Quantitative approaches to landscape spatial planning: clues from landscape ecology

Quantitative approaches to analyse and interpret landscape spatial patterns have developed rapidly during the last decade. The landscape ecological paradigm, based on a foundation of island bio-geography and meta-population dynamic theories, has emerged as a conceptual basis for incorporating such approaches to sustainable landscape planning and development. In this paper we describe two approaches to landscape pattern analysis that originate in landscape ecology: landscape pattern indices (i.e. landscape metrics) and cost-surface modelling. Landscape pattern indices quantify the composition and configuration of ecosystems across a landscape (e.g., patch size, shape, nearest-neighbor distance; proximity index; etc.) thus allowing quantitative comparison between different landscapes or within the same landscape at different times. Cost-surface modelling evaluates potential pathways between landscape elements (e.g., habitat patches) thus allowing quantitative estimation of landscape connectivity and/or fragmentation. The two approaches are described in terms of data requirements, GIS-based algorithms, and results interpretation. The approaches are then compared for applicability to landscape planning and we discuss the validity of approaches for different planning objectives. The two approaches are illustrated with examples on rural landscapes from Canada and Italy and the resulting quantities compared for implications to landscape planning. We conclude with practical advice for professionals seeking to incorporate quantitative approaches to sustainable landscape planning and development.