Plant diversity effects on grassland productivity are robust to both nutrient enrichment and drought

Dylan Craven (1, 2) , Forest Isbell (2) , Pete Manning (3) , John Connolly (4) , Helge Bruelheide (2) , Anne Ebeling (5) , Christiane Roscher (2) , Jasper van Ruijven (6) , Alexandra Weigelt (2) , Brian Wilsey (7) , Carl Beierkuhnlein (8) , Enrica de Luca (9) , John Griffin (10) , Yann Hautier (11) , Andy Hector (12) , Anke Jentsch (8) , Jürgen Kreyling (13) , Vojtech Lanta (14) , Michel Loreau (15) , Sebastian Meyer (16) , Akira Mori (17) , Shahid Naeem (18) , Cecilia Palmborg (19) , H. Wayne Polley (20) , Peter Reich (21) , Bernhard Schmid (9) , Alrun Siebenkäs (22) , Eric Seabloom (23) , Madhav Thakur (2) , David Tilman (23) , Anja Vogel (2) , Nico Eisenhauer (2)

1 Leipzig University / Universität Leipzig
2 iDiv - German Centre for Integrative Biodiversity Research
3 UNIBE - Universität Bern / University of Bern
4 UCD - University College Dublin [Dublin]
5 Friedrich-Schiller-Universität = Friedrich Schiller University Jena [Jena, Germany]
6 WUR - Wageningen University and Research [Wageningen]
7 ISU - Iowa State University
8 University of Bayreuth
9 UZH - Universität Zürich [Zürich] = University of Zurich
10 Swansea University
11 Universiteit Utrecht / Utrecht University [Utrecht]
12 University of Oxford
13 Universität Greifswald - University of Greifswald
14 University of South Bohemia
15 SETE - Station d'écologie théorique et expérimentale
16 TUM - Technische Universität Munchen - Technical University Munich - Université Technique de Munich
17 Yokohama National University
18 Columbia University [New York]
19 SLU - Swedish University of Agricultural Sciences = Sveriges lantbruksuniversitet
20 National Center for Cool and Cold Water Aquaculture, ARS-USDA
21 Western Sydney University
22 UFZ - Helmholtz Zentrum für Umweltforschung = Helmholtz Centre for Environmental Research
23 UMN - University of Minnesota [Twin Cities]

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.

Mots clés: soil nutrients; plant diversity; resource reduction; resource amendment; global change drivers; drought

Domaines: Sciences de l'environnement

Dylan Craven, Forest Isbell, Pete Manning, John Connolly, Helge Bruelheide, et al.. Plant diversity effects on grassland productivity are robust to both nutrient enrichment and drought. Philosophical Transactions of the Royal Society B: Biological Sciences, 2016, 371 (1694), ⟨10.1098/rstb.2015.0277⟩. ⟨hal-02962385⟩