@article {KNZ001746, title = {Beyond arctic and alpine: the influence of winter climate on temperate ecosystems}, journal = {Ecology}, volume = {97}, year = {2016}, pages = {372 - 382}, abstract = {

Winter climate is expected to change under future climate scenarios, yet the majority of winter ecology research is focused in cold-climate ecosystems. In many temperate systems, it is unclear how winter climate relates to biotic responses during the growing season. The objective of this study was to examine how winter weather relates to plant and animal communities in a variety of terrestrial ecosystems ranging from warm deserts to alpine tundra. Specifically, we examined the association between winter weather and plant phenology, plant species richness, consumer abundance, and consumer richness in 11 terrestrial ecosystems associated with the U.S. Long-Term Ecological Research (LTER) Network. To varying degrees, winter precipitation and temperature were correlated with all biotic response variables. Bud break was tightly aligned with end of winter temperatures. For half the sites, winter weather was a better predictor of plant species richness than growing season weather. Warmer winters were correlated with lower consumer abundances in both temperate and alpine systems. Our findings suggest winter weather may have a strong influence on biotic activity during the growing season and should be considered in future studies investigating the effects of climate change on both alpine and temperate systems.

}, keywords = {LTER-KNZ}, doi = {10.1890/15-0153.1}, url = {https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/15-0153.1}, author = {L. Ladwig and Z. Ratajczak and Ocheltree, T.W. and Hafich, K.A. and Churchill, A.C. and Frey, S.J.K. and Fuss, C.B. and Kazanski, C.E. and Mu{\~n}oz, J.D. and Petrie, M.D. and Reinmann, A.B. and Smith, J.G.} } @article {KNZ001612, title = {Abrupt transition of mesic grassland to shrubland: evidence for thresholds, alternative attractors, and regime shifts}, journal = {Ecology}, volume = {95}, year = {2014}, pages = {2633 -2645}, abstract = {

Ecosystems with alternative attractors are susceptible to abrupt regime shifts that are often difficult to predict and reverse. In this study, we quantify multiple system dynamics to determine whether the transition of mesic grassland to shrubland, a widespread phenomenon, represents a linear reversible process, a nonlinear but reversible threshold process, or a transition between alternative attractors that is nonlinear and prone to hysteresis. Using a 28-yr data set with annual resolution and extensive spatial replication, we found that shrub cover is correlated with distinct thresholds of fire and C4 grass cover, resulting in temporal bimodality of shrub cover and abrupt shifts of shrub cover despite gradual changes in grass cover. These abrupt increases in shrub cover are the most rapid ever reported in grasslands, and illustrate internal thresholds that separate grasslands and shrublands. Nonlinear transitions from low to high shrub cover were also closely associated with positive feedback mechanisms that alter fire and competition (r2 = 0.65), suggesting that grasslands and shrublands could show hysteresis, and by definition exist as alternative attractors. Thus, the response of this ecosystem to anthropogenic activity should tend to be rapid, nonlinear, and perhaps difficult to reverse. Regime shifts in this mesic grassland were predictable: we found that grassland and shrubland attractors were differentiated by critical thresholds of \∼50\–70\% grass cover, 5\–10\% shrub cover, and a fire return interval of \∼3 yr. These thresholds may provide adaptive potential for managing nonlinear behavior in socio-ecological systems in a changing environment.

}, keywords = {LTER-KNZ}, doi = {10.1890/13-1369.1}, url = {https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/13-1369.1}, author = {Z. Ratajczak and Jesse B. Nippert and Ocheltree, T.W.} } @article {KNZ001607, title = {Lack of eutrophication in a tallgrass prairie ecosystem over 27 years}, journal = {Ecology}, volume = {95}, year = {2014}, pages = {1225 -1235}, abstract = {

Many North American grasslands are receiving atmospheric nitrogen (N) deposition at rates above what are considered critical eutrophication thresholds. Yet, potential changes in grassland function due to anthropogenic N deposition are poorly resolved, especially considering that other dynamic factors such as land use and precipitation can also affect N availability. To better understand whether elevated N deposition has altered ecosystem structure or function in North American grasslands, we analyzed a 27-year record of ecophysiological, community, and ecosystem metrics for an annually burned Kansas tallgrass prairie. Over this time, despite increasing rates of N deposition that are within the range of critical loads for grasslands, there was no evidence of eutrophication. Plant N concentrations did not increase, soil moisture did not decline, forb diversity did not decline, and the relative abundance of dominant grasses did not shift toward more eutrophic species. Neither aboveground primary productivity nor N availability to plants increased. The fates of deposited N in grasslands are still uncertain, and could include management losses through burning and grazing. However, evidence from this grassland indicates that eutrophication of North American grassland ecosystems is not an inevitable consequence of current levels of N deposition.

}, keywords = {LTER-KNZ}, doi = {10.1890/13-1068.1}, url = {https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/13-1068.1}, author = {McLauchlan, K.K. and Craine, J.M. and Jesse B. Nippert and Ocheltree, T.W.} } @article {KNZ001556, title = {Stomatal responses to changes in vapor pressure deficit reflect tissue-specific differences in hydraulic conductance}, journal = {Plant, Cell and Environment}, volume = {37}, year = {2014}, pages = {132 -139}, abstract = {

The vapor pressure deficit (D) of the atmosphere can negatively affect plant growth as plants reduce stomatal conductance to water vapor (gwv) in response to increasing D, limiting the ability of plants to assimilate carbon. The sensitivity of gwv to changes in D varies among species and has been correlated with the hydraulic conductance of leaves (Kleaf), but the hydraulic conductance of other tissues has also been implicated in plant responses to changing D. Among the 19 grass species, we found that Kleaf was correlated with the hydraulic conductance of large longitudinal veins (Klv, r2\ =\ 0.81), but was not related to Kroot (r2\ =\ 0.01). Stomatal sensitivity to D was correlated with Kleaf relative to total leaf area (r2\ =\ 0.50), and did not differ between C3 and C4 species. Transpiration (E) increased in response to D, but 8 of the 19 plants showed a decline in E at high D, indicative of an \‘apparent feedforward\’ response. For these individuals, E began to decline at lower values of D in plants with low Kroot (r2\ =\ 0.72). These results show the significance of both leaf and root hydraulic conductance as drivers of plant responses to evaporative demand.

}, keywords = {LTER-KNZ}, doi = {10.1111/pce.12137}, url = {https://onlinelibrary.wiley.com/doi/full/10.1111/pce.12137}, author = {Ocheltree, T.W. and Jesse B. Nippert and Prasad, P.V.V.} } @article {KNZ001606, title = {Evidence of physiological decoupling from grassland ecosystem drivers by an encroaching woody shrub}, journal = {PLoS ONE}, volume = {8}, year = {2013}, pages = {81630 -}, abstract = {

Shrub encroachment of grasslands is a transformative ecological process by which native woody species increase in cover and frequency and replace the herbaceous community. Mechanisms of encroachment are typically assessed using temporal data or experimental manipulations, with few large spatial assessments of shrub physiology. In a mesic grassland in North America, we measured inter- and intra-annual variability in leaf δ13C in Cornus drummondii across a grassland landscape with varying fire frequency, presence of large grazers and topographic variability. This assessment of changes in individual shrub physiology is the largest spatial and temporal assessment recorded to date. Despite a doubling of annual rainfall (in 2008 versus 2011), leaf δ13C was statistically similar among and within years from 2008-11 (range of \−28 to \−27\‰). A topography*grazing interaction was present, with higher leaf δ13C in locations that typically have more bare soil and higher sensible heat in the growing season (upland topographic positions and grazed grasslands). Leaf δ13C from slopes varied among grazing contrasts, with upland and slope leaf δ13C more similar in ungrazed locations, while slopes and lowlands were more similar in grazed locations. In 2011, canopy greenness (normalized difference vegetation index \– NDVI) was assessed at the centroid of individual shrubs using high-resolution hyperspectral imagery. Canopy greenness was highest mid-summer, likely reflecting temporal periods when C assimilation rates were highest. Similar to patterns seen in leaf δ13C, NDVI was highest in locations that typically experience lowest sensible heat (lowlands and ungrazed). The ability of Cornus drummondii to decouple leaf physiological responses from climate variability and fire frequency is a likely contributor to the increase in cover and frequency of this shrub species in mesic grassland and may be generalizable to other grasslands undergoing woody encroachment.

}, keywords = {LTER-KNZ, Ecosystems, Grasslands, Grazing, Leaves, Plant physiology, Seasons, Shrubs, Water resources}, doi = {10.1371/journal.pone.0081630}, url = {https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0081630}, author = {Jesse B. Nippert and Ocheltree, T.W. and Orozco, G.L. and Z. Ratajczak and Ling, B. and Skibbe, A.M.} } @article {KNZ001488, title = {Global diversity of drought tolerance and grassland climate-change resilience}, journal = {Nature Climate Change}, volume = {3}, year = {2013}, pages = {63 -67}, abstract = {

Drought reduces plant productivity, induces widespread plant mortality and limits the geographic distribution of plant species1, 2, 3, 4, 5, 6, 7. As climates warm and precipitation patterns shift in the future8, 9, understanding the distribution of the diversity of plant drought tolerance is central to predicting future ecosystem function and resilience to climate change10, 11, 12. These questions are especially pressing for the world\’s 11,000 grass species13, which dominate a large fraction of the terrestrial biosphere14, yet are poorly characterized with respect to responses to drought. Here, we show that physiological drought tolerance, which varied tenfold among 426 grass species, is well distributed both climatically and phylogenetically, suggesting most native grasslands are likely to contain a high diversity of drought tolerance. Consequently, local species may help maintain ecosystem functioning in response to changing drought regimes without requiring long-distance migrations of grass species. Furthermore, physiologically drought-tolerant species had higher rates of water and carbon dioxide exchange than intolerant species, indicating that severe droughts may generate legacies for ecosystem functioning. In all, our findings suggest that diverse grasslands throughout the globe have the potential to be resilient to drought in the face of climate change through the local expansion of drought-tolerant species.

}, keywords = {LTER-KNZ, Climate-change ecology, Drought, Grassland ecology}, doi = {10.1038/nclimate1634}, url = {https://www.nature.com/articles/nclimate1634}, author = {Craine, J.M. and Ocheltree, T.W. and Jesse B. Nippert and Towne, E.G. and Skibbe, A.M. and Kembel, S.W. and Fargione, J.E.} } @article {KNZ001554, title = {Identifying the water sources consumed by bison: implications for large mammalian grazers worldwide}, journal = {Ecosphere}, volume = {4}, year = {2013}, pages = {23 -}, abstract = {

The sources of drinking water consumed by grazers vary over time and may be highly selective, similar to choices in diet. Water sources consumed by large grazers in natural populations are not typically measured directly. Instead, consumption is inferred based on animal proximity to water sources. Here, we analysed the stable isotopic signature of water (δ18O and δD) extracted from fecal samples from a herd of bison in mesic grassland as a direct estimation of the water sources consumed over time. Bison at this site have their choice of a range of habitats and drinking water sources. Potential source-water samples measured had a large range of isotopic signatures, allowing the isotopic composition of water from bison fecal samples to be proportionally estimated based on varying sources. Results indicate bison have low reliance on multiple streams on site; rather, the majority of water consumed was from rainfall-fed sources (puddles and wallows) and from forage. Our research suggests that source-water analysis from fecal samples is a robust technique when samples from large grazers can be collected soon after production. These results have implications for analyses of the foraging patterns and landscape utilization by this and other large grazers, because hotter and drier future conditions are likely to reduce the frequency and amount of rainfall-fed puddles available for consumption in many grassland systems worldwide.

}, keywords = {LTER-KNZ}, doi = {10.1890/ES12-00359.1}, url = {https://esajournals.onlinelibrary.wiley.com/doi/full/10.1890/ES12-00359.1}, author = {Jesse B. Nippert and Culbertson, T.S.F. and Orozco, G.L. and Ocheltree, T.W. and Helliker, B.R.} } @article {KNZ001502, title = {Changes in stomatal conductance along grass blades reflect changes in leaf structure}, journal = {Plant Cell and Environment}, volume = {35}, year = {2012}, pages = {1040 -1049}, abstract = {

Identifying the consequences of grass blade morphology (long, narrow leaves) on the heterogeneity of gas exchange is fundamental to an understanding of the physiology of this growth form. We examined acropetal changes in anatomy, hydraulic conductivity and rates of gas exchange in five grass species (including C3 and C4 functional types). Both stomatal conductance and photosynthesis increased along all grass blades despite constant light availability. Hydraulic efficiency within the xylem remained constant along the leaf, but structural changes outside the xylem changed in concert with stomatal conductance. Stomatal density and stomatal pore index remained constant along grass blades but interveinal distance decreased acropetally resulting in a decreased path length for water movement from vascular bundle to stomate. The increase in stomatal conductance was correlated with the decreased path length through the leaf mesophyll. A strong correlation between the distance from vascular bundles to stomatal pores and stomatal conductance has been identified across species; our results suggest this relationship also exists within individual leaves.

}, keywords = {LTER-KNZ}, doi = {10.1111/j.1365-3040.2011.02470.x}, url = {https://onlinelibrary.wiley.com/doi/full/10.1111/j.1365-3040.2011.02470.x}, author = {Ocheltree, T.W. and Jesse B. Nippert and Prasad, P.V.V.} } @article {KNZ001462, title = {Community traitscape of foliar nitrogen isotopes reveals N availabiity patterns in a tallgrass prairie}, journal = {Plant and Soil}, volume = {356}, year = {2012}, pages = {395 -403}, abstract = {

Background and aims Nutrients are important determinants of community assembly, yet the roles they play in structuring plant communities are still poorly understood. One inferential approach to understanding how environmental factors structure plant communities is examining the distribution of key functional traits among species of a community\—a community traitscape. Methods To better understand how nitrogen (N) and water availability structure grasslands, we measured N concentrations and isotope ratios for 366 herbaceous species in a mesic N-limited temperate grassland, Konza Prairie. We also compared foliar N concentrations and N isotopes between Konza species and a global dataset. Results Species that had either high foliar N concentrations or high δ15NL were not necessarily more or less abundant on the landscape nor more or less likely to be found in uplands, grazed areas, or burned areas. Apparently there are unique hot spots of high N availability at Konza and the typical non-Fabaceae Konza species occupies sites with greater N availability than found globally. Conclusions Although nascent, the Konza traitscapes suggest that plant diversity in nutrient-limited communities might be strongly dependent on high-nutrient availability sites that enable high-fertility species to persist in a matrix of low nutrient availability.

}, keywords = {LTER-KNZ, Community assembly, disturbance, Grasslands, Isotopes, Konza Prairie, Resource limitation}, doi = {10.1007/s11104-012-1141-7}, url = {https://link.springer.com/article/10.1007\%2Fs11104-012-1141-7}, author = {Craine, J.M. and Towne, E.G. and Ocheltree, T.W. and Jesse B. Nippert} } @phdthesis {KNZ001477, title = {Growth and survival during drought: The link between hydraulic architecture and drought tolerance in grasses}, volume = {PhD Dissertation}, year = {2012}, pages = {1 -1117}, school = {Kansas State University}, type = {Ph.D. Thesis}, address = {Manhattan, KS}, abstract = {

The pathway for the movement of water through plants, from the soil matrix to the atmosphere, constitutes the hydraulic architecture of a plant. The linkage between the hydraulic architecture of woody plants and drought tolerance has received considerable attention, but much less work has been done on grasses. I investigated the linkage between the hydraulic architecture of grasses to physiological patterns of water use across a range of species and conditions. The rate of stomatal conductance (g[subscript]s) and photosynthesis (A) increased acropetally along the leaves of 5 grass species, which is a unique feature of this growth form. The internal structure of leaves also changed acropetally in order to minimize the pressure gradient across the mesophyll that would otherwise occur as a result of increasing g[subscript]s. The resistance to water movement through the mesophyll represented 80-90\% of leaf resistance in six genotypes of Sorghum bicolor L. (Moench). This resistance was most important in controlling g[subscript]s and A when water was readily available, but as soil-moisture decreased it was the efficient transport of water through the xylem that was most important in maintaining plant function. I also investigated the relationship between hydraulic architecture and stomatal responses of grasses to increasing Vapor Pressure Deficit (D). Grasses with a larger proportion of their hydraulic resistance within the xylem were less sensitive to increasing D and plants with high root conductance maintained higher rates of gas exchange D increased. Finally, I investigated the tolerance of grasses to extreme drought events to test if there was a trade-off between drought tolerance and growth in grasses. Plants with drought tolerant leaf traits typically sacrificed the ability to move water efficiently through their leaves. Having drought tolerant leaves did not limit the plants ability to have high rates of gas exchange, and, in fact, the most drought tolerant plants had the high rates of g[subscript]s when expressed on a mass basis. Leaf-level drought tolerance did contribute to species\’ occurrence, as the drought intolerant species I studied are not commonly found in low precipitation systems. The results presented here highlight the importance of studying the hydraulic architecture of plants to provide a better understanding of what controls plant function across a range of environmental conditions.

}, keywords = {LTER-KNZ, Drought Tolerance, Grass Anatomy, Grass Physiology, Plant Hydraulic Architecture, Stomatal Conductance}, url = {http://hdl.handle.net/2097/13803}, author = {Ocheltree, T.W.} } @article {KNZ001501, title = {Root characteristics of C-4 grasses limit reliance on deep soil water in tallgrass prairie}, journal = {Plant and Soil}, volume = {355}, year = {2012}, pages = {385 -394}, abstract = {

Background C4 grass species in the mesic tallgrass prairie of central North America can exhibit both high root production and deep rooting in the soil profile (\>2 m). Differences in root growth and the types of roots produced vary according to local environmental gradients and management practices. The production of deep roots in tallgrass prairie has been historically presumed as a mechanism for water uptake when surface soils are dry. Methods We examined changes in root biomass, total root length, root width, and theoretical hydraulic conductivity using roots collected from deep soil cores in upland and lowland topographic positions in grazed and ungrazed watersheds of the Konza Prairie Biological Station in north-eastern Kansas, USA. Results Root biomass, total root length, and theoretical hydraulic conductivity were highest in roots found in the top 20 cm of the soil profile, and then declined exponentially with increasing soil depth. Compared to grazed areas, ungrazed locations had more root biomass and total root length of roots in the most superficial soil layers. No differences in rooting profiles were present among topographic contrasts. Theoretical hydraulic conductivity of axial root xylem did not vary by topographic position or grazing contrasts, and declines in conductivity by depth were driven by changes in the number of vessels per stele, rather than changes in vessel size. Conclusions Irrespective of differences by grazing treatment or topographic position, significant reductions in root biomass, total root length, and theoretical hydraulic conductivity of grass roots at soil depths greater than 1 m suggest deep roots in this grassland have limited functional significance for water uptake.

}, keywords = {LTER-KNZ, Andropogon gerardii, C4 grass, Mesic grassland, Root biomass, Theoretical hydraulic conductivity, Total root length}, doi = {10.1007/s11104-011-1112-4}, url = {https://link.springer.com/article/10.1007\%2Fs11104-011-1112-4}, author = {Jesse B. Nippert and Wieme, R.A. and Ocheltree, T.W. and Craine, J.M.} } @article {KNZ001387, title = {Linking plant growth responses across topographic gradients in tallgrass prairie}, journal = {Oecologia}, volume = {166}, year = {2011}, pages = {1131 -1142}, abstract = {

Aboveground biomass in grasslands varies according to landscape gradients in resource availability and seasonal patterns of growth. Using a transect spanning a topographic gradient in annually burned ungrazed tallgrass prairie, we measured changes in the height of four abundant C4 grass species, LAI, biomass, and cumulative carbon flux using two closely located eddy flux towers. We hypothesized that seasonal patterns of plant growth would be similar across the gradient, but the magnitude of growth and biomass accumulation would vary by topographic position, reflecting spatial differences in microclimate, slope, elevation, and soil depth. Thus, identifying and measuring local growth responses according to topographic variability should significantly improve landscape predictions of aboveground biomass. For most of the growth variables measured, classifying topography into four positions best captured the inherent spatial variability. Biomass produced, seasonal LAI and species height increased from the upland and break positions to the slope and lowland. Similarly, cumulative carbon flux in 2008 was greater in lowland versus upland tower locations (difference of 64 g m\−2 by DOY 272). Differences in growth by topographic position reflected increased production of flowering culms by Andropogon gerardii and Sorghastrum nutans in lowland. Varying growth responses by these species may be a significant driver of biomass and carbon flux differences by topographic position, at least for wet years. Using a digital elevation model to classify the watershed into topographic positions, we performed a geographically weighted regression to predict landscape biomass. The minimum and maximum predictions of aboveground biomass for this watershed had a large range (86\–393 t per 40.4 ha), illustrating the drastic spatial variability in growth within this annually-burned grassland.

}, keywords = {LTER-KNZ, ANPP, Eddy covariance, Flux footprint, LAI, Mesic grassland, topography}, doi = {10.1007/s00442-011-1948-6}, url = {https://link.springer.com/article/10.1007\%2Fs00442-011-1948-6}, author = {Jesse B. Nippert and Ocheltree, T.W. and Skibbe, A.M. and Kangas, L.C. and J.M. Ham and Shonkwiler-Arnold, K.B. and N. Brunsell} } @article {KNZ001450, title = {Positive feedbacks amplify rates of woody encroachment in mesic tallgrass prairie}, journal = {Ecosphere}, volume = {2}, year = {2011}, pages = {121 -}, abstract = {

Over the last century, many grasslands worldwide have transitioned from a graminoid to a tree/shrub-dominated state in a short period of time, a phenomenon referred to as woody encroachment. Positive feedbacks and bi-stability are thought to be important drivers of woody encroachment, but there is little empirical evidence to suggest that positive feedbacks accelerate the woody encroachment of mesic grasslands. In mesic tallgrass prairie, shrub establishment does not directly facilitate seedling establishment. Yet, shrub establishment may facilitate the clonal spread of existing shrubs into nearby patches, because clonal reproduction might circumvent barriers that typically limit woody seedlings. Our results show that when Cornus drummondii (the predominate encroacher of mesic tallgrass prairie) extends rhizomatous stems into open grasslands, these stems use the same deep soil water sources as mature stems\—thereby avoiding competition with grasses and gaining access to a reliable water source. In addition, herbaceous fuel concentrations are lower at the shrub/grass interface than in open grasslands, reducing the potential impacts of subsequent grassland fires. We propose that the release from resource and fire limitation results in a positive feedback loop as clonal stems are able to extend into surrounding patches, circumvent demographic barriers, mature, and spread by developing their own clonal stems. Long-term data on site (26 years) corroborates this interpretation: the size of deep-rooted clonal shrub species has increased 16-fold and their cover has increased from 0 to 27\%, whereas the cover of shallow-rooted species (both clonal and non-clonal) has only increased marginally. Together, these results suggest that (1) positive feedbacks can facilitate mesic woody encroachment and (2) bi-stability exists in mesic tallgrass prairie.

}, keywords = {LTER-KNZ}, doi = {10.1890/ES11-00212.1}, url = {https://esajournals.onlinelibrary.wiley.com/doi/full/10.1890/ES11-00212.1}, author = {Z. Ratajczak and Jesse B. Nippert and Hartman, J.C. and Ocheltree, T.W.} } @article {KNZ001304, title = {Thirteen decades of foliar isotopes indicate declining nitrogen availability in central North American grasslands}, journal = {New Phytologist}, volume = {187}, year = {2010}, pages = {1135 -1145}, abstract = {

\•Humans are increasing both the deposition of reactive nitrogen (N) and concentrations of atmospheric CO2 on Earth, but the combined effects on terrestrial ecosystems are not clear. In the absence of historical records, it is difficult to know if N availability is currently increasing or decreasing on regional scales. \•To determine the nature and timing of past changes in grassland ecosystem dynamics, we measured the composition of stable carbon (C) and N isotopes in leaf tissue from 545 herbarium specimens of 24 vascular plant species collected in Kansas, USA from 1876 to 2008. We also parameterized a simple model of the terrestrial N cycle coupled with a stable isotope simulator to constrain processes consistent with observed patterns. \•A prolonged decline in foliar N concentrations began in 1926, while a prolonged decline in foliar δ15N values began in 1940. Changes in the difference between foliar and atmospheric C isotopes reveal slightly increased photosynthetic water use efficiency since 1876. \•The declines in foliar N concentrations and foliar δ15N suggest declining N availability in these grasslands during the 20th century despite decades of anthropogenic N deposition. Our results are consistent with progressive-nitrogen-limitation-type hypotheses where declines in N availability are driven by increased ecosystem N storage as a result of increased atmospheric CO2.

}, keywords = {LTER-KNZ}, doi = {10.1111/j.1469-8137.2010.03322.x}, url = {https://nph.onlinelibrary.wiley.com/doi/full/10.1111/j.1469-8137.2010.03322.x}, author = {McLauchlan, K.K. and Ferguson, C.J. and Wilson, I.E. and Ocheltree, T.W. and Craine, J.M.} }