Using land-use history and multiple baselines to determine bird responses to cocoa agroforestry.

Abstract

Agroforests can play an important role for biodiversity conservation in complex landscapes. A key factor distinguishing among agroforests is land-use history - whether agroforests are established inside forests or on historically forested but currently open lands. The disparity between these land-use histories means that the appropriate biodiversity baselines may differ, which should be accounted for when assessing the conservation value of agroforests. Specifically, comparing against multiple baselines in forest and open land could enrich our understanding of species responses by contextualizing them. Here, we implemented this approach using data from a recently published meta-analysis on the response of bird diversity to various kinds of cocoa (Theobroma cacao) agroforestry (rustic, mixed shade cocoa, low shade cocoa). First, we re-grouped cocoa agroforests based on land-use history into forest-derived and open-land derived agroforests. Second, we compared forest- and open-land-derived agroforests to forest and open land, representing two alternative baselines. We found that forest-derived agroforests hosted bird diversity similar to forests. Open-land-derived agroforests were significantly less diverse than forests and comparable to open lands. There are two key contributions of this work: first, given the biodiverse forest baseline, we highlight the risk of forest degradation through cocoa agroforest establishment. Moreover, we emphasize rehabilitation opportunities through open-land-derived cocoa agroforestry on historically forested open land, but more studies are needed to determine how birds may benefit. Second, comparing against multiple baselines offers the opportunity to discuss relative contributions of agroforestry to bird conservation on a landscape-scale. This article is protected by copyright. All rights reserved.