The largest uncertainty in the future trajectory of peatlands in the UK and the policy surrounding their management has to be that of Climate change and its potential impact on their form and processes. Although management currently stems around encouraging rehabilitation of natural surfaces to increase biodiversity and carbon sequestration as seen in the EU habitat directive 7110, the implications of climate change may force changes in peatlands and therefore the management priorities surrounding them.
The work conducted by Harriet Orr and colleagues at the Environment Agency Climate change research group has aimed to answer the questions below:
· What are the climate and hydrogeographic conditions which determine where peat exists now and where it will be found in the future?
· Will peat still form in the uplands in 2100?
(Holden 2009)
The group have gone about answering these by employing “Bioclimatic envelope models” which relate the distribution of Upland blanket peat to environmental variables such as temperature and precipitation. This allows them to assess the vulnerability of peatland surfaces within the UK to future climate predictions. The UKCIP (a great online resource by the way: http://www.ukcip.org.uk/ ) have produced predictions of future climate based for low, medium and high emission scenarios for 2020, 2050 and 2080. Employing these data within the model, a listing of the “most” down to the “least” vulnerable peatlands was produced for the regions of the UK.
Figure 1: A vulnerability assessment of UK peatland ranked from “most” to “least”.
(Sourced from: Environment Agency Climate Change Science Programme and the NERC QUEST joint working group meeting on: Climate change and uplands: science to inform adaptation November 2007, Bristol
As we can see the vulnerability varies across all the Nations of the UK however, the Highlands which constitute the largest single resource are predicted to be the least vulnerable, with other large agglomerations in Scotland such as the Grampians, Western Isles, Argyle, Bute and Trossachs also facing relatively lower vulnerability.
Large resource areas such as Northumbria, Peak District and the Central Belt are however, vulnerable. This is particularly poignant as these regions are bordered by densely populated regions and therefore influence relatively important drainage catchments as previously discussed. They also provide key regions of biodiversity and thus a drying will most probably translate to a shift in ecosystem composition from individual species and loss of essential habitat in for the regions biodiversity (Weltzein et al. 2003).
This is noted by the conservation agencies responsible for these sites. The Peak District National Park Authority (2012) identify the issue of increased fire risk on the upland peatland in relation to climate change as well as a potential increase in the erosion of peat.
Blanket bog already exists within its climatic limit within the Peak District and thus a change could prove fatal to the species assemblages present as re introduction and conservation schemes could not sustainably maintain the vegetation assemblages. This may serve to; along with a reduction or even halt to peat production, to change the management policies
The findings of this study and other models that suggest that the role of blanket peatlands in carbon sequestration will decrease, suggest perhaps a change in policies that are currently shaping the management of UK peatlands. The current focus on managing bodies on regeneration efforts within regions of greatest vulnerability may prove to be a misuse of resources as changes to climate may exceed the environmental limits of the current species composition (Holden 2009).
In conclusion, climate is changing and will alter peatlands within the next century. The net result of the change in climate inputs is still uncertain however, modelling can provide a means to focus management schemes as different peatlands across the UK are vulnerable to climate by differing factors. The focus of management schemes may have to alter within the next century as the impacts of climate change become apparent.
Yours
Matt
References:
Peak District National Park Authority., 2012. Blanket Bog.[pdf] Derbyshire: Peak District National Park Authority Available at:
[Accessed 19 November 2012].
Holden, J., 2009. A grip-blocking overview.[pdf] Edale:Moors for the Future Partnership.
Available at: http://www.moorsforthefuture.org.uk/sites/default/files/Holden%20(2009)%20grip%20block%20review.pdf [Accessed 19 November 2012].
Weltzin, J.F., Bridgham, S.D, Pastor, J., Chen, J. and Harth, C. 2003. Potential effects of warming and drying on peatland plant community composition. Global Change Biology 9, 141-151
No comments:
Post a Comment