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Restoration of blanket bog vegetation for biodiversity, carbon storage and water regulation - BD5104

Description
UK peatlands represent large stores of carbon (C). During photosynthesis, peatland plants take up carbon dioxide (CO2) some of which is subsequently respired back to the atmosphere. The remaining C is converted into organic matter which, after the plants die, decays over time releasing the C back into the atmosphere as either CO2 or methane (CH4). Crucially, water logged conditions suppress decay leading to active peat formation as C inputs exceed C losses. In the UK this has been the case during many millennia, contributing to a net cooling effect on the global climate due to reduced atmospheric greenhouse gas (GHG) concentrations. However, the balance of CO2 versus CH4 is important as CH4 is a GHG with a global warming potential about 25 times higher than CO2.
In the UK, many blanket bogs are managed for grazing having been drained for this purpose, often combined with regular burning, which frequently leads to increased dominance of heather (Calluna vulgaris). Over dominance by heather tends to dry the peat further as well as causing underground erosion (peat pipes and suppressing active peat forming plants such as Sphagnum spp. mosses (Lindsay, 2010). Whilst the drains, (called grips) can be blocked to raise the water table and help restore active peat accumulation, there is still a widespread need to reverse the dominance of heather which impedes this process. Wetter conditions also tend to benefit bird populations feeding on soil animals (e.g. crane flies) that rely on wet peatlands. However, certain heather reduction strategies currently in use may have detrimental effects on, for example, peat C stocks and air quality (burning) or water quality (herbicides). Therefore, restoration schemes must also consider these environmental consequences, which are linked to fundamental ecosystem services provided by UK peatlands for many millions of people. Recent studies by Defra (and elsewhere) have highlighted these issues. Importantly, the consequences of changes in management practice are likely to be slow to emerge so that long-term monitoring is needed.
services.
Objective
The overarching aim of this study is to acquire experimental data to underpin the development of possible management techniques, applicable through Environmental Stewardship, to reduce the dominance of heather and facilitate the progression towards an „active‟ blanket bog (with peat-forming species, particularly Sphagnum spp). This requires screening for the most suitable management techniques and then including those restoration techniques as part of a long-term manipulative experiment to provide scientifically sounds data upon which to base policy advice and subsequently decisions. The project will address four main objectives:

1. Review potential techniques to reduce heather cover and restore appropriate „active‟ peatland vegetation on blanket peatlands, and identify practical management options for experimental testing.
2. Field test the identified options and evaluate their effect on:
a) plant species composition, including bryophytes, to indicate likely impact on peat formation,
b) water table and peat fluvial and gaseous carbon fluxes through measurements.
3. Provide a cost-benefit analysis to determine the cost of achieving a range of ecosystem services.
4. Evaluate the impact of treatments on vegetation dynamics, stream flow, water budgets, carbon stocks and fluxes (including GWP) based on measurements and model approaches.
Project Documents
• EVID4 - Final project report : Defra BD5104 Two page summary and publications   (158k)
• FRP - Final Report : Defra BD5104 Final Report   (12459k)
• ANX - Annex : Defra BD5104 Annex A Literature Review   (644k)
• ANX - Annex : Defra BD5104 Annex A.1 Stakeholders Workshop 2013 report   (434k)
• ANX - Annex : Defra BD5104 Appendix 1 Environmental monitoring   (1216k)
• ANX - Annex : Defra BD5104 Appendix 10 Cranefly monitoring and modelling   (1504k)
• ANX - Annex : Defra BD5104 Appendix 11 Bird modelling   (762k)
• ANX - Annex : Defra BD5104 Appendix 12 Heather nutrition   (433k)
• ANX - Annex : Defra BD5104 Appendix 13 Palaeo-ecological assessments on past burn frequencies and peat accumulation   (389k)
• ANX - Annex : Defra BD5104 Appendix 14 Mycorrhizal and charcoal impacts on peat decomposition   (719k)
• ANX - Annex : Defra BD5104 Appendix 15 Peat carbon and hydrological modelling (MILLENNIA model)   (953k)
• ANX - Annex : Defra BD5104 Appendix 2 Peat depth, pipes and carbon stock measurements   (1125k)
• ANX - Annex : Defra BD5104 Appendix 3 Vegetation surveys   (4013k)
• ANX - Annex : Defra BD5104 Appendix 3a Ecological Vegetation Assessment by Richard A Lindsay   (355k)
• ANX - Annex : Defra BD5104 Appendix 4 Hydrological monitoring   (992k)
• ANX - Annex : Defra BD5104 Appendix 5 Water quality assessments   (330k)
• ANX - Annex : Defra BD5104 Appendix 6 Carbon flux measurements and modelling   (584k)
• ANX - Annex : Defra BD5104 Appendix 7 Decomposition rates and peat chemistry   (3365k)
• ANX - Annex : Defra BD5104 Appendix 8 GHG emissions and modelling   (460k)
• ANX - Annex : Defra BD5104 Appendix 9 Micro-topography and peat shrinkage expansion assessments   (296k)
• SUP - Supplementary Report : Defra BD5104_01_Peer Review Synthesis   (847k)
• SUP - Supplementary Report : Defra BD5104_02_Complete peer review exchange_Appendix 16   (1099k)
Time-Scale and Cost
From: 2011

To: 2017

Cost: £979,326
Contractor / Funded Organisations
University of York
Keywords
Agriculture and Water Quality              
Habitats