Browsing by Author "Griffin, John N"

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    Biodiversity increases the resistance of ecosystem productivity to climate extremes
    (Nature Publishing Group, 2015) Isbell, Forest; Craven, Dylan; Connolly, John; Loreau, Michel; Schmid, Bernhard; Beierkuhnlein, Carl; Bezemer, T. Martijn; Bonin, Catherine; Bruelheide, Helge; de Luca, Enrica; Ebeling, Anne; Griffin, John N; Guo, Qinfeng; Hautier, Yann; Hector, Andy; Jentsch, Anke; Kreyling, Jürgen; Lanta, Vojtěch; Manning, Pete; Meyer, Sebastian T; Mori, Akira S.; Naeem, Shahid; Niklaus, Pascal A; Polley, H. Wayne; Reich, Peter B; Roscher, Christiane; Seabloom, Eric W; Smith, Melinda D; Thakur, Madhav P; Tilman, David; Tracy, Benjamin F; van der Putten, Wim H; van Ruijven, Jasper; Weigelt, Alexandra; Weisser, Wolfgang W; Wilsey, Brian; Eisenhauer, Nico
    It remains unclear whether biodiversity buffers ecosystems against climate extremes, which are becoming increasingly frequent worldwide. Early results suggested that the ecosystem productivity of diverse grassland plant communities was more resistant, changing less during drought, and more resilient, recovering more quickly after drought, than that of depauperate communities. However, subsequent experimental tests produced mixed results. Here we use data from 46 experiments that manipulated grassland plant diversity to test whether biodiversity provides resistance during and resilience after climate events. We show that biodiversity increased ecosystem resistance for a broad range of climate events, including wet or dry, moderate or extreme, and brief or prolonged events. Across all studies and climate events, the productivity of low-diversity communities with one or two species changed by approximately 50% during climate events, whereas that of high-diversity communities with 16-32 species was more resistant, changing by only approximately 25%. By a year after each climate event, ecosystem productivity had often fully recovered, or overshot, normal levels of productivity in both high- and low-diversity communities, leading to no detectable dependence of ecosystem resilience on biodiversity. Our results suggest that biodiversity mainly stabilizes ecosystem productivity, and productivity-dependent ecosystem services, by increasing resistance to climate events. Anthropogenic environmental changes that drive biodiversity loss thus seem likely to decrease ecosystem stability, and restoration of biodiversity to increase it, mainly by changing the resistance of ecosystem productivity to climate events.
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    Plant diversity effects on grassland productivity are robust to both nutrient enrichment and drought
    (The Royal Society, 2016) Craven, Dylan; Isbell, Forest; Manning, Pete; Connolly, John; Bruelheide, Helge; Ebeling, Anne; Roscher, Christiane; Van Ruijven, Jasper; Weigelt, Alexandra; Wilsey, Brian; Beierkuhnlein, Carl; De Luca, Enrica; Griffin, John N; Hautier, Yann; Hector, Andy; Jentsch, Anke; Kreyling, Jürgen; Lanta, Vojtech; Loreau, Michel; Meyer, Sebastian T; Mori, Akira S; Naeem, Shahid; Palmborg, Cecilia; Polley, H Wayne; Reich, Peter B; Schmid, Bernhard; Siebenkäs, Alrun; Seabloom, Eric; Thakur, Madhav P; Tilman, David; Vogel, Anja; Eisenhauer, Nico
    Global change drivers are rapidly altering resource availability and biodiversity. While there is consensus that greater biodiversity increases the functioning of ecosystems, the extent to which biodiversity buffers ecosystem productivity in response to changes in resource availability remains unclear. We use data from 16 grassland experiments across North America and Europe that manipulated plant species richness and one of two essential resources—soil nutrients or water—to assess the direction and strength of the interaction between plant diversity and resource alteration on above-ground productivity and net biodiversity, complementarity, and selection effects. Despite strong increases in productivity with nutrient addition and decreases in productivity with drought, we found that resource alterations did not alter biodiversity–ecosystem functioning relationships. Our results suggest that these relationships are largely determined by increases in complementarity effects along plant species richness gradients. Although nutrient addition reduced complementarity effects at high diversity, this appears to be due to high biomass in monocultures under nutrient enrichment. Our results indicate that diversity and the complementarity of species are important regulators of grassland ecosystem productivity, regardless of changes in other drivers of ecosystem function.