New approaches to the restoration of shallow marginal peatlands

ArticleGlobally, the historic and recent exploitation of peatlands through management practices such as agricultural reclamation, peat harvesting or forestry, have caused extensive damage to these ecosystems. Their value is now increasingly recognised, and restoration and rehabilitation programmes are underway to improve some of the ecosystem services provided by peatlands: blocking drainage ditches in deep peat has been shown to improve the storage of water, decrease carbon losses in the long-term, and improve biodiversity. However, whilst the restoration process has benefitted from experience and technical advice gained from restoration of deep peatlands, shallow peatlands have received less attention in the literature, despite being extensive in both uplands and lowlands. Using the experience gained from the restoration of the shallow peatlands of Exmoor National Park (UK), and two test catchments in particular, this paper provides technical guidance which can be applied to the restoration of other shallow peatlands worldwide. Experience showed that integrating knowledge of the historical environment at the planning stage of restoration was essential, as it enabled the effective mitigation of any threat to archaeological features and sites. The use of bales, commonly employed in other upland ecosystems, was found to be problematic. Instead, ‘leaky dams’ or wood and peat combination dams were used, which are both more efficient at reducing and diverting the flow, and longer lasting than bale dams. Finally, an average restoration cost (£306 ha-1) for Exmoor, below the median national value across the whole of the UK, demonstrates the cost-effectiveness of these techniques. However, local differences in peat depth and ditch characteristics (i.e. length, depth and width) between sites affect both the feasibility and the cost of restoration. Overall, the restoration of shallow peatlands is shown to be technically viable; this paper provides a template for such process over analogous landscapes.South West WaterUniversity of ExeterTechnology Strategy BoardNERCKnowledge Transfer Partnership programm

Heather burning in peatland environments : effects on soil organic matter and peat accumulation

The Uplands are very distinctive environments for their habitats, wildlife, land use, and management history. They mostly support heather communities and organic soils; their functioning is intrinsically linked to management practices (heather burning, draining and grazing). Recent habitat losses in the uplands have shown a need for their protection. This study focuses on the consequences of heather burning on peat soil characteristics in the Pennines. Two areas of research were investigated: (1) the modifications of the organic matter characteristics and input of black carbon (BC) to soil as a result of heather burning, and (2) the potential alteration of the soil accumulation rate due to fire regimes. The use of 13C NMR spectroscopy of soil organic matter has shown none of the structural changes usually observed for vegetation and soil affected by fire (e.g. increase of aromatic C), possibly indicating insufficient number of successive fires for changes to be noticeable. Instead, the changes were related to the degree of soil decomposition. A laboratory controlled burning experiment estimated low charcoal production from heather «1% vegetation biomass), representing a potentially low input of aromatic C and BC in soils. BC analyses of soil samples did not show any direct increase of BC content in soil either immediately after the fire, or at longer fire rotations (i.e. every 10 and 20 years). Rather, the BC content in soils is thought to originate from fossil fuel combustion. Dating techniques e1oPb), chronological indicators (total Pb, stable isotopes), and their comparison with external references to assess the soil accumulation rate indicate possible overestimations of the values. In this particular context, the validity of the 210Pb technique is questioned. The alteration of the signal in soils could be due to a volatilisation and redeposition of 210Pb during the fire. This needs further investigation.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Using airborne thermal imaging data to measure near-surface hydrology in upland ecosystems

This is the accepted version of the following article: Luscombe D. J., Anderson K., Gatis N., Grand-Clement E., and Brazier R. E. (2015), Using airborne thermal imaging data to measure near-surface hydrology in upland ecosystems, Hydrol. Process., 29; pages 1656–1668, which has been published in final form at http://dx.doi.org/10.1002/hyp.10285Upland ecosystems are recognized for their importance in providing valuable ecosystem services including water storage, water supply and flood attenuation alongside carbon storage and biodiversity. The UK contains 10-15% of the global resource of upland blanket peatlands, the hydrology and ecology of which are highly sensitive to external anthropogenic and climatic forcing. In particular, drainage of these landscapes for agricultural intensification and peat extraction has resulted in often unquantified damage to the peatland hydrology, and little is understood about the spatially distributed impacts of these practices on near-surface wetness. This paper develops new techniques to extract spatial data describing the near-surface wetness and hydrological behaviour of drained blanket peatlands using airborne thermal imaging data and airborne Light Detection and Ranging (LiDAR) data. The relative thermal emissivity (E{open}r) of the ground surface is mapped and used as a proxy for near-surface wetness. The results show how moorland drainage and land surface structure have an impact on airborne measurements of thermal emissivity. Specifically, we show that information on land surface structure derived from LiDAR can help normalize signals in thermal emissivity data to improve description of hydrological condition across a test catchment in Exmoor, UK. An in situ field hydrological survey was used to validate these findings. We discuss how such data could be used to describe the spatially distributed nature of near-surface water resources, to optimize catchment management schemes and to deliver improved understanding of the drivers of hydrological change in analogous ecosystems.South West Water Ltd.University of Exete

Project planning practices based on ERP projects in SMEs

Journal ArticleResearch Support, Non-U.S. Gov't© 2014 Published by Elsevier B.V.This is the author's version of a work accepted for publication by Elsevier. A definitive version was published in Science of The Total Environment Volume 493, 15 September 2014, Pages 961–973. doi:10.1016/j.scitotenv.2014.06.091Losses of dissolved organic carbon (DOC) from drained peatlands are of concern, due to the effects this has on the delivery of ecosystem services, and especially on the long-term store of carbon and the provision of drinking water. Most studies have looked at the effect of drainage in deep peat; comparatively, little is known about the behaviour of shallow, climatically marginal peatlands. This study examines water quality (DOC, Abs(400), pH, E4/E6 and C/C) during rainfall events from such environments in the south west UK, in order to both quantify DOC losses, and understand their potential for restoration. Water samples were taken over a 19 month period from a range of drains within two different experimental catchments in Exmoor National Park; data were analysed on an event basis. DOC concentrations ranging between 4 and 21 mg L(-1) are substantially lower than measurements in deep peat, but remain problematic for the water treatment process. Dryness plays a critical role in controlling DOC concentrations and water quality, as observed through spatial and seasonal differences. Long-term changes in depth to water table (30 days before the event) are likely to impact on DOC production, whereas discharge becomes the main control over DOC transport at the time scale of the rainfall/runoff event. The role of temperature during events is attributed to an increase in the diffusion of DOC, and therefore its transport. Humification ratios (E4/E6) consistently below 5 indicate a predominance of complex humic acids, but increased decomposition during warmer summer months leads to a comparatively higher losses of fulvic acids. This work represents a significant contribution to the scientific understanding of the behaviour and functioning of shallow damaged peatlands in climatically marginal locations. The findings also provide a sound baseline knowledge to support research into the effects of landscape restoration in the future

Continental-scale measurement of the soil organic carbon pool with climatic, edaphic, and biotic controls

We present data on soil organic carbon (SOC) inventory for 7050 soil cores collected from a wide range of environmental conditions throughout Australia. The data set is stratified over the spatial distribution of trees and grass to account for variability of SOC inventory with vegetation distribution. We model controls on SOC inventory using an index of water availability and mean annual temperature to represent the climatic control on the rate of C input into the SOC pool and decomposition of SOC, in addition to the fraction of soil particles <63 μm in diameter as a measure of textural control on SOC stabilization. SOC inventories in the top 30 cm of soil increase from 35 mg/cm2 in the driest regions to a modeled plateau with respect to a threshold of water availability at 335 mg/cm2, excluding variables controlling SOC decomposition. Above this threshold, decomposition factors begin to control SOC inventory, which we attribute to energetic control on microbial decomposition rates, and relatively weak stabilization of SOC in association with fine particles. When combined, these relationships provide an overall prediction of SOC inventory that accounts for 89–90% of the variance observed in the measured data set. Deviations from this relationship are most likely due to additional factors that also control decomposition rate such as hydrochemical and soil drainage conditions not accounted for by soil texture. Outliers within this data set are explained with respect to these conditions