Structure, function and resilience of avian communities in tropical ecosystems

研究生物多样性及其在自然生态系统中的作用是一个紧迫的优先事项，因为地球正面临着气候和土地使用方面前所未有的迅速变化。这些变化将在热带地区感受最强烈，不仅因为它们将经历最大的人口增长，栖息地丧失和经济发展，而且因为它们支持绝大多数物种（>80%），许多物种的范围很小，气候限制很窄，使它们很容易灭绝。然而，部分由于对温带系统的研究偏见，我们对范围转移和保护将如何影响热带地区的生态系统结构和恢复力的理解非常不完整。在所有热带生物多样性中，脊椎动物是保护的标志性象征。它们是种子传播、授粉和捕食等一系列关键生态系统过程的核心。了解支撑其群落结构、功能和复原力的力量的重要性是显而易见的，但由于调查脊椎动物的困难，答案仍然难以捉摸。此外，脊椎动物的分子数据覆盖范围直到最近才完成。在这个项目中，我们将利用最著名的热带脊椎动物-鸟类的新的高分辨率数据集，使用群落系统发育方法在对比的空间尺度上测试生态理论。我们将使用近几十年来在新热带地区收集的基于地点的动物群列表。我们还将使用基于样地的社区和丰富的数据收集，通过实地考察在热带安第斯山脉的海拔梯度。这些数据集将与每个物种的生态位和功能特征的信息相结合。在所有情况下，分析都将由新的物种水平的进化遗传学框架，它有能力揭示社区成员之间的进化关系的结构，并揭示生态位和特征随着时间的推移而进化的方式。这将有助于我们比较不同生境退化和破碎化程度的群落。为了有效地管理生态系统，我们需要了解管理对变化的反应的机制，以及这些变化如何可能随着时间的推移影响群落的生态功能和恢复力。本研究的主要目标是了解（1）来自区域库的物种如何组装到当地社区，（2）社区的系统发育结构和生态功能如何与气候和人类影响有关，以及（3）我们如何应用（1）和（2）的见解来改进各种全球变化情景下的生态预测方法。这些结果将使我们更全面地了解塑造和调节全球生物群落的力量，并提高我们预测环境变化后果的能力，特别是在热带系统中。

The study of biodiversity and its role in natural ecosystems is an urgent priority because the Earth is facing unprecedentedly rapid changes in climate and land-use. These changes will be felt most acutely in tropical regions, not only because they are set to experience the biggest increase in human population, habitat loss and economic development, but also because they support the vast majority of species (>80%), many with small ranges and narrow climatic limits, making them vulnerable to extinction. However, partly because of a research bias towards temperate systems, we have a very incomplete understanding of how range shifts and extinctions will affect ecosystem structure and resilience in tropical regions.Of all tropical biodiversity, vertebrates are the iconic figureheads for conservation. They are central to a range of key ecosystem processes, such as seed dispersal, pollination and predation. The importance of understanding the forces underpinning the structure, function and resilience of their communities is clear, yet the answers remain elusive because of the difficulty of surveying vertebrates. In addition, the coverage of molecular data for vertebrates has until very recently been incomplete.In this project, we will capitalise on new high-resolution datasets for the best-known group of tropical vertebrates - birds - to test ecological theory at contrasting spatial scales using community phylogenetic approaches. We will use site-based faunal lists gathered throughout the Neotropics in recent decades. We will also use plot-based community and abundance data collected through fieldwork across an elevational gradient in the tropical Andes. These datasets will be coupled with information about ecological niches and functional traits for each species. In all cases analyses will be framed by newly available species-level phylogenies, which have the power to reveal the structure of evolutionary relationships between community members, and uncover the way niches and traits have evolved through time. This will help us to compare communities from sites with differing levels of habitat degradation and fragmentation.To manage ecosystems effectively we need to understand the mechanisms governing responses to change, and how these changes are likely to influence the ecological function and resilience of communities over time. The main goals of this research are to understand (1) how species from a regional pool are assembled into local communities, (2) how the phylogenetic structure and ecological function of communities varies in relation to climate and human impacts, and (3) how we can apply insights from (1) and (2) to improve methods for ecological forecasting under various global change scenarios. The results will provide a more complete understanding of the forces shaping and regulating biological communities worldwide, and enhance our ability to predict the consequences of environmental change, particularly in tropical systems.