Edge effects can influence species composition and community structure as a result of changes in microenvironment and edaphic variables. We investigated effects of habitat edges on vegetation structure, abundance and body mass of one vulnerable Microcebus species in northwestern Madagascar. We trapped mouse lemurs along four 1000-m transects (total of 2424 trap nights) that ran perpendicular to the forest edge. We installed 16 pairs of 20 m2 vegetation plots along each transect and measured nine vegetation parameters. To determine the responses of the vegetation and animals to an increasing distance to the edge, we tested the fit of four alternative mathematical functions (linear, power, logistic and unimodal) to the data and derived the depth of edge influence (DEI) for all parameters. Logistic and unimodal functions best explained edge responses of vegetation parameters, and the logistic function performed best for abundance and body mass of M. ravelobensis. The DEI varied between 50 m (no. of seedlings, no. of liana, dbh of large trees [dbh ≥ 10 cm]) and 460 m (tree height of large trees) for the vegetation parameters, whereas it was 340 m for M. ravelobensis abundance and 390 m for body mass, corresponding best to the DEI of small tree [dbh < 10 cm] density (360 m). Small trees were significantly taller and the density of seedlings was higher in the interior than in the edge habitat. However, there was no significant difference in M. ravelobensis abundance and body mass between interior and edge habitats, suggesting that M. ravelobensis did not show a strong edge response in the study region. Finally, regression analyses revealed three negative (species abundance and three vegetation parameters) and two positive relationships (body mass and two vegetation parameters), suggesting an impact of vegetation structure on M. ravelobensis which may be partly independent of edge effects. A comparison of our results with previous findings reveals that edge effects are variable in space in a small nocturnal primate from Madagascar. Such an ecological plasticity could be extremely relevant for mitigating species responses to habitat loss and anthropogenic disturbances.

中文翻译：

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栖息地边缘对马达加斯加西北部植被结构和脆弱的金棕色小鼠狐猴（Microcebus ravelobensis）的影响

边缘效应会由于微环境和水生变量的变化而影响物种组成和群落结构。我们调查了栖息地边缘对马达加斯加西北部一种脆弱的小盲species物种的植被结构，丰度和体重的影响。我们沿着垂直于森林边缘的四个1000-m断面（总共2424个诱捕夜）捕获了老鼠狐猴。我们在每个样条线上安装了16对20平方米的植被图，并测量了9个植被参数。为了确定植被和动物对到边缘的距离增加的响应，我们测试了四个替代数学函数（线性，幂，对数和单峰）对数据的拟合度，并得出了所有区域的边缘影响深度（DEI）参数。Logistic和单峰函数可以最好地解释植被参数的边缘响应，而Logistic函数对于ravelobensis的丰度和体重表现最佳。植被参数的DEI在50 m（幼苗数量，藤本植物数量，大树的dbh [dbh≥10 cm]）和460 m（大树的树高）之间变化，而M的变化范围为340 m 。ravelobensis丰度，体重390 m，最适合小树[dbh <10 cm]密度（360 m）的DEI。小树高得多，内部的幼苗密度高于边缘生境。但是，内部和边缘生境之间的毛ra支原体的丰度和体重没有显着差异，这表明毛支支原体在研究区域没有显示出强烈的边缘响应。最后，回归分析显示了三个负值（物种丰度和三个植被参数）和两个正值关系（体重和两个植被参数），这表明植被结构对红花苜蓿的影响可能部分与边缘效应无关。将我们的结果与以前的发现进行比较，发现在马达加斯加的一个夜灵长类灵长类动物中，边缘效应在空间上是可变的。这种生态可塑性对于减轻物种对生境丧失和人为干扰的反应可能极为重要。将我们的结果与以前的发现进行比较，发现在马达加斯加的一个夜灵长类灵长类动物中，边缘效应在空间上是可变的。这种生态可塑性对于减轻物种对生境丧失和人为干扰的反应可能极为重要。将我们的结果与以前的发现进行比较，发现在马达加斯加的一个夜灵长类灵长类动物中，边缘效应在空间上是可变的。这种生态可塑性对于减轻物种对生境丧失和人为干扰的反应可能极为重要。