Browsing by Author "Hovi, Tiina"

Finnish agriculture has faced radical changes since the mid-20th century due to intensification of agricultural production. These changes have resulted into considerable wildlife habitat loss and degradation of biodiversity. Open ditches and their boundaries are one such habitat. They were widely replaces by subsurface drainage. This thesis aims to understand the role open ditches for agricultural biodiversity; what kinds of plants live the ditch habitat and can ditches enhance agrobiodiversity? To answer these questions we surveyed the vegetation of ditch slopes and ditch banks. Both vegetation composition and species richness were studied. The survey concerns only vegetation, but it is assumed that plant species diversity supports diversity of other groups of organisms. The data was collected in summers 2008 and 2009 in Lepsämä river catchment in Southern Finland in co-operation with MYTVAS (Significance of the Finnish agri-environment support scheme for biodiversity and landscape) -project. Ditch habitat characterization was done by studying the most common species and their indicative values in the data. Also NMS-ordination graph was created. Environmental variables were analyzed too. According to the literature review ditches can have significant role in maintaining agrobiodiversity, and their existence has probably reduced biodiversity loss. However, the vegetation analysis shows that the study area was species-poor and homogenous. Probable explanations are the habitat’s humidity and high levels of nutrients alongside the dominance of few strong weed species. In order to improve ditches as wildlife habitats their quality should be enhanced. For example fertilizer and herbicide drifts should be reduced and ditch banks could be widened. Also tending the ditch habitat by cutting or grazing are highly recommendable methods to enhance biodiversity.