Beetle diversity of chalk river floodplains

Anthropogenic land use changes have increasingly altered and fragmented floodplain landscapes. While the impacts of these alterations are being recognised for many plant and vertebrate taxa, limited information is available for highly diverse invertebrate families. Using a variety of approaches to diversity measurement, this thesis investigates carabid and staphylinid beetle assemblages across a range of chalk floodplain habitats in Norfolk, England. It aims to establish the roles anthropogenic and environmental factors play in shaping their communities in order to inform tailored conservation practices. Site management was identified as the dominant influence on beetle assemblages, underpinning the development of distinct communities amongst floodplain meadow, fen and woodland habitats. Surrounding landscape configuration also influenced beetle assemblages, confirming the wide-ranging, multi-faceted impacts of anthropogenic land use changes. Beetle communities in floodplain woodlands were both specimen- and species-rich across the highly heterogeneous forest microhabitats hosted within. Functional diversity analysis highlighted the vulnerability of certain functional groups to management and fragmentation. It confirmed the importance of conserving remaining remnants of natural floodplain woodlands to support vulnerable beetle communities. Floodplain fens harboured rare species, while their overall beetle diversity was surprisingly low. This was attributed to their limited habitat extent, fragmented distribution, and potentially legacies of past land use. This thesis suggests that traditional management regimes must be maintained in fen habitats, and their connectivity promoted, to safeguard and restore the unique biological communities supported within. Anthropogenic land use changes have increasingly altered and fragmented floodplain landscapes. While the impacts of these alterations are being recognised for many plant and vertebrate taxa, limited information is available for highly diverse invertebrate families. Using a variety of approaches to diversity measurement, this thesis investigates carabid and staphylinid beetle assemblages across a range of chalk floodplain habitats in Norfolk, England. It aims to establish the roles anthropogenic and environmental factors play in shaping their communities in order to inform tailored conservation practices. Site management was identified as the dominant influence on beetle assemblages, underpinning the development of distinct communities amongst floodplain meadow, fen and woodland habitats. Surrounding landscape configuration also influenced beetle assemblages, confirming the wide-ranging, multi-faceted impacts of anthropogenic land use changes. Beetle communities in floodplain woodlands were both specimen- and species-rich across the highly heterogeneous forest microhabitats hosted within. Functional diversity analysis highlighted the vulnerability of certain functional groups to management and fragmentation. It confirmed the importance of conserving remaining remnants of natural floodplain woodlands to support vulnerable beetle communities. Floodplain fens harboured rare species, while their overall beetle diversity was surprisingly low. This was attributed to their limited habitat extent, fragmented distribution, and potentially legacies of past land use. This thesis suggests that traditional management regimes must be maintained in fen habitats, and their connectivity promoted, to safeguard and restore the unique biological communities supported within. This study highlights the importance of adopting habitat-specific conservation objectives to ensure the persistence of specialist species, whilst maintaining a matrix of different floodplain habitats to preserve wider catchment diversity. As anthropogenic impacts on floodplain environments will continue, the potential role of beetles in biodiversity research and conservation, and in particular of staphylinid beetles that dominate the floodplain ground fauna, warrants increasing interest and recognition.