Land‐use change differentially affects endemic, forest and open‐land butterflies in Madagascar

Abstract

1. The conversion of tropical forests into agriculture reduces biodiversity dramatically.However, species might differ in their responses, depending on their habitat specialisation and geographic origin. In this study, we assess how butterfly assemblages differ between old-growth forests, forest fragments, forest-derived vanilla agroforests, fallow-derived vanilla agroforests, woody fallows, herbaceous fallows, and rice paddies in Madagascar.2. We recorded 88 butterfly species, of which 65 species are endemic to Madagascar.Land-use types with woody vegetation sustained many endemic (mean: 6.8 species) and forest butterfly species (mean: 4.8 species). Rice paddies and herbaceous fallows were richer in open-land species (mean: 7.6 species) and poorer in forest species (mean: 1.7 species) compared to other land-use types. Compared to herbaceous fallows, fallow-derived vanilla agroforests hosted more endemic (+164%) and forest (+239%) species. Richness of open-land species in forestderived vanilla agroforests was six times higher than in forest fragments.

The grassy ecosystems of Madagascar in context: Ecology, evolution, and conservation

“…Of 92 species surveyed, 13 were characterized as “savanna” species, while of the 65 species pre‐classified as “forest species,” 15 species were found to be edge specialists, 38 were ubiquitous (i.e., found throughout the landscape), and only 12 were strictly forest interior species. These examples along with the butterfly study mentioned above (Wurz et al, 2022) point to the fact that we know very little about how different species, often labeled as forest restricted, also depend on and utilize open ecosystems. Furthermore, these examples also point to the likelihood that diverse, mosaiced landscapes of forests and open, grassy systems may actually promote higher overall landscape biodiversity than just simply forest or open ecosystems alone.…”

“…It is noteworthy that mosaiced landscapes may not only have promoted evolution of various faunal clades but also may promote higher landscape biodiversity today (cf. Benjara et al, 2021; Wurz et al, 2022).…”

“…But little effort has been made to assess the extent to which these species also utilize open ecosystems (e.g., Benjara et al, 2021). A recent study of butterfly biodiversity (Wurz et al, 2022) found that the highest diversity was found in mosaiced landscapes in northeastern Madagascar, which include both patches of forest and open, grassy systems. The expectation for forested landscapes is that their greater three-dimensional habitat structure should generally support higher alpha diversity of vertebrate groups.…”

Diverging responses to environmental change and different landscape structure in Aftrotropical birds and butterflies

“…Thus, birds often establish larger territories and hereby occupy various types of habitats across a landscape (Nally et al 2004), while many butter y species are restricted to one speci c habitat or even micro-habitat structures within habitats (Habel et al 2022a,b). Furthermore, dispersal behaviour of birds is comparatively high (Greenwood & Harvey 1982), and in most cases signi cantly higher than that of butter ies, which are frequently characterized by high site-delity (Wurz et al 2022). The two taxonomic groups also have remarkable differences in their use of resources, which again impact their sensitivity with respect to habitat disturbance (Ulrich et al 2016(Ulrich et al , 2017.…”

Land‐use change in the Amazon decreases ant diversity but increases ant‐mediated predation

“…These studies seek to conserve biodiversity and mitigate anthropogenic impacts (Gardner et al, 2013;Newbold et al, 2015). The conversion from semi-natural habitats to anthropogenic land uses and other drivers can affect biodiversity differently (de Chazal & Rounsevell, 2009), with varied effects, from positive (e.g., higher butterfly species richness in forest-derived vanilla agroforests compared to forest fragment; Wurz et al, 2022) to negative (e.g., conversion of tropical savanna to pasture negatively affects ant species richness; Queiroz et al, 2020), or even neutral (e.g., conversion of Amazon Forest to shaded coffee does not affect ant species richness; Escobar-Ramírez et al, 2020). However, conversion from semi-natural habitats to anthropogenic land uses, such as mechanised production, usually generates negative effects, such as decreased species richness and biomass of most taxa, including invertebrates, birds, and plants ( Barnes et al, 2017).…”