How anthropogenic shifts in plant community composition alter soil food webs.

Jonathan R De Long,Paul Kardol

doi:10.12688/f1000research.13008.1

Jonathan R De Long, Paul Kardol

Open Access

https://doi.org/10.12688/f1000research.13008.1

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Abstract

There are great concerns about the impacts of soil biodiversity loss on ecosystem functions and services such as nutrient cycling, food production, and carbon storage. A diverse community of soil organisms that together comprise a complex food web mediates such ecosystem functions and services. Recent advances have shed light on the key drivers of soil food web structure, but a conceptual integration is lacking. Here, we explore how human-induced changes in plant community composition influence soil food webs. We present a framework describing the mechanistic underpinnings of how shifts in plant litter and root traits and microclimatic variables impact on the diversity, structure, and function of the soil food web. We then illustrate our framework by discussing how shifts in plant communities resulting from land-use change, climatic change, and species invasions affect soil food web structure and functioning. We argue that unravelling the mechanistic links between plant community trait composition and soil food webs is essential to understanding the cascading effects of anthropogenic shifts in plant communities on ecosystem functions and services.

Highlights

The soil food web consists of a large diversity of organisms differing in size and function
We focus on areas of research that illustrate how anthropogenic disturbances can affect plant community trait values, leading to shifts in soil food webs
The following areas in particular warrant future attention: (1) We know relatively well how functional differences among individual plant species affect soil food webs, but much less is known about the effects of complex plant communities where multiple species coexist and interact

Summary

Introduction

The soil food web consists of a large diversity of organisms differing in size and function. Changes to plant community trait composition that affect indirect interactions initiated by belowground predators (that is, behavioral traits) could change the productivity and defense strategy traits of soil organisms on lower trophic levels in ways that affect soil food web connectivity[64], which is important because more tightly connected soil food webs are known to promote nutrient retention[9] We explore this framework of trait packing and diversity and, more generally, shifts in litter and root trait values. For randomly assembled plant communities, the effects of lower plant species and functional group richness on soil biota are mostly negative but weaker for soil biota occupying higher levels in the soil food web[102] These effects of plant species and functional group diversity have been linked to changes in litter quality (that is, plant shoot C:N ratio)[103], but potential effects mediated through shifts in root nutrient acquisition, architectural, and chemical traits remain to be tested. There is a lack of empirical evidence for these effects and further studies are needed to understand how range expansion impacts on trait packing in the plant community and thereby the soil food web (Figure 4)

Conclusions

Morriën E

15. Wolkovich EM

51. Laliberté E

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