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into processes that may be operating nationally. It will now be necessary to test for the ubiquity of 52 these changes using appropriate broader spatial scale survey data. 53

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The Millennium Ecosystem Assessment (MA 2003) framework was applied to provide a holistic assessment and comparison of ecosystem services delivery from 11 environmental change network (ECN) sites, following a workshop of ECN site managers. A list of common variables was agreed to represent the high level categories defined by the MA. The resultant 73 variables, either direct ecosystem services or proxies, were divided into two subsets (readily accessible biogeographical data from all sites and additional site specific data). Similarity analysis of the biogeographical data indicated four site clusters: land with at least 50% forest cover, productive livestock farmland, uplands and a lowland grass/arable group. The first three clusters were also evident for both the additional data and for the larger combined dataset. The lowland grass/arable sites were a 'mixed use' cluster that was not apparent in the analysis of the additional or combined datasets indicating a mismatch between particular ecosystem services and specific landscapes/habitats. Procrustes analysis of the biogeographical data and the combined dataset suggested that the primary differences between datasets were due to variables associated with local management decisions which prevented harvesting of provisioning services or denied public access to the site. Drawing on comparable data from some of the most intensively researched and monitored ecosystems in the UK, this study demonstrates the challenges and limitations involved in attempting holistic assessments of ecosystem services at the site and inter-site level and highlights the importance of both local expert knowledge and consistent scientific measurement in contributing to the process.

Oxygen demand in river substrates providing important habitats for the early life stages of aquatic ecology, including lithophilous fish, can arise due to the oxidation of sediment‐associated organic matter. Oxygen depletion associated with this component of river biogeochemical cycling, will, in part, depend on the sources of such material. A reconnaissance survey was therefore undertaken to assess the relative contributions from bed sediment‐associated organic matter sources potentially impacting on the River Axe Special Area of Conservation (SAC), in SW England. Source fingerprinting, including Monte Carlo uncertainty analysis, suggested that the relative frequency‐weighted average median source contributions ranged between 19% (uncertainty range 0–82%) and 64% (uncertainty range 0–99%) for farmyard manures or slurries, 4% (uncertainty range 0–49%) and 35% (uncertainty range 0–100%) for damaged road verges, 2% (uncertainty range 0–100%) and 68% (uncertainty range 0–100%) for decaying instream vegetation, and 2% (full uncertainty range 0–15%) and 6% (uncertainty range 0–48%) for human septic waste. A reconnaissance survey of sediment oxygen demand (SOD) along the channel designated as a SAC yielded a mean SOD5 of 4 mg O2 g−1 dry sediment and a corresponding SOD20 of 7 mg O2 g−1 dry sediment, compared with respective ranges of 1–15 and 2–30 mg O2 g−1 dry sediment, measured by the authors for a range of river types across the UK. The findings of the reconnaissance survey were used in an agency (SW region) catchment appraisal exercise for informing targeted management to help protect the SAC.