Living on the edge: forest edge effects on microclimate and terrestrial mammal activity in disturbed lowland forest in Sumatra, Indonesia

Abstract

Species–environment relationships are often studied at large spatial scales, but effective conservation requires an understanding of local-scale environmental drivers and pressures. Widespread degradation and fragmentation of forests have increased the proportion of tropical mammal habitat that is affected by edge effects. Edge effects include greater exposure to anthropogenic disturbance and abiotic changes that synergistically influence how well populations can cope with climate change. We investigated relationships between distance to the forest edge, forest structure, microclimate and terrestrial mammal detections in a selectively logged forest at the boundary of Gunung Leuser National Park in Sumatra, Indonesia. We collected mammal detection data from motion-activated camera traps, microclimate data from automated climate data loggers and forest structure data from vegetation plots. Daily mean and maximum temperatures significantly decreased with distance from the forest edge, whereas tree height and minimum temperature increased. Mammal diversity was lower at the forest edge compared to the interior. Mammals were detected less frequently at the forest edge, although this relationship varied between mammal orders. Mammal detections were best explained by temperature, tree height and tree diameter at breast height. These results demonstrate that abiotic changes in forests brought on by edge effects have negative impacts on mammals, but these effects vary between mammal taxa because of differing sensitivities to human disturbance. Our findings highlight the importance of considering local-scale environmental drivers in determining species–environment relationships to identify key habitat features such as microclimate refuges that should be prioritized in ecosystem management.

Drivers of jaguar (Panthera onca) and puma (Puma concolor) predation on endangered primates within a transformed landscape in southern Mexico

“…When considering both primate species together, our results indicate that felid predation on primates is increased with the reduction of tall evergreen forest. This agrees with reports that forest transformation may intensify predation on canopy dwelling primates by facilitating access to prey (Irwin et al, 2009), due to a lack of large trees and especially in areas close to the forest edge, where the presence of other mammals can be lower (Slater et al, 2023). Additionally, changes in the environment and habitat structure (e.g., microclimate and large tree availability) may also force both spider and howler monkeys to seek resources such as water on the ground (Delgado‐Martínez et al, 2021; Youlatos & Guillot, 2015), or to cross through open areas to reach disconnected forest fragments (Campbell et al, 2005; Martínez‐Mota et al, 2007), which potentially explains the high levels of primate consumption at our study site.…”

Massive Bird Nest Losses: A Neglected Threat for Passerine Birds in Atlantic Forest Fragments from the Pernambuco Endemism Center

“…Animal species and local populations have been extirpated worldwide because of the effects of habitat loss and fragmentation, and the impacts can be more dramatic in megadiverse regions in which the whole habitat is degraded [1][2][3]. Habitat fragmentation can affect organisms in many ways, including the habitat reduction for habitat-dependent species [1]; reduction in movements and gene flow [4]; exposure to border effects [5]; invasion of alien species [6]; impediment of certain organisms to change their geographic distributions in response to global climate changes [7]; and increase in conflicts between humans and wildlife [8]. Many bird species or local populations also have vanished because of high nest predation rates resulting from habitat disturbances.…”