Plant and lemur responses to forest edges in Madagascar

点击翻译按钮获取中文摘要

A fundamental issue in ecology and conservation biology is determining how forest edges influence plant and animal communities. Forest edges are dynamic zones between forested and nonforested environments or between two habitats of contrasting composition or structure. Forests are becoming increasingly fragmented in many parts of the world, which results in edge habitats comprising a proportionally larger part of each fragment. Edge influences can occur through fragment-level impacts, such as spatial variability in resource abundance, and landscape-level impacts, such as changes in community structure. For the lemurs of Madagascar, these issues are of particular ecological interest and conservation concern because humans have transformed approximately 90% of the primary forests on the island. Although conceptual models have been used to investigate animal responses to forest edges, the associated predictions are best applied to taxa that exploit the matrix (e.g., nonforested habitats). The question arises then as to how models perform for forest-dwelling animals, such as most lemurs, that do not use the matrix. I propose two new research projects at the fragment and landscape levels in and around Ankarafantsika National Park in northwest Madagascar. First, my students and I will use observational and experimental studies to test hypotheses on how forest edges influence plant community dynamics, dendrometrics, and abiotic factors. Second, we will test hypotheses from recent conceptual models on edge influences on lemur abundance (density and biomass) and behavioral ecology (diet, activity, and ranging patterns). We will focus our lemur studies on two folivores (Lepilemur edwardsi and Avahi occidentalis), two frugivores (Eulemur fulvus and Eulemur mongoz), one folivore/frugivore (Propithecus coquereli), and three omnivores (Microcebus ravelobensis, Microcebus murinus, and Cheirogaleus medius). The proposed research is of special significance because it tests hypotheses on edge influences at various spatial scales, applies data to serious conservation issues, and supports the training of highly qualified personnel from Canada and Madagascar.