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81.
82.
Ulrike Hirt Judith Mahnkopf Mathias Gadegast Lukas Czudowski Ute Mischke Claudia Heidecke Gerald Schernewski Markus Venohr 《Regional Environmental Change》2014,14(3):1123-1138
We introduce an approach for establishing reference conditions (RC) for rivers of the German Baltic Sea catchment, based on predictive modelling. An extensive data set of statistics from the year 1880 was coupled with literature data, providing a comprehensive basis for the calculation of regional historical nutrient emissions into rivers, river nutrient concentrations, and nutrient loading into the sea. Four different scenarios were calculated: scenario 1 assumed RC following previously established criteria for lakes (Poikane et al. in Environ Manag 45(6):1286–1298, 2010), scenario 4 applied the nutrient emission conditions of 1880 (considering non-intensive land usage, the presence of tile drainage systems, sewer systems, and the human population from 1880), and scenarios 2 and 3 considered intermediate conditions. Our results showed that nutrient emissions from scenario 1 accounted for approximately one-tenth of the currently observed total nitrogen (TN) and total phosphorus (TP) emissions. The nutrient emissions calculated for 1880 (scenario 4) were found to be 47 % (TN) and 55 % (TP) higher than those calculated considering reference lake conditions (scenario 1). Our results suggest that RC nutrient concentrations in rivers in the German Baltic Sea catchment were clearly below 0.05 mg/l for TP and 1 mg/l for TN. This range is in accordance with historical and calculated pristine nutrient concentrations from other rivers in similar catchments. 相似文献
83.
P��n��lope Lamarque Ulrike Tappeiner Catherine Turner Melanie Steinbacher Richard D. Bardgett Ute Szukics Markus Schermer Sandra Lavorel 《Regional Environmental Change》2011,11(4):791-804
The concept of ecosystem services is increasingly being used by scientists and policy makers. However, most studies in this area have focussed on factors that regulate ecosystem functions (i.e. the potential to deliver ecosystem services) or the supply of ecosystem services. In contrast, demand for ecosystem services (i.e. the needs of beneficiaries) or understanding of the concept and the relative ranking of different ecosystem services by beneficiaries has received limited attention. The aim of this study was to identify in three European mountain regions the ecosystem services of grassland that different stakeholders identify (which ecosystem services for whom), the relative rankings of these ecosystem services, and how stakeholders perceive the provision of these ecosystem services to be related to agricultural activities. We found differences: (1) between farmers?? perceptions of ecosystem services across regions and (2) within regions, between knowledge of ecosystem services gained by regional experts through education and farmers?? local field-based knowledge. Nevertheless, we identified a common set of ecosystem services that were considered important by stakeholders across the three regions, including soil stability, water quantity and quality, forage quality, conservation of botanical diversity, aesthetics and recreation (for regional experts), and forage quantity and aesthetic (for local farmers). We observed two contrasting stakeholder representations of the effects of agricultural management on ecosystem services delivery, one negative and the other positive (considering low to medium management intensity). These representations were determined by stakeholders?? perceptions of the relationships between soil fertility and biodiversity. Overall, differences in perceptions highlighted in this study show that practitioners, policy makers and researchers should be more explicit in their uses of the ecosystem services concept in order to be correctly understood and to foster improved communication among stakeholders. 相似文献