Abstract The persistence of tropical rainforests, together with their flora and fauna, is highly threatened by anthropogenic disturbances. In this study, we investigate to what extent selective logging influences the structure and composition of a tropical rainforest in Madagascar and subsequently lemur encounter rates and cluster sizes. We quantified forest structure variables and conducted transect surveys of seven sympatric diurnal lemur species in five protected forest sites with different logging histories. We found that DBH, tree height, the interquartile ranges of DBH and tree height (measure of forest heterogeneity), tree species and family richness were relatively high and tree density was relatively low in less disturbed compared to disturbed sites. Although the disturbed forests have not fully recovered to previous conditions, they seem to have recovered from a functional perspective into suitable lemur habitat, as lemur encounter rates and cluster sizes were similar in disturbed and less disturbed sites. We only found slightly higher encounter rates for Varecia variegata (P = 0.078) and lower encounter rates for Eulemur rufifrons (P = 0.059) in less disturbed forests. This is one of the first studies that report the presence of V. variegata, a species characterised by its drastic decline, in previously logged sites. Lemurs travelling between disturbed and less disturbed sites disperse seeds and hereby facilitate forest regeneration. Therefore, we promote the need for better attention to the value of logged forests for biodiversity conservation in Madagascar and suggest that there is considerable potential for regenerating logged forests to support lemur communities.

中文翻译：

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人为干扰效应在森林结构中仍然可见，但在狐猴丰度中不可见

摘要 热带雨林及其动植物群的持续存在受到人为干扰的高度威胁。在这项研究中，我们调查了选择性伐木在多大程度上影响了马达加斯加热带雨林的结构和组成，以及随后的狐猴遭遇率和集群大小。我们量化了森林结构变量，并对五个具有不同采伐历史的受保护森林地点的七个同域昼夜狐猴物种进行了横断面调查。我们发现 DBH、树高、DBH 的四分位距和树高（森林异质性的度量）、树种和家庭丰富度相对较高，与受干扰的地点相比，受干扰较少的树木密度相对较低。尽管受到干扰的森林还没有完全恢复到以前的状态，从功能的角度来看，它们似乎已经恢复到合适的狐猴栖息地，因为狐猴的遭遇率和集群大小在受干扰和不受干扰的地点相似。我们只发现在较少受干扰的森林中，Varecia variegata 的遭遇率略高（P = 0.078），而 Eulemur rufifrons 的遭遇率较低（P = 0.059）。这是最早报告 V. variegata 存在的研究之一，V. variegata 是一种以急剧下降为特征的物种，存在于先前记录的地点。狐猴在受干扰和不受干扰的地点之间穿行，传播种子，从而促进森林再生。因此，我们提倡需要更好地关注伐木森林对马达加斯加生物多样性保护的价值，并建议再生伐木森林以支持狐猴群落具有相当大的潜力。