Diversity promotes temporal stability across levels of ecosystem organization in experimental grasslands.

Raphaël Proulx,Wolfgang W Weisser,Guido Schwichtenberg,François Buscot,Gerd Gleixner,Alexandra Weigelt,Stefan Halle,Christiane Roscher,Christoph Scherber,Esther Kowalski,Christian Wirth,Romain L Barnard,Stephan Rosenkranz,Winfried Voigt,Yvonne Oelmann,Sabine Attinger,Vicky M Temperton,Annely Kuu,Bernhard Schmid,Jens Schumacher,Nico Eisenhauer,Pascal A Niklaus,Nina Buchmann,Wolfgang Wilcke,Stefan Scheu,Markus Fischer,Anke Hildebrandt,Jussi Baade,Alexandru Milcu ,Jean‐François Soussana ,Michael Scherer‐Lorenzen ,Alexander C.w Sabais ,Ernst Detlef Schulze ,Bastien Lange

doi:10.1371/journal.pone.0013382

Abstract

The diversity–stability hypothesis states that current losses of biodiversity can impair the ability of an ecosystem to dampen the effect of environmental perturbations on its functioning. Using data from a long-term and comprehensive biodiversity experiment, we quantified the temporal stability of 42 variables characterizing twelve ecological functions in managed grassland plots varying in plant species richness. We demonstrate that diversity increases stability i) across trophic levels (producer, consumer), ii) at both the system (community, ecosystem) and the component levels (population, functional group, phylogenetic clade), and iii) primarily for aboveground rather than belowground processes. Temporal synchronization across studied variables was mostly unaffected with increasing species richness. This study provides the strongest empirical support so far that diversity promotes stability across different ecological functions and levels of ecosystem organization in grasslands.

Highlights

Ecosystems are subjected to natural environmental perturbations ranging from small- to large-scale processes
The mechanisms by which species-specific variations in response to perturbations translate into ecosystem stability are still debated [5,6] and it remains largely unknown whether the diversity–stability hypothesis holds for ecological functions other than plant community biomass
Ecological functions at various organizational levels were stabilized with increasing plant species richness, as indicated by a decrease of the variance CV for the abundance of parasitic hymenoptera, the suppression of non-resident plant species, vegetation structure and biomass production, the abundance and diversity of invertebrates, as well as trace gas fluxes

Summary

Introduction

Ecosystems are subjected to natural environmental perturbations ranging from small- to large-scale processes. The mechanisms by which species-specific variations in response to perturbations translate into ecosystem stability are still debated [5,6] and it remains largely unknown whether the diversity–stability hypothesis holds for ecological functions other than plant community biomass. In a recent meta-analysis, Jiang and Pu [7] showed that biodiversity stabilizes community variables and may stabilize species populations in multi-trophic systems Their result led to the proposition that in the presence of temporal synchronization —when different variables respond to environmental perturbations— stabilization of ecological functions at the component level (e.g., population) of organization may promote stabilization at the system level (e.g., community). We analyzed this question for multiple ecological functions measured in a single experiment

Methods

Results

Conclusion