@article {KNZ001544, title = {Influence of macroconsumers, stream position, and nutrient gradients on invertebrate assemblage development following flooding in intermittent prairie streams}, journal = {Hydrobiologia}, volume = {714}, year = {2013}, pages = {169 -182}, abstract = {

Climate change in the US Great Plains is expected to result in less frequent but more severe floods. This will affect hydrologic cycles, stream organisms, and ultimately ecosystem structure and function. We examined factors influencing invertebrate assemblages following flooding in 3 reaches (20 pools) of Kings Creek, an intermittent prairie stream on the Konza Prairie Biological Station, using replicated macroconsumer enclosures (fishless, dace, shiners, ambient). Invertebrate densities and biomass increased rapidly following scouring, including rapid colonizing taxa and relatively long-lived taxa, but macroconsumers had no significant effects. Rather, distance, which was negatively correlated with the concentration of dissolved inorganic nitrogen, from the downstream confluence with a larger stream significantly influenced assemblage structure, with higher richness and greater nutrient concentrations closer to the confluence. Results support previous findings that recovery patterns following flooding in this grassland stream are strongly influenced by proximity to refuges. Furthermore, physical rather than biological factors appear more influential in structuring invertebrate assemblages in these frequently disturbed systems. Predicted increases in the intensity and duration of hydrologic disturbances will increase direct impacts on stream communities, relative to indirect effects through potential changes in macroconsumer communities. Human activities that alter refuges may further impede recovery following hydrologic disturbances.

}, keywords = {LTER-KNZ, disturbance, Flood, Invertebrate, Macroconsumer Gradients, Prairie stream}, doi = {10.1007/s10750-013-1534-5}, url = {https://link.springer.com/article/10.1007\%2Fs10750-013-1534-5}, author = {Bertrand, K.N. and M.R. Whiles and K. B. Gido and Murdock, J.N.} } @article {KNZ001260, title = {Consumer return chronology alters recovery trajectory of stream ecosystem structure and function following drought}, journal = {Ecology}, volume = {91}, year = {2010}, pages = {1048 -1062}, abstract = {

Consumers are increasingly being recognized as important drivers of ecological succession, yet it is still hard to predict the nature and direction of consumer effects in nonequilibrium environments. We used stream consumer exclosures and large outdoor mesocosms to study the impact of macroconsumers (i.e., fish and crayfish) on recovery of intermittent prairie streams after drying. In the stream, macroconsumers altered system recovery trajectory by decreasing algal and macroinvertebrate biomass, primary productivity, and benthic nutrient uptake rates. However, macroconsumer influence was transient, and differences between exclosures and controls disappeared after 35 days. Introducing and removing macroconsumers after 28 days resulted mainly in changes to macroinvertebrates. In mesocosms, a dominant consumer (the grazing minnow Phoxinus erythrogaster) reduced macroinvertebrate biomass but had little effect on algal assemblage structure and ecosystem rates during recovery. The weak effect of P. erythrogaster in mesocosms, in contrast to the strong consumer effect in the natural stream, suggests that both timing and diversity of returning consumers are important to their overall influence on stream recovery patterns. Although we found that consumers significantly altered ecosystem structure and function in a system experiencing rapid changes in abiotic and biotic factors following disturbance, consumer effects diminished over time and trajectories converged to similar states with respect to primary producers, in spite of differences in consumer colonization history. Thus, consumer impacts can be substantial in recovering ecosystems and are likely to be dependent on the disturbance regime and diversity of the consumer community.

}, keywords = {LTER-KNZ}, doi = {10.1890/08-2168.1}, url = {https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/08-2168.1}, author = {Murdock, J.M. and K. B. Gido and W. K. Dodds and Bertrand, K.N. and M.R. Whiles} } @proceedings {KNZ001432, title = {Disturbance mediated effects of stream fishes on ecosystem processes: concepts and results from highly variable prairie streams}, journal = {Advances in Stream Fish Community Ecology: Concepts, Approaches and Techniques}, year = {2010}, pages = {593 -617}, abstract = {

Stream fishes can have strong top-down and bottom-up effects on ecosystem processes. However, the dynamic nature of streams constrains our ability to generalize these effects across systems with different disturbance regimes and species composition. To evaluate the role of fishes following disturbance, we used a series of field and mesocosm experiments that quantified the influence of grazers and water column minnows on primary productivity, periphyton structure, organic matter pools, and invertebrate communities following either scouring floods or drying of prairie streams. Results from individual experiments revealed highly significant effects of fishes, but the direction or magnitude of effects varied among experiments. Meta-analyses across experiments indicated that grazers consistently reduced the relative amount of fine benthic organic matter (FBOM) and chironomid abundance within 2 weeks after disturbances. However, effect sizes (log response ratios) were heterogeneous across experiments for algal biomass and algal filament lengths measured more than 4 weeks after a disturbance and potentially associated with system productivity and grazer densities. A similar analysis of 3\–4 experiments using water column minnows only found a consistent trend of decreasing FBOM in fish treatments relative to controls when measured less than 2 weeks after disturbances and increase in gross primary productivity measured more than 4 weeks after disturbance. These results, along with those of others, were used to develop a conceptual framework for predicting the potential role of fishes in streams following disturbances (flood and drying). Both theoretical and empirical research shows that recovery of stream ecosystem processes will depend on the resilience of autotrophic and heterotrophic communities following disturbance. Fish effects may vary among functional groups but are generally predicted to be greatest during early stages of succession when algal and invertebrate communities are less complex and their biomass is low relative to fish biomass. Our analysis underscores the context dependency of consumer effects on ecosystem structure and function in nonequilibrium conditions and suggests that factors regulating fish densities and colonization of algal and invertebrate taxa need to be evaluated to predict the consequences of biodiversity loss in streams with variable or human-modified disturbance regimes.

}, keywords = {LTER-KNZ}, url = {https://www.k-state.edu/fishecology/msreprints/Gido\%20et\%20al.2010\%20AFSbook\%20chapter.pdf}, author = {K. B. Gido and Bertrand, K.N. and Murdock, J.N. and W. K. Dodds and M.R. Whiles} } @article {KNZ001237, title = {Disturbance frequency and functional identity mediate ecosystem processes in prairie streams}, journal = {Oikos}, volume = {118}, year = {2009}, pages = {917 -933}, abstract = {

A major consequence of climate change will be the alteration of precipitation patterns and concomitant changes in the flood frequencies in streams. Species losses or introductions will accompany these changes, which necessitates understanding the interactions between altered disturbance regimes and consumer functional identity to predict dynamics of streams. We used experimental mesocosms and field enclosures to test the interactive effects of flood frequency and two fishes from distinct consumer groups (benthic grazers and water-column minnows) on recovery of stream ecosystem properties (algal form and biomass, invertebrate densities, metabolism and nutrient uptake rates). Our results generally suggest that periphyton communities under nutrient limitation are likely to recover more quickly when grazing and water-column minnows are present and these effects can diminish or reverse with time since the disturbance. We hypothesized that increased periphyton production and biomass was the result of increased nutrient turnover, but decreased light limitation and indirect effects on other trophic levels are alternative explanations. Recovery of stream ecosystem properties after a natural flood differed from mesocosms (e.g. lower algal biomass and no long algal filaments present) and species manipulations did not explain recovery of ecosystem properties; rather, ecosystem processes varied along a downstream gradient of increasing temperature and nutrient concentrations. Different results between field enclosures and experimental mesocosms are attributable to a number of factors including differences in algal and invertebrate communities in the natural stream and relatively short enclosure lengths (mean area=35.8 m2) compared with recirculating water in the experimental mesocosms. These differences may provide insight into conditions necessary to elicit a strong interaction between consumers and ecosystem properties.

}, keywords = {LTER-KNZ}, doi = {10.1111/j.1600-0706.2008.16849.x}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1600-0706.2008.16849.x}, author = {Bertrand, K.N. and K. B. Gido and W. K. Dodds and Murdock, J.N. and M.R. Whiles} } @article {KNZ001207, title = {Comparing ecosystem goods and services provided by restored and native lands}, journal = {BioScience}, volume = {58}, year = {2008}, pages = {837 -845}, abstract = {

We determined the relative benefits for eight categories of ecosystem goods and services associated with native and restored lands across the conterminous United States. Less than 10\% of most native US ecosystems remain, and the proportion that is restored varies widely by biome. Restored lands offer 31\% to 93\% of native land benefits within a decade after restoration, with restored wetlands providing the most economic value and deserts providing the least. Restored ecosystems that recover rapidly and produce valuable commodities return a higher proportion of total value. The relative values of the benefits provided by restoration vary both by biome and by the ecosystem goods and services of interest. Our analysis confirms that conservation should be the first priority, but that restoration programs across broad geographic regions can have substantial value. \“No net loss\” policies should recognize that restored lands are not necessarily equivalent to native areas with regard to estimated ecosystem benefits.

}, keywords = {LTER-KNZ, conservation, ecosystem goods, ecosystem services, ecosystem valuation, restoration}, doi = {10.1641/B580909}, url = {https://academic.oup.com/bioscience/article/58/9/837/250939}, author = {W. K. Dodds and Wilson, K.C. and Rehmeier, R.L. and Knight, G.L. and Wiggam, S. and Falke, J.A. and Dalgleish, H.J. and Bertrand, K.N.} } @article {KNZ001108, title = {Effects of the herbivorous minnow, southern redbelly dace (Phoxinus erythrogaster) on stream ecosystem structure and function}, journal = {Oecologia}, volume = {151}, year = {2007}, pages = {69 -81}, abstract = {We used field and mesocosm experiments to measure effects of southern redbelly dace (Phoxinus erythrogaster), a grazing minnow, on stream ecosystem structure and function. Ecosystem structure was quantified as algal filament length, algal biomass, size distribution of particulate organic matter (POM), algal assemblage structure, and invertebrate assemblage structure, whereas ecosystem function was based on gross and net primary productivity. Our experiments showed that moderate densities of Phoxinus temporarily reduced mean algal filament length and mean size of POM relative to fishless controls. However, there was no detectable effect on algal biomass or ecosystem primary productivity. Several factors could explain the lack of effect of Phoxinus on primary productivity including increased algal production efficiency in grazed treatments or increased grazing by other organisms in fishless treatments. The inability of Phoxinus to reduce algal biomass and system productivity contrasts with experimental results based on other grazing minnows, such as the central stoneroller (Campostoma anomalum), and questions the generality of grazer effects in stream ecosystems. However, environmental venue and the spatial and temporal scale of ecosystem measurements can greatly influence the outcome of these experiments.}, keywords = {LTER-KNZ, grazers, prairie streams, Stream metabolism}, doi = {10.1007/s00442-006-0569-y}, author = {Bertrand, K.N. and K. B. Gido} } @phdthesis {KNZ001103, title = {Fishes and floods: stream ecosystem drivers in the Great Plains}, volume = {PhD Dissertation}, year = {2007}, pages = {1 -141}, school = {Kansas State University}, type = {Ph.D. Thesis}, address = {Manhattan, KS}, abstract = {

Global climate change could lead to less frequent but more severe precipitation events in the Great Plains, altering the hydrologic regimes of streams. It is important to quantify species roles in these dynamic systems, because changes in stream communities are likely to accompany predicted changes in hydrology. The effects of species on ecosystem processes also are limited by the frequency of disturbance, because prairie streams are harsh, nonequilibrium systems characterized by a wide range of disturbances. In particular, frequent floods that reset the ecosystem to an early successional state can override the influence of consumer populations because the availability of resources is too unpredictable to maintain stable populations of those species or because species are absent following the flood. As flood frequency decreases, potential consumer effects may intensify. Using a combination of field and experimental stream mesocosm experiments, I (1) characterized the ecosystem effects of southern redbelly dace (Phoxinus erythrogaster), a grazing minnow, (2) tested the interactive effects of flood frequency and the presence of water column (red shiner; Cyprinella lutrensis) or grazing minnows (Phoxinus) on ecosystem processes, and (3) tested the effects of species loss from the grazer functional feeding group on stream ecosystem structure and function. I found that dace affected some aspects of ecosystem structure but not function, which suggested that grazer effects in prairie streams may not be consistent across taxa. In the context of flood frequency, both the water column omnivore and dace affected recovery of prairie stream primary producers following flooding disturbance by stimulating production, presumably through nutrient remineralization. However, some of these effects were transient or dependent on flood frequency, and my results indicate that consumer effects depend not only on environmental venue but also on the balance between consumptive losses and nutrient stimulation. In a comparison of the effects of removing different taxa from a grazer assemblage, the loss of crayfish, snails, or dace from a grazer assemblage did not differentially affect ecosystem processes, suggesting overlap in the ecosystem roles of these species in the context of this experiment.

}, keywords = {LTER-KNZ, Biodiversitym, Ecosystem function, Flood frequency, Grazing minnow, Omnivorous minnow, Prairie stream}, url = {http://hdl.handle.net/2097/297 }, author = {Bertrand, K.N.} } @article {KNZ001109, title = {Effects of floods on fish assemblages in an intermittent prairie stream}, journal = {Freshwater Biology}, volume = {51}, year = {2006}, pages = {2072 -2086}, abstract = {1. Floods are major disturbances to stream ecosystems that can kill or displace organisms and modify habitats. Many studies have reported changes in fish assemblages after a single flood, but few studies have evaluated the importance of timing and intensity of floods on long-term fish assemblage dynamics. 2. We used a 10-year dataset to evaluate the effects of floods on fishes in Kings Creek, an intermittent prairie stream in north-eastern, Kansas, U.S.A. Samples were collected seasonally at two perennial headwater sites (1995{\textendash}2005) and one perennial downstream flowing site (1997{\textendash}2005) allowing us to evaluate the effects of floods at different locations within a watershed. In addition, four surveys during 2003 and 2004 sampled 3{\textendash}5 km of stream between the long-term study sites to evaluate the use of intermittent reaches of this stream. 3. Because of higher discharge and bed scouring at the downstream site, we predicted that the fish assemblage would have lowered species richness and abundance following floods. In contrast, we expected increased species richness and abundance at headwater sites because floods increase stream connectivity and create the potential for colonisation from downstream reaches. 4. Akaike Information Criteria (AIC) was used to select among candidate regression models that predicted species richness and abundance based on Julian date, time since floods, season and physical habitat at each site. At the downstream site, AIC weightings suggested Julian date was the best predictor of fish assemblage structure, but no model explained >16\% of the variation in species richness or community structure. Variation explained by Julian date was primarily attributed to a long-term pattern of declining abundance of common species. At the headwater sites, there was not a single candidate model selected to predict total species abundance and assemblage structure. AIC weightings suggested variation in assemblage structure was associated with either Julian date or local habitat characteristics. 5. Fishes rapidly colonised isolated or dry habitats following floods. This was evidenced by the occurrence of fishes in intermittent reaches and the positive association between maximum daily discharge and colonisation events at both headwater sites. 6. Our study suggests floods allow dispersal into intermittent habitats with little or no downstream displacement of fishes. Movement of fishes among habitats during flooding highlights the importance of maintaining connectivity of stream networks of low to medium order prairie streams.}, keywords = {LTER-KNZ}, doi = {10.1111/j.1365-2427.2006.01640.x}, author = {Franssen, N.R. and K. B. Gido and Strakosh, T.R. and Bertrand, K.N. and Franssen, C.M. and Paukert, C.P. and Pitts, K.L. and Guy, C.S. and Tripe, J.A. and Shrank, S.J.} } @article {KNZ001057, title = {An evaluation of single-pass versus three-pass backpack electrofishing to estimate trends in species abundance and richness in prairie streams}, journal = {Transactions of the Kansas Academy of Science}, volume = {109}, year = {2006}, pages = {131 -138}, abstract = {Backpack electrofishing is a common method used to compare total species richness and relative abundance of stream fishes across space and time. However, as with any sampling method, it is important to evaluate the sampling effort necessary to capture patterns of variation in fish assemblage structure across samples. Thus, we evaluated the efficacy of single-pass versus multiple-pass backpack electrofishing for minnows and darters in intermittent prairie streams. We found that in 14 of 19 three-pass electrofishing samples, we detected all species during the first pass. The samples where we missed species on the first pass were in pools with six to nine species, suggesting a single-pass sample worked best for pools with lower species richness. We also found that both the raw abundance (i.e., catch rates) and rank abundance of four common species based on the first pass is highly concordant with the second and third passes. Nevertheless, differences in capture efficiency varied by species and density. In particular, our ability to deplete a species from a stream pool was highly variable when fish densities were low, and for Phoxinus erythrogaster, it was variable across all densities. Overall, our data suggest single-pass electrofishing can be used to detect spatial and temporal trends in abundance and species richness given standardized effort, but may not be representative of absolute population densities.}, keywords = {LTER-KNZ, backpack electrofishing, darters, intermittent prairie streams, minnows, sampling efficiency}, doi = {10.1660/0022-8443(2006)109[131:AEOSVM]2.0.CO;2}, author = {Bertrand, K.N. and K. B. Gido and Guy, C.S.} }