Preface: High spatial resolutionremote sensing for environmental monitoring and management

This special feature in the journal of Spatial Science brings together a collection of papers showing environmental monitoring and management applications of high spatial resolution remotely sensed image data. As illustrated by the papers in this special feature, and a growing number of papers in ecology, environmental management and remote sensing journals (Butler, 2006; Mumby et aL, 2001; Zanoni and Goward, 2003), there is an increasing need for spatial information derived from multi-spectral sensors at the scales of traditional aerial photography. The application of moderate spatial resolution image data has produced limited results for mapping and monitoring small features (< 10 m) within terrestrial and aquatic habitats, Such as individual tree crowns and their associated biophysical variables, coral reef structures and seagrass distribution. With nominal spatial resolutions less than 5 m x 5 m, there now exists the capacity to acquire fully radiometrically and geometrically corrected data to map and monitor complex structures and patterns of small features. High spatial resolution airborne and satellite digital image sources in various forms are now easily obtainable for agencies responsible for monitoring natural and built environments. Spatial data, including airborne and satellite images, are globally accessible thanks to Virtual Globes, such as GoogleEarth and Microsoft's Virtual Earth. Organisations responsible for managing natural and built environments are now faced with choices of how to transform these data into management-relevant spatial information. Many standard per-pixel based approaches developed for moderate spatial resolution image data do not work on single- or multidate high spatial resolution image data, and it is not efficient to subject these data to visual interpretation. The papers presented in this special issue illustrate a variety of approaches developed to address some of these challenges in terrestrial and aquatic environments.