Managing Upland Heath for Carbon Sequestration
Managing upland heath for carbon sequestration
Supervisors
Dr Sarah Woodin, Universityof Aberdeen (01224 272688)
,
Dr Rebekka Artz, Macaulay Land Use Research Institute, Aberdeen,
,
Dr Sarah Crowe, University of the Highlands & Islands, Thurso,
,
Dr Andrew Coupar, Scottish Natural Heritage, Inverness
,
Background
The Millennium Ecosystem Assessment and Stern Report haveincreased awareness of the contribution that land managers can make to mitigating greenhouse gas emissions, through strengthening carbon sinks and implementing management that will help enhance carbon storage. The challenge is to apply this principle to the management of land for nature conservation, which is currently governed by the EU Habitats Directive requirement to “maintain or restore, at favourable conservation status, natural habitats and species of wild fauna and flora of Community interest”. Favourable condition of sites is defined in relation to the character of the habitat itself and does not include the wider issue of the functional integrity of the system necessary for the effective provision of ecosystem services, including carbon sequestration, which we must now take into consideration. We have an excellent base of knowledge and experience for the conservation of species and habitats. We do not have the same basis for informed management of habitats to promote carbon sequestration. This project will provide fundamental understanding which is essential as we move forward to a scenario in which habitat management objectives are as much based on ecosystem services as on biodiversity.
The amount of carbon stored in UK peatlands has been estimated to be equivalent to at least three years of the UK’s total greenhouse gas emissions. The management of habitats with highly organic soil will influence whether they add to this carbon store, or release the stored carbon, with major implications for the national carbon budget. This project will investigate how management of one such habitat, upland heath, influences its carbon dynamics.
UK upland heaths encompass a range of Annex 1 habitats for which there is statutory obligation to achieve favourable conservation status. Upland Heath is also a UK Biodiversity Action Plan habitat with an Action Plan that aims to restore and recreate heath with at least 25% dwarf shrub cover. There are many upland sites in Britain where attempts are being made to restore heather dominance on what has become a grass dominated sward. This involves either the removal/reduction of grazing or more interventionist approaches typically including herbicide application and/or seeding. We have previously undertaken a study of the success of such projects in restoring the character and diversity of upland heath vegetation and phytophagous invertebrate communities (Littlewood et al2008). This project will use a new benchmark for assessing the success of habitat restoration, investigating the carbon sequestration potentials of intact, degraded, and restored heaths to inform future developments in upland land management policy and practice.
Specific objectives
(i)To compare the carbon sequestration potential of upland heath in “favourable condition” with that of degraded, grass dominated communities.
(ii)To investigate the effect of heathland restoration, by various methods, on carbon sequestration potential of the habitat.
(iii)To inform conservation management planning on the relative carbon sequestration potential of different upland heath vegetation “states”, and thus of the management practices which underpin them.
(iv)By elucidating the relative carbon sequestration potential of different functional groups within the vegetation, to enable conservation staff to predict the “carbon outcome” of management practices with well known effects on vegetation composition (eg burning, grazing).
Scientific approach
A set of upland heath sites will be selected at which comparisons can be made between adjacent areas of “intact” shrub dominated sward, “degraded” grass dominated sward, and restored vegetation. Eight such sites have already been located, ranging between North East Scotland and the English Peak District. With advice from SNH staff more Scottish sites will be added to this set for initial consideration. A subset of 4-6 sites most ideally suited to this project (based on SNH preference, logistics and site characteristics) will then be selected for intensive measurement of carbon dynamics (i & ii below), a wider range of sites will be used for assessment of carbon stocks (iii below). To ensure wide applicability of the results, examples of both wet and dry heath will be included in the study.
Current vegetation composition will be surveyed and, at sites where the vegetation history is uncertain, past trends in heather and grass abundance will be investigated by macrofossil analysis. All sites studied are likely to have been subject to burning, and we will quantify this by charcoal analysis of soil cores so that a relative index of burning can be included in data analysis, thus enabling us to detect correlative relationships between burning history and carbon dynamics.
To compare the intact, degraded and restored systems, carbon dynamics and pools will be measured on three different timescales:
(i) Instantaneous flux
Net ecosystem photosynthesis and gross ecosystem respiration will be measured using field gas exchange equipment available at the University of Aberdeen. Six independent gas flux measurement units enable simultaneous measurement at six different places, which is ideal for comparing adjacent vegetation types within a site. Measurements will be made in different seasons. This will provide an indication of current CO2 flux status.
(ii) Seasonal/annual sequestration
The retention of assimilated carbon in the different plant and soil components of the ecosystem over the growing season and the subsequent winter will be assessed by 13CO2 incubation of the intact vegetation in the field at peak productivity in early summer, and 13C analysis of plant/soil material harvested 3 and 12 months later. This will demonstrate whether assimilated carbon is being held within the system and, if so, which plant functional types and soil and microbial carbon pools are important for its storage.
(iii) Long term carbon stocks
Plant and soil material will be sampled with appropriate replication, and analysed for % C, to determine the stocks of carbon held within the system.
The PhD student will keep abreast with the literature on this subject and network to ensure familiarity with related work which is ongoing but not yet published.
Training opportunities and logistics
Working with all the supervisory organisations, the student will gain both technical skills and experience of conservation policy development and application, in a subject that is crucial to the future of the global environment. The student will be based primarily in Aberdeen, joining a vibrant community of postgraduate students who work jointly at the University and MLURI. Training will be provided by both institutions in all the specialist technical methodologies required and also in generic skills including project planning, statistics, experimental design and communication. Fieldwork will be carried out at upland locations in northern Britain and training in field botanical skills and macrofossil analysis will be provided by the UHI supervisor. The opportunity to carry out this research in collaboration with SNH will ensure that the student has an excellent grasp of the conservation context and applications of his/her research, and can thus develop into either a researcher who is well able to target their research to meet natural heritage stakeholder needs, or a conservation professional who is well able to interpret and apply ecosystem science to the future development of conservation management policy. The student will be expected to communicate their research in a wide range of formats, from information notes to land managers, through presentations to both conservation and scientific audiences, to peer reviewed publications.
Applications
This studentship is available to UK and EU students only.
Potential applicants are welcome to contact the supervisors informally if you wish to discuss the project or have further questions.
Applicants should complete a CV and covering letter, along with the University Postgraduate Application form which should be downloaded from . These should be submitted to Sandra Skilling () and be copied to Sarah Woodin ().
Applications should be made as soon as possible. There is no formal closing date, the studentship will remain open until a suitable candidate is appointed. Start date 1 Oct 08.