology, economics, and policy may yield productive approaches to slowing the invasion.1 aLeis, Sherry, A.1 aBlocksome, Carol, E.1 aTwidwell, Dirac1 aFuhlendorf, Sam, D.1 aBriggs, J., M.1 aSanders, Larry, D. uhttps://www.sciencedirect.com/science/article/pii/S0190052817300159?via%3Dihub02673nas a2200181 4500008004100000245008000041210006900121490000600190520210100196100001702297700001902314700001702333700001502350700001902365700001502384700001702399856007502416 2017 eng d00aTemporal variability in large grazer space use in an experimental landscape0 aTemporal variability in large grazer space use in an experimenta0 v83 aLand use, climate change, and their interaction each have great potential to affect grazing systems. With anticipated more frequent and extensive future drought, a more complete understanding of the mechanisms that determine large grazer landscape-level distribution under varying climatic conditions is integral to ecosystem management. Using an experimental setting with contrasting fire treatments, we describe the inter-annual variability of the effect of landscape topography and disturbance from prescribed spring fire on large grazer space use in years of variable resource availability. Using GPS telemetry, we investigated space use of plains bison (Bison bison bison) as they moved among watersheds managed with variable experimental burn treatments (1-, 2-, 4-, and 20-year burn intervals) during a seven-year period spanning years of average-to-above average forage production and severe drought. At the landscape scale, bison more strongly favored high-elevation and recently burned watersheds with watersheds burned for the first time in 2 or 4 yr consistently showing higher use relative to annually burned watersheds. In particular, watersheds burned for the first time in 4 yr were avoided to lesser extent than other more frequently burned watersheds during the dormant season. This management type also maintained coupling between bison space use and post-fire regrowth across post-drought growing season months, whereas watersheds with more frequent fire-return intervals attracted bison in only the first month post-fire. Hence, fire frequency played a role in maintaining the coupling of grazer and post-fire regrowth, the fire–grazer interaction, in response to drought-induced reduction in fuel loads. Moreover, bison avoided upland habitat in poor forage production years, when forage regrowth is less likely to occur in upland than in lowland habitats. Such quantified responses of bison to landscape features can aid future conservation management efforts and planning to sustain fire–grazer interactions and resulting spatial heterogeneity in grassland ecosystems.1 aRaynor, E.J.1 aJoern, Anthony1 aSkibbe, A.M.1 aSowers, M.1 aBriggs, J., M.1 aLaws, A.N.1 aGoodin, D.G. uhttps://esajournals.onlinelibrary.wiley.com/doi/full/10.1002/ecs2.167402806nas a2200253 4500008004100000245012700041210006900168300001400237490000700251520198600258653002402244653001602268653002102284653001802305653001502323653001902338100001802357700001902375700001702394700001502411700002302426700002002449856008302469 2016 eng d00aAssessing the potential for transitions from tallgrass prairie to woodlands: are we operating beyond critical transitions?0 aAssessing the potential for transitions from tallgrass prairie t a280–2870 v693 a

A growing body of evidence suggests humans are pushing ecosystems near or beyond key ecological thresholds, resulting in transitions to new, sometimes undesirable phases or states that are costly to reverse. We used remotely sensed fire data to assess if the Flint Hills—a landscape of tallgrass prairie in the Central Great Plains, United States—is operating beyond fire frequency thresholds. Long-term fire experiments and observational evidence suggests that applying prescribed fire at return intervals > 3 yr can lead to transitions from grassland to shrubland. Fire return intervals > 10 yr and complete fire suppression, in particular, can result in transitions to woodlands over 30 − 50 yr. Once shrublands and woodlands are established, restoration back to grassland is difficult with prescribed fires. We applied these fire frequency cutoffs to remotely sensed fire data from 2000 to 2010 in the Flint Hills, identifying the extent of tallgrass prairie susceptible to shrub and tree expansion. We found that 56% (15 620 km2) of grasslands in this region are burned less than every 3 yr and are therefore susceptible to conversion to shrub or tree dominance. The potential effects of this large-scale shift are greater risk for evergreen (Juniperus virginiana) woodland fires, reduced grazing potential, and increased abundance of woodland adapted species at the expense of the native grassland biota. Of the 12 127-km2 area likely to remain grassland, 43% is burned approximately annually, contributing to vegetative homogenization and potential air-quality issues. While this synthesis forecasts a precarious future for tallgrass prairie conservation and their ecosystem services, increases in shrub or tree dominances are usually reversible until fire frequency has been reduced for more than 20 yr. This delay leaves a small window of opportunity to return fire to the landscape and avoid large-scale transformation of tallgrass prairie.

10acatastrophic shifts10aforecasting10amesic grasslands10aregime shifts10aresilience10atipping points1 aRatajczak, Z.1 aBriggs, J., M.1 aGoodin, D.G.1 aMohler, R.1 aNippert, Jesse, B.1 aObermeyer, B.K. uhttps://www.sciencedirect.com/science/article/pii/S1550742416300021?via%3Dihub00472nas a2200145 4500008004100000022001400041245008700055210006900142300001100211490000800222100001900230700002000249700001600269856004100285 2016 eng d a0022-844300aEcohydrological and climate change studies at the Konza Prairie Biological Station0 aEcohydrological and climate change studies at the Konza Prairie  a5 - 110 v1191 aBriggs, J., M.1 aBlair, John, M.1 aHorne, E.A. uhttps://doi.org/10.1660/062.119.010302240nas a2200157 4500008004100000245012900041210006900170300001700239490000600256520167900262100001701941700001901958700002301977700001902000856006302019 2016 eng d00aForaging decisions underlying restricted space use: effects of fire and forage maturation on large herbivore nutrient uptake0 aForaging decisions underlying restricted space use effects of fi a5843–5853 0 v63 a

Recent models suggest that herbivores optimize nutrient intake by selecting patches of low to intermediate vegetation biomass. We assessed the application of this hypothesis to plains bison (Bison bison) in an experimental grassland managed with fire by estimating daily rates of nutrient intake in relation to grass biomass and by measuring patch selection in experimental watersheds in which grass biomass was manipulated by prescribed burning. Digestible crude protein content of grass declined linearly with increasing biomass, and the mean digestible protein content relative to grass biomass was greater in burned watersheds than watersheds not burned that spring (intercept; F1,251 = 50.57, P < 0.0001). Linking these values to published functional response parameters, ad libitum protein intake, and protein expenditure parameters, Fryxell's (Am. Nat., 1991, 138, 478) model predicted that the daily rate of protein intake should be highest when bison feed in grasslands with 400–600 kg/ha. In burned grassland sites, where bison spend most of their time, availability of grass biomass ranged between 40 and 3650 kg/ha, bison selected foraging areas of roughly 690 kg/ha, close to the value for protein intake maximization predicted by the model. The seasonal net protein intake predicted for large grazers in this study suggest feeding in burned grassland can be more beneficial for nutrient uptake relative to unburned grassland as long as grass regrowth is possible. Foraging site selection for grass patches of low to intermediate biomass help explain patterns of uniform space use reported previously for large grazers in fire-prone systems.

1 aRaynor, E.J.1 aJoern, Anthony1 aNippert, Jesse, B.1 aBriggs, J., M. uhttps://onlinelibrary.wiley.com/doi/full/10.1002/ece3.230402957nas a2200145 4500008004100000245008700041210006900128300001500197490000700212520246300219100001702682700001902699700001902718856007402737 2015 eng d00aBison foraging responds to fire frequency in nutritionally heterogeneous grassland0 aBison foraging responds to fire frequency in nutritionally heter a1586 -15970 v963 a

Foraging decisions by native grazers in fire-dependent landscapes modulate the fire–grazing interaction. Uncovering the behavioral mechanisms associated with the attraction of grazers to recently burned areas requires understanding at multiple spatial scales in the ecological foraging hierarchy. This study focused on feeding in the area between steps in a foraging bout, the feeding station, as forage chemistry and vegetation architecture play central roles in these fine-scale, feeding-station decisions. The forage maturation hypothesis (FMH) uses the temporal dynamics of forage quality and quantity in grasslands to explain the distribution of large herbivores, but does not address herbivore responses to inter-patch variation caused by fire-induced nutrient increases of forage quality. Using an experimental setting with contrasting fire treatments we describe the effects of variable burn history on foraging kinetics by bison at Konza Prairie Biological Station (KPBS). We assessed the potential to link the FMH in a complementary fashion to the transient maxima hypothesis (TMH) to explain temporal variation in bison responses to grassland forage quality and quantity in response to burning at different temporal frequencies. Forage attributes met predictions of the TMH that allowed us to investigate how forage maturation affects feeding station foraging behavior across watersheds with varying burn frequency. At sites burned in the spring after several years without burning, both bite mass and intake rate increased with increasing biomass at a greater rate during the growing season than during the transitional midsummer seasonal period. In these infrequently burned watersheds, early growing season bite mass (0.6 ± 0.05 g; mean ± SE), bite rate (38 ± 1.5 bites/min), and intake rate (21 ± 2.3 g/min) was reduced by ~15%, 13%, and 29% during the midsummer transitional period. A behavioral response in foraging kinetics at the feeding station occurred where a nonequilibrial pulse of high-quality resource was made available and then retained by repeated grazing over the growing season. Our results provide the first experimental evidence for demonstrating the fine-scale behavioral response of a large grazer to fire-induced changes in forage attributes, while linking two prominent hypotheses proposed to explain spatial variation in forage quality and quantity at local and landscape scales.

1 aRaynor, E.J.1 aJoern, Anthony1 aBriggs, J., M. uhttps://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/14-2027.103435nas a2200157 4500008004100000245010900041210006900150260004300219490002200262520274400284653008703028100001703115700001903132700001903151856010703170 2015 eng d00aEcological hierarchy of foraging in a large herbivore: the plains bison perspective in tallgrass prairie0 aEcological hierarchy of foraging in a large herbivore the plains aManhattan, KSbKansas State University0 vPhD. Dissertation3 a

Foraging decisions by native grazers in fire-dependent landscapes reflect fire-grazing interactions. I assessed behavioral responses associated with the attraction of grazers to recently burned areas at multiple spatial scales. (a) I focused on feeding in the area between steps in a foraging bout – the feeding station – where forage quality and vegetation architecture underlie these fine-scale decisions. The ‘forage maturation hypothesis’ (FMH) predicts the distribution of large herbivores based on the temporal dynamics of forage quality and quantity, but does not address herbivore responses to inter-patch variation caused by fire-induced increases of forage quality. The ‘transient maxima hypothesis’ (TMH) also predicts variable forage quality and quantity, but in response to intermittent disturbance from fire. I described the effects of variable spring burn history to bison foraging and their spatio-temporal distribution at Konza Prairie. Forage attributes met predictions of the TMH to explain how forage maturation affects foraging behavior across watersheds with varying burn frequency. At sites burned in the spring after several years without burning, intake rate increased with increasing vegetation biomass at a greater rate during the early growing season than during the transitional mid-summer period. This foraging behavior occurred in response to a non-equilibrial pulse of high quality resource that set the stage in the burned area, and was then retained by repeated grazing over the growing season. Thus, bison responded increased forage resource availability resulting from transient maxima in infrequently-burned watersheds burned that spring and they intensely used these areas until forage availability and forage regrowth was not possible. (b) At the patch scale, bison selected areas of low-to-moderate grass cover in which to feed and avoided areas of high forb cover in the growing season. During the dormant season, however, bison selected feeding-sites with uniformly high canopy cover in watersheds that were not burned. (c) At the landscape-scale, infrequently burned watersheds (compared to watersheds that were not burned) provided the strongest significant predictor of bison space use in all early growing- and transitional-season months. (d) The probability of habitat selection was driven by availability of high foliar, protein and low-to-intermediate herbaceous biomass throughout the growing season. These results explain the hierarchy of foraging by a dominant consumer in an experimental landscape by linking two prominent hypotheses, TMH-FMH, proposed to explain spatial variation in forage quality and quantity at local and landscape scales.

10aBison; Foraging Behavior; Forage Maturation; Movement; Space Use; Transient Maxima1 aRaynor, E.J.1 aJoern, Anthony1 aBriggs, J., M. uhttp://krex.k-state.edu/dspace/bitstream/handle/2097/20348/EdwardRaynor2015.pdf?sequence=1&isAllowed=y02633nas a2200253 4500008004100000245013900041210006900180300001500249490000800264520182600272653001002098653001502108653001202123653001502135653001202150653003102162653001002193653001502203100001802218700002302236700001902259700002002278856008102298 2014 eng d00aFire dynamics distinguish grasslands, shrublands, and woodlands as alternative attractors in the Central Great Plains of North America0 aFire dynamics distinguish grasslands shrublands and woodlands as a1374 -13850 v1023 a

Grasslands are threatened globally due to the expansion of woody plants. The few remaining headwater streams within tallgrass prairies are becoming more like typical forested streams due to rapid conversion of riparian zones from grassy to wooded. Forestation can alter stream hydrology and biogeochemistry. We estimated the rate of riparian woody plant expansion within a 30 m buffer zone surrounding the stream bed across whole watersheds at Konza Prairie Biological Station over 25 years from aerial photographs. Watersheds varied with respect to experimentally-controlled fire and bison grazing. Fire frequency, presence or absence of grazing bison, and the historical presence of woody vegetation prior to the study time period (a proxy for proximity of propagule sources) were used as independent variables to predict the rate of riparian woody plant expansion between 1985 and 2010. Water yield was estimated across these years for a subset of watersheds. Riparian woody encroachment rates increased as burning became less frequent than every two years. However, a higher fire frequency (1–2 years) did not reverse riparian woody encroachment regardless of whether woody vegetation was present or not before burning regimes were initiated. Although riparian woody vegetation cover increased over time, annual total precipitation and average annual temperature were variable. So, water yield over 4 watersheds under differing burn frequencies was quite variable and with no statistically significant detected temporal trends. Overall, burning regimes with a frequency of every 1–2 years will slow the conversion of tallgrass prairie stream ecosystems to forested ones, yet over long time periods, riparian woody plant encroachment may not be prevented by fire alone, regardless of fire frequency.

10abison10aEcosystems10aForests10aGrasslands10aGrazing10aLinear regression analysis10aTrees10aWatersheds1 aRatajczak, Z.1 aNippert, Jesse, B.1 aBriggs, J., M.1 aBlair, John, M. uhttps://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2745.1231100428nas a2200157 4500008004100000245002200041210002200063260003800085300001200123490000600135100002000141700002300161700001900184700001400203856005300217 2014 eng d00aGrassland Ecology0 aGrassland Ecology bSpringer-Verlag Berlin Heidelberg a389-4230 v81 aBlair, John, M.1 aNippert, Jesse, B.1 aBriggs, J., M.1 aMonson, R uhttp://knz.lternet.edu/content/grassland-ecology01883nas a2200169 4500008004100000245007400041210006900115300001300184490000800197520135700205100001801562700002001580700001901600700001401619700001901633856006101652 2013 eng d00aGenetic variation and mating success in managed American plains bison0 aGenetic variation and mating success in managed American plains  a182 -1910 v1043 a

The American plains bison (Bison bison) was pushed to the brink of extinction in the late 1800s but has since rebounded. Less than 5% of animals currently exist in conservation herds that are critical for maintaining genetic variability. Here, we use 25 microsatellite loci to assess genetic diversity and patterns of mating success over a 3-year period in a managed conservation herd at Konza Prairie Biological Station, Kansas (total number of individuals genotyped = 587). Heterozygosity was comparable to and allelic diversity higher than that in 11 other wild and managed herds for which similar estimates are available. Parentage analyses revealed that males within the oldest age classes (5–7 years) sired >90% of calves over the study period, consistent with a polygynous breeding system. Asymmetries in siring success also were observed within age classes, with the same males enjoying high siring success over multiple seasons. Empirical results of paternity will facilitate future modeling and empirical efforts to determine how demographic factors, population size, and variation in siring success interact to determine the retention (or loss) of genetic diversity in natural and managed herds, thus allowing informed recommendations for management practices and conservation efforts of this symbolic North American species.

1 aUngerer, M.C.1 aWeitekamp, C.A.1 aJoern, Anthony1 aTowne, G.1 aBriggs, J., M. uhttps://academic.oup.com/jhered/article/104/2/182/80210500506nas a2200133 4500008004100000245009500041210006900136300001500205490000700220100002000227700001900247700001600266856009000282 2012 eng d00aCommunity stability does not preclude ecosystem sensitivity to chronic resource alteration0 aCommunity stability does not preclude ecosystem sensitivity to c a1231 -12330 v261 aKnapp, Alan, K.1 aBriggs, J., M.1 aSmith, M.D. uhttps://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/j.1365-2435.2012.02053.x03092nas a2200193 4500008004100000245012700041210006900168260004300237300001000280490001400290520242700304653002202731653001802753653003002771653002302801100001802824700001902842856003702861 2012 eng d00aMechanisms driving woody encroachment in the tallgrass prairie: an analysis of fire behavior and physiological integration0 aMechanisms driving woody encroachment in the tallgrass prairie a aManhattan, KSbKansas State University a1 -720 vMS Thesis3 a

Woody encroachment has altered the vegetative structure of grasslands worldwide and represents a potentially irreversible shift in grassland dynamics and biodiversity. Clonal woody species appear to be one of the greatest contributors to the shift from graminoid to woody dominance in the tallgrass prairie. Part of the high success rate of clonal species may be attributed to an ability to circumvent recruitment filters through the integration of environmental heterogeneity and acropetal translocation of resources from mother to daughter ramets. The clonal shrub Cornus drummondii persists in a tension zone of the graminoid-dominated tallgrass prairie, where the dominance structure is primarily maintained through the direct and indirect effects of fire. The competitive displacement of native herbaceous vegetation associated with the establishment and expansion of C. drummondii causes a major alteration in the fuel dynamics responsible for the propagation and sustainment of fire, potentially contributing to biofeedback mechanisms that facilitate shrub expansion. The goal of this research was to quantify fire behavior parameters (temperature, intensity, rate of spread, and heat flux) in relation to C. drummondii invasions and to test physiological integration as a mechanism driving encroachment, using manipulation experiments at the Konza Prairie Biological Station. We observed a significant decrease in fireline intensity associated with the encroachment of C. drummondii, which was amplified by the effects of stem density and shrub island area. This alteration in fire behavior also led to reduced heat flux at stems within shrub islands, reducing the likelihood of tissue necrosis and top-kill. With additional fuel, temperatures and fire intensities were higher, similar to open grasslands. In severing rhizomes, and effectively severing the integration of clonal ramets, we observed a higher risk of mortality of daughter ramets. These rhizome severed ramets were more water stressed, had lower photosynthetic rates, and lower woody and foliar biomass production. These results indicate that C. drummondii significantly alters fire behavior, releasing ramets from the fire trap of successive top-killing, while the integration of intraclonal ramets allows daughter ramets to survive mid-summer drought and increases the likelihood of successful establishment and further clonal reproduction.

10aCornus drummondii10aFire behavior10aPhysiological integration10awoody encroachment1 aKillian, P.D.1 aBriggs, J., M. uhttp://hdl.handle.net/2097/1419702031nas a2200229 4500008004100000245011400041210006900155260002400224300001300248520129100261100002001552700001901572700001901591700001501610700001801625700001501643700002001658700001901678700001601697700002001713856006801733 2008 eng d00aEcological consequences of the replacement of native grassland by Juniperus virginiana and other woody plants0 aEcological consequences of the replacement of native grassland b bSpringer-Verlag, NY a156 -1693 a

Although grasslands have been altered by humans for thousands of years (Wedel 1961; Bond et al. 2003), the loss of grassland as a result of anthropogenic activities has increased dramatically over the past 150 years. When Europeans first settled the Midwest and Great Plains, the greatest threat to native grasslands was the conversion of the most highly productive of these ecosystems to row-crop agriculture (Samson and Knopf 1994). Later, with improvements in soil moisture management and irrigation technology, even low-productivity grasslands were plowed. Today, those remnants of the most productive grasslands that escaped the plow are threatened, as are most of Earth’s ecosystems, by a variety of global change phenomena (Vitousek et al. 1997), with the invasion and expansion of woody species into grasslands one of the greatest of these threats. The replacement of grasslands by shrubland, woodland, and forest is a concern not only in the United States but worldwide (Archer et al. 1988; Van Auken 2000; Roques et al. 2001; Silva et al. 2001). Species of woody plants that invade grasslands may include both native plants which previously existed as more minor components of the ecosystem as well as alien species (Bragg and Hulbert 1976; Harcombe et al. 1993).

1 aKnapp, Alan, K.1 aMcCarron, J.K.1 aSilletti, A.M.1 aHoch, G.A.1 aHeisler, J.L.1 aLett, M.S.1 aBlair, John, M.1 aBriggs, J., M.1 aSmith, M.D.1 aVan Auken, O.W. uhttps://link.springer.com/chapter/10.1007%2F978-0-387-34003-6_801892nas a2200241 4500008004100000245013500041210006900176300001300245490000700258520110800265100002001373700001901393700002401412700001701436700002101453700001601474700001701490700001601507700001701523700001601540700001701556856007701573 2008 eng d00aShrub encroachment in North American grasslands: Shifts in growth form dominance rapidly alters control of ecosystem carbon inputs0 aShrub encroachment in North American grasslands Shifts in growth a615 -6230 v143 a

Shrub encroachment into grass-dominated biomes is occurring globally due to a variety of anthropogenic activities, but the consequences for carbon (C) inputs, storage and cycling remain unclear. We studied eight North American graminoid-dominated ecosystems invaded by shrubs, from arctic tundra to Atlantic coastal dunes, to quantify patterns and controls of C inputs via aboveground net primary production (ANPP). Across a fourfold range in mean annual precipitation (MAP), a key regulator of ecosystem C input at the continental scale, shrub invasion decreased ANPP in xeric sites, but dramatically increased ANPP (>1000 g m−2) at high MAP, where shrub patches maintained extraordinarily high leaf area. Concurrently, the relationship between MAP and ANPP shifted from being nonlinear in grasslands to linear in shrublands. Thus, relatively abrupt (<50 years) shifts in growth form dominance, without changes in resource quantity, can fundamentally alter continental-scale pattern of C inputs and their control by MAP in ways that exceed the direct effects of climate change alone.

1 aKnapp, Alan, K.1 aBriggs, J., M.1 aCollins, Scott., L.1 aArcher, S.R.1 aBret-Harte, M.S.1 aEwers, B.E.1 aPeters, D.P.1 aYoung, D.R.1 aShaver, G.R.1 aPendall, E.1 aCleary, M.B. uhttps://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2486.2007.01512.x00931nas a2200157 4500008004100000245009900041210006900140260003200209300001100241520032100252100002000573700001900593700001900612700001500631856012700646 2007 eng d00aEstimating aboveground net primary production in grassland and herbaceous dominated ecosystems0 aEstimating aboveground net primary production in grassland and h bOxford University Press, NY a27 -483 aThis paper reviews past and currently accepted methods of estimating aboveground net primary production (NPP) in grass and herb-dominated ecosystems, provides some guiding principles and recommendations to facilitate accurate determination of aboveground NPP, and discusses biases and errors and sampling adequacy. 1 aKnapp, Alan, K.1 aBriggs, J., M.1 aChilders, D.L.1 aSala, O.E. uhttp://knz.lternet.edu/content/estimating-aboveground-net-primary-production-grassland-and-herbaceous-dominated-ecosystems02841nas a2200145 4500008004100000245012700041210006900168260006100237300001100298520225200309100001802561700002002579700001902599856007702618 2007 eng d00aFire and resource availability influence carbon and water relations of the C3 shrub Cornus drummondii in a mesic grassland0 aFire and resource availability influence carbon and water relati aTall Timbers Research Station, Tallahassee, Florida, USA a86 -933 a

A dramatic increase in cover by woody vegetation has been observed in grasslands worldwide, due to independent and interacting global changes. In the C4-dominated mesic tallgrass prairie of North America, the most proximate factor driving this shift in growth-form dominance is fire exclusion. In 2001, we reintroduced annual fire into a C4-dominated mesic grassland where it had been excluded for 10 y, and evaluated changes in stem density and ecophysiology of an increasingly abundant C3 woody plant, roughleaf dogwood(Cornus drummondii). Our primary objective was to quantify the impacts of fire-induced aboveground mortality and resource constraints on the persistence of roughleaf dogwood in this ecosystem.

In both years of the study (2001–2002), burned shrubs suffered a complete loss of aboveground biomass due to top-kill from spring fire but persisted via resprouting. A considerable reduction in total growing-season precipitation in 2002, as compared to 2001, revealed that resprouts had lower mortality with reduced soil moisture, were less vulnerable to reductions in soil moisture availability, and maintained higher predawn xylem pressure potentials and rates of photosynthesis than did unburned shrubs. Additionally, enrich-ment of13Cleaf in burned shrubs in 2002 was indicative of greater water use efficiency of resprouting stems. During the drought that occurred in the second growing season, mortality of stems within unburned shrub islands increased and was nearly 9 times more than in burned shrub islands. Thus, resprouting shrubs—with their characteristics of reduced leaf tissue, taller stems, and greater stem densities—are efficient in rapidly reoccupying post-fire environments, even with the added stress of below-average precipitation during the growing season. The results of this study suggest that within this grassland, reintroduction of fire will not eliminate rough leaf dogwood in the short term because of its ability to resprout vigorously and persist, even under stressful moisture conditions. Given that North American grasslands are important both economically and ecologically, fire management plans should therefore emphasize frequent fire to prevent shrub establishment

1 aHeisler, J.L.1 aKnapp, Alan, K.1 aBriggs, J., M. uhttp://talltimbers.org/wp-content/uploads/2014/03/Heisleretal2007_op.pdf02991nas a2200217 4500008004100000245009600041210006900137300001100206490000800217520225200225653000902477653001902486653001402505653003002519653001802549653002202567100002302589700002002612700001902632856012202651 2006 eng d00aIntra-annual rainfallvariability and grassland productivity: can the past predictthe future0 aIntraannual rainfallvariability and grassland productivity can t a65 -740 v1843 aPrecipitation quantity has been shown to influence grassland aboveground net primary productivity (ANPP) positively whereas experimental increases in of temporal variability in water availability commonly exhibit a negative relationship with ANPP. We evaluated long term ANPP datasets from the Konza Prairie Long Term Ecological Research (LTER) program (1984–1999) to determine if similar relationships could be identified based on patterns of natural variability (magnitude and timing) in precipitation. ANPP data were analyzed from annually burned sites in native mesic grassland and productivity was partitioned into graminoid (principally C4 grasses) and forb (C3 herbaceous) components. Although growing season precipitation amount was the best single predictor of total and grass ANPP (r 2=0.62), several measures of precipitation variability were also significantly and positively correlated with productivity, independent of precipitation amount. These included soil moisture variability, expressed as CV, for June (r 2=0.45) and the mean change in soil moisture between weekly sampling periods in June and August (%wv) (r 2=0.27 and 0.32). In contrast, no significant relationships were found between forb productivity and any of the precipitation variables (p>0.05). A multiple regression model combining precipitation amount and both measures of soil moisture variability substantially increased the fit with productivity (r 2=0.82). These results were not entirely consistent with those of short-term manipulative experiments in the same grassland, however, because soil moisture variability was often positively, not negatively related to ANPP. Differences in results between long and short term experiments may be due to low variability in the historic precipitation record compared to that imposed experimentally as experimental levels of variability exceeded the natural variability of this dataset by a factor of two. Thus, forecasts of ecosystem responses to climate change (i.e. increased climatic variability), based on data constrained by natural and recent historical rainfall patterns may be inadequate for assessing climate change scenarios if precipitation variability in the future is expected to exceed current levels.10aANPP10aClimate change10agrassland10aPrecipitation variability10asoil moisture10atallgrass prairie1 aNippert, Jesse, B.1 aKnapp, Alan, K.1 aBriggs, J., M. uhttp://knz.lternet.edu/content/intra-annual-rainfallvariability-and-grassland-productivity-can-past-predictthe-future01955nas a2200253 4500008004100000245010600041210006900147300001300216490000700229520114300236653000901379653001501388653001201403653002201415653002101437100001901458700002001477700002001497700001801517700001501535700001501550700001901565856011701584 2005 eng d00aAn ecosystem in transition: causes and consequences of the conversion of mesic grassland to shrubland0 aecosystem in transition causes and consequences of the conversio a243 -2540 v553 aWoody plant expansion is one of the greatest contemporary threats to mesic grasslands of the central United States. In this article, we synthesize more than 20 years of research to elucidate the causes and consequences of the ongoing transition of C4-dominated grasslands to savanna-like ecosystems codominated by grasses and woody plants. This transition is contingent on fire-free intervals, which provide the opportunity for recruitment both of new individuals and of additional shrub and tree species into this grassland. Once shrubs establish, their cover increases regardless of fire frequency, and infrequent fires accelerate the spread of some shrub species. This process has resulted in a new dynamic state of shrub–grass coexistence in the mesic grasslands of North America. Important consequences of this shift in plant life-form abundance include alterations in plant productivity, species diversity, and carbon storage. Without drastic measures such as mechanical removal of shrubs, it is unlikely that management of fire and grazing regimes alone will be sufficient to restore historic grass dominance in these ecosystems.10afire10aGrasslands10aGrazing10atallgrass prairie10awoody vegetation1 aBriggs, J., M.1 aKnapp, Alan, K.1 aBlair, John, M.1 aHeisler, J.L.1 aHoch, G.A.1 aLett, M.S.1 aMcCarron, J.K. uhttp://knz.lternet.edu/content/ecosystem-transition-causes-and-consequences-conversion-mesic-grassland-shrubland02939nas a2200169 4500008004100000245010700041210006900148300001500217490000700232520231200239100001802551700001902569700002002588700002002608700001402628856012702642 2004 eng d00aDirect and indirect effects of fire on shrub density and aboveground productivity in a mesic grassland0 aDirect and indirect effects of fire on shrub density and abovegr a2245 -22570 v853 aDeterminants of the balance between grass and woody vegetation in grasslands and savannas have received considerable attention because of the potential for dramatic shifts in ecosystem structure and function as one growth form replaces the other. We studied a mesic grassland where recently established “shrub islands” are increasing in abundance due to fire suppression. Our objective was to assess the role of the direct effects of fire vs. indirect alterations in resource availability (N and light), as mechanisms that may constrain/facilitate shrub (Cornus drummondii) encroachment. The direct effects of fire in 2001 and 2002 were 100% aboveground mortality of C. drummondii shoots and removal of the detrital layer. Post-fire resprouting resulted in ∼600% increase in stem density compared to a 200% increase in shrub islands protected from fire. In burned shrub islands with an added detrital layer, temperature and light penetration to the soil surface were reduced (by 6.5°C and to <3% of full sunlight), but stem density still increased by ∼400%. Thus, both the direct effects of fire and the indirect effect on the energy environment increased C. drummondii stem densities. In contrast, N additions did not influence new stem production or aboveground net primary productivity (ANPP; grams per square meter per year), suggesting that N availability did not constrain shrub growth during this study. While fire did not impact total ANPP, it did shift the relative abundance of growth forms. Grass productivity (360.7 ± 20.1 g/m2 [mean ± 1 se]) was stimulated (an increase of ∼30%) by the high light conditions of the post-fire environment, while C. drummondii ANPP (34.2 ± 2.4 g/m2) was reduced by ∼30%. In shrub islands protected from fire, C. drummondii ANPP was greatest (50.4 ± 2.2 g/m2), whereas lower graminoid ANPP (282.5 ± 19.9 g/m2) was observed. The persistence of woody vegetation, despite two successive fires, along with a significant reduction in grass ANPP (∼30%) suggests that once established, C. drummondii can persist and exclude C4 grasses. Thus, restoring fire to mesic grasslands may prevent further conversion to shrub/woodland, but the abundance of shrubs is likely to remain unchanged with community structure co-dominated by multiple growth forms.1 aHeisler, J.L.1 aBriggs, J., M.1 aKnapp, Alan, K.1 aBlair, John, M.1 aSeery, A. uhttp://knz.lternet.edu/content/direct-and-indirect-effects-fire-shrub-density-and-aboveground-productivity-mesic-grassland02236nas a2200157 4500008004100000245012800041210006900169300001500238490000700253520161900260100001501879700002001894700001901914700002001933856012501953 2004 eng d00aInfluence of shrub encroachment on aboveground net primary productivity and carbon and nitrogen pools in a mesic grassland0 aInfluence of shrub encroachment on aboveground net primary produ a1363 -13700 v823 aThe clonal shrub Cornus drummondii C.A. Mey. is rapidly increasing in cover and displacing mesic grassland species in the central USA as a consequence of fire suppression. We assessed the impact of C. drummondii on carbon (C) and nitrogen (N) pools and C fluxes in a tallgrass prairie in eastern Kansas, USA, through a comparison of both burned and unburned C. drummondii islands with open grassland areas. Allometric equations relating C. drum mondii foliage and wood biomass to basal stem diameter were developed to estimate aboveground biomass and net primary productivity (ANPP) of C. drummondii. Within C. drummondii islands, ANPP was 496 ± 45 g C·m–2·year–1, nearly three times that within open grassland (167 ± 13 g C·m–2·year–1). As a result of greater aboveground biomass, aboveground C and N storage within shrub islands (3270 ± 466 g C·m–2, 37.9 ± 5.3 g N·m–2) was substantially greater than that within open grassland (241 ± 33 g C·m–2, 6.1 ± 0.8 g N·m–2). No change in soil organic C or total N to 10-cm depth was evident; however, soil CO2 flux was significantly reduced in C. drummondii islands relative to the open grassland. The storage of C in aboveground biomass of C. drummondii represents a significant short-term increase in C storage relative to open grassland. However, potential alterations in belowground processes must be quantified before the long-term net effect of shrub encroachment on C and N pools within this mesic grassland can be determined.Key words: aboveground biomass, Cornus drummondii, net primary productivity, shrub encroachment, tallgrass prairie.1 aLett, M.S.1 aKnapp, Alan, K.1 aBriggs, J., M.1 aBlair, John, M. uhttp://knz.lternet.edu/content/influence-shrub-encroachment-aboveground-net-primary-productivity-and-carbon-and-nitrogen02184nas a2200205 4500008004100000245013200041210006900173300001300242490000700255520143300262653001701695653001901712653002901731653001101760653002301771100001801794700001901812700002001831856012701851 2003 eng d00aLong-term patterns of shrub expansion in a C4-dominated grassland: fire frequency and the dynamics of shrub cover and abundance0 aLongterm patterns of shrub expansion in a C4dominated grassland  a423 -4280 v903 aWorldwide, grassland ecosystems have experienced a major shift in growth-form dominance as woody plant species have expanded and replaced native grasses. In the C4-dominated grasslands of central North America, a reduction in fire frequency is the most cited cause of this shift in growth forms as fire both enhances grass productivity and constrains the establishment and expansion of native woody vegetation. Using an 18-yr plant species composition data set, we quantified patterns of change in shrub cover, frequency, and species richness associated with three distinct fire regimes. During the study period (1983–2000), shrub cover increased most dramatically in sites in which the frequency of fire was once every 4 yr (intermediate frequency; 28.6%) followed by sites in which fire occurred only once during the 18-yr period (low frequency; 23.7%). Annual fire effectively prevented the recruitment of new woody species, but even with this high fire frequency, shrub cover increased slightly (3.7%). Comparatively, shrub species richness increased by three and six, respectively, in the intermediate- and low-frequency fire sites. These data indicate that within this grassland, periods without fire are necessary for recruitment of both new individuals and additional shrub species; however, once established, shrub cover will increase regardless of fire frequency and even annual fire will not reduce shrub abundance.10aC4 grassland10aFire frequency10agrowth form substitution10aShrubs10awoody encroachment1 aHeisler, J.L.1 aBriggs, J., M.1 aKnapp, Alan, K. uhttp://knz.lternet.edu/content/long-term-patterns-shrub-expansion-c4-dominated-grassland-fire-frequency-and-dynamics-shrub00675nas a2200181 4500008004100000245009700041210006900138260004800207300001300255653001400268653001400282100001300296700001400309700001900323700001200342700001700354856012200371 2002 eng d00aApplications of advanced technologies in studying and managing grassland landscape integrity0 aApplications of advanced technologies in studying and managing g aCambridge, U.K.bCambridge University Press a390 -41110agrassland10alandscape1 aHoch, G.1 aBrock, B.1 aBriggs, J., M.1 aLiu, J.1 aTaylor, W.W. uhttp://knz.lternet.edu/content/applications-advanced-technologies-studying-and-managing-grassland-landscape-integrity02469nas a2200241 4500008004100000245011700041210006900158300001300227490000600240520165700246653000901903653002101912653001201933653002501945653002201970653002001992653001402012653002202026100001502048700001902063700001802082856012702100 2002 eng d00aAssessing the rate, mechanism and consequences of conversion of tallgrass prairie to Juniperus virginiana forest0 aAssessing the rate mechanism and consequences of conversion of t a578 -5860 v53 aWe assessed the determinants and consequences of the expansion of Juniperus virginiana L. (red cedar) populations into central US grasslands using historical aerial photos and field measurements of forest extent, tree growth, fire-induced mortality, and responses in herbaceous species diversity and productivity. Photos from northeast Kansas dating back to 1956 indicate that native tallgrass prairie can be converted to closed-canopy red cedar forest in as little as 40 years (a 2.3% increase in forest cover per year). Mean tree density in 21 forested sites ranged from 130 to 3500 trees/ha, with most sites at more than 800 trees/ha. In younger stands, maximum growth rates of individual red cedar trees exceeded 20 cm/y in height. Land management practices were critical to the establishment and growth of red cedar forest. Grazing reduced the fuel loads by more than 30% in tallgrass prairie. Based on measurements of mortality for more than 1800 red cedar trees, fire-induced mortality in grazed areas averaged 31.6% versus more than 90% at ungrazed sites. When tallgrass prairie was converted to red cedar forest, herbaceous species diversity and productivity were drastically reduced, and most grassland species were virtually eliminated. Consequently, community structure shifted from dominance by herbaceous C4 species to evergreen woody C3 species; this shift is likely to be accompanied by alterations in carbon storage and other ecosystem processes in a relatively short time period. Here we present a conceptual model that integrates the ecological and socioeconomic factors that underlie the conversion of grassland to red cedar forest.10afire10aforest expansion10aGrazing10aJuniperus virginiana10aland-cover change10aland-use change10ared cedar10atallgrass prairie1 aHoch, G.A.1 aBriggs, J., M.1 aJohnson, L.C. uhttp://knz.lternet.edu/content/assessing-rate-mechanism-and-consequences-conversion-tallgrass-prairie-juniperus-virginiana02486nas a2200157 4500008004100000245009000041210006900131300001300200490000700213520191500220653002202135100002402157700001602181700001902197856011202216 2002 eng d00aEffect of local and regional processes on plant species richness in tallgrass prairie0 aEffect of local and regional processes on plant species richness a571 -5790 v993 aHistorically, diversity in a community was often believed to result primarily from local processes, but recent evidence suggests that regional diversity may strongly influence local diversity as well. We used experimental and observational vegetation data from Konza Prairie, Kansas, USA, to determine if: (1) there is a relationship between local and regional richness in tallgrass prairie vegetation; (2) local dominance reduces local species richness; and (3) reducing local dominance increases local and regional species richness. We found a positive relationship between regional and local richness; however, this relationship varied with grazing, topography and fire frequency. The decline in variance explained in the grazed vegetation, in particular, suggested that local processes associated with grazing pressure on the dominant grasses strongly influenced local species richness. Experimental removal of one of the dominant grasses, Andropogon scoparius, from replicate plots resulted in a significant increase in local species richness compared to adjacent reference plots. Overall all sites, species richness was higher in grazed (192 spp.) compared to ungrazed (158 spp.) areas. Across the Konza Prairie landscape, however, there were no significant differences in the frequency distribution of species occurrences, or in the relationship between the number of sites occupied and average abundance in grazed compared to ungrazed areas. Thus, local processes strongly influenced local richness in this tallgrass prairie, but local processes did not produce different landscape-scale patterns in species distribution and abundance. Because richness was enhanced at all spatial scales by reducing the abundance of dominant species, we suggest that species richness in tallgrass prairie results from feedbacks between, and interactions among, processes operating at multiple scales in space and time.10atallgrass prairie1 aCollins, Scott., L.1 aGlenn, S.M.1 aBriggs, J., M. uhttp://knz.lternet.edu/content/effect-local-and-regional-processes-plant-species-richness-tallgrass-prairie02365nas a2200169 4500008004100000245010600041210006900147300001300216490000800229520174200237653002201979653001602001100001902017700002002036700001402056856012502070 2002 eng d00aExpansion of woody plants in tallgrass prairie: a 15 year study of fire and fire-grazing interactions0 aExpansion of woody plants in tallgrass prairie a 15 year study o a287 -2940 v1473 aTemporal changes in the abundance of trees and a common shrub, Cornus drummondii, were quantified for 15 y (1981–1996) in seven tallgrass prairie watersheds in Northeast Kansas. Woody plant responses to different fire frequencies and grazing were assessed with a data set that included >9000 individuals. Although 15 tree species were included in this data set, only four (Juniperus virginiana, Celtis occidentalis, Gleditsia triacanthos and Ulmus americana) were sufficiently abundant for detailed analysis. Over the 15 y study tree density increased by two- to 10-fold, except in watersheds burned annually where woody plants remained almost completely absent throughout the study. Although increased woody plant abundance was expected in watersheds protected from fire, tree and shrub density also increased substantially in watersheds burned only once in 4 y. An intermediate fire frequency (burned every 3–5 y) actually increased the abundance of C. drummondii relative to a low fire frequency (burned only once in 15 y). Moreover, a severe wildfire in 1991, which affected all watersheds, did not markedly reverse this pattern of increase in abundance in most tree species. Four years after the addition of native herbivores (Bos bison) to three of the long-term experimental watersheds (infrequently and annually burned) woody plant abundance increased by four- and 40-fold, respectively, compared to corresponding ungrazed watersheds. Thus, the presence of large ungulate grazers in tallgrass prairie resulted in a significant increase in woody plant abundance. The most parsimonious explanation for this phenomenon is that fire intensity and extent was reduced in grazed grasslands allowing greater success of woody species.10atallgrass prairie10awoody plant1 aBriggs, J., M.1 aKnapp, Alan, K.1 aBrock, B. uhttp://knz.lternet.edu/content/expansion-woody-plants-tallgrass-prairie-15-year-study-fire-and-fire-grazing-interactions01826nas a2200169 4500008004100000245007300041210006900114300001300183490000700196520125600203653002201459100002301481700002001504700001901524700001501543856009801558 2002 eng d00aWhite-tailed deer browsing on six shrub species of tallgrass prairie0 aWhitetailed deer browsing on six shrub species of tallgrass prai a141 -1560 v123 aNative grasses and forbs were once dominant in tallgrass prairies, but nonnative plants have largely replaced natives in most grassland of Illinois. Ample evidence indicates that white-tailed deer (Odocoileus virginianus) have a strong impact on native forests and prairie, but we know little about their impact on nonnative grasslands. This study tested the hypothesis that foraging by deer on native forbs and woody plants increases the dominance of introduced grasses as succession proceeds in old fields of central Illinois. We tested that hypothesis using fencing that excluded deer, but not other herbivores, from replicated plots in three old fields at different successional stages. The composition of the plant community changed rapidly in early succession and showed relatively little effect of deer, other than slowing the invasion by woody plants. In mid- and late successional fields, however, fenced plots had higher relative abundance of native forbs, particularly goldenrod (Solidago spp.), and lower relative abundance of introduced perennial grasses than did control plots. Thus, deer facilitated introduced perennial grasses and inhibited native forbs and woody plants in old fields, thereby delaying succession to deciduous forest.10atallgrass prairie1 aVan Der Hoek, D.J.1 aKnapp, Alan, K.1 aBriggs, J., M.1 aBokdam, J. uhttp://knz.lternet.edu/content/white-tailed-deer-browsing-six-shrub-species-tallgrass-prairie02233nas a2200217 4500008004100000245007800041210006900119300001200188490000800200520152900208653003901737653001701776653000901793653001001802653001501812653002601827653002201853100001901875700002001894856010101914 2001 eng d00aDeterminants of C3 forb growth and production in a C4 dominated grassland0 aDeterminants of C3 forb growth and production in a C4 dominated  a93 -1000 v1523 aForbs are the most abundant species within the vascular flora of tallgrass prairie and they make the greatest contribution to biodiversity of all growth forms. However, little is known about the factors that determine their productivity and growth rates. The objective of this study was to assess the controls of forb growth (absolute and relative) and production in tallgrass prairie from a long-term burning experiment at the Konza Prairie in NE Kansas. Over the 14-year study, forbs comprised 9% of the total biomass production on sites with a high fire frequency vs. 29% on the low fire frequency site, with gramminoids accounting for the remainder. Although interannual variations in peak biomass of the grasses was strongly correlated with environmental variables related to water availability, there were no similar relationships for forbs, suggesting that production of forbs and grasses responded to interannual variations in climate in different ways. Multivariate analysis of climatic controls on growth rates of grasses and forbs yielded similar results. Although forbs had low biomass and absolute growth per unit ground area in frequently burned prairie, their relative growth rates were highest in such sites. Thus, it appears that reduced growth rates of individual forbs per se do not limit forb success in annually burned prairie. Instead, direct negative effects of fire on forbs (increased mortality) may be responsible. Determinants of forb growth and productivity in unburned prairie remain unresolved.10aaboveground net primary production10aBiodiversity10afire10aforbs10aGraminoids10aRelative growth rates10atallgrass prairie1 aBriggs, J., M.1 aKnapp, Alan, K. uhttp://knz.lternet.edu/content/determinants-c3-forb-growth-and-production-c4-dominated-grassland02606nas a2200253 4500008004100000245009800041210006900139300001100208490000600219520178000225653002402005653001602029653001002045653001402055653001502069653002502084653002302109653002202132653002102154100002002175700001902195700002002214856011802234 2001 eng d00aFrequency and extent of water limitation to primary production in a mesic temperate grassland0 aFrequency and extent of water limitation to primary production i a19 -280 v43 aThe frequency and extent of water limitation to aboveground net primary production (ANPP) in a mesic grassland in NE Kansas (Konza Prairie, USA) was assessed with an 8-year irrigation experiment. Since 1991, transects spanning upland and lowland sites in annually burned, ungrazed tallgrass prairie were provided with supplemental water to satisfy evapotranspirational demands. This protocol minimized water limitations during the growing season, as well as interannual variability in water stress. Irrigation of this mesic grassland increased ANPP in 6 of 8 years by an average of 26% when compared to control transects. Although interannual variation in ANPP was greater in uplands than lowlands at nominal levels of precipitation, reducing interannual variability in water availability via irrigation eliminated topographic differences; the irrigation protocol also reduced interannual variability in ANPP by as much as 40%. The addition of supplemental water enabled us to extend the relationship between annual precipitation and ANPP in grasslands to precipitation levels (average, 1153 mm; maximum, 1346 mm) similar to those experienced by more mesic grasslands that today exist only as remnants several hundred kilometers east of Kansas. This relationship was linear (r 2= 0.81), with maximum ANPP (738 g/m2) similar to values reported for sites in Illinois and Wisconsin. After 8 years of irrigation, production of the C3 forb component was twice that in control sites. These results indicate that water limitations in grasslands at the western edge of the presettlement extent of tallgrass prairie affect ANPP in most years and that this high frequency of water limitation may lead to greater dominance of the C4 grasses than is seen in more eastern grassland sites.10aAndropogon gerardii10aC 4 grasses10aforbs10agrassland10airrigation10aleaf water potential10aPrimary production10atallgrass prairie10awater limitation1 aKnapp, Alan, K.1 aBriggs, J., M.1 aKoelliker, J.K. uhttp://knz.lternet.edu/content/frequency-and-extent-water-limitation-primary-production-mesic-temperate-grassland00481nas a2200121 4500008004100000245008400041210006900125300001300194490000700207100001600214700001900230856011000249 2001 eng d00aSpecies, season, and density of buried seeds surviving fox squirrel depredation0 aSpecies season and density of buried seeds surviving fox squirre a197 -2080 v331 aSmith, C.C.1 aBriggs, J., M. uhttp://knz.lternet.edu/content/species-season-and-density-buried-seeds-surviving-fox-squirrel-depredation00520nas a2200133 4500008004100000245007100041210006900112260005100181300001000232100001500242700001900257700001900276856009100295 1999 eng d00aExpansion of eastern red cedar in the northern Flint Hills, Kansas0 aExpansion of eastern red cedar in the northern Flint Hills Kansa aKearney, NEbUniversity of Nebraska at Kearney a9 -151 aHoch, G.A.1 aBriggs, J., M.1 aSpringer, J.T. uhttp://knz.lternet.edu/content/expansion-eastern-red-cedar-northern-flint-hills-kansas00565nas a2200181 4500008004100000245006700041210006300108300001100171490000700182100002000189700002000209700001900229700002400248700001900272700001800291700001600309856005800325 1999 eng d00aThe keystone role of bison in North American tallgrass prairie0 akeystone role of bison in North American tallgrass prairie a39 -500 v491 aKnapp, Alan, K.1 aBlair, John, M.1 aBriggs, J., M.1 aCollins, Scott., L.1 aHartnett, D.C.1 aJohnson, L.C.1 aTowne, E.G. uhttp://www.jstor.org/stable/10.1525/bisi.1999.49.1.3901614nas a2200169 4500008004100000245009700041210006900138300001200207490000700219520101500226100001601241700001901257700001701276700001401293700001901307856011801326 1999 eng d00aManaging Data from Multiple Disciplines, Scales, and Sites to Support Synthesis and Modeling0 aManaging Data from Multiple Disciplines Scales and Sites to Supp a99 -1070 v703 aThe synthesis and modeling of ecological processes at multiple spatial and temporal scales involves bringing together and sharing data from numerous sources. This article describes a data and information system model that facilitates assembling, managing, and sharing diverse data from multiple disciplines, scales, and sites to support integrated ecological studies. Cross-site scientific-domain working groups coordinate the development of data associated with their particular scientific working group, including decisions about data requirements, data to be compiled, data formats, derived data products, and schedules across the sites. The Web-based data and information system consists of nodes for each working group plus a central node that provides data access, project information, data query, and other functionality. The approach incorporates scientists and computer experts in the working groups and provides incentives for individuals to submit documented data to the data and information system.1 aOlson, R.J.1 aBriggs, J., M.1 aPorter, J.H.1 aMah, G.R.1 aStafford, S.G. uhttp://knz.lternet.edu/content/managing-data-multiple-disciplines-scales-and-sites-support-synthesis-and-modeling03187nas a2200169 4500008004100000245011900041210006900160300001100229490000700240520255700247100001702804700001602821700001802837700002002855700001902875856012302894 1999 eng d00aRelationships between leaf area index and Landsat TM spectral vegetation indices across three temperate zone sites0 aRelationships between leaf area index and Landsat TM spectral ve a52 -680 v703 aMapping and monitoring of leaf area index (LAI) is important for spatially distributed modeling of vegetation productivity, evapotranspiration, and surface energy balance. Global LAI surfaces will be an early product of the MODIS Land Science Team, and the requirements for LAI validation at selected sites have prompted interest in accurate LAI mapping at a more local scale. While spectral vegetation indices (SVIs) derived from satellite remote sensing have been used to map LAI, vegetation type, and related optical properties, and effects of Sun–surface–sensor geometry, background reflectance, and atmospheric quality can limit the strength and generality of empirical LAI–SVI relationships. In the interest of a preliminary assessment of the variability in LAI–SVI relationships across vegetation types, we compared Landsat 5 Thematic Mapper imagery from three temperate zone sites with on-site LAI measurements. The sites differed widely in location, vegetation physiognomy (grass, shrubs, hardwood forest, and conifer forest), and topographic complexity. Comparisons were made using three different red and near-infrared-based SVIs (NDVI, SR, SAVI). Several derivations of the SVIs were examined, including those based on raw digital numbers (DN), radiance, top of the atmosphere reflectance, and atmospherically corrected reflectance. For one of the sites, which had extreme topographic complexity, additional corrections were made for Sun–surface–sensor geometry. Across all sites, a strong general relationship was preserved, with SVIs increasing up to LAI values of 3 to 5. For all but the coniferous forest site, sensitivity of the SVIs was low at LAI values above 5. In coniferous forests, the SVIs decreased at the highest LAI values because of decreasing near-infrared reflectance associated with the complex canopy in these mature to old-growth stands. The cross-site LAI–SVI relationships based on atmospherically corrected imagery were stronger than those based on DN, radiance, or top of atmosphere reflectance. Topographic corrections at the conifer site altered the SVIs in some cases but had little effect on the LAI–SVI relationships. Significant effects of vegetation properties on SVIs, which were independent of LAI, were evident. The variability between and around the best fit LAI–SVI relationships for this dataset suggests that for local accuracy in development of LAI surfaces it will be desirable to stratify by land cover classes (e.g., physiognomic type and successional stage) and to vary the SVI.1 aTurner, D.P.1 aCohen, W.B.1 aKennedy, R.E.1 aFassnacht, K.S.1 aBriggs, J., M. uhttp://knz.lternet.edu/content/relationships-between-leaf-area-index-and-landsat-tm-spectral-vegetation-indices-across00648nas a2200217 4500008004100000245003900041210003900080260003800119300001300157653002200170100001800192700001800210700001400228700002000242700001600262700002000278700001900298700001900317700002400336856007000360 1998 eng d00aAnimal populations and communities0 aAnimal populations and communities aNew YorkbOxford University Press a113 -13910atallgrass prairie1 aKaufman, D.W.1 aKaufman, G.A.1 aFay, P.A.1 aZimmerman, J.L.1 aEvans, E.W.1 aKnapp, Alan, K.1 aBriggs, J., M.1 aHartnett, D.C.1 aCollins, Scott., L. uhttp://knz.lternet.edu/content/animal-populations-and-communities00677nas a2200229 4500008004100000245003800041210003800079260003800117300001300155653002200168100001700190700001500207700002000222700001900242700001800261700001700279700002000296700001900316700001900335700002400354856006900378 1998 eng d00aBelowground biology and processes0 aBelowground biology and processes aNew YorkbOxford University Press a244 -26410atallgrass prairie1 aRice, C., W.1 aTodd, T.C.1 aBlair, John, M.1 aSeastedt, T.R.1 aRamundo, R.A.1 aWilson, G.T.1 aKnapp, Alan, K.1 aBriggs, J., M.1 aHartnett, D.C.1 aCollins, Scott., L. uhttp://knz.lternet.edu/content/belowground-biology-and-processes00779nas a2200205 4500008004100000245012500041210006900166260003800235300001300273653002200286100001900308700001700327700001800344700002000362700002000382700001900402700001900421700002400440856010900464 1998 eng d00aClimate change, elevated CO2 and predictive modeling: Past and future climate change scenarios for the tallgrass prairie0 aClimate change elevated CO2 and predictive modeling Past and fut aNew YorkbOxford University Press a283 -30010atallgrass prairie1 aSeastedt, T.R.1 aHayden, B.P.1 aOwensby, C.E.1 aKnapp, Alan, K.1 aKnapp, Alan, K.1 aBriggs, J., M.1 aHartnett, D.C.1 aCollins, Scott., L. uhttp://www.colostate.edu/Depts/GDPE/Distinguished_Ecologists/2005/Hayden/grassland%20dynamics%20ch16.pdf00994nas a2200181 4500008004100000245001500041210001500056260008800071520046700159100001900626700001700645700001600662700001800678700001900696700001700715700001900732856006100751 1998 eng d00aData entry0 aData entry aAlbuquerquebLong-Term Ecological Research Network Office, University of New Mexico3 aOne of the many issues that an information management specialist must consider is the need to convert data into a usable electronic format. This frequently means converting data collected in the field, usually on paper, into an electronic form that can then be used in a statistical or graphical package by the researcher. The purpose of this paper is to present guidelines that we have found useful in making this conversion as quick and error-free as possible.1 aBriggs, J., M.1 aBenson, B.J.1 aHartman, M.1 aIngersoll, R.1 aMichener, W.K.1 aPorter, J.H.1 aStafford, S.G. uhttp://www.ecoinformatics.org/pubs/guide/briggs2.fv2.htm00520nas a2200121 4500008004100000245006000041210005900101260010600160300001100266100001900277700001600296856008600312 1998 eng d00aData management at a long-term ecological research site0 aData management at a longterm ecological research site aTsukuba, JapanbCenter for Global Environmental Research National Institute for Environmental Studies a52 -571 aBriggs, J., M.1 aIwakuma, T. uhttp://knz.lternet.edu/content/data-management-long-term-ecological-research-site00664nas a2200181 4500008004100000245007300041210006900114260003800183300001300221653002200234100002400256700002000280700002000300700001900320700001900339700002400358856010000382 1998 eng d00aDisturbance, diversity and species interactions in tallgrass prairie0 aDisturbance diversity and species interactions in tallgrass prai aNew YorkbOxford University Press a140 -15610atallgrass prairie1 aCollins, Scott., L.1 aSteinauer, E.M.1 aKnapp, Alan, K.1 aBriggs, J., M.1 aHartnett, D.C.1 aCollins, Scott., L. uhttp://knz.lternet.edu/content/disturbance-diversity-and-species-interactions-tallgrass-prairie00620nas a2200205 4500008004100000245004000041210004000081260003800121300001300159653002200172100001800194700001400212700001800226700002000244700002000264700001900284700001900303700002400322856006800346 1998 eng d00aDiversity of terrestrial macrofauna0 aDiversity of terrestrial macrofauna aNew YorkbOxford University Press a101 -11210atallgrass prairie1 aKaufman, D.W.1 aFay, P.A.1 aKaufman, G.A.1 aZimmerman, J.L.1 aKnapp, Alan, K.1 aBriggs, J., M.1 aHartnett, D.C.1 aCollins, Scott., L. uhttp://knz.lternet.edu/content/diversity-terrestrial-macrofauna00721nas a2200205 4500008004100000245007200041210006700113260003800180300001300218653002200231100002400253700002000277700001900297700001900316700002000335700001900355700001900374700002400393856009800417 1998 eng d00aThe dynamic tallgrass prairie: Synthesis and research opportunities0 adynamic tallgrass prairie Synthesis and research opportunities aNew YorkbOxford University Press a301 -31510atallgrass prairie1 aCollins, Scott., L.1 aKnapp, Alan, K.1 aHartnett, D.C.1 aBriggs, J., M.1 aKnapp, Alan, K.1 aBriggs, J., M.1 aHartnett, D.C.1 aCollins, Scott., L. uhttp://knz.lternet.edu/content/dynamic-tallgrass-prairie-synthesis-and-research-opportunities00537nas a2200133 4500008004100000245007000041210006900111260008800180100001900268700001900287700001700306700001900323856006100342 1998 eng d00aEvolution of the Konza Prairie LTER Information Management System0 aEvolution of the Konza Prairie LTER Information Management Syste aAlbuquerquebLong-Term Ecological Research Network Office, University of New Mexico1 aBriggs, J., M.1 aMichener, W.K.1 aPorter, J.H.1 aStafford, S.G. uhttp://www.ecoinformatics.org/pubs/guide/briggsk.fv2.htm00628nas a2200169 4500008004100000245007800041210006900119260003800188300001100226653002200237100001800259700002000277700001900297700001900316700002400335856009900359 1998 eng d00aThe flora of Konza Prairie: A historical review and contemporary patterns0 aflora of Konza Prairie A historical review and contemporary patt aNew YorkbOxford University Press a69 -8010atallgrass prairie1 aFreeman, C.C.1 aKnapp, Alan, K.1 aBriggs, J., M.1 aHartnett, D.C.1 aCollins, Scott., L. uhttp://knz.lternet.edu/content/flora-konza-prairie-historical-review-and-contemporary-patterns00522nas a2200169 4500008004100000245003900041210003900080260003800119300001100157653002200168100001700190700002000207700001900227700001900246700002400265856006300289 1998 eng d00aGeomorphology of the Konza Prairie0 aGeomorphology of the Konza Prairie aNew YorkbOxford University Press a35 -4710atallgrass prairie1 aOviatt, C.G.1 aKnapp, Alan, K.1 aBriggs, J., M.1 aHartnett, D.C.1 aCollins, Scott., L. uhttp://knz.lternet.edu/content/geomorphology-konza-prairie00600nam a2200157 4500008004100000245007500041210006900116260003800185300001300223653002200236100002000258700001900278700001900297700002400316856010200340 1998 eng d00aGrassland Dynamics: Long-Term Ecological Research in Tallgrass Prairie0 aGrassland Dynamics LongTerm Ecological Research in Tallgrass Pra aNew YorkbOxford University Press a364 -36410atallgrass prairie1 aKnapp, Alan, K.1 aBriggs, J., M.1 aHartnett, D.C.1 aCollins, Scott., L. uhttp://knz.lternet.edu/content/grassland-dynamics-long-term-ecological-research-tallgrass-prairie00634nas a2200181 4500008004100000245006400041210006200105260003800167300001000205653002200215100002000237700001900257700002000276700001900296700001900315700002400334856009400358 1998 eng d00aGrasslands, Konza Prairie and long-term ecological Research0 aGrasslands Konza Prairie and longterm ecological Research aNew YorkbOxford University Press a3 -1510atallgrass prairie1 aKnapp, Alan, K.1 aSeastedt, T.R.1 aKnapp, Alan, K.1 aBriggs, J., M.1 aHartnett, D.C.1 aCollins, Scott., L. uhttp://knz.lternet.edu/content/grasslands-konza-prairie-and-long-term-ecological-research00617nas a2200205 4500008004100000245003600041210003600077260003800113300001300151653002200164100001500186700002300201700002000224700001800244700002000262700001900282700001900301700002400320856006700344 1998 eng d00aHydrology and aquatic chemistry0 aHydrology and aquatic chemistry aNew YorkbOxford University Press a159 -17610atallgrass prairie1 aGray, L.J.1 aMacpherson, G., L.1 aKoelliker, J.K.1 aDodds, W., K.1 aKnapp, Alan, K.1 aBriggs, J., M.1 aHartnett, D.C.1 aCollins, Scott., L. uhttp://knz.lternet.edu/content/hydrology-and-aquatic-chemistry00738nas a2200217 4500008004100000245007500041210006900116260003800185300001300223653002200236100001900258700001700277700001700294700001800311700001100329700002000340700001900360700001900379700002400398856009800422 1998 eng d00aA landscape perspective of patterns and processes in tallgrass prairie0 alandscape perspective of patterns and processes in tallgrass pra aNew YorkbOxford University Press a265 -27910atallgrass prairie1 aBriggs, J., M.1 aNellis, M.D.1 aTurner, C.L.1 aHenebry, G.M.1 aSu, H.1 aKnapp, Alan, K.1 aBriggs, J., M.1 aHartnett, D.C.1 aCollins, Scott., L. uhttp://knz.lternet.edu/content/landscape-perspective-patterns-and-processes-tallgrass-prairie00640nas a2200169 4500008004100000245008500041210006900126260005100195300001300246653000900259100002000268700002000288700001900308700001700327700001800344856010800362 1998 eng d00aLong-term ecological consequences of varying fire frequency in a humid grassland0 aLongterm ecological consequences of varying fire frequency in a  aTallahassee, FLbTall Timbers Research Station a173 -17810afire1 aKnapp, Alan, K.1 aBlair, John, M.1 aBriggs, J., M.1 aPruden, T.L.1 aBrennan, L.A. uhttp://knz.lternet.edu/content/long-term-ecological-consequences-varying-fire-frequency-humid-grassland01416nas a2200181 4500008004100000245007800041210006900119300001300188490000800201520080000209653002201009100002401031700002001055700001901075700002001094700002001114856010001134 1998 eng d00aModulation of diversity by grazing and mowing in native tallgrass prairie0 aModulation of diversity by grazing and mowing in native tallgras a745 -7470 v2803 aSpecies diversity has declined in ecosystems worldwide as a result of habitat fragmentation, eutrophication, and land-use change. If such decline is to be halted ecological mechanisms that restore or maintain biodiversity are needed. Two long-term field experiments were performed in native grassland to assess the effects of fire, nitrogen addition, and grazing or mowing on plant species diversity. In one experiment, richness declined on burned and fertilized treatments, whereas mowing maintained diversity under these conditions. In the second experiment, loss of species diversity due to frequent burning was reversed by bison, a keystone herbivore in North American grasslands. Thus, mowing or the reestablishment of grazing in anthropogenically stressed grasslands enhanced biodiversity.10atallgrass prairie1 aCollins, Scott., L.1 aKnapp, Alan, K.1 aBriggs, J., M.1 aBlair, John, M.1 aSteinauer, E.M. uhttp://knz.lternet.edu/content/modulation-diversity-grazing-and-mowing-native-tallgrass-prairie00742nas a2200205 4500008004100000245008500041210006900126260003800195300001300233653002200246100002000268700001900288700002000307700001700327700002000344700001900364700001900383700002400402856011000426 1998 eng d00aPatterns and controls of aboveground net primary production in tallgrass prairie0 aPatterns and controls of aboveground net primary production in t aNew YorkbOxford University Press a193 -22110atallgrass prairie1 aKnapp, Alan, K.1 aBriggs, J., M.1 aBlair, John, M.1 aTurner, C.L.1 aKnapp, Alan, K.1 aBriggs, J., M.1 aHartnett, D.C.1 aCollins, Scott., L. uhttp://knz.lternet.edu/content/patterns-and-controls-aboveground-net-primary-production-tallgrass-prairie00577nas a2200181 4500008004100000245004600041210004500087260003800132300001200170653002200182100001900204700001400223700002000237700001900257700001900276700002400295856007600319 1998 eng d00aPlant populations: Patterns and processes0 aPlant populations Patterns and processes aNew YorkbOxford University Press a81 -10010atallgrass prairie1 aHartnett, D.C.1 aFay, P.A.1 aKnapp, Alan, K.1 aBriggs, J., M.1 aHartnett, D.C.1 aCollins, Scott., L. uhttp://knz.lternet.edu/content/plant-populations-patterns-and-processes00615nas a2200169 4500008004100000245006300041210006300104260003800167300001100205653002200216100001700238700002000255700001900275700001900294700002400313856010800337 1998 eng d00aRegional climate and the distribution of tallgrass prairie0 aRegional climate and the distribution of tallgrass prairie aNew YorkbOxford University Press a19 -3410atallgrass prairie1 aHayden, B.P.1 aKnapp, Alan, K.1 aBriggs, J., M.1 aHartnett, D.C.1 aCollins, Scott., L. uhttp://www.colostate.edu/Depts/GDPE/Distinguished_Ecologists/2005/Hayden/grassland%20dynamics%20ch2.pdf00576nas a2200205 4500008004100000245002500041210002500066260003800091300001100129653002200140100001700162700001700179700001500196700002100211700002000232700001900252700001900271700002400290856005600314 1998 eng d00aSoils and soil biota0 aSoils and soil biota aNew YorkbOxford University Press a48 -6610atallgrass prairie1 aRansom, M.D.1 aRice, C., W.1 aTodd, T.C.1 aWehmueller, W.A.1 aKnapp, Alan, K.1 aBriggs, J., M.1 aHartnett, D.C.1 aCollins, Scott., L. uhttp://knz.lternet.edu/content/soils-and-soil-biota00589nas a2200181 4500008004100000245005000041210005000091260003800141300001300179653002200192100001500214700001800229700002000247700001900267700001900286700002400305856007800329 1998 eng d00aStructure and dynamics of aquatic communities0 aStructure and dynamics of aquatic communities aNew YorkbOxford University Press a177 -18910atallgrass prairie1 aGray, L.J.1 aDodds, W., K.1 aKnapp, Alan, K.1 aBriggs, J., M.1 aHartnett, D.C.1 aCollins, Scott., L. uhttp://knz.lternet.edu/content/structure-and-dynamics-aquatic-communities00666nas a2200205 4500008004100000245005400041210005400095260003800149300001300187653002200200100002000222700001900242700001700261700001800278700002000296700001900316700001900335700002400354856008200378 1998 eng d00aTerrestrial nutrient cycling in tallgrass prairie0 aTerrestrial nutrient cycling in tallgrass prairie aNew YorkbOxford University Press a222 -24310atallgrass prairie1 aBlair, John, M.1 aSeastedt, T.R.1 aRice, C., W.1 aRamundo, R.A.1 aKnapp, Alan, K.1 aBriggs, J., M.1 aHartnett, D.C.1 aCollins, Scott., L. uhttp://knz.lternet.edu/content/terrestrial-nutrient-cycling-tallgrass-prairie00428nas a2200133 4500008004100000245005100041210005100092300000900143490000800152653002200160100001700182700001900199856007600218 1997 eng d00aModelling impact of bison on tallgrass prairie0 aModelling impact of bison on tallgrass prairie a3 -90 v10010atallgrass prairie1 aNellis, M.D.1 aBriggs, J., M. uhttp://knz.lternet.edu/content/modelling-impact-bison-tallgrass-prairie01694nas a2200181 4500008004100000245006700041210006700108300001100175490000800186520112600194100001901320700001601339700001701355700001801372700001701390700001701407856008801424 1997 eng d00aSpatial and temporal patterns of vegetation in the Flint Hills0 aSpatial and temporal patterns of vegetation in the Flint Hills a10 -200 v1003 aIn tallgrass prairie, complex interactions among multiple limiting resources in combination with a variety of land use practices can lead to a heterogeneous landscape. Remote-sensing data (AVHRR) were coupled with abiotic factors to explore spatial and temporal vegetation patterns of the Flint Hills in Kansas and Oklahoma. This information should enable the detection of both natural (e.g., interannual variation in precipitation and temperature) and anthropogenic (e.g., climate change, over-grazing, land-use practices) stresses on this grassland ecosystem. Shifts in the spatial and temporal patterns of vegetation (as measured from NDVI by AVHRR) have been correlated with meteorological data (from 117 weather stations) to identify key abiotic variables that determined vegetation patterns across this region. In 4 years, the combination of annual precipitation and growing degree days was useful to detect spatial and temporal vegetation patterns of the Flint Hills. However, it is imperative that land-use patterns are known in order to assess adequately spatial and temporal patterns of vegetation in this area.1 aBriggs, J., M.1 aRieck, D.R.1 aTurner, C.L.1 aHenebry, G.M.1 aGoodin, D.G.1 aNellis, M.D. uhttp://knz.lternet.edu/content/spatial-and-temporal-patterns-vegetation-flint-hills01455nas a2200169 4500008004100000245012000041210006900161300001500230520080800245653002201053100001101075700001901086700002001105700002001125700001801145856012201163 1996 eng d00aDetecting spatial and temporal patterns of aboveground production in a tallgrass prairie using remotely-sensed data0 aDetecting spatial and temporal patterns of aboveground productio a2361 -23653 aSpatial and temporal patterns of aboveground production in a tallgrass prairie ecosystem constitute one of the important spatial components associated with ecological processes and biophysical resources (e.g., water and nutrients). This study addresses the effects of disturbance, topography, and climate on the spatial and temporal patterns of North American tallgrass prairie at a landscape level by using high resolution satellite data. Spatial heterogeneity (SH) derived from the satellite data was related to the impacts of the disturbance of fire and grazing, topographical gradient, and amount of precipitation during the growing season. The result suggests that ecological processes and biophysical resources can be quantified with high resolution satellite data for tallgrass prairie management10atallgrass prairie1 aSu, H.1 aBriggs, J., M.1 aKnapp, Alan, K.1 aBlair, John, M.1 aKrummel, J.R. uhttp://knz.lternet.edu/content/detecting-spatial-and-temporal-patterns-aboveground-production-tallgrass-prairie-using02948nas a2200181 4500008004100000245011400041210006900155300001300224490000700237520227900244653002202523100001702545700001902562700001902581700002002600700001802620856012802638 1996 eng d00aFire and topographic effects on decomposition rates and nitrogen dynamics of buried wood in tallgrass prairie0 aFire and topographic effects on decomposition rates and nitrogen a323 -3290 v283 aDecay rates and N dynamics of wood in soils of annually burned and unburned tallgrass prairie were measured over a 3-y period. Wooden dowels were placed at upland, mid-slope and lowland sites in two annually burned and two unburned watersheds. After 3 y, an average of only 15% of initial wood mass remained in burned watersheds, while 34% remained in unburned watersheds. Topographic position also significantly affected decay rates, with dowels decaying faster in the shallow-soil, upland sites and slope sites than in the deep-soil, lowland sites. This pattern is opposite of that generally observed for plant productivity (i.e. greater at lowland sites compared to uplands), and suggests that the controls of belowground decomposition and plant productivity are dissimilar. Dowels in both burned and unburned watersheds showed significant increases in N concentration over 3 y. Topographic position did not affect N concentration in the residual dowel material. Burn treatment, however, did affect N concentration, with dowels decomposing in burned watersheds having a higher average N concentration (0.5% after 3 y exposure) than dowels in unburned watersheds (0.43%). Relatively rapid decay rates resulted in net release of N, despite increased N concentration in the residual material. Faster net N release on the annually burned watershed was due to faster mass loss, since there were no differences in the rate of increase in N concentration per unit mass lost. Surface soil temperatures on burned prairie following spring fire usually exceed those on unburned prairie. However, average monthly summer soil temperatures (May–August) at a 10 cm depth in burned and unburned plots during the study were not statistically different and could not explain decay rate differences. Additionally, one of our unburned watersheds was accidentally burned during the first year of the study. Surprisingly, there were no significant differences in rates of wood decay between that watershed and the other unburned watershed. This suggests that indirect effects of annual fire (i.e. changes in the composition of soil flora and fauna) may override the short-term effects of fire (i.e. changes in soil temperature and moisture) on belowground decomposition in tallgrass prairie.10atallgrass prairie1 aO'Lear, H.A.1 aSeastedt, T.R.1 aBriggs, J., M.1 aBlair, John, M.1 aRamundo, R.A. uhttp://knz.lternet.edu/content/fire-and-topographic-effects-decomposition-rates-and-nitrogen-dynamics-buried-wood-tallgrass01969nas a2200145 4500008004100000245016500041210006900206300001500275490000700290520142300297653002201720100001901742700002001761856004201781 1995 eng d00aInterannual variability in primary production in tallgrass prairie: climate, soil moisture, topographic position and fire as determinants of aboveground biomass0 aInterannual variability in primary production in tallgrass prair a1024 -10300 v823 aFrom 1975 to 1993, aboveground net primary production (NPP) at the Konza Prairie Research Natural Area in NE Kansas varied from 179 g/m2 to 756 g/m2. Across a variety of sites, NPP was significantly related to precipitation (r2 = 0.37), but much variability was unexplained. Thus, we evaluated the relationship between NPP with meteorological variables and soil moisture measurements in tallgrass prairie sites that varied in fire frequency and topographic position. Annually burned lowland sites had significantly higher NPP than either annually burned upland or unburned sites. NPP in burned sites was more strongly related to meteorological variables and soil moisture when compared to unburned sites. The lack of significant correlation between soil moisture with NPP on unburned sites suggests that factors other than water availability limit production in these sites. When NPP data were analyzed separately by life forms, interannual variability in forb NPP was not correlated with any meteorological variables, but was negatively correlated with grass NPP (r = -0.49). The inability of a single factor, such as precipitation to explain a large portion of the interannual variability in NPP is consistent with the concept that patterns of NPP in tallgrass prairie are a product of spatial and temporal variability in light, water, and nutrients, driven by a combination of topography, fire history, and climate.10atallgrass prairie1 aBriggs, J., M.1 aKnapp, Alan, K. u http://www.jstor.org/stable/244623200657nas a2200193 4500008004100000245007700041210006900118300001300187653002200200100001900222700002100241700001300262700002000275700001800295700001600313700001800329700001400347856010200361 1994 eng d00aAboveground biomass in tallgrass prairie: effect of time since last fire0 aAboveground biomass in tallgrass prairie effect of time since la a165 -17010atallgrass prairie1 aBriggs, J., M.1 aFahnestock, J.T.1 aWard, L.1 aKnapp, Alan, K.1 aWickett, R.G.1 aLewis, P.D.1 aWoodliffe, A.1 aPratt, P. uhttp://images.library.wisc.edu/EcoNatRes/EFacs/NAPC/NAPC13/reference/econatres.napc13.jbriggs.pdf00617nas a2200157 4500008004100000245009700041210006900138260003500207300001200242100001900254700001100273700001900284700001600303700001900319856012100338 1994 eng d00aDevelopment and refinement of the Konza Prairie LTER Research Information Management Program0 aDevelopment and refinement of the Konza Prairie LTER Research In aLondonbTaylor and Francis Ltd a87 -1001 aBriggs, J., M.1 aSu, H.1 aMichener, W.K.1 aBrunt, J.W.1 aStafford, S.G. uhttp://knz.lternet.edu/content/development-and-refinement-konza-prairie-lter-research-information-management-program00631nas a2200145 4500008004100000245011200041210006900153260005700222300001300279653002200292100001100314700002000325700001900345856012100364 1994 eng d00aEffects of topography and fire on spatial and temporal distribution of soil moisture in a tallgrass prairie0 aEffects of topography and fire on spatial and temporal distribut bUnited States Department of Interior Bureau of Mines a154 -16210atallgrass prairie1 aSu, H.1 aKnapp, Alan, K.1 aBriggs, J., M. uhttp://knz.lternet.edu/content/effects-topography-and-fire-spatial-and-temporal-distribution-soil-moisture-tallgrass02140nas a2200205 4500008004100000245007900041210006900120300001300189490000600202520153300208653001201741653001901753653000801772653002301780653002201803100001701825700001901842700001701861856005601878 1994 eng d00aExpansion of gallery forest on Konza Prairie Research Natural Area, Kansas0 aExpansion of gallery forest on Konza Prairie Research Natural Ar a117 -1250 v93 aTo determine the dynamics of the spatial extent of gallery forest on Konza Prairie Research Natural Area (KPRNA), aerial photographs taken over a 46 year time frame were digitized into an ARC-INFO Geographic Information System (GIS). A Global Positioning System (GPS) was used to collect ground control points to co-register the photographs for each year. Gallery forest areas for the three major drainage boundaries (Kings Creek, Shane Creek, and White Pasture) were analyzed to assess the uniformity of change in the landscape system. Results indicated that the total gallery forest area on KPRNA has increased in area from 157 ha in 1939 to over 241 ha in 1985. During this time, there was an increase in the total number of patches and a decrease in the mean size of forest patches. However, the rate of increase was not consistent over this time period, nor was it uniform from one drainage basin or stream order to another. Detailed spatial analysis of the forested area with a geomorphology and digital elevation model of Konza Prairie showed that in 1985, 58% of the forest was on alluvial/colluvial soil, yet only 15% of that soil type was forested. In addition, over 70% of the forest was on the 0–15% slope interval, but only 15–20% of that slope interval was forested. These results may be attributed to a variety of factors such as changing management practices (i.e., frequency of fires and herbicide spraying) and the temporal constraints on extent to which the gallery forest can expand across the landscape.10aburning10agallery forest10aGIS10ahistorical landuse10atallgrass prairie1 aKnight, C.L.1 aBriggs, J., M.1 aNellis, M.D. uhttp://link.springer.com/article/10.1007/BF0012437800407nas a2200109 4500008004100000245006100041210006100102300001100163100001900174700001800193856008600211 1994 eng d00aImpact of El Nino on Konza Prairie Research Natural Area0 aImpact of El Nino on Konza Prairie Research Natural Area a46 -471 aBriggs, J., M.1 aGreenland, D. uhttp://knz.lternet.edu/content/impact-el-nino-konza-prairie-research-natural-area01014nas a2200157 4500008004100000245005500041210005500096300000900151490000700160520058200167100001300749700001900762700001900781700001600800856004000816 1994 eng d00aOdor as a factor in nut discovery by fox squirrels0 aOdor as a factor in nut discovery by fox squirrels a1 -30 v973 aWalnuts and bur oak acorns were buried in alternate positions in a 10-×-10 grid in a riparian forest with 10-m spacing between nuts. Bur oak acorns soaked in walnut extract and walnuts were buried in a second grid of similar spacing. Fox squirrels removed walnuts fastest and at the same rate in both grids, whereas acorns soaked in walnut extract were removed faster than unsoaked acorns but slower than walnuts. In the light of earlier studies, these observations are interpreted as showing that squirrels can smell buried walnuts from a greater distance than buried acorns.1 aLuft, J.1 aMalinowski, J.1 aBriggs, J., M.1 aSmith, C.C. uhttp://www.jstor.org/stable/362824600430nas a2200121 4500008004100000245005900041210005900100300001300159100001700172700001400189700001900203856008600222 1994 eng d00aSpace shuttle photography for monitoring global change0 aSpace shuttle photography for monitoring global change a532 -5341 aNellis, M.D.1 aLulla, K.1 aBriggs, J., M. uhttp://knz.lternet.edu/content/space-shuttle-photography-monitoring-global-change00481nas a2200121 4500008004100000245007300041210006900114300001300183653002200196100001900218700002400237856009800261 1994 eng d00aUsing remote sensing to determine heterogeneity in tallgrass prairie0 aUsing remote sensing to determine heterogeneity in tallgrass pra a113 -11910atallgrass prairie1 aBriggs, J., M.1 aCollins, Scott., L. uhttp://knz.lternet.edu/content/using-remote-sensing-determine-heterogeneity-tallgrass-prairie00691nas a2200193 4500008004100000245010700041210006900148300001300217653002000230100002000250700002000270700002100290700001900311700001800330700001600348700001800364700001400382856010100396 1994 eng d00aWater relations and biomass responses to irrigation across a topographic gradient in tallgrass prairie0 aWater relations and biomass responses to irrigation across a top a215 -22010aWater relations1 aKnapp, Alan, K.1 aKoelliker, J.K.1 aFahnestock, J.T.1 aBriggs, J., M.1 aWickett, R.G.1 aLewis, P.D.1 aWoodliffe, A.1 aPratt, P. uhttp://images.library.wisc.edu/EcoNatRes/EFacs/NAPC/NAPC13/reference/econatres.napc13.aknapp.pdf02612nas a2200157 4500008004100000245012300041210006900164300001100233490000700244520200800251653002002259100001602279700002002295700001902315856012002334 1993 eng d00aComparative water relations of seedling and adult Quercus species during gallery forest expansion in tallgrass prairie0 aComparative water relations of seedling and adult Quercus specie a29 -410 v563 aSeasonal patterns in xylem pressure potential (ψ) and stomatal conductance to water vapor (g) were compared between seedlings (1–5 years old) invading tallgrass prairie and adult trees of Quercus macrocarpa (Bur oak) and Quercus muehlenbergii (Chinquapin oak) in adjacent gallery forest. Water is often limiting to productivity in the Flint Hills of NE Kansas, thus, we hypothesized that seedlings invading a grassland would have lower ψ and g compared with adult trees, reflecting competitive interactions for water between seedlings and the dominant grasses. We found that ψ was usually lower in adult trees than in older seedlings, but in the very smallest seedlings ψ was significantly reduced compared with mature (greater than 50 years) individuals. Adult and 1- to 2-year-old seedlings had similar g during the season with highest g occurring in older (4- to 5-year-old) seedlings. In general, Q. muehlenbergii had higher ψ and lower g than Q. macrocarpa consistent with reports that Q. muehlenbergii is more drought tolerant. Rapid and extensive root growth characteristic of Quercus seedlings reduced the period of time when seedlings invading prairie must compete with the grasses for water, although water stress may still be an important factor affecting first-year seedlings in this ecosystem. In contrast, strong intraspecific competition for water within mature gallery forests may have reduced ψ and g in forest trees. Thus, the potential for water stress to impact Quercus survival and growth in this drought-prone ecosystem is greatest during establishment and then after forest development is complete. Older seedlings (greater than 4–5 years old), saplings and isolated trees within the prairie may experience the least water stress due to a reduction in both inter- and intraspecific competition for water. These data suggest that in the absence of severe fire or drought occurring during the growing season, gallery forests will continye to expand into tallgrass prairie.10aWater relations1 aBragg, W.K.1 aKnapp, Alan, K.1 aBriggs, J., M. uhttp://knz.lternet.edu/content/comparative-water-relations-seedling-and-adult-quercus-species-during-gallery-forest01982nas a2200169 4500008004100000245011800041210006900159300001100228490000800239520134400247653002201591100001701613700001901630700001601649700001901665856012801684 1993 eng d00aThe interactive effects of fire, bison (Bison bison) grazing and plant community composition in tallgrass prairie0 ainteractive effects of fire bison Bison bison grazing and plant  a10 -180 v1293 aFire and native large herbivore grazing were two important influences on the structure and function of North American grasslands. In 1988 and 1989 the influence of fire regime on grazing patterns of North American bison (Bison bison) was studied on the Konza Prairie in northeastern Kansas. Bison grazing was spatially and temporally nonrandom and was influenced by fire regime and local plant community composition. During the growing season, bison were observed up to 3 x more frequently than expected on watersheds burned in the spring. Summer grazing was concentrated in large watershed areas (79-119 ha) dominated by warm-season, perennial, C4 grasses. During the autumn and winter, bison grazed both burned and unburned watersheds more uniformly but grazed most intensively in areas with large stands of cool-season, C3 grasses. On a smaller spatial scale (5-10 m2), bison selected patches during the growing season with low forb cover dominated by the perennial C4 grass, Andropogon gerardii. Grazed patches were larger on frequently burned than on infrequently burned watersheds. The importance of fire history in determining patterns of bison grazing over the landscape indicates that interactions between bison grazing and fire regime may be important to the composition and spatial heterogeneity of tallgrass prairie vegetation.10atallgrass prairie1 aVinton, M.A.1 aHartnett, D.C.1 aFinck, E.J.1 aBriggs, J., M. uhttp://knz.lternet.edu/content/interactive-effects-fire-bison-bison-bison-grazing-and-plant-community-composition-tallgrass01488nas a2200157 4500008004100000245011400041210006900155300001300224490000700237520088400244653002201128100001701150700001901167700001901186856012501205 1993 eng d00aManagement practices in tallgrass prairie: Large- and small-scale experimental effects on species composition0 aManagement practices in tallgrass prairie Large and smallscale e a247 -2550 v303 aMany studies from grasslands have reported how differing management techniques affect production levels and species composition (e.g., Ehrenreich & Aikman 1963; Wells 1980; Parr & Way 1988). In most studies the main emphasis has been on a single treatment (e.g., mowing, grazing or burning) under either highly controlled small-scale, experimental conditions (Hover & Bragg 1981; Collins 1987; Cox 1988) or less rigorous large-scale descriptive field studies (e.g., Abrams & Hulbert 1987; Gibson & Hulbert 1987). There are inherent strengths and weaknesses to both these approaches. Experimental studies, usually carried out at only one site or in small plots, may reflect local conditions; conversely, large-scale field observations usually lack statistical rigour (Hurlbert 1984) and treatment effects may be obscured by large-scale landscape heterogeneity (e.g. Gibson 1988a).10atallgrass prairie1 aGibson, D.J.1 aSeastedt, T.R.1 aBriggs, J., M. uhttp://knz.lternet.edu/content/management-practices-tallgrass-prairie-large-and-small-scale-experimental-effects-species01964nas a2200145 4500008004100000245007800041210006900119300001300188490000800201520146600209653000901675100001901684700001701703856009801720 1992 eng d00aEffects of fire on tree spatial patterns in a tallgrass prairie landscape0 aEffects of fire on tree spatial patterns in a tallgrass prairie  a300 -3070 v1193 a

Spatial patterns of trees invading a tallgrass prairie in NE Kansas, USA were examined using a Geographical Information System. Without burning and with adequate moisture levels, the number of trees increased over a five year period by over 60%, while in an area burned annually the number of trees decreased. Under a variety of burning regimes, Juniperus virginiana and Celtis occidentalis were significantly more uniform in their distribution pattern than Populus deltoides and Gleditsia triacanthos. In addition, three tree species (G. triacanthos, J. virginiana and U. americana) had a significant increase in the degree of aggregation with increasing tree height, while C. occidentalis showed no relationship between aggregation and tree height. There were significant associations between adult and juvenile trees at various scales, with bird dispersed J. virginiana having a higher critical distance (39 m) than wind dispersed G. triacanthos and U. americana. The spatial pattern of tree species appears to be affected by the means of dispersion; trees with wind-dispersed seeds had clumped distributions, whereas most trees with bird-dispersed seeds were regular to random in their dispersion patterns. The spatial pattern of trees invading tallgrass prairie is a function of the burning regime, dispersal vectors, habitat availability, and reproductive mode. Key words: tallgrass prairie, spatial patterns, trees, Geographical Information System

10aWind1 aBriggs, J., M.1 aGibson, D.J. uhttp://knz.lternet.edu/content/effects-fire-tree-spatial-patterns-tallgrass-prairie-landscape00549nas a2200145 4500008004100000245008600041210006900127300001300196490000600209653002400215100001700239700001900256700001900275856010900294 1992 eng d00aGeographic information systems for modeling bison impact on Konza Prairie, Kansas0 aGeographic information systems for modeling bison impact on Konz a618 -6230 v210aInformation Systems1 aNellis, M.D.1 aBathgate, J.D.1 aBriggs, J., M. uhttp://knz.lternet.edu/content/geographic-information-systems-modeling-bison-impact-konza-prairie-kansas01460nas a2200157 4500008004100000245010400041210006900145300001500214490000700229520086900236653002401105100001701129700001901146700001701165856012001182 1992 eng d00aGrowth and transition: Remote sensing and geographic information systems at Kansas State University0 aGrowth and transition Remote sensing and geographic information  a1159 -11610 v583 a

Remote sensing and geographic information systems education and research at Kansas State University have grown tremendously in the past decade. Dramatic improvements in hardware and software have enhanced offerings in a wide range of spatial analysis (including remote sensing) courses. Success in extramural funding through such agencies as the U.S. Agency for International Development and the National Science Foundation have created a major research thrust in Kansas State University's Geography and Biology programs relative to the application of remote sensing and geographic information systems for natural resource assessment and landscape ecology. The State of Kansas initatives have also enhanced Kansas State University's role in providing a significant contribution in remote sensing/geographic information systems research and education

10aInformation Systems1 aNellis, M.D.1 aBriggs, J., M.1 aSeyler, H.L. uhttp://knz.lternet.edu/content/growth-and-transition-remote-sensing-and-geographic-information-systems-kansas-state00527nas a2200121 4500008004100000245011800041210006900159300001100228490000700239100001700246700001900263856012300282 1992 eng d00aTransformed vegetation index for measuring spatial variation in drought impacted biomass on Konza Prairie, Kansas0 aTransformed vegetation index for measuring spatial variation in  a93 -990 v951 aNellis, M.D.1 aBriggs, J., M. uhttp://knz.lternet.edu/content/transformed-vegetation-index-measuring-spatial-variation-drought-impacted-biomass-konza02208nas a2200157 4500008004100000245005700041210005700098300001100155490000700166520169600173653004401869100001901913700001901932700001701951856008201968 1991 eng d00aControls of nitrogen limitation in tallgrass prairie0 aControls of nitrogen limitation in tallgrass prairie a72 -790 v873 a

The relationship between fire frequency and N limitation to foliage production in tallgrass prairie was studied with a series of fire and N addition experiments. Results indicated that fire history affected the magnitude of the vegetation response to fire and to N additions. Sites not burned for over 15 years averaged only a 9% increase in foliage biomass in response to N enrichment. In contrast, foliage production increased an average of 68% in response to N additions on annually burned sites, while infrequencly burned sites, burned in the year of the study, averaged a 45% increase. These findings are consistent with reports indicating that reduced plant growth on unburned prairie is due to shading and lower soil temperatures, while foliage production on frequently burned areas is constrained by N availability. Infrequent burning of unfertilized prairie therefore results in maximum production response in the year of burning relative to either annually burned or long-term unburned sites. Foliage biomass of tallgrass prairie is dominated by C4 grasses; however, forb species exhibited stronger production responses to nitrogen additions than did the grasses. After four years of annual N additions, forb biomass exceeded that of grass biomass on unburned plots, and grasses exhibited a negative response to fertilizer, probably due to competition from the forbs. The dominant C4 grasses may out-compete forbs under frequent fire conditions not only because they are better adapted to direct effects of burning, but because they can grow better under low available N regimes created by frequent fire. Key words: Andropogon gerardii, fire, nitrogen, prairie, productivity

10afire;soil temperature;tallgrass prairie1 aSeastedt, T.R.1 aBriggs, J., M.1 aGibson, D.J. uhttp://knz.lternet.edu/content/controls-nitrogen-limitation-tallgrass-prairie01315nas a2200145 4500008004100000245015800041210006900199300000900268490000700277520069900284653002200983100001901005700002001024856012501044 1991 eng d00aEstimating aboveground biomass in tallgrass prairie with the harvest method: determining proper sample size using jackknifing and Monte Carlo simulations0 aEstimating aboveground biomass in tallgrass prairie with the har a1 -60 v363 a

Sample adequacy for estimating aboveground biomass in the Flint Hills (Kansas) tallgrass prairie was determined by using a combination of jackknifing and Monte Carlo simulations. Based on this analysis, we concluded that 14 and 16 0.1 -m2 (20 by 50 cm) quadrats should be harvested in burned and unburned sites, respectively, when estimating total, live graminoid and previous years dead biomass. However, 20 quadrats should be harvested to detect at least a 20% difference in production between sites due to treatments such as fire. Due to high variability in forb biomass, other measurements (cover or density) may be more appropriate for detecting fire effects on this group of plants

10atallgrass prairie1 aBriggs, J., M.1 aKnapp, Alan, K. uhttp://knz.lternet.edu/content/estimating-aboveground-biomass-tallgrass-prairie-harvest-method-determining-proper-sample03882nas a2200157 4500008004100000245014800041210006900189260003800258300001300296520321200309653002203521100001903543700001903562700001703581856012603598 1991 eng d00aLongterm ecological questions and considerations for taking longterm measurements: Lessons from the LTER and FIFE programs on tallgrass prairie0 aLongterm ecological questions and considerations for taking long aChichesterbJohn Wiley & Sons a153 -1723 a

The earth, with its global problems of overpopulation, over-use and abuse of fossil fuel and nuclear energy, and production of toxic wastes, has often been compared to a sick patient. Illness is recognized as a significant deviation from known, long-term trends. Long-term monitoring represents a minimal activity for responsible individuals and agencies interested in placing current environmental problems into perspective. Long-term measurements are directed at questions involving phenomena not interpretable or perhaps not useful when viewed over short (annual or less) time scales, but are related to the long-term "health" or functioning of the system. At a minimum, the Long-term Ecological Research (LTER) data therefore provide the context in which short-term observational or experimental results can be interpreted (Magnuson, 1990). A much more interesting, albeit potentially less relevant, use of LTER data involves the study of a set of complex questions that cannot be resolved with short-term studies. The juxtaposition of basic and applied science within the context of a single research effort is a strength of the LTER program. This chapter attempts to identify a set of long-term ecological questions that are useful to a national or international network of research sites. While there exists a nearly infinite list of interesting questions that could be addressed with long-term studies, a realistic and goal-oriented list of measurements is presented. The criteria for selecting these questions involved identiying variables that 1) are useful for intersite comparisons, 2) are not strongly biased by spatial scaling factors, and 3) can provide the necessary linkages between atmospheric/climatological variables and biological measurements. "Focused studies of the interactions between the atmosphere and the biosphere that regulate trace gases can improve both our understanding of terrestrial ecosystems and our ability to predict regional- and global-scale changes in atmospheric chemistry". The list of proposed variables for study was devvelpoped from the "core LTER measurements", a guideling used since the inception of the LTER effort from recommendations suggested in Earth System Science, and from practical experience with the recent NASA- ISLSCP (International Surface Land Climatology Project) conducted on the Konza Prairie LTER site. While appropriate examples are taken from many systems, particular emphasis has been given to questions that have interested researchers studying grasslands. We build on the work of Strayer et al. (1986). Their extensive overview of long-term studies provided useful definitions of research productivity, of what constitutes "long- term research", and reasons for the "successes" of previous and existing long-term research efforts. Their findings emphasized that individual scientists and not specific research protocols or experimental designs were largely responsible for successful long-term research efforts. Here, however, we suggest that certain constraints on research designs are important if a goal of the research is to benefit directly a regional or global network

10atallgrass prairie1 aSeastedt, T.R.1 aBriggs, J., M.1 aRisser, P.J. uhttp://knz.lternet.edu/content/longterm-ecological-questions-and-considerations-taking-longterm-measurements-lessons-lter01471nas a2200145 4500008004100000245010600041210006900147300001300216490000700229520090300236653002201139100001901161700001701180856012801197 1991 eng d00aSeasonal variation of heterogeneity in tallgrass prairie: a quantitative measure using remote sensing0 aSeasonal variation of heterogeneity in tallgrass prairie a quant a407 -4110 v573 a

Remote sensing may be a tool to quantitatively measure the change in heterogeneity that takes place in a landscape over a growing season. Seven different SPOT satellite scenes of the Konza Prairie Research Natural Area were analyzed to assess the potential of using textural algorithms as a quantitative measure of seasonal variation in heterogeneity. Unburned watersheds usually have greater heterogeneity than annually burned watersheds. However, the greatest amount of heterogeneity as measured by textural analysis occurs in those area with a mixture of forest and upland tallgrass prairie. Results suggest that remote sensing textural algorithms, in combination with normalized vegetation difference indices, can provide insight regarding both temporal changes that occur seasonally and the influences of periodic spring fires and management practices on the tallgrass prairie ecosystem

10atallgrass prairie1 aBriggs, J., M.1 aNellis, M.D. uhttp://knz.lternet.edu/content/seasonal-variation-heterogeneity-tallgrass-prairie-quantitative-measure-using-remote-sensing01735nas a2200157 4500008004100000245012100041210006900162300001300231490000700244520112700251653002201378100001901400700001901419700001701438856012201455 1989 eng d00aComparative analysis of temporal and spatial variability in aboveground production in a deciduous forest and prairie0 aComparative analysis of temporal and spatial variability in abov a130 -1360 v123 a

Production patterns of tallgrass prairie and adjacent eastern deciduous forest were summarized for a five to seven year period. Each system responded differentially to annual or growing season rainfall and solar energy (measured by pan water evaporation). Overall, forest productivity was negatively correlated with annual precipitation; the prairie exhibited no relationship with precipitation. These differences probably reflect the lack of water limitation of the forest and the "downstream" position of the forest. Wood and seed production in the forest were the most variable components measured in our study. Neither variable was related to forest foliage production. Seed production in the prairie was also variable within and between years but was related to prairie foliage production. Prairie seed production was not correlated with seed production of the forest. The two ecosystems respond differentially and independently of each other within the range of climatic variation observed here. Such differences have potential significance to consumers who use both systems for habitat or resources

10atallgrass prairie1 aBriggs, J., M.1 aSeastedt, T.R.1 aGibson, D.J. uhttp://knz.lternet.edu/content/comparative-analysis-temporal-and-spatial-variability-aboveground-production-deciduous01588nas a2200145 4500008004100000245009100041210006900132300001200201490000600213520105300219653002201272100001701294700001901311856011201330 1989 eng d00aThe effects of spatial scale on Konza landscape classification using textural analysis0 aeffects of spatial scale on Konza landscape classification using a93 -1000 v23 a

Spatial scale is inherent in the definition of landscape hererogeneity and diversity. For example, a landscape may appear heterogenous at one scale but not quite homogeneous at another scale. In assessing the impact of burning and grazing on the Konza Prairie Research Natural Area (a tallgrass prairie), spatial scale is extremely important. Textural contrast algorithms were applied to various scales of remote sensing data and related to landscape units for assessment of heterogeneity under a variety of burning treatments. Acquired data sets included Landsat multispectral scanner (MSS), with 80 m resolution, Landsat thematic mapper (TM), with 30 m resolution, and high resolution density sliced aerial photography (with a 5 m resolution). Results suggest that heterogeneous areas of dense patchiness (e.g., unburned areas) must be analyzed at a finer scale than more homogeneous areas which are burned at least every four years. Key words: spatial scale, textural analysis, tallgrass prairie, remote sensing, landscape ecology, Kansas

10atallgrass prairie1 aNellis, M.D.1 aBriggs, J., M. uhttp://knz.lternet.edu/content/effects-spatial-scale-konza-landscape-classification-using-textural-analysis01681nas a2200229 4500008004100000245004100041210003700082260004600119300001300165520104300178653000901221100001601230700001601246700001901262700001701281700001601298700001801314700001901332700001601351700002101367856006301388 1989 eng d00aIs fire a disturbance in grasslands?0 afire a disturbance in grasslands aLincoln, NEbUniversity of Nebraska Press a159 -1613 a

Many grasslands, and in particular the tallgrass prairies of North America, are generally thought to be maintained by periodic fire. Semantic disagreement among researchers, however, threatens to hamper discussion of fire as an ecological force in grassland ecosystems. Some authors emphasize that fires are disturbances (or perturbations) since these fires disrupt or alter ecosystem states, trends and dynamics (e.g., accumulating nitrogen is volatilized, plant and animal communities change in composition). Other researchers point out that, because these fire-induced disruptions and alterations can maintain the status quo of the ecosystem (e.g., prevent it from becoming woodland), it is the lack of fire rather than fire itself that should be considered a disturbance. We argue that, since both points of view are useful, there is little to be gained by labeling loosely either fire or lack thereof as a "disturbance" in grassland ecosystems. Key Words: disturbance, fire, grasslands, perturbation, prairie, Kansas

10afire1 aEvans, E.W.1 aFinck, E.J.1 aBriggs, J., M.1 aGibson, D.J.1 aJames, S.W.1 aKaufman, D.W.1 aSeastedt, T.R.1 aBragg, T.B.1 aStubbendieck, J. uhttp://knz.lternet.edu/content/fire-disturbance-grasslands02046nas a2200133 4500008004100000245006700041210006700108300001100175490000700186520159500193100001901788700001601807856008901823 1989 eng d00aInfluence of habitat on acorn selection by Peromyscus leucopus0 aInfluence of habitat on acorn selection by Peromyscus leucopus a35 -430 v703 a

Acorn selection by white-footed mice (Peromyscus leucopus) was tested with mice from four different habitats and acorns from six species of oaks (Quercus). Three mice captured in white-oak (subgenus Lepidobalanus) forests in northwestern Arkansas selected acorns from the white-oak group (post [Q. stellata] and white [Q. alba] oaks) over those from the red-oak (subgenus Erthrobalanus) group (pin [Q. palustris], willow [Q. phellos], and black [Q. velutine] oaks). These mice were able to subsist for more than two months on a diet of only acorns, provided that acorns from post oaks were available. These mice developed signs of tannin poisoning when maintained on acorns only from the red-oak group. Eleven mice captured in white-oak forests in eastern Kansas also consumed more acorns from the white-oak (post, bur [Q. macrocarpa], and chinquapin [Q. muehlengergii] oaks) than from the red-oak group (black, norther red [Q. rubra], and pin oaks). However, seven mice captured in red-oak group forest in eastern Kansas consumed more acorns from the red-oak group than from the white-oak group and showed no signs of tannin poisoning. Five mice captured in habitats without oaks consumed equal amounts of acorns from the two subgenera. These results suggest that exposure to acorns may determine acorn selection by P. leucopus independent of fat, protein, or tannin content of the acorns. Acorn selection may be labile, as seven mice captured in white-oak forests in eastern Kansas consumed equal amounts of bur and black oak acorns after being given only red-oak acorns for 9 days

1 aBriggs, J., M.1 aSmith, K.G. uhttp://knz.lternet.edu/content/influence-habitat-acorn-selection-peromyscus-leucopus02220nas a2200169 4500008004100000245010900041210006900150260004600219300001100265520155800276653002201834100001901856700001701875700001601892700002101908856012101929 1989 eng d00aLandsat thematic mapper digital data for predicting aboveground biomass in a tallgrass prairie ecosystem0 aLandsat thematic mapper digital data for predicting aboveground  aLincoln, NEbUniversity of Nebraska Press a53 -553 a

Landstat thematic mapper digital data was found to offer an excellent potential for regular monitoring of the tallgrass prairie ecosystem by providing estimates of aboveground biomass production. Data from several channels of a May thematic mapper scene were analyzed individually and in various combinations using stepwise regression in Statistical Analysis System (SAS). These procedures were used to determine the most appropriate multiple regression equation for estimating production of 1) total live aboveground biomass, 2) grasses, 3) forbs, 4) previous years dead, and 5) current years dead. Regression equations were based on satellite-derived estimates relative to ground level biomass values for watersheds on Konza Prairie Research Natural Area under a variety of burning treatments. Results suggest that multiple channel equations were most appropriate for measuring production of forbs and total live aboveground biomass. Channel one (0.45 to 0.52 æmeters) and channel four (0.76 to 0.90 æmeters) were applicable to estimate production of grass and levels of previous years litter, respectively. However, none of the channels were accurate in predicting current years dead. Further plans involve using thematic mapper data to estimate aboveground biomass over an entire growing season on Konza and exploring the potential of using satellite data to monitor grassland production across the Great Plains. Key Words: tallgrass prairie, remote sensing, aboveground biomass, Landstat, thematic mapper, monitoring, Konza Prairie, Kansas

10atallgrass prairie1 aBriggs, J., M.1 aNellis, M.D.1 aBragg, T.B.1 aStubbendieck, J. uhttp://knz.lternet.edu/content/landsat-thematic-mapper-digital-data-predicting-aboveground-biomass-tallgrass-prairie01232nas a2200145 4500008004100000245012400041210006900165300001100234490000600245520065800251653002200909100001700931700001900948856011900967 1988 eng d00aSPOT satellite data for pattern recognition on the North American tall-grass prairie Long-term Ecological Research Site0 aSPOT satellite data for pattern recognition on the North America a37 -400 v33 a

The cluster routine uses a two-pass sequential clustering algorithm. In the first pass, the program reads through the entire data set, and sequentially builds clusters (groups of points in spectral space) based on parameters selected by the user, and computes the mean value for each cluster. These clusters become the signatures used to assign classes in the output GIS file. The second pass classifies each pixel in the data set according to a minimum distance classifier. The algorithm calculates the spectral distance between the candidate pixel and the mean value for every cluster, using the mean values that were computed in the first pass

10atallgrass prairie1 aNellis, D.M.1 aBriggs, J., M. uhttp://knz.lternet.edu/content/spot-satellite-data-pattern-recognition-north-american-tall-grass-prairie-long-term01548nas a2200145 4500008004100000245012700041210006900168300001100237490000700248520096300255653002201218100001701240700001901257856012601276 1987 eng d00aMicro-based Landsat TM data processing for tallgrass prairie monitoring in the Konza Prairie Research Natural Area, Kansas0 aMicrobased Landsat TM data processing for tallgrass prairie moni a76 -800 v103 a

Despite the large amount of evidence supporting the important role that burning and frequency of burning have on grassland resources, information on the spatial extent of burning in the Flint Hills of Kansas has not been developed. This is primarily due to the massive data requirements needed to access burning on a regional scale. This study assesses the regional potential for monitoring burning practices in the Flint Hills of Kansas using satellite data. The specific objective of this study was to ascertain the utility of Landsat thematic mapper digital data for delineating the spatial characteristics of burning in the Konza Prairie Research Natural Area. The Konza Prairie is an area exceeding 8,000 acres owned by Nature Conservancy and leased to Kansas State University for long-term ecological research. The management objectives of the research area are based on the efforts of periodic fire and grazing on a tall grass prairie ecosystem

10atallgrass prairie1 aNellis, M.D.1 aBriggs, J., M. uhttp://knz.lternet.edu/content/micro-based-landsat-tm-data-processing-tallgrass-prairie-monitoring-konza-prairie-research