Similar recovery time of microbial functions from fungicide stress across biogeographical regions

Verena C Schreiner,Katherine Muñoz,Alexander Feckler,Ben J Kefford,Eduard Szöcs,Josepha Axelsen,Katharina Frisch,Nina Cedergreen,Ralf B Schäfer,Jochen P Zubrod,Diego Fernández,Jes J Rasmussen,Mirco Bundschuh

doi:10.1038/s41598-018-35397-1

Abstract

Determining whether the structural and functional stress responses of communities are similar across space and time is paramount for forecasting and extrapolating the consequences of anthropogenic pressures on ecosystems and their services. Stream ecosystems are under high anthropogenic pressure; however, studies have only examined the response of stream communities across large scales over multiple generations. We studied the responses of leaf-associated microbial communities in streams within three European biogeographical regions to chemical stress in a microcosm experiment with multiple cycles of fungicide pollution and resource colonisation. Fungal community composition and the ecosystem function leaf decomposition were measured as response variables. Microbial leaf decomposition showed similar recovery times under environmental levels of fungicide exposure across regions. Initially, the decomposition declined (between 19 and 53%) under fungicide stress and recovered to control levels during the third cycle of pollution and colonisation. Although community composition and its stress response varied between regions, this suggests similar functional community adaptation towards fungicide stress over time. Genetic, epigenetic and physiological adaptations, as well as species turnover, may have contributed to community adaptation but further studies are required to determine if and to which extent these mechanisms are operating. Overall, our findings provide the first evidence of a similar functional response of microbial leaf decomposition to chemical stress across space and time.

Highlights

Determining whether the structural and functional stress responses of communities are similar across space and time is paramount for forecasting and extrapolating the consequences of anthropogenic pressures on ecosystems and their services
The experiment was performed with communities from three biogeographical regions to detect if functional as well as structural stress responses caused by fungicides are similar across space
We found similar effect patterns and recovery time periods of leaf decomposition from fungicide exposure across biogeographical regions

Summary

Introduction

Determining whether the structural and functional stress responses of communities are similar across space and time is paramount for forecasting and extrapolating the consequences of anthropogenic pressures on ecosystems and their services. We studied the responses of leaf-associated microbial communities in streams within three European biogeographical regions to chemical stress in a microcosm experiment with multiple cycles of fungicide pollution and resource colonisation. The physico-chemical properties of certain pollutants allow for their long-range transport and occurrence on a global scale[4], chemical pollution predominantly affects local processes[5] Setting thresholds, such as planetary boundaries, as well as to reliably extrapolate results across regions would require a similar local stress response[6,7]. We examined the functional (i.e., leaf decomposition) and structural (i.e., community dynamics) stress responses of microbial communities in different European biogeographical regions over multiple cycles of pollution and resource colonisation. The experiment was performed with communities from three biogeographical regions (the Central Plains, Denmark; the Western Highlands, Germany; and the Fenno-Scandian Shield, Sweden) to detect if functional as well as structural stress responses caused by fungicides are similar across space

Methods

Results

Conclusion