Living on the edge: The use of fruit‐feeding butterflies to evaluate edge effect on subtropical assemblages

Abstract

This study evaluated how the edge effect influences the structuration of fruit‐feeding butterfly assemblages in swamp forest fragments of the subtropical Atlantic Forest, Southern Brazil. Sampling was carried out twice in 10 fragments using baited traps placed in sampling units both at the forest edge and 50 m within the forest interior, with the habitats being defined by a set of environmental variables. Richness and abundance were higher for edge habitats with an effect of temperature depending on humidity and luminosity. The subfamily/tribe composition of fruit‐feeding butterflies was segregated between edge and interior and was predicted by wind speed and the interaction between humidity and luminosity. Fifty meters within the forest interior is not sufficient to cause homogenization of butterfly composition between the edge and interior of swamp forest fragments, indicating distinct assemblages in each habitat. The interior harboured forest‐loving butterfly groups while the edge harboured generalist sun‐loving and common butterflies associated with disturbed areas, suggesting resistance to the effects of habitat fragmentation. We highlight the importance of using fruit‐feeding butterfly groups, instead of species, to evaluate edge effects. We also suggest that a heterogeneous matrix with native habitats and distinct semi‐natural land‐use systems be maintained to manage subtropical areas by increasing connectivity within the landscape. Considering the impacts that the Atlantic Forest suffers, increased knowledge of modifications caused at small and regional scales is crucial for the maintenance of ecological processes and represents a tool for conservation planning and environmental agendas.

Structure of the assemblage of fruit-feeding butterflies in a high Andean anthropogenic landscape

“…At the local scale, our study shows a high differentiation among habitats with forest and paramo indicating a high divergence between species assemblage, and signaling the importance of the diversity of habitats for ecological processes related to conservation, including distinct land-use environments in a heterogeneous landscape (Lorandi et al 2023;Bellaver et al 2022). In this case, our study show that native habitats are responsible to the increasing diversity of Andean butter ies, including speci c resource availability and optimal environmental conditions for butter ies in these environments.…”

“…This may increase the survivorship of local butter ies and its movement and dispersion in the landscape, allowing the maintenance of metacommunity dynamics in this unique and threatened area in the Colombian Andes. Thus, it is crucial to increasing knowledge on small scale research by evaluating the modi cation of habitats and its associated fauna as a useful tool for future management and conservation purposes aiming the preservation of biodiversity (Bellaver et al 2022). According to Bonebrake et al (2010), the development of a predictive theory of the impacts of habitat loss on tropical butter y diversity requires more research on speci c biogeography patterns, demographics and life history strategies, and interactions between species.…”

Hoist the colours: silviculture impacts butterfly assemblage colours in the Atlantic Forest

“…general, eurytopic and generalist ones with great movement capabilities(Bellaver et al 2022), in which butter ies shared with other habitats suggest these environments are being used as dispersal corridors. This use may be observed in butter ies with defence strategies like bright warning colours(Pinheiro et al 2016), masquerade(Skelhorn et al 2010) and disruptive colouration(Young 1971;Doucet and Meadows 2009).…”