Spatial and functional components of diversity in tropical mammals

全球各地的热带森林正在转变为人类主导的景观。尽管如此，热带森林在群落内仍然具有高度的物种多样性（α多样性），在群落之间也具有高度的物种差异（β多样性）。虽然这些热带群落中的哺乳动物生活在一系列的空间尺度上，但大多数地理学研究都集中在它们的α多样性上，表明栖息地面积通常是与物种丰富度相关的主要因素（即较大的栖息地比较小的栖息地包含更多的物种）。最近的理论和实证研究表明，阿尔法多样性是密切相关的景观和区域物种池和哺乳动物的功能特征，如体重，可以影响他们的持久性在破碎的景观。然而，许多重要的研究问题仍然没有答案，因为空间和功能的组成部分的多样性很少在热带哺乳动物进行了研究。举例来说：更大、更复杂的栖息地所包含的物种群落是否比更小、不太复杂的栖息地更类似于景观物种群落？哺乳动物的某些功能特征是否会导致当地群落组成的变化？β多样性是否在更大程度上比森林破碎化更能控制整个景观的生物多样性？在接下来的5年里，我和我的学生将研究景观环境如何影响马达加斯加西北部24种非飞行哺乳动物的多样性模式和过程。尽管从1955年到2014年失去了44%的森林覆盖率，但该岛仍然是生物多样性的热点，使其成为景观生态学研究的天然实验室。我们的研究目标将是确定：1）在人类主导的景观中，当地和景观物种池之间的关系，2）如果某些功能特征导致一些哺乳动物物种比其他物种在破碎的景观中更常见，以及3）如果当地社区之间的物种多样性差异决定了物种多样性在更大程度上比森林破碎化。我们将使用标准样线调查以及笼，桶和相机陷阱的组合来收集数据，以检验我们的假设。我们还将进行植被采样和遥感数据分析，以更新我们在过去10年中在研究景观中完成的广泛的栖息地测绘。了解空间尺度如何影响生物多样性是至关重要的研究在保护植物地理学，但缺乏数据的多样性模式和过程中的非飞行哺乳动物在热带地区。因此，我们的研究将有助于更好地了解栖息地的空间格局如何影响哺乳动物群落，提高马达加斯加珍稀哺乳动物保护工作的有效性，并为对保护动物地理学感兴趣的加拿大学生提供广泛的培训和研究机会。

Tropical forests are being converted to human-dominated landscapes across the planet. Nonetheless, tropical forests still contain high species diversity within communities (alpha diversity) and high species variations between communities (beta diversity). Although mammals in these tropical communities live across a range of spatial scales, most biogeographic research has focused on their alpha diversity, indicating that habitat area is typically the main factor associated with species richness (i.e. larger habitats contain more species than smaller habitats). Recent theoretical and empirical research indicates that alpha diversity is strongly related to landscape and regional species pools and that mammal functional traits, such as body mass, can influence their persistence in fragmented landscapes. However, many important research questions remain unanswered because the spatial and functional components of diversity have rarely been studied in tropical mammals. For example: Do larger, more complex habitats contain a species community more similar to that of the landscape species community than smaller, less complex habitats? Do certain functional traits of mammals result in variations in local community composition? And does beta diversity govern overall biodiversity across landscapes to a greater extent than forest fragmentation? Over the next 5 years, my students and I will study how landscape context influences diversity patterns and processes in 24 species of nonvolant mammals in northwest Madagascar. This island is a biodiversity hot spot, despite losing 44% of its forest cover from 1955-2014, making it a natural laboratory for research on landscape ecology. Our research objectives will be to determine: 1) the relationship between local and landscape species pools in human-dominated landscapes, 2) if certain functional traits result in some mammal species being more common than others in fragmented landscapes, and 3) if differences in species diversity between local communities determines landscape-wide diversity to a greater extent than forest fragmentation. We will use a combination of standard line transect surveys as well as cage, bucket, and camera traps to collect data to test our hypotheses. We will also conduct vegetation sampling and analysis of remote sensing data to update the extensive habitat mapping we have completed over the last 10 years in our study landscapes. Understanding how spatial scale influences biodiversity is critical for research in conservation biogeography, but there is a lack of data on diversity patterns and processes of nonvolant mammals in the tropics. Thus, our research will contribute to a better understanding of how spatial patterns of habitat influence mammal communities, increase effectiveness of conservation efforts for rare mammals in Madagascar, and provide extensive training and research opportunities to Canadian students interested in conservation biogeography.