Sebastian Klimek

Developing result-orientated payment schemes for environmental services in grasslands: Results from two case studies in North-western Germany

Abstract Semi-natural habitats resulting from a long history of traditional low-intensity farming systems have undergone a dramatic decline in both quantity and quality in Europe over the last decades. There is evidence that semi-natural habitats including grasslands play an important role in providing goods and services that are of high value to human society. Preserving species diversity in these agricultural habitats and the services it provides requires compensation payments to farmers through agri-environmental subsidies. Since 1992, Agri-Environmental Schemes (AES) are important components of the second pillar of the Common Agricultural Policy (CAP). In this context, result-orientated payments are a relatively novel approach aiming to provide incentives to conserve semi-natural grasslands. In contrast to action-orientated payments, the subsidy amount is directly linked to the ecological result. Here, we first introduce AES that employ result-orientated payment schemes to conserve agricultural biodiversity. We present results from two case studies in North-western Germany that use vascular plants as indicators for high-value grasslands within a result-orientated payment scheme. The sets of indicators used were defined independently for both case studies, but were generally suitable to identify species-rich grassland communities and proved to be explicable to farmers. Second, we introduce a result-orientated payment scheme that further integrates market mechanisms. In order to improve the cost-effectiveness of AES, a regional market for biodiversity is established by means of an auction-based payment scheme.

Hydrochemistry, water table depth and related distribution patterns of vascular plants in a mixed mire

Abstract The hydrological and floristic variation within a mire vegetation is mostly controlled by three ecological gradients: nutrient availability, acidity – alkalinity, and water table depth. The objectives of this study were: (a) to analyse the hydrochemistry of a mixed mire in relation to different habitat conditions; (b) to evaluate the patterns of vascular plant composition in relation to nutrient availability, acidity – alkainity, and water table depth, and to partition the pure effects of these gradients. Within a mixed mire, we sampled 36 smalling a growing season. Water chemistry proved to be significantly different between the various vegetation types. Two biological systems could be identified according to hydrochemistry and vascular plant composition: (1) several fen vegetation types lacking raised Sphagnum structures where the water chemistry reflected groundwater properties; (2) bog Sphagnum-dominated vegetation, where the convex shape of the mire surface prevented mixing with the groundwater. The results of the partitioning indicated that the acidity – alkalinity gradient was more important in controlling the patterns of plant distribution than water table depth.

Using selective herbicides to manage beneficial and rare weed species in winter wheat

Weed species within arable farming systems act as a source of food and provide habitat for various taxa at higher trophic levels. Using field experiments in winter wheat, we investigated whether selective herbicides can be used as a potential tool for sustaining beneficial, less competitive weed species and rare species of high conservation value while controlling highly competitive weed species. We tested three selective herbicides with different active ingredients (amidosulfuron + iodosulfuron, fluroxypyr, mecoprop-P) at two application rates. We analysed cover of selected focal species (Centaurea cyanus and Papaver rhoeas) as well as weed species richness, winter wheat yield and weed community composition as influenced by herbicide treatments. Herbicide treatments involving fluroxypyr generally allowed for the selective retention of the regionally threatened weed species C. cyanus and P. rhoeas as a beneficial species of high value for associated trophic level and provided considerable control of the competitive species G. aparine. Herbicide treatments significantly affected weed species composition. The PRC method clearly showed the time-dependent herbicide treatment effects on weed community composition and allowed an estimate of the variance in species composition that is explained by the herbicide treatments. Our results indicated that applying selective herbicides can provide a feasible option for in-crop management of weed diversity by retention of beneficial or rare weed species occurring at moderate densities and control of highly-competitive weeds. However, weed control strategies must be tailored to site-specific conditions to account for increased abundance of competitive species.ZusammenfassungUnkräuter können Ressource und Habitat für nützliche Arten höherer trophischer Ebenen bereitstellen. Anhand von Feldversuchen in Winterweizen wurde der Einsatz selektiver Herbizide zur Förderung nützlicher, weniger konkurrenzstarker und seltener Unkrautarten bei gleichzeitiger Kontrolle von konkurrenzstarken Unkrautarten untersucht. Es wurden drei selektive Herbizide (Amidosulfuron + Iodosulfuron, Fluroxypyr, Mecoprop-P) anhand von zwei Aufwandmengen getestet. Dabei wurden der Deckungsgrad der untersuchten Arten (Centaurea cyanus und Papaver rhoeas), die Gesamtartenzahl, der Winterweizenertrag sowie die Zusammensetzung der Unkrautpopulation analysiert. Die Applikation von Fluroxypyr erwies sich als geeignet für sowohl die Erhaltung der regional bedrohten Art C. cyanus und der Art P. rhoeas, die eine hohe Bedeutung für höhere trophischen Ebenen aufweist, als auch für die Bekämpfung der konkurrenzstarken Art G. aparine. Die Herbizidbehandlungen hatten einen signifikanten Einfluss auf die Zusammensetzung der Unkrautpopulationen. Die multivariate Principal Response Curve (PRC) Methode veranschaulichte die Auswirkungen der Herbizidbehandlungen auf die Populationszusammensetzung in Abhängigkeit von der Versuchslaufzeit und ermöglichte zudem eine Abschätzung der durch die Herbizidbehandlungen erklärten Varianz. Die Ergebnisse zeigen, dass selektive Herbizide eingesetzt werden können, um seltene oder nützliche Unkrautarten zu erhalten und konkurrenzstarke Arten zu bekämpfen. Allerdings sollte die jeweilige Behandlung situationsspezifisch an die vorhandenen Unkrautarten angepasst werden um ein erhöhtes Aufkommen von konkurrenzstarken Arten zu vermeiden.