Litter decomposition driven by soil fauna, plant diversity and soil management in urban gardens

TitleLitter decomposition driven by soil fauna, plant diversity and soil management in urban gardens
Publication TypeJournal Article
Year of Publication2019
AuthorsTresch S, Frey D, Le Bayon RC, Zanetta A, Rasche F, Fliessbach A, Moretti M
JournalScience of the Total Environment
Volume658
Pagination1614-1629
Date PublishedMar
Type of ArticleArticle
ISBN Number0048-9697
Accession NumberWOS:000456175700149
Keywordsbiodiversity, Biodiversity ecosystem, carbon, Ecosystem services, Environmental Sciences & Ecology, foliar litter, functional diversity, functioning (BEF), green spaces, Litter bag decomposition, mass-loss, MidDRIFTS analysis, midinfrared spectroscopy, oak leaf-litter, organic-matter, Urban ecosystem services, urban gardening, Urban soil biodiversity, Urban warming
Abstract

In the face of growing urban densification, green spaces in cities, such as gardens, are increasingly important for biodiversity and ecosystem services. However, the influences of urban green space management on biodiversity and ecosystem functioning (BEF) relationships is poorly understood. We investigated the relationship between soil fauna and litter decomposition in 170 urban garden sites along a gradient of urbanisation intensity in the city of Zurich, CH. We used litter bags of 1 and 4 mm mesh size to evaluate the contribution of soil meso- and macrofauna on litter decomposition. By using multilevel structural equation models (SEM), we investigated direct and indirect environmental effects and management practices on litter decomposition and litter residue quality. We evaluated the role of taxonomic, functional and phylogenetic diversity of soil fauna species on litter decomposition, based on a sample of 120 species (81,007 individuals; 39 collembola, 18 earthworm, 16 isopod, 47 gastropod species). We found highest litter decomposition rates using 4 mm mesh size litter bags, highlighting the importance of soil macrofauna. Urban warming, a proxy for urbanisation intensity, covaried positively, whereas soil disturbances, such as intensive soil and crop management, were negatively correlated with decomposition rates. Interestingly, soil fauna species richness decreased, with the exception of gastropods, and soil fauna abundance increased with urban warming. Our data also show that plant species richness positively affected litter decomposition by increasing soil fauna species richness and microbial activity. A multivariate analysis of organic compounds in litter residues confirmed the importance of soil fauna species richness and garden management on litter decomposition processes. Overall, we showed, that also in intensively managed urban green spaces, such as gardens, biodiversity of plants and soil fauna drives key ecosystem processes. Urban planning strategies that integrate soil protecting management practices may help to maintain important ecosystem services in this heavily used urban environment. (C) 2018 Elsevier B.V. All rights reserved.

Alternate JournalSci. Total Environ.