Landscape ecology of lemurs in Madagascar

一个对生态学至关重要的问题是了解植物和动物群落如何对森林砍伐过程（森林损失、森林破碎化和边缘效应）作出反应。在世界许多地方，森林正变得越来越支离破碎，这导致边缘栖息地在每个碎片中所占的比例更大。对于马达加斯加的狐猴来说，这些问题具有特别的生态意义和保护问题，因为人类已经将岛上的大部分原始森林变成了草原。虽然已经开发出概念模型来预测动物群落将如何因森林丧失和破碎化而发生变化，但对热带哺乳动物的相关假设进行的经验检验很少，更不用说对狐猴等树栖灵长类动物了。我和我的学生们建议在马达加斯加西北部Ankarafantsika国家公园及其周边的景观和景观层面上，重点研究两种昼生食腐动物（fulvus和蒙古食腐动物）、一种昼生食腐/食腐动物（prothecus coquereli）、两种夜行食腐/食腐动物（Lepilemur edwardsi和Avahi occidentalis）和三种夜行杂食/食腐动物（Microcebus ravelobensis、Microcebus murinus和Cheirogaleus medius）的景观生态学。我们将在6个3000 - 4000公顷的破碎森林景观中进行实地研究。首先，我们将检验来自物种-区域关系、超种群模型和物种-破碎区域关系的假设，以确定景观过程如何影响物种丰富度。物种-区域关系预示着更大的区域将包含更多的物种。在元种群动态中，斑块占用率反映了灭绝率和定殖率之间的动态关系，灭绝率随面积的增加而降低，定殖率随隔离程度的增加而降低。新提出的物种-破碎区关系将超种群动态与物种-区域关系相结合，以预测灭绝风险如何影响高度破碎景观中的物种丰富度。其次，我们将在景观水平上检验栖息地数量如何影响物种丰富度的另一种假设。该模型认为，无论物种灭绝-殖民动态如何，相同大小的样本碎片上的物种数量应该随着每个样本地点“当地景观”中栖息地的总量而增加。我和我的学生们进行的研究是更好地理解人类改造景观中狐猴种群生态的基础。我们的研究也将是第一批在景观尺度上收集和分析灵长类动物数据的研究之一；大多数研究只对一个研究地点及其周围的几个物种群体进行了研究。

A question of fundamental importance to ecology is understanding how plant and animal communities respond to deforestation processes (forest loss, forest fragmentation, and edge effects). Forests are becoming increasingly fragmented in many parts of the world, which result in edge habitats comprising a greater proportion of each fragment. For the lemurs of Madagascar, these issues are of particular ecological interest and conservation concern because humans have transformed most of the primary forests to grassland on the island. Although conceptual models have been developed to predict how animal communities will change due to forest loss and fragmentation, there are few empirical tests of the associated hypotheses on tropical mammals, let alone for arboreal primates, such as lemurs. My students and I propose to focus our research on the landscape ecology of two diurnal frugivores (Eulemur fulvus and Eulemur mongoz), one diurnal folivore/frugivore (Propithecus coquereli), two nocturnal folivores (Lepilemur edwardsi and Avahi occidentalis), and three nocturnal omnivores/frugivores (Microcebus ravelobensis, Microcebus murinus, and Cheirogaleus medius) at the fragment and landscape levels in and around Ankarafantsika National Park in northwest Madagascar. We will conduct our field research in six 3,000-4,000 ha fragmented forest landscapes. First, we will test hypotheses from species-area relationships, metapopulation models, and the species-fragmented area relationship to determine how landscape processes influence species richness. Species-area relationships predict that larger areas will contain more species. In metapopulation dynamics, patch occupancy reflects a dynamic relationship between extinction rates, which decrease with increasing area, and colonization rates, which decrease with increasing isolation. The newly proposed species-fragmented area relationship combines metapopulation dynamics with species-area relationships to predict how extinction risk influences species richness in highly fragmented landscapes.  Second, we will test an alternative hypothesis on how habitat amount influences species richness at the landscape level. This model holds that the number of species across sample fragments of the same size should increase with the total amount of habitat in the `local landscape' of each sample site, irrespective of extinction-colonization dynamics. The research that my students and I conduct is fundamental to a better understanding of the ecology of lemur populations in human-modified landscapes. Our research will also be amongst the first to collect and analyze data from primates at a landscape scale; most research has been on only a few groups of a species in and around one research site.