The Carbon Cycle of and Artificial Tropical Ecosystem.

Location: University of Exeter, Streatham Campus, Exeter EX4 4QJ

This project is one of a number that are in competition for funding from the NERC Great Western Four+ Doctoral Training Partnership (GW4+ DTP). The GW4+ DTP consists of the Great Western Four alliance of the University of Bath, University of Bristol, Cardiff University and the University of Exeter plus five Research Organisation partners: British Antarctic Survey, British Geological Survey, Centre for Ecology and Hydrology, the Natural History Museum and Plymouth Marine Laboratory. The partnership aims to provide a broad training in earth and environmental sciences, designed to train tomorrow’s leaders in earth and environmental science. For further details about the programme please see http://nercgw4plus.ac.uk/


Project details

The carbon cycle is a fundamental Earth system process with profound influences on the global climate. Human activities have altered ecosystem composition and functioning around the world, through habitat destruction and by species introductions. This PhD will study the carbon cycle of one of the world’s most famous artificial ecosystems: the rainforest biome (RFB) of the Eden Project in Cornwall. The RFB is an enclosed space of around 1 ha, containing plants gathered from tropical ecosystems around the world. While water and air can enter and leave the system, most plant and animal populations are contained within the dome. Thus, processes like carbon assimilation and nutrient cycling are performed by a limited set of species that have little evolutionary history as an ecosystem. A key question in applied ecology is how these introduced species form novel ecosystems, and how ecosystem services like carbon cycling are affected.

Project Aims and Methods

The carbon cycle of a forest biome comprises a number of pools (above-ground biomass in trees and other plants and animals, below-ground carbon in roots, litter and soil, carbon dioxide in the atmosphere, and dissolved organic matter in water) and fluxes (photosynthesis and respiration by plants, leaf litter fall, consumption and respiration by herbivores and microbes). You will measure these pools and fluxes using standard techniques developed for forests around the world.

You will quantify the size of the carbon pools, by measuring the size and estimating the biomass of the trees and plants, and by measuring the organic carbon in the soil and roots. You will quantify the carbon fluxes in the system by measuring changes in tree diameter to estimate biomass accumulation, the fall and decay rates of leaf litter, loss of plant material to herbivores and pathogens, consumption of herbivores by predators, carbon dioxide fluxes from the soil, and losses of organic carbon in irrigation water. By identifying the interacting species, and how their populations change over time, you will build up a detailed, dynamic food web and so understand how these different species interact.

Training

The student will attend mandatory courses of direct relevance to the project, on spatial data management (GIS) and analysis (R programming) and earth system modelling. The student will spend a week working with former colleagues of Dan Bebber at Wytham Woods, Oxfordshire, where a detailed forest carbon cycle monitoring programme has been in place since 2007. In addition, the student will receive training on molecular species identification for fungal pathogens and decomposer organisms (e.g. ITS sequencing).