@inbook {KNZ001941, title = {Will climate change push grasslands past critical thresholds?}, booktitle = {Grasslands and Climate Change}, year = {2019}, pages = {98 - 114}, publisher = {British Ecological Society and Cambridge University Press}, organization = {British Ecological Society and Cambridge University Press}, address = {Cambridge, UK.}, keywords = {LTER-KNZ}, url = {https://www.cambridge.org/core/books/grasslands-and-climate-change/will-climate-change-push-grasslands-past-critical-thresholds/368C9316D9C5A8A3C6B6881779BA5EB5}, author = {Z. Ratajczak and L. Ladwig}, editor = {Gibson, D. and Newman, J.} } @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 {KNZ001698, title = {Anthropogenic nitrogen deposition predicts local grassland primary production worldwide}, journal = {Ecology}, volume = {96}, year = {2015}, pages = {1459 -1465}, abstract = {

Humans dominate many important Earth system processes including the nitrogen (N) cycle. Atmospheric N deposition affects fundamental processes such as carbon cycling, climate regulation, and biodiversity, and could result in changes to fundamental Earth system processes such as primary production. Both modelling and experimentation have suggested a role for anthropogenically altered N deposition in increasing productivity, nevertheless, current understanding of the relative strength of N deposition with respect to other controls on production such as edaphic conditions and climate is limited. Here we use an international multiscale data set to show that atmospheric N deposition is positively correlated to aboveground net primary production (ANPP) observed at the 1-m2 level across a wide range of herbaceous ecosystems. N deposition was a better predictor than climatic drivers and local soil conditions, explaining 16\% of observed variation in ANPP globally with an increase of 1 kg N\·ha\−1\·yr\−1 increasing ANPP by 3\%. Soil pH explained 8\% of observed variation in ANPP while climatic drivers showed no significant relationship. Our results illustrate that the incorporation of global N deposition patterns in Earth system models are likely to substantially improve estimates of primary production in herbaceous systems. In herbaceous systems across the world, humans appear to be partially driving local ANPP through impacts on the N cycle.

}, keywords = {LTER-KNZ}, doi = {http://dx.doi.org/10.1890/14-1902.1}, url = {https://esajournals.onlinelibrary.wiley.com/doi/full/10.1890/14-1902.1}, author = {Stevens, C.J. and Lind, E.M. and Hautier, Y. and Harpole, W.S. and E.T. Borer and Hobbie, S. and Seabloom, E.Q. and L. Ladwig and J.D. Bakker and Chu, C. and Scott. L. Collins and Davies, K.F. and Firn, J. and Hillebrand, H. and Kimberly J. La Pierre and MacDougall, A.S. and Melbourne, B.A. and McCulley, R.L. and J.W. Morgan and Orrock, J.L. and Prober, S.M. and A. Risch and Schultz, M. and Wragg, P.D.} } @article {KNZ001788, title = {Grassland productivity limited by multiple nutrients}, journal = {Nature Plants}, volume = {1}, year = {2015}, pages = {15080}, abstract = {

Terrestrial ecosystem productivity is widely accepted to be nutrient limited1. Although nitrogen (N) is deemed a key determinant of aboveground net primary production (ANPP)2,3, the prevalence of co-limitation by N and phosphorus (P) is increasingly recognized4,​5,​6,​7,​8. However, the extent to which terrestrial productivity is co-limited by nutrients other than N and P has remained unclear. Here, we report results from a standardized factorial nutrient addition experiment, in which we added N, P and potassium (K) combined with a selection of micronutrients (K+μ), alone or in concert, to 42 grassland sites spanning five continents, and monitored ANPP. Nutrient availability limited productivity at 31 of the 42 grassland sites. And pairwise combinations of N, P, and K+μ co-limited ANPP at 29 of the sites. Nitrogen limitation peaked in cool, high latitude sites. Our findings highlight the importance of less studied nutrients, such as K and micronutrients, for grassland productivity, and point to significant variations in the type and degree of nutrient limitation. We suggest that multiple-nutrient constraints must be considered when assessing the ecosystem-scale consequences of nutrient enrichment.

}, keywords = {LTER-KNZ}, doi = {10.1038/nplants.2015.80}, url = {https://www.nature.com/articles/nplants201580}, author = {Fay, P.A. and Prober, S.M. and Harpole, W.S. and Knops, J.M.H. and J.D. Bakker and E.T. Borer and Lind, E.M. and MacDougall, A.S. and Seabloom, E.W. and Wragg, P.D. and P. Adler and D.M. Blumenthal and Buckley, Y.M. and Chu, C. and Cleland, E.E. and Scott. L. Collins and Davies, K.F. and G. Du and Feng, X. and Firn, J. and Gruner, D.S. and Hagenah, N. and Hautier, Y. and Heckman, R.W. and Jin, V.L. and Kirkman, K.P. and Klein, J. and L. Ladwig and Li, Q. and McCulley, R.L. and Melbourne, B.A. and Mitchell, C.E. and Joslin L. Moore and J.W. Morgan and A. Risch and sch{\"u}tz, M. and Stevens, C.J. and Wedin, D.A. and Yang, L.H.} } @article {KNZ001697, title = {Plant species{\textquoteright} origin predicts dominance and response to nutrient enrichment and herbivores in global grasslands}, journal = {Nature Communications}, volume = {6}, year = {2015}, pages = {7710 -}, abstract = {

Exotic species dominate many communities; however the functional significance of species\’ biogeographic origin remains highly contentious. This debate is fuelled in part by the lack of globally replicated, systematic data assessing the relationship between species provenance, function and response to perturbations. We examined the abundance of native and exotic plant species at 64 grasslands in 13 countries, and at a subset of the sites we experimentally tested native and exotic species responses to two fundamental drivers of invasion, mineral nutrient supplies and vertebrate herbivory. Exotic species are six times more likely to dominate communities than native species. Furthermore, while experimental nutrient addition increases the cover and richness of exotic species, nutrients decrease native diversity and cover. Native and exotic species also differ in their response to vertebrate consumer exclusion. These results suggest that species origin has functional significance, and that eutrophication will lead to increased exotic dominance in grasslands.

}, keywords = {LTER-KNZ, Biological sciences, ecology, Plant sciences}, doi = {10.1038/ncomms8710}, url = {https://www.nature.com/articles/ncomms8710}, author = {Seabloom, E.W. and E.T. Borer and Buckley, Y. and Cleland, E.E. and Davies, K.F. and Firn, J. and Harpole, W.S. and Hautier, Y. and Lind, E. and MacDougall, A.S. and Orrock, J.L. and Prober, S.M. and P. Adler and Anderson, T.M. and J.D. Bakker and L.A. Biederman and D.M. Blumenthal and C.S. Brown and Brudvig, L.A. and Cadotte, M. and Chu, C. and Cottingham, K.L. and Crawley, M.J. and Damschen, E.I. and D{\textquoteright}Antonio, C.M. and CeCrappeo, N.M. and G. Du and Fay, P.A. and Frater, P. and Gruner, D.S. and Hagenah, N. and Hector, A. and Hillebrand, H. and Hofmockel, K.S. and Humphries, H.C. and Jin, V.L. and Kay, A.D. and Kirkman, K.P. and Klein, J.A. and Knops, J.M.H. and Kimberly J. La Pierre and L. Ladwig and Lambrinos, J.G. and Li, Q. and Li, W. and Marushia, R.} } @article {KNZ001790, title = {Predicting invasion in grassland ecosystems: is exotic dominance the real embarrassment of richness?}, journal = {Global Change Biology}, volume = {19}, year = {2013}, pages = {3677 - 3687}, abstract = {

Invasions have increased the size of regional species pools, but are typically assumed to reduce native diversity. However, global-scale tests of this assumption have been elusive because of the focus on exotic species richness, rather than relative abundance. This is problematic because low invader richness can indicate invasion resistance by the native community or, alternatively, dominance by a single exotic species. Here, we used a globally replicated study to quantify relationships between exotic richness and abundance in grass-dominated ecosystems in 13 countries on six continents, ranging from salt marshes to alpine tundra. We tested effects of human land use, native community diversity, herbivore pressure, and nutrient limitation on exotic plant dominance. Despite its widespread use, exotic richness was a poor proxy for exotic dominance at low exotic richness, because sites that contained few exotic species ranged from relatively pristine (low exotic richness and cover) to almost completely exotic-dominated ones (low exotic richness but high exotic cover). Both exotic cover and richness were predicted by native plant diversity (native grass richness) and land use (distance to cultivation). Although climate was important for predicting both exotic cover and richness, climatic factors predicting cover (precipitation variability) differed from those predicting richness (maximum temperature and mean temperature in the wettest quarter). Herbivory and nutrient limitation did not predict exotic richness or cover. Exotic dominance was greatest in areas with low native grass richness at the site- or regional-scale. Although this could reflect native grass displacement, a lack of biotic resistance is a more likely explanation, given that grasses comprise the most aggressive invaders. These findings underscore the need to move beyond richness as a surrogate for the extent of invasion, because this metric confounds monodominance with invasion resistance. Monitoring species\&$\#$39; relative abundance will more rapidly advance our understanding of invasions.

}, keywords = {LTER-KNZ}, doi = {10.1111/gcb.12370}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.12370}, author = {Seabloom, E.W. and E.T. Borer and Buckley, Y. and Cleland, E.E. and Davies, K. and Firn, J. and Harpole, W.S. and Hautier, Y. and Lind, E. and MacDougall, A. and Orrock, J.L. and Prober, S.M. and P. Adler and J. Alberti and Anderson, M.T. and J.D. Bakker and L.A. Biederman and D.M. Blumenthal and C.S. Brown and Brudvig, L.A. and Caldeira, M. and Chu, C. and Crawley, M.J. and Daleo, P. and Damschen, E.I. and D{\textquoteright}Antonio, C.M. and DeCrappeo, N.M. and Dickman, C.R. and G. Du and Fay, P.A. and Frater, P. and Gruner, D.S. and Hagenah, N. and Hector, A. and Helm, A. and Hillebrand, H. and Hofmockel, K.S. and Humphries, H.C. and Iribarne, O. and Jin, V.L. and Kay, A. and Kirkman, K.P. and Klein, J.A. and Knops, J.M.H. and Kimberly J. La Pierre and L. Ladwig and Lambrinos, J.G. and Leakey, A.D.B. and Li, Q. and Li, W. and McCulley, R. and Melbourne, B. and Mitchell, C.E. and Joslin L. Moore and J.W. Morgan and Mortensen, B. and O{\textquoteright}Halloran, L.R. and P{\"a}rtel, M. and Pascual, J and Pyke, D.A. and A. Risch and Salguero-Gomez, R. and Sankaran, M. and Schuetz, M. and Simonsen, A. and M.D. Smith and Stevens, C. and Sullivan, L. and Wardle, G.M. and Wolkovich, E.M. and Wragg, P.D. and Wright, J. and Yang, L.} }