The need for carbon finance schemes to tackle overexploitation of tropical forest wildlife

Abstract

Defaunation of tropical forests, particularly from unsustainable hunting, has diminished populations of key seed dispersers for many tree species, driving shifts in forest community composition toward small-fruited or wind-dispersed trees with low wood density. Such shifts can reduce aboveground biomass, prompting calls for overexploitation to be included in bioeconomic policy, but a synthesis of existing literature for wildlife impacts on carbon stores is lacking. We evaluated the role of wildlife in tropical forest tree recruitment and found that it was critical to tropical forest carbon dynamics. The emerging financial value of ecosystem services provided by tropical forest fauna highlights the need for carbon-based payments for ecosystem services schemes to include wildlife protection. We argue for three cost-effective actions within carbon finance schemes that can facilitate wildlife protection: support land security opportunities for Indigenous peoples and local communities; provide support for local people to protect forest fauna from overexploitation; and focus on natural regeneration in restoration projects. Incorporating defaunation in carbon-financing schemes more broadly requires an increased duration of carbon projects and an improved understanding of defaunation impacts on carbon stores and ecosystem-level models. Without urgent action to halt wildlife losses and prevent empty forest syndrome, the crucial role of tropical forests in tackling climate change may be in jeopardy.

Keywords: bosques tropicales; carbon cycle; ciclo del carbono; climate finance; finanzas climáticas; overexploitation; sobreexplotación; tropical forests; 气候金融; 热带森林; 碳循环; 过度利用.

FIGURE 1

Effect of defaunation on regeneration of woody plants with large seeds and small seeds or that disperse seeds abiotically (numbers in parentheses, number of pair‐wise comparisons between high fauna and low fauna treatments per category; circles, mean standardized effect size [Hedges g]; whiskers, 95% confidence intervals; asterisks, categories for which confidence intervals do not overlap zero) (reproduced from Gardner et al. [2019]).

FIGURE 2

Impacts of defaunation on animal functional groups, ecological processes, and aboveground carbon stocks (red arrows, negative effects; black arrows, positive effects; dashed lines, effects that are less well understood; large icon size, population increase; small icon size, population decrease; thick arrows, defaunation increases a particular process or relationship; thin arrows, defaunation decreases process or relationship).