Characterising historic ecological conditions in lowland rivers : applying palaeoecological techniques to river restoration planning

摘要: It is widely recognized that anthropogenic activities have resulted in significant changes to the ecology and hydromorphology of riverine ecosystems globally. Across much lowland England a number habitats flora fauna inhabiting them, been lost or disadvantaged by historic channel modifications. Many most modifications took place decades following World War II, drive increase food security through improved land drainage associated flood management. A better understanding geomorphological, hydrological biodiversity elements compromised required order characterise benefits planned measures restore reinstate form function for EU WFD, Habitats Directive other conservation designations (e.g. SSSI condition assessments). To generate this an environment where natural processes impacted over large spatial scales, innovative palaeoecological approach employed thesis provides window on habitat conditions so contemporary community it can be gauged prior implementation river restoration programmes. The analysis archival material (maps, photographs, local authority management records), detailed investigation sedimentary records sub-fossil insect remains (Trichoptera, Coleoptera Gastropoda) with in-channel bars, weirs, bridges palaeochannels used achieve this. These will provide data regarding aquatic macroinvertebrate instream within specific reaches/biotopes/habitats subjected historical physical modification. (documents palaeoenvironmental data) analysed parallel faunal composition define benchmark three Site Special Scientific Interest rivers. This enables comparison between past present communities. characterisation benchmarks baseline future policies help pre-impacted reference conditions. research presented has relevance objectives rivers special Directive) wildlife meeting wider requirements Water Framework Directive.