Unravelling how urbanization influences soil invertebrate community assembly, food web interactions and associated ecosystem functions

点击翻译按钮获取中文摘要

With increasing urbanization across the planet, a majority of humans are living in urban ecosystems that are still poorly understood. Urban soils have diverse origins, are heavily disturbed and managed through human activity and host novel plant communities that include nonnative species selected by urban planners and gardeners. These plants provide new sources of organic matter input to soils, but are also often removed from the ecosystem (e.g. autumn leaf litter, dead wood) with potentially important consequences for soil biota. Despite invertebrates contributing to key ecosystem functions such as organic matter decomposition, soil structure and nutrient cycling, little is known about how the mosaic of habitat types and management practices in cities affects soil invertebrate communities and their food web interactions. This research program aims to understand how different abiotic filters (e.g. soil compaction, sealed surfaces or pollutants) and biotic filters (leaf litter removal, nonnative plant species and microbial communities) linked with urbanization influence soil invertebrate community assembly, soil food web interactions and associated ecosystem functions. Do we observe homogenization of soil invertebrate consumers and their resources or is functional diversity maintained across urbanization gradients in Canadian cities? Does urbanization influence the spatial covariation of consumer and resource traits and subsequently consumer-resource interactions in urban soil food webs? Can understanding dispersal traits of dominant invertebrates, the presence of non-native earthworms or fragmentation due to removal of leaf litter help explain such patterns? Is supporting ecosystem service provision such as nutrient cycling during litter decomposition or soil infiltration constant with urbanization? Using observational, experimental and modelling approaches in the field and laboratory, as well as state-of-the-art tools like compound specific stable isotope analysis of amino acids, we will explore these questions. This research program is poised to make novel contributions to advance fundamental understanding of soil food webs and functional interactions among litter and soil-dwelling invertebrates. Additionally, it will provide critical baseline knowledge for urban ecosystem managers and urban developers, based on research in Canadian cities, to make more informed decisions in city planning by considering soil biodiversity and the ecosystem services they support.