Plant diversity maintains multiple soil functions in future environments

Nico Eisenhauer,Clare E Kazanski,Mengyun Liu,Peter B Reich,Jes Hines,Anja Vogel,Kally Worm,Alfred Lochner,Matthias C Rillig,Sarah E Hobbie,Anika Lehmann,Fons Van Der Plas,Forest Isbell

doi:10.7554/elife.41228

Abstract

Biodiversity increases ecosystem functions underpinning a suite of services valued by society, including services provided by soils. To test whether, and how, future environments alter the relationship between biodiversity and multiple ecosystem functions, we measured grassland plant diversity effects on single soil functions and ecosystem multifunctionality, and compared relationships in four environments: ambient conditions, elevated atmospheric CO2, enriched N supply, and elevated CO2 and N in combination. Our results showed that plant diversity increased three out of four soil functions and, consequently, ecosystem multifunctionality. Remarkably, biodiversity-ecosystem function relationships were similarly significant under current and future environmental conditions, yet weaker with enriched N supply. Structural equation models revealed that plant diversity enhanced ecosystem multifunctionality by increasing plant community functional diversity, and the even provision of multiple functions. Conserving local plant diversity is therefore a robust strategy to maintain multiple valuable ecosystem services in both present and future environmental conditions.

Highlights

Many experimental studies have shown that both the average levels (Hooper et al, 2005; Cardinale et al, 2012; Duffy et al, 2017) and temporal stability (Isbell et al, 2015) of ecosystem functions increase with biodiversity
Our study shows the first empirical evidence that significant plant diversity effects on multiple soil functions, and ecosystem multifunctionality, are largely robust to changes in environmental conditions caused by elevated atmospheric CO2 concentrations, N inputs, and both factors in combination
Plant diversity effects on ecosystem multifunctionality at higher thresholds of functionality may be impaired under future environmental conditions (Figure 4), potentially by reducing the taxonomic and functional diversity of the plant community (Figure 5)

Summary

Introduction

Many experimental studies have shown that both the average levels (Hooper et al, 2005; Cardinale et al, 2012; Duffy et al, 2017) and temporal stability (Isbell et al, 2015) of ecosystem functions increase with biodiversity. While the generality of positive relationships between biodiversity and ecosystem functioning is well established (Cardinale et al, 2012; Duffy et al, 2017; Isbell et al, 2015; Lefcheck et al, 2015), current research focuses on the underlying mechanisms (Eisenhauer et al, 2016; Zuppinger-Dingley et al, 2014; Laforest-Lapointe et al, 2017) and context-dependencies (Craven et al, 2016; Guerrero-Ramırez et al, 2017) of biodiversity-ecosystem function relationships, given that ecosystems face progressive environmental changes Biodiversity effects may depend on the environmental context, such as climatic conditions and resource availability (Craven et al, 2016; Guerrero-Ramırez et al, 2017), and may change in future environments. Studies testing biodiversity-ecosystem function relationships under future conditions are rare (Reich et al, 2001; He et al, 2002; Hooper et al, 2012; Thakur et al, 2015), and typically investigate only one or a few ecosystem functions

Methods

Results

Conclusion