Large-scale processes in ecology and hydrology

1. Several papers published in the 1980s stressed the importance of scaling issues, the inter-relatedness of patterns and processes at different scales of time and space, to our understanding of ecological systems. Scaling issues are of major theoretical interest and increasingly are of considerable applied importance. 2. In recognition of this, the Natural Environment Research Council, in partnership with the Scottish Executive Rural Affairs Department, funded a Thematic Programme entitled 'Large-scale Processes in Ecology and Hydrology'. The principal aim of this Programme was to integrate recent major developments in information resources and technologies with current theory in order to improve understanding of large-scale patterns and processes and their relationship to patterns and processes at smaller scales. 3. The Thematic Programme, which ran from 1995 until 1999, funded six research projects that have generated a large body of published papers. This volume, dedicated to the findings of the Programme, brings together outputs from all six projects with the aim of ensuring a rapid and widespread dissemination of the Programme's findings. A brief resume of each of the papers is presented. 4. The papers in this volume cover a wide variety of subjects ranging from ions to the flora and fauna of the United Kingdom. Nonetheless, each study has sought in various ways to quantify observed spatio-temporal patterns at a range of scales, to determine whether those patterns are consistent across scales and to identify the interactions between small-scale patterns and processes and those at larger scales. The importance of the spatial and temporal scales at which studies are conducted, the key role played by dispersal in spatial population dynamics, and the diversity of ways in which large-scale patterns and processes relate to those at smaller scales are highlighted in many of the papers. 4. All of the papers presented here have direct relevance to applied issues. These issues are diverse and include the control of invasive alien species, the conservation of declining, threatened or endangered species, the development of survey techniques, strategies for farmland, woodland and forestry management, and the assessment of pollution sensitivity. Thus, the Thematic Programme has addressed issues of considerable theoretical interest and has at the same time generated results and predictive models that are of considerable practical and policy relevance.