Measuring the Impact of Forest Edges on the Highly Arboreal Sahamalaza Sportive Lemur, Lepilemur Sahamalaza, in North-Western Madagascar

Abstract

The progressive fragmentation of forest habitat is causing an increase in edge areas that may differ structurally and in quality from forest interiors. We investigated the impact of edge effects on habitat structure, behaviour, and ecology of the small, nocturnal, and highly arboreal Sahamalaza sportive lemur, Lepilemur sahamalaza. To understand edge effects, we established edge-to-interior gradients using temperature, humidity, and light intensity measurements along transects. From 773 h of behavioural observations on 14 individual sportive lemurs between 2015 and 2016, we compared home range sizes, activity budgets, and habitat use of animals inhabiting the edge area and those in the core forest. We found that microclimatic edge effects penetrated the forest up to 165 m, but that there was no significant edge effect on vegetation; forest vegetation was structurally variable throughout. Individual sportive lemurs living in the edge area used more trees with a diameter at breast height of less than 5 cm but showed no other behavioural differences to individuals inhabiting the core forest. The study shows that this species may not be impacted by edge effects, at least in situations in which vegetation structure is not affected, despite microclimatic differences.

Forest fragmentation and edge effects impact body condition, fur condition and ectoparasite prevalence in a nocturnal lemur community

“…Secondly, vegetation plots measuring tree species diversity, size and forest structural diversity ( Hending et al. , 2023a ), and transects measuring the variation of microclimatic and abiotic variables (temperature, humidity and light intensity) from the forest edge into the forest core ( Mandl et al. , 2023 ) have already been conducted to establish the edge boundary of the forests of SIRNP.…”

“…, 2023 ) have already been conducted to establish the edge boundary of the forests of SIRNP. This edge boundary has been determined to be 165 m ( Mandl et al. , 2023 ).…”

Effects of forest fragmentation on the dietary ecology and activity of a nocturnal lemur community in North West Madagascar

“…This is first because SIRNP contains two remaining forests: the 1169 Ha Anabohazo forest, a continuous forest block that has undergone very little anthropogenic disturbance (Randriatahina et al, 2014), and the 976 Ha Ankarafa forest, a highly fragmented forest encompassed of many fragments of varying size, levels of degradation, and anthropogenic disturbance (Seiler, Holderied, et al, 2013a). Second, analyses of tree species diversity, tree size, and structural diversity (Hending, Randrianarison, Andriamavosoloarisoa, Ranohatra‐Hending, Holderied, et al, 2023), and transects measuring the variation of microclimatic and abiotic variables (temperature, humidity, and light intensity) from the forest edge into the forest core (Mandl, 2018, unpublished thesis; Mandl et al, 2022) have already established the edge‐core gradient of SIRNP's forest as 165 m. The Anabohazo and Ankarafa forests are separated by only ~25 km of grassland, and this provides an opportunity to study the behavioral responses of a lemur community to forest fragmentation on a localized scale, where environmental and habitat‐related covariates can be easily controlled for, in comparison to other studies that have attempted to answer similar research questions over a much larger study area (e.g., Chaves et al, 2011; Cristóbal‐Azkarate & Arroyo‐Rodríguez, 2007).…”

Assessment on Farmers Tree Growing Practices and Tree Species Diversity in the Home Garden, Farmlands, and nearby Forest of Abaychomen District, Oromia Region, Ethiopia

“…The researcher made transect walking especially in the forest nearest to agricultural lands (250 m by 200 m) or 5 ha of the total plots. The transect lines were spaced 50 m between and within the parallel lines following (Gaya et al, 2022;Mandl et al, 2022). Transect lines were laid on the edge and inside of the natural forest, home garden, and agricultural lands using GPs, tape meters, and sample plots with 20 m x 20 m intervals of spacing (Berhe Mengistu et al, 2021) established for tree species.…”