Epsilon Open Archive

Abstract

This dissertation focuses on changes over time within patches of remnant rural vegetation after their inclusion in built-up settings. The dissertation is a compilation of four papers preceded by a summary part. The basis for the study is a unique data set collected over a 30 year period at Järvafältet, in the north western part of the city of Stockholm. Empirical contributions are made in three principal areas: recreational use of remnant vegetation, dynamics of remnant vegetation and conservation assessment of urban properties. In paper I the recreational use of areas with remnant vegetation close to and within built-up areas was found to increase between the two studied time periods, 1978–1982 and 2002–2004 with children being the largest user group. The dynamics of remnant vegetation studied in papers II and III were found to vary greatly depending on the specific vegetation's properties. Abandoned pastures were, apparently, not impacted at all. The forest field layer showed a modest and gradual composition change. Bryophytes experienced a curvilinear decrease in cover. Fruticose lichens growing on bedrock was rapidly and fully exchanged by crustose lichens and worn out ground was substantially formed on heavily worn areas. Wear and tear was assessed to be the major driver of the observed vegetation changes. In paper IV the development of a novel tool for the assessment of the biodiversity depletion state at the urban property-level, 'EcoEffect Outdoors – habitat depletion', is described. The dissertation's summary part provides a background to the study, a synthesis of the papers and an account of the author's part in the work presented. A short exposition of the research field including the most important associated research areas and a condensed review of the benefits of and the threats to remnant vegetation is also forwarded. The summary part also contains a general scheme for possible outcomes of wear and tear in patches of remnant vegetation. The scheme suggests a promising approach to the further development of our understanding of the importance of different vegetation processes in connection with wear and tear.