Tree communities, airborne remote sensing and ecosystem function: new connections through a traits framework applied to a tropical elevation gradient

Lead Research Organisation: University of Edinburgh


What is the relationship between the composition of an ecological community and its ecosystem function? How do changes in community composition affect carbon and nutrient cycling? How does a shift in ecosystem productivity (e.g. through fertilization) feed through to changes in diversity? These are perhaps the most important questions in ecology day, in the context of direct human pressure on ecosystems and indirect pressure through global atmospheric change. Here we propose to collect the data and develop and evaluate a framework to advance these ideas, in the context of tree community composition of tropical forests.

We take advantage of three powerful tools that our team of investigators and project partners have developed: (i) an elevation transect of study sites in the Andes-Amazon where tree community composition and dynamics have been described in detail; (ii) airborne hyperspectral and lidar data that have recently been collected over this same transect, that enable determination of forest structure and chemistry in unprecedented detail, and (iii) a theoretical framework that utilises plant traits to propose a mechanistic approach to scale from community composition to ecosystem function.

We will add to these datasets by:
1. Conducting an extensive leaf and wood traits collection campaign for seven sites along this transect, and
2. Collecting data on nitrogen and phosphorus cycling.
Then we will develop a 3D model of the forest canopy of each plot (based on forest tree census and lidar data) to:
3. Explore the relationship between leaf traits and tree level characteristics (gross primary production, wood production, above-ground net primary production and nutrient cycling)
4. Scale from individual trees to the whole plot ecosystem characteristics (productivity, wood production, nutrient cycling)

Having developed this detailed framework for relating individual tree properties to plot-level function, we will try to simplify the system to see if ecosystem level properties can be derived from an understanding of the mean value and distribution of traits in a community. Finally, we will explore how well tree-level characteristics can be described by airborne hyperspectra and lidar, and thus explore whether it is possible to describe landscape level ecosystem functioning at the scale of thousands of hectares.

We have assembled a team of leading UK and USA researchers, and have an opportunity to make major advances and novel contributions to these important questions. Ultimately, we seek to acquire a mechanistic understanding of the relationship between forest community assembly and ecosystem level processes. Achievement of this goal would represent a major advance in ecology, in developing a both a theoretical and empirical toolkit with which to reach this goal.

Planned Impact

Scientific community engaged in understanding tropical forest ecology and function, and its sensitivity to environmental change

The scientific beneficiaries have been outlined in the academic beneficiaries section. Many of the needs of this community will be met through conventional routes (paper publication, conference presentation, guest seminars). All investigators and project partners have very strong publication records, and this will continue. In addition, the PI has a strong philosophical commitment to free, fairly rapid and unrestricted availability of our field data for use by the wider community, and have set up a portal where, for example, our recent Amazonian and African data are freely available (

Peruvian Junior Researchers

This project will continue its record of capacity building in Peru by training and further developing 10 Peruvian students and field researchers in data collection and analysis, with the aim of ultimately moving some of them onto PhD and MSc programmes, and publishing aspects of their data as first author -papers. In addition, we seek to train a wider body of students in both countries in the concepts and elements of the research, and encourage and assist local students to attach dissertation projects to the core research. To this end we will hold a wider participation and training workshop in Cusco at the start of the field campaign, and a data analysis workshop later in the field campaign. The workshop is explicitly budgeted for, and responsibility for organising and leading this workshop will be written into the PDRA contracts.

Public and schools seeking to understand and be motivated by modern tropical forest science

Using Pathways to Impact funding on a current NERC grant (focussed on African forests), we have just developed an innovative Geoweb Portal that brings together data, imagery and stories from our global network of ecosystem ecology sites (40+ sites, in Peru, Brazil, Bolivia, Chile, UK, Ghana, Gabon and Ethiopia). The site is launched in Dec 2011 and will be fully populated by mid-2012 ( Innovative aspects of the site include a "plots social network" where students in different regions (e.g. Peru and Ghana) can communicate with each other about techniques, science and questions, and a "public questions forum" where members of the public can pose questions that are answered by researchers and students. The whole Portal is designed in a form where it is easy for researchers and students to upload information, text and imagery.
We plan to incorporate stories and information from the current work within the framework of this Geoweb Portal, both from the field campaigns and from the attractive airborne 3D imagery. A key challenge can be to find time to make continually update and maintain the information on this portal. To incentivise this involvement, we have found that paying a fee of £10/hour for substantive contributions and really motivate and raise the quality of both UK and Peruvian contributions.

Peruvian students and public seeking greater general understanding of forests and climate

We will write some simple introductory material on tropical forests, carbon cycle and climate change (at a more basic level than the concepts researched in this proposal) in the context of our Andes-Amazon transect, that will be translated into Spanish and can be used by secondary schools, university students and the wider public. This material will be distributed to some schools and partner institutes, and made available for free download from the web. A 1-page flyer will also highlight the existence of this resource and be distributed in the Cusco region. A small amount of time to refine/distribute these materials will be written into the PDRA contract.


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Description We are showing in current submissions/recent acceptances how the capacity for carbon assimilation does not vary with elevation in Andean rainforests. We have begun to link remote sensing of these carbon-physiology traits with our on the ground measurements to see if remote sensing can be used to quantify ecosystem processes. The results are encouraging and novel. Our data have been included in a global review of leaf respiration, work that will influence land surface modelling of global plant respiration. We have shown that temperature and light are likely to be the key determinants of low productivity in montane, a long-standing conundrum; more recently we have added tothat by focusing on the importance of solar radiation and plant traits for integrating these responses. We have also recorded seasonal variation in productivity at different elevations in the Andes-Amazon corridor and have successfully modelled the canopy physiology of this biome for the first time. The remote sensing element of this work is still in progress but results are looking encouraging.
Exploitation Route Economic and land use policy
International climate negotiations
Tropical cosystem science research
Sectors Creative Economy,Education,Environment,Leisure Activities, including Sports, Recreation and Tourism

Description Our initial unpublished results have already influenced local government to help improve their understanding of carbon and biodiversity resources in Peru and helped in preparation for IPCC/climate conference meetings. We have also had an impact in training Peruvian students, with new members joining UK PhD programs. Recent research highlights include: (i) a paper in Ecology Letters suggesting using empirical and model-based evidence that trait variation and radiation flux dominate the pattern in GPP with elevation; (ii) a paepr in Ecology demonstrating that soil microbial diversity decreases with increased elevation on tropical mountains. This finding shows that microbial community responses, in terms of species diversity, follow similar patterns to those of plants and animals, a fundamental observation that has not been advanced upon since von Humboldt's first descriptions of species distribution and elevation in 1805; and (iii) a submitted manuscript (to New Phyt) demonstrating the ecophysiological limits with regard to climate warming for different species in Andean mountain forest, obtained from a pioneering seedling translocation study.
First Year Of Impact 2017
Sector Education,Environment
Impact Types Societal,Economic

Description Human Modified Tropical Forests Programme
Amount £4,000,000 (GBP)
Funding ID NE/K01627X/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 09/2013 
End 09/2018