A general framework for predicting delayed responses of ecological communities to habitat loss

Youhua Chen,Tsung-Jen Shen

doi:10.1038/s41598-017-01070-2

Abstract

Although biodiversity crisis at different spatial scales has been well recognised, the phenomena of extinction debt and immigration credit at a crossing-scale context are, at best, unclear. Based on two community patterns, regional species abundance distribution (SAD) and spatial abundance distribution (SAAD), Kitzes and Harte (2015) presented a macroecological framework for predicting post-disturbance delayed extinction patterns in the entire ecological community. In this study, we further expand this basic framework to predict diverse time-lagged effects of habitat destruction on local communities. Specifically, our generalisation of KH’s model could address the questions that could not be answered previously: (1) How many species are subjected to delayed extinction in a local community when habitat is destructed in other areas? (2) How do rare or endemic species contribute to extinction debt or immigration credit of the local community? (3) How will species differ between two local areas? From the demonstrations using two SAD models (single-parameter lognormal and logseries), the predicted patterns of the debt, credit, and change in the fraction of unique species can vary, but with consistencies and depending on several factors. The general framework deepens the understanding of the theoretical effects of habitat loss on community dynamic patterns in local samples.

Highlights

Habitat destruction, one of the principal factors driving global biodiversity crisis, causes time-lagged, if not instantaneous, loss of species
Kitzes and Harte (2015) developed a novel method to estimate the magnitude of extinction debt or immigration credit from two ecological community patterns, namely regional species abundance distribution (SAD) and species-specific spatial abundance distribution (SAAD)
Their method was based on several important assumptions: firstly, local communities in the region are always open to speciation or immigration; secondly, the number of species in a local community is determined jointly by SAD and SAAD; thirdly, regional SAD before habitat loss and after a long run since habitat loss is assumed to be in steady equilibrium; and lastly but most importantly, the whole community or region after reaching new steady state will follow the same parametric SAD curve as the original regional SAD before habitat loss

Summary

Introduction

One of the principal factors driving global biodiversity crisis, causes time-lagged, if not instantaneous, loss of species. Kitzes and Harte (2015) (hereinafter referred as KH for brevity) developed a novel method to estimate the magnitude of extinction debt or immigration credit from two ecological community patterns, namely regional species abundance distribution (SAD) and species-specific spatial abundance distribution (SAAD) Their method was based on several important assumptions: firstly, local communities in the region are always open to speciation or immigration; secondly, the number of species in a local community is determined jointly by SAD and SAAD; thirdly, regional SAD before habitat loss and after a long run since habitat loss is assumed to be in steady equilibrium; and lastly but most importantly, the whole community or region after reaching new steady state will follow the same parametric SAD curve as the original regional SAD before habitat loss. A parsimonious, tractable, and synthetic framework that can link and explain these temporal ecological phenomena is unavailable until date

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Results

Conclusion