Biodiversity across trophic levels drives multifunctionality in highly diverse forests

Andreas Schuldt,Peter Kühn,François Buscot,Jessica Gutknecht,Werner Härdtle,Alexandra‐Maria Klein ,Witoon Purahong,Thomas Scholten,Matteo Brezzi,Zhiyao Tang,Michael Staab,Xiaojuan Liu,Stefan Trogisch,Pascal A Niklaus,Bernhard Schmid,Christian Wirth,Goddert Von Oheimb,Chao Zhu ,Tesfaye Wubet,Keping Ma,Jin Sheng He ,Thorsten Aßmann ,David Eichenberg,Michael Scherer‐Lorenzen ,Katherina A Pietsch,Helge Bruelheide

doi:10.1038/s41467-018-05421-z

Abstract

Human-induced biodiversity change impairs ecosystem functions crucial to human well-being. However, the consequences of this change for ecosystem multifunctionality are poorly understood beyond effects of plant species loss, particularly in regions with high biodiversity across trophic levels. Here we adopt a multitrophic perspective to analyze how biodiversity affects multifunctionality in biodiverse subtropical forests. We consider 22 independent measurements of nine ecosystem functions central to energy and nutrient flow across trophic levels. We find that individual functions and multifunctionality are more strongly affected by the diversity of heterotrophs promoting decomposition and nutrient cycling, and by plant functional-trait diversity and composition, than by tree species richness. Moreover, cascading effects of higher trophic-level diversity on functions originating from lower trophic-level processes highlight that multitrophic biodiversity is key to understanding drivers of multifunctionality. A broader perspective on biodiversity-multifunctionality relationships is crucial for sustainable ecosystem management in light of non-random species loss and intensified biotic disturbances under future environmental change.

Highlights

Human-induced biodiversity change impairs ecosystem functions crucial to human wellbeing
Our study shows that diversity effects of individual trophic levels on ecosystem multifunctionality cascade through the food web, highlighting the need for a multitrophic perspective when trying to disentangle the drivers of biodiversity–ecosystem functioning (BEF) relationships
We found significant diversity effects on multifunctionality when analyzing these relationships on individual trophic levels in separate analyses, excluding functions directly mediated by the given trophic level being analyzed

Summary

Results

We found significant diversity effects on multifunctionality when analyzing these relationships on individual trophic levels in separate analyses, excluding functions directly mediated by the given trophic level being analyzed (e.g., parasitism for parasitoids, predation for predators). The six trophic levels showed significant diversity effects on multifunctionality that were not dependent on functions directly mediated by the respective trophic level This indicates that these diversity-multifunctionality relationships propagate through the food web (Fig. 3, Supplementary Table 7). The significant predictors of average and threshold-based multifunctionality had significant effects on at least one (and up to four) of the nine ecosystem functions when functions were analyzed individually (Fig. 5, Supplementary Figs 8, 9, Supplementary Table 10). Aboveground functions mediated by higher tropic levels (herbivory resistance, predation, parasitism) were more strongly affected by aboveground heterotrophic species richness and plant diversity or composition (Fig. 5, Supplementary Figs 8, 9, Supplementary Table 10)

Discussion

20 Without herbivory resistance

Methods