Distinct Community-Wide Responses to Forecasted Climate Change in Afrotropical Forests

Chase L Núñez,John R Poulsen,Lee J T White,James S Clark,Vincent Medjibe

doi:10.3389/fevo.2021.742626

Abstract

More refined knowledge of how tropical forests respond to changes in the abiotic environment is necessary to mitigate climate change, maintain biodiversity, and preserve ecosystem services. To evaluate the unique response of diverse Afrotropical forest communities to disturbances in the abiotic environment, we employ country-wide tree species inventories, remotely sensed climate data, and future climate predictions collected from 104 1-ha plots in the central African country of Gabon. We predict a 3–8% decrease in Afrotropical forest species richness by the end of the century, in contrast to the 30–50% loss of plant diversity predicted to occur with equivalent warming in the Neotropics. This work reveals that forecasts of community species composition are not generalizable across regions, and more representative studies are needed in understudied diverse biomes. This study serves as an important counterpoint to work done in the Neotropics by providing contrasting predictions for Afrotropical forests with substantially different ecological, evolutionary, and anthropogenic histories.

Highlights

Neotropical studies demonstrate that community composition and Community Responses to Climate Change function are degrading in response to climate change (Engelbrecht et al, 2007; Bongers et al, 2009; Poorter et al, 2017; Whitworth et al, 2021), with early successional species thriving in warmer soil temperatures at the expense of latesuccessional species that require cooler microhabitats (Colwell et al, 2008)
To evaluate how Afrotropical tree species will respond to future climate change, we model tropical forest tree species distributions using a systematic country-wide array of randomly placed tree plots, remotely sensed historic climatic data, and future climate predictions for the densely forested central African country of Gabon
We demonstrate a 3–8% decrease in Afrotropical forest species richness by the end of the century for the most abundant tree species

Summary

Introduction

The anticipated pace of global warming is predicted to result in large declines of tropical biodiversity (Aubry-Kientz et al, 2019), leading to biotic attrition of the lowland tropics (Sala et al, 2000; van Vuuren et al, 2006; Colwell et al, 2008; Feeley et al, 2011; Hooper et al, 2012; Dexter et al, 2018, but see Feeley and Silman, 2010). Neotropical studies demonstrate that community composition and Community Responses to Climate Change function are degrading in response to climate change (Engelbrecht et al, 2007; Bongers et al, 2009; Poorter et al, 2017; Whitworth et al, 2021), with early successional species thriving in warmer soil temperatures at the expense of latesuccessional species that require cooler microhabitats (Colwell et al, 2008) These processes have contributed to predictions of 30–50% loss of plant diversity with a 5◦C temperature increase for most South American tropical forests (Colwell et al, 2008; Feeley and Silman, 2010)

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Results

Conclusion