Potential for the wider application of national forest inventories to estimate the contagion metric for landscapes.

National forest inventories (NFIs) have traditionally been designed to assess the production value of forests as well as forest biodiversity. However, in this study, the aim is to show a new application of NFIs, namely the estimation of the landscape metric contagion. This metric is commonly calculated on raster-based land cover/use maps. In this study, a sample-based dataset from the Swedish NFI was used. The estimated contagion metric is based on a distance-dependent function so that the value of the metric is small for longer distances, whereas the corresponding estimated variance is large for longer distances. With this procedure, comparisons can be made for different landscapes at a given time and or to compare any given landscape over time. The main advantages are that the approach can be applied where raster-based land cover/use maps of the landscape are not available and that the data obtained from NFIs (e.g., land cover type) typically are of high quality in comparison with remotely sensed data due to being based on direct observation in the field survey. The procedure applied here accommodates both the patch-mosaic and the gradient-based model approach to landscape structure.