Structure, function and resilience of avian communities in tropical ecosystems

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.

The UK government, scientists and many national and international NGOs have specific interest in improved understanding of the ecological and evolutionary processes determining range limits and abundance of vertebrates, as well as the implications that those processes have for ecosystem function. This knowledge is a key step to developing effective strategies for managing biodiversity in the context of global change.
Scientists and NGOs will benefit from new information about factors determining the distribution and abundance of species in tropical regions (the epicentre of the current extinction crisis). The results will enable refinement of predictive models of tropical species distributions. They will also help to clarify the extent to which environmental changes impact on ecosystem functioning, and in particular on key ecosystem processes-such as seed dispersal and pollination-that feed into long-term stability and resilience. In addition, they will provide the first information about population density and community interactions for hundreds of tropical bird species, which will directly support IUCN conservation status assessments, and strategic assessments of biodiversity risk.
Policy makers and private sector will benefit from some of the same resources, and from improved methods for mapping and predicting patterns of biodiversity, and long-term ecosystem resilience, aspects with useful applications for channelling Reduced Emissions from Deforestation and Degradation (REDD) and carbon market funding.
Public sector will benefit from high-quality information about environmental science in high-profile ecosystems (Andean and Amazonian forests, the world's most diverse terrestrial biomes).
We will exchange knowledge with scientists via symposia, seminars and meetings, and by publication of peer-reviewed articles, including submissions to top-rank journals. Applications have already been submitted for a symposium titled "Competition and the structure of avian communities" for the Neotropical Ornithology Congress in Cusco, Nov 2011. Five speakers (including project staff) have been arranged, and all relevant parties associated with the Andean transect study are attending.
To engage users from science, NGOs and the private sector, we will run a 2-day meeting co-hosted by the Biodiversity Institute (Zoology Dept., Oxford University) and the Oxford Centre for Tropical Forests (OCTF). All project members will attend, along with members of the Andes Biodiversity & Ecosystem Research Group (ABERG), members of key NGOs, and researchers studying the dynamics of biodiversity in relation to environmental change. We will invite private-sector carbon companies with an interest in channelling carbon offset funding or other carbon finance mechanisms to maximise benefits to biodiversity conservation (e.g. REDD++). The results communicated during the meeting will form the basis for a publication about global change and tropical ecosystems, with the longer-term goal of spearheading collaborative interactions in a global network of studies (mainly UK- and US-based) focused on questions about global change and the management of biodiversity and ecosystem services. We will also exchange knowledge with NGOs directly via our close professional links with RSPB, BirdLife International, IUCN and CI.
To engage with the public sector, we will produce at least one mainstream article and at least one television report of our research. We will also update & develop the ABERG website to provide a range of educational materials for public download, including information about our study plots, and relevant images and sound files. To deliver useful outputs to scientists, as well as to a wider audience, all project data will be accessible through the ABERG website portal, as will printable colour webguides of Andean birds (partly to train fieldworkers and support long-term monitoring programmes, but also useful to the public).