Extensive Schweinefreilandhaltung und ihre Auswirkung auf tierische Lebensgemeinschaften am Beispiel der Laufkäfer (Coleoptera: Carabidae)

In den Jahren 2000-2002 wurden auf 4 neu etablierten, extensiv genutzten Schweineweiden sowie auf angrenzenden Referenzflächen (Brachen, konventionelles Grünland) die Laufkäferzönosen erfasst. Die Standorte im Weserbergland, in der brandenburgischen Elbaue und auf der Schwäbischen Alb bildeten ein m...

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Bibliographic Details
Main Author: Hill, Benjamin T.
Contributors: Beck, Lothar (Prof. Dr.) (Thesis advisor)
Format: Dissertation
Language:German
Published: Philipps-Universität Marburg 2012
Biologie
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Table of Contents: Between 2000-2002 the ground beetle communities on 4 especially created low-intensity pig-pastures, adjacent fallows and conventionally used grasslands were analysed. The study sites in the Weserbergland, the Elbe floodplain and the Swabian Alb were selected for their environmental variability in order to examine the possible use of pig-grazing as a conservation management tool. Carabid beetles were collected with different types of pitfall-traps. Also, different structural parameters were assessed (e.g. extent of open soil, litter layer, vegetation structure). Apart from the development of species communities in space and time, I analysed the response of several functional traits as well as the development of wings in dimorphic species between land-use type. In total, 34.248 ground beetles of 155 species were collected. The highest species richness and beetle diversity occured on the pig-pastures. In general, the proportion of xero- and thermophilic ground beetles increased on the pig-pastures, whereas on the fallows hygrophilic and eurytopic species exhibited a higher activity density. Low-intensity pig-grazing increases the structural diversity of the studied grasslands. The amount of bare soil increases, while vegetation height and litter layer decrease, The importance of pig rooting behaviour for ground beetle diversity can be determined from the correlation between bare soil and species richness as well as species turnover. The multivariate analysis shows that the heterogeneity of the study sites overlies the differences of the land-use types. For each separate site the most important parameters for the development of the carabid communities are the proportion of bare soil and succession. Specific functional traits respond to the changes in land-use, although the difference of the study sites overlies this effect. Albeit it becomes apparent that on the fallow sites very small, nocturnal, non-pubescent and lightly coloured carabids have higher activity densities. The proportion of brachypterous beetles, which are considered to correlate with environmental stability, increased of the fallow sites. Species with a genetic disposition for wing polymorphism, exhibiting individuals with long and short wings, showed higher activity density on the more dynamic pig-pastures. This was in line with the study hypothesis. Practically all ground beetles present in the regional species pool are able to colonise the pig-pastures. Moreover, the pastures provide specific habitat patches (e.g. wet bare soil) which are normally absent from agricultural grasslands and therefore lead to an increase of regional diversity. From a conservation viewpoint it can be noted that pig-grazing leads to the highest amount of endangered carabid beetles. During the course of the research project the number of species listed in the red data book increased only here. The study shows that low-intensity pig-grazing as a dynamic land-use type has high potential as a conservation management tool. It helps to establish habitat structures otherwise lacking on the regional scale. This is beneficial to other taxa (e.g. grassland birds, arable weeds) as well as providing specific landscape qualities (e.g. premium food production, animal welfare, recreation). This land-use can therefore be considered a positive example of multifunctional agriculture. The possibilities for establishing pig-pastures, management details and the importance of landscape structure for agro-biodiversity are discussed. Finally, the legal implications of animal hygiene, which are important for the socio-economics of outdoor pig-keeping as well as the future of the EU Common Agricultural Policy (CAP) are mentioned.