TY - JOUR T1 - Global change effects on plant communities are magnified by time and the number of global change factors imposed JF - Proceedings of the National Academy of Sciences Y1 - 2019 A1 - Kimberly J. Komatsu A1 - M.L. Avolio A1 - Lemoine, Nathan P. A1 - Isbell, Forest A1 - Grman, Emily A1 - Houseman, Gregory R. A1 - Koerner, Sally E. A1 - Johnson, D.S. A1 - K.R. Wilcox A1 - Juha M. Alatalo A1 - Anderson, J.P. A1 - Aerts, R. A1 - S.G. Baer A1 - Baldwin, Andrew H. A1 - Bates, J. A1 - Beierkuhnlein, C. A1 - Belote, R.T. A1 - John M. Blair A1 - Bloor, J.M.G. A1 - Bohlen, P.J. A1 - Edward W. Bork A1 - Elizabeth H. Boughton A1 - W.D. Bowman A1 - Britton, Andrea J. A1 - Cahill, James F. A1 - Chaneton, Enrique J. A1 - Chiariello, N.R. A1 - Cheng, Jimin. A1 - Scott. L. Collins A1 - Cornelissen, J.H.C. A1 - G. Du A1 - Eskelinen, Anu A1 - Firn, Jennifer A1 - Foster, B. A1 - Gough, L. A1 - Gross, K. A1 - Hallett, L.M. A1 - Han, X. A1 - Harmens, H. A1 - Hovenden, M.J. A1 - Jagerbrand, A. A1 - Jentsch, A. A1 - Kern, Christel A1 - Klanderud, Kari A1 - Alan K. Knapp A1 - Kreyling, Juergen A1 - Li, W. A1 - Luo, Yiqi A1 - McCulley, R.L. A1 - McLaren, Jennie R. A1 - Megonigal, Patrick A1 - J.W. Morgan A1 - Onipchenko, Vladimir A1 - Pennings, S.C. A1 - Prevéy, J.S. A1 - Price, Jodi N. A1 - P.B. Reich A1 - Robinson, Clare H. A1 - Russell, L.F. A1 - Sala, O.E. A1 - Seabloom, E.W. A1 - M.D. Smith A1 - Soudzilovskaia, Nadejda A. A1 - Souza, Lara A1 - K.N. Suding A1 - Suttle, B.K. A1 - Svejcar, T. A1 - Tilman, David A1 - Tognetti, P. A1 - Turkington, R. A1 - White, S. A1 - Xu, Zhuwen A1 - Yahdjian, L. A1 - Yu, Q. A1 - Zhang, Pengfei A1 - Zhang, Yunhai AB -

Global change drivers (GCDs) are expected to alter community structure and consequently, the services that ecosystems provide. Yet, few experimental investigations have examined effects of GCDs on plant community structure across multiple ecosystem types, and those that do exist present conflicting patterns. In an unprecedented global synthesis of over 100 experiments that manipulated factors linked to GCDs, we show that herbaceous plant community responses depend on experimental manipulation length and number of factors manipulated. We found that plant communities are fairly resistant to experimentally manipulated GCDs in the short term (<10 y). In contrast, long-term (≥10 y) experiments show increasing community divergence of treatments from control conditions. Surprisingly, these community responses occurred with similar frequency across the GCD types manipulated in our database. However, community responses were more common when 3 or more GCDs were simultaneously manipulated, suggesting the emergence of additive or synergistic effects of multiple drivers, particularly over long time periods. In half of the cases, GCD manipulations caused a difference in community composition without a corresponding species richness difference, indicating that species reordering or replacement is an important mechanism of community responses to GCDs and should be given greater consideration when examining consequences of GCDs for the biodiversity–ecosystem function relationship. Human activities are currently driving unparalleled global changes worldwide. Our analyses provide the most comprehensive evidence to date that these human activities may have widespread impacts on plant community composition globally, which will increase in frequency over time and be greater in areas where communities face multiple GCDs simultaneously.

VL - 116 UR - https://www.pnas.org/content/early/2019/08/14/1819027116 IS - 36 ER - TY - JOUR T1 - Climate modifies response of non-native and native species richness to nutrient enrichment JF - Philosophical Transactions of the Royal Society B: Biological Sciences Y1 - 2016 A1 - Flores-Moreno, H. A1 - P.B. Reich A1 - Lind, E.M. A1 - L.L. Sullivan A1 - Seabloom, E.W. A1 - Yahdjian, L. A1 - MacDougall, A.S. A1 - Reichmann, L.G. A1 - J. Alberti A1 - Báez, S. A1 - J.D. Bakker A1 - Cadotte, M.W. A1 - Caldeira, M.C. A1 - Chaneton, E.J. A1 - D'Antonio, C.M. A1 - Fay, P.A. A1 - Firn, J. A1 - Hagenah, N. A1 - Harpole, W. S. A1 - Iribarne, O. A1 - Kirkman, K.P. A1 - Knops, J.M. H. A1 - Kimberly J. La Pierre A1 - Laungani, R. A1 - Leakey, A.D. B. A1 - McCulley, R.L. A1 - Joslin L. Moore A1 - Pascual, J. A1 - E.T. Borer AB -

Ecosystem eutrophication often increases domination by non-natives and causes displacement of native taxa. However, variation in environmental conditions may affect the outcome of interactions between native and non-native taxa in environments where nutrient supply is elevated. We examined the interactive effects of eutrophication, climate variability and climate average conditions on the success of native and non-native plant species using experimental nutrient manipulations replicated at 32 grassland sites on four continents. We hypothesized that effects of nutrient addition would be greatest where climate was stable and benign, owing to reduced niche partitioning. We found that the abundance of non-native species increased with nutrient addition independent of climate; however, nutrient addition increased non-native species richness and decreased native species richness, with these effects dampened in warmer or wetter sites. Eutrophication also altered the time scale in which grassland invasion responded to climate, decreasing the importance of long-term climate and increasing that of annual climate. Thus, climatic conditions mediate the responses of native and non-native flora to nutrient enrichment. Our results suggest that the negative effect of nutrient addition on native abundance is decoupled from its effect on richness, and reduces the time scale of the links between climate and compositional change.

VL - 3719371 UR - https://royalsocietypublishing.org/doi/10.1098/rstb.2015.0273 IS - 1694 ER - TY - JOUR T1 - Coordinated distributed experiments: an emerging tool for testing global hypotheses in ecology and environmental science JF - Frontiers in Ecology and the Environment Y1 - 2013 A1 - Fraser, L.H. A1 - Henry, H.A. A1 - Carlyle, C.N. A1 - White, S.R. A1 - Beierkuhnlein, C. A1 - Cahill, J.F. A1 - Casper, B.B. A1 - Cleland, E.E. A1 - Scott. L. Collins A1 - Dukes, J.S. A1 - Alan K. Knapp A1 - Lind, E. A1 - Long, R. A1 - Luo, Y. A1 - P.B. Reich A1 - M.D. Smith A1 - Sternberg, M. A1 - Turkington, R. AB -

There is a growing realization among scientists and policy makers that an increased understanding of today's environmental issues requires international collaboration and data synthesis. Meta-analyses have served this role in ecology for more than a decade, but the different experimental methodologies researchers use can limit the strength of the meta-analytic approach. Considering the global nature of many environmental issues, a new collaborative approach, which we call coordinated distributed experiments (CDEs), is needed that will control for both spatial and temporal scale, and that encompasses large geographic ranges. Ecological CDEs, involving standardized, controlled protocols, have the potential to advance our understanding of general principles in ecology and environmental science.

VL - 11 UR - https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/110279 ER - TY - JOUR T1 - The effect of experimental warming and precipitation change on proteolytic enzyme activity: positive feedbacks to nitrogen availability are not universal JF - Global Change Biology Y1 - 2012 A1 - Brozostek, E.R. A1 - John M. Blair A1 - Dukes, J.S. A1 - Frey, S.D. A1 - Hobbie, S.E. A1 - Melillo, J.M. A1 - Mitchell, R.J. A1 - Pendall, E.S. A1 - P.B. Reich A1 - Shaver, G.R. A1 - Stefanskii, A. A1 - Tjoelker, M.G. A1 - Finzi, A.C. AB -

Nitrogen regulates the Earth's climate system by constraining the terrestrial sink for atmospheric CO2. Proteolytic enzymes are a principal driver of the within-system cycle of soil nitrogen, yet there is little to no understanding of their response to climate change. Here, we use a single methodology to investigate potential proteolytic enzyme activity in soils from 16 global change experiments. We show that regardless of geographical location or experimental manipulation (i.e., temperature, precipitation, or both), all sites plotted along a single line relating the response ratio of potential proteolytic activity to soil moisture deficit, the difference between precipitation and evapotranspiration. In particular, warming and reductions in precipitation stimulated potential proteolytic activity in mesic sites – temperate and boreal forests, arctic tundra – whereas these manipulations suppressed potential activity in dry grasslands. This study provides a foundation for a simple representation of the impacts of climate change on a central component of the nitrogen cycle.

VL - 18 UR - https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2486.2012.02685.x ER -