Effects of landscape configuration on the occurrence and abundance of an arboreal marsupial from the Valdivian rainforest

Victoria P Fernández,Francisco E Fontúrbel,Dimas A Molina-Marín,Gabriel J Castaño-Villa,Gloria B Rodríguez-Gómez

doi:10.1186/s40693-022-00107-9

Abstract

BackgroundHabitat fragmentation and degradation processes affect biodiversity by reducing habitat quantity and quality, with differential effects on the resident species. However, their consequences are not always noticeable as some ecological processes affected involve idiosyncratic responses among different animal groups. The Valdivian temperate rainforests of southern Chile are experiencing a rapid fragmentation and degradation process despite being a biodiversity hotspot. Deforestation is one of the main threats to these forests. There inhabits the arboreal marsupial Dromiciops gliroides, an iconic species from the Valdivian rainforest, it is the only extant representative of the ancient Microbiotheria order, and it is currently threatened by habitat loss. Here we tested the effects of habitat configuration on D. gliroides occurrence and abundance along 12 landscapes of southern Chile with different disturbance levels.MethodsWe estimated D. gliroides occurrence and abundance using camera traps and related those metrics with landscape configuration indices obtained from FRAGSTATS (i.e., forest %, connectivity, patch number, contiguity, and distance to the nearest patch) using Bayesian linear mixed models.ResultsWe found that D. gliroides occurrence was not influenced by landscape configuration, while its abundance was positively influenced by forest contiguity.ConclusionsAlthough this arboreal marsupial is present in disturbed forests, its restricted movement capabilities and high dependency on the forest three-dimensional structure may affect its long-term persistence. We urge to rethink native forest conservation and management policies to improve habitat connectivity with possible positive consequences for native fauna.

Highlights

Habitat fragmentation and degradation processes affect biodiversity by reducing habitat quantity and quality, with differential effects on the resident species
Its abundance and occurrence were variable among sites, disturbance conditions, and years (Table 1)
Dromiciops gliroides abundance decreased with habitat disturbance, and its occurrence at the sampling landscapes varied

Summary

Introduction

Habitat fragmentation and degradation processes affect biodiversity by reducing habitat quantity and quality, with differential effects on the resident species. Their consequences are not always noticeable as some ecological processes affected involve idiosyncratic responses among different animal groups. Habitat fragmentation process involves the subdivision of a continuous habitat in several smaller fragments, altering its spatial configuration and increasing edge effects [1,2,3]. Those habitat fragments are surrounded by a contrasting matrix that may preclude animal dispersal, reducing functional connectivity [4, 5]. Habitat fragmentation is usually accompanied by habitat degradation [13], which implies a reduction in habitat quality due to the scarcity of key structures, such as perches or tree cavities, usually limiting in disturbed habitats [14]

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Conclusion