NERC has developed NORA to enable users to access research outputs wholly or partially funded by NERC. Copyright and other rights for material on this site are retained by the rights owners. Users should read the terms and conditions of use of this material at http://nora.nerc.ac.uk/policies.html#access This document is the author's final manuscript version of the journal article, incorporating any revisions agreed during the peer review process. Some differences between this and the publisher's version remain. You are advised to consult the publisher's version if you wish to cite from this article.The definitive version is available at http://onlinelibrary.wiley.com Contact CEH NORA team at noraceh@ceh.ac.ukThe NERC and CEH trademarks and logos ('the Trademarks') are registered trademarks of NERC in the UK and other countries, and may not be used without the prior written consent of the Trademark owner. (Evans et al., 2005). In the water 55 industry, the high cost of DOC removal, and associated health risks through trihalomethane 56 formation (e.g. Chow et al., 2003), result in it being widely viewed as a pollutant. Changes in DOC 57 export to surface waters also affect aquatic energy supply and light regime (due to the 58 chromophoric properties of organic compounds), with potentially major consequences for the 59 functioning of aquatic ecosystems (Cole et al., 2001; Battin et al., 2009;Karlsson et al., 2010). When 60 first detected, DOC increases were thought to be a consequence of climate change (Freeman et al., 61 2001; Hejzlar et al., 2003;Worrall & Burt, 2007; Hongve et al., 2004), and thus evidence of 62 ecosystem destabilisation, contributing to terrestrial carbon losses (Bellamy et al., 2005). Some 63 recent studies also suggest high climate-sensitivity of DOC leaching (e.g. Larssen et al., 2011; Fenner 64 & Freeman, 2011 Oulehle & Hruska, 2009; Chapman et 72 al., 2010; Arvola et al., 2010; Clark et al., 2011; Ekström et al., 2011;SanClements et al., 2012) and 73 challenging (e.g. Roulet & Moore, 2006; Eimers et al., 2008;Worrall et al., 2008; Clair et al., 2008; 74 Sarkkola et al., 2009;Sarkkola et al., 2009;Zhang et al., 2010; Couture et al., 2011; Löfgren and 75 Zetterberg, 2011; Pärn & Mander, 2012) Figure S1b). 167At the Afon Gwy AWMN site, 50 km to the south, DOC has increased by 51% over the same period , pH range 3.9 to 4.4). In addition, the Peak District peat 237 and Migneint podzol sites exhibited some pre-treatment differences in mean DOC concentrations 238 between control and treatment plots ( Figure 1, Table 1). To explore underlying relationships 239 between DOC and pH change, we therefore standardised DOC concentrations by dividing mean DOC 240 for each treatment at each site and sampling interval by the corresponding pre-treatment mean. 241Deviation from this initial level due to treatment was quantified as the ratio of mean standardised habitats showed an increase in mean pH between the two surveys, and these mean values were 296 used to calculate RH std as above,...

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Abstract. Peatlands are large terrestrial stores of carbon, and sustained CO 2 sinks, but over 1 the last century large areas have been drained for agriculture and forestry, potentially 2 converting them into net carbon sources. More recently, some peatlands have been re-wetted 3 by blocking drainage ditches, with the aims of enhancing biodiversity, mitigating flooding 4 and promoting carbon storage. One potential detrimental consequence of peatland re-wetting 5 is an increase in methane (CH 4 ) emissions, offsetting the benefits of increased CO 2 6 sequestration. We examined differences in CH 4 emissions between an area of ditch-drained 7 blanket bog, and an adjacent area where drainage ditches were recently infilled. Results 8 showed that Eriophorum vaginatum colonisation led to a 'hotspot' of CH 4 emissions from the 9 infilled ditches themselves, with smaller increases in CH 4 from other re-wetted areas. 10Extrapolated to the area of blanket bog surrounding the study site, we estimated that CH 4 11 emissions were around 60 kg CH 4 ha -1 yr -1 prior to drainage, reducing to 44 kg CH 4 ha -1 yr

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(300) 1Previous studies have shown a correspondence between the abundance of particular plant 2 species and methane flux. Here we apply multivariate analyses, including a weighted 3 averaging approach, to assess the suitability of vegetation composition as a predictor of 4 methane flux. We developed a functional classification of the vegetation, in terms of a 5 number of plant traits expected to influence methane production and transport, and compared 6 this with a purely taxonomic classification at species-level and higher. We applied both 7 weighted averaging and indirect and direct ordination approaches to six sites in the UK, and 8 found good relationships between methane flux and vegetation composition (classified both 9 taxonomically and functionally). Plant species and functional groups also showed meaningful 10 responses to management and experimental treatments. In addition to the UK, we applied the 11 functional group classification across different geographical regions (Canada and 12 Netherlands) to assess the generality of the method. Again, the relationship appeared good at 13 the site level, suggesting some general applicability of the functional classification. The 14 method seems to have the potential for incorporation into large-scale (national) greenhouse 15 gas accounting programmes (in relation to peatland condition/management) using vegetation 16 mapping schemes. The results presented here strongly suggest that robust predictive models 17 can be derived using plant species data (for use in national-scale studies). For trans-national-18 scale studies, where the taxonomic assemblage of vegetation differs widely between study 19 sites, a functional classification of plant species data provide an appropriate basis for 20 predictive models of methane flux. 21

No abstract

This study describes changes in the trophic status of 12 lakes within Suwałki Landscape Park (SLP). All of the trophic classifications of the lakes were based on the trophic continuum division. Trophic status was determined by means of multiparameter indices using several diverse criteria. In this study, the assessment of the trophic status of lakes included water quality; abundance and biomass of bacterioplankton, phytoplankton, and zooplankton; and primary production of phytoplankton. The Carlson trophic state index (TSI) describes the level of water fertility and indicated the dominance of moderately eutrophic waters. Lakes Perty, Jeglówek, and Hańcza have a trophic status that indicates mesotrophy (TSI <50). The trophic status of the studied lakes was determined based on the bacterial abundance and clearly showed a lack of oligotrophic lakes in SLP. Based on the number of bacteria, only Lake Szurpiły can be classified as β-mesotrophic, whereas Lake Linówek can be characterized as hypertrophic with some features typical for humic waters. The greatest value of gross primary production was observed in Lake Linówek (126.4 mg C/m3/h). The phytoplankton trophy index varied from 1.59 to 2.28, and its highest value, which indicated eutrophy, was determined for Lake Udziejek. In the case of Lakes Hańcza, Szurpiły, Perty, Jeglówek, and Kojle, the index ranged from 1.25 to 1.74, which indicated mesotrophy. The majority of the lakes were classified as mesoeutrophic (1.75–2.24). The highest trophic status was assessed for lakes with a marked dominance of cyanobacteria (Lake Przechodnie, Lake Krajwelek, Lake Udziejek, and Lake Pogorzałek), which is commonly recognized as an indicator of high trophic status. Considering all of the indices of trophic status, the analysis of rotifer community structure indicates that the studied group of lakes is mesoeutrophic or eutrophic. The values of crustacean zooplankton indices indicated that the trophic status of the studied lakes was close to that determined using a TSI. The parameters of zooplankton abundance and species structure allowed for the observance of changes in the tropic levels of lakes, which are difficult to detect by a chemical assay alone.

Summary Dissolved organic carbon (DOC) is an important component of the global carbon (C) cycle and has profound impacts on water chemistry and metabolism in lakes and rivers. Reported increases of DOC concentration in surface waters across Europe and Northern America have been attributed to several drivers, including changing climate, changing land‐use to eutrophication and declining acid deposition. The latter of these suggests that acidic deposition suppressed the solubility of DOC, and that this historic suppression is now being reversed by reducing emissions of acidifying pollutants. We studied a set of four parallel acidification and alkalization experiments in organic matter‐rich soils, which, after three years of manipulation, have shown distinct soil solution DOC responses to acidity change. We tested whether these DOC concentration changes were related to changes in the acid/base properties of DOC. Based on laboratory determination of DOC site density (S.D. = amount of carboxylic groups per milligram DOC) and charge density (C.D. = organic acid anion concentration per milligram DOC) we found that the change in DOC soil–solution partitioning was tightly related to the change in degree of dissociation (α = C.D.:S.D. ratio) of organic acids (R2 = 0.74, P < 0.01). Carbon turnover in soil organic matter (SOM), determined by soil respiration and β‐D‐glucosidase enzyme activity measurements, also appears to have some impact on DOC leaching, via constraints on the actual supply of available DOC from SOM; when the turnover rate of C in SOM is small, the effect of α on DOC leaching is reduced. Thus, differences in the magnitude of DOC changes seen across different environments might be explained by interactions between physicochemical restrictions of DOC soil–solution partitioning and SOM carbon turnover effects on DOC supply.