The Role of Species Traits in Mediating Functional Recovery during Matrix Restoration

Abstract

Reversing anthropogenic impacts on habitat structure is frequently successful through restoration, but the mechanisms linking habitat change, community reassembly and recovery of ecosystem functioning remain unknown. We test for the influence of edge effects and matrix habitat restoration on the reassembly of dung beetle communities and consequent recovery of dung removal rates across tropical forest edges. Using path modelling, we disentangle the relative importance of community-weighted trait means and functional trait dispersion from total biomass effects on rates of dung removal. Community trait composition and biomass of dung beetle communities responded divergently to edge effects and matrix habitat restoration, yielding opposing effects on dung removal. However, functional dispersion—used in this study as a measure of niche complementarity—did not explain a significant amount of variation in dung removal rates across habitat edges. Instead, we demonstrate that the path to functional recovery of these altered ecosystems depends on the trait-mean composition of reassembling communities, over and above purely biomass-dependent processes that would be expected under neutral theory. These results suggest that any ability to manage functional recovery of ecosystems during habitat restoration will demand knowledge of species' roles in ecosystem processes.

Species richness and biomass explain spatial turnover in ecosystem functioning across tropical and temperate ecosystems

“…Furthermore, after holding constant any effects of species richness on energy flux, spatial variation in litter invertebrate biomass still had a very strong effect on spatial variation in energy flux, most likely owing to the strong correlation between total biomass and a community's energetic demand [11]. This indicates that, regardless of any resource diversity effects, total biomass of organisms expectedly plays an important role in determining ecosystem process rates [28].…”

“…Specifically, MRM regresses a response matrix on any number of explanatory matrices composed of dissimilarities or distances, allowing for the inference of how differently measured multi-or univariate variables might influence each other across environmental and spatial distances [27]. Previous studies have proven path modelling to be a highly effective tool for disentangling the complex causal relationships among environmental change, community attributes and ecosystem functioning [28,29]. Here, we use Shipley's [30] d-separation method of generalized causal path analysis, as this method is highly flexible for using a variety of model types, such as MRMs in this case.…”

Trophic position determines functional and phylogenetic recovery after disturbance within a community

“…; Barnes et al . ). For example, under a scenario where species functional traits are phylogenetically conserved, phylogenetic and functional community composition may exhibit similar recovery trajectories (Fig.…”

“…; Barnes et al . ), in spite of global increases in disturbance frequency and intensity (Turner ). Understanding whether different components of ecological communities recover in a similar fashion is critical to guide conservation ‘triage’ for functionally and trophically diverse groups such as beetles (Lawrence et al .…”

Functionally richer communities improve ecosystem functioning: Dung removal and secondary seed dispersal by dung beetles in the Western Palaearctic

“…Even more disruptive than the loss of a single species is a functional shift in species assemblages. When species with unique traits disappear we would expect significant changes in ecosystem functioning and restructuring of ecological pathways (Barnes, Emberson, Krell, & Didham, ). Many studies highlight the importance of facilitation or niche complementarity and the value of multispecies assemblages for specific ecosystem functions (Cardinale, Palmer, & Collins, ).…”