Satellite based land use and landscape complexity indices as predictors for regional plant species diversity

It is known that habitats composed of spatially heterogeneous abiotic conditions provide a great diversity of potentially suitable niches for plant species. The scientific premises of landscape ecology suggest that, at a higher spatial level, also the composition and structure of the landscape mosaic, influences biotic processes and hence species richness. In this exploratory study we investigated if plant species diversity could be correlated with landscape structure and complexity indices which were based on Landsat Thematic Mapper satellite imagery. Plant species data were derived from the 4 km x 4 km resolution Flora Database of Flanders (i.e. northern Belgium). Plant species number within the 4 km x 4 km grid cells was positively correlated with most of the landscape diversity indices whereas landscape fragmentation indices only affected the group of the threatened species. We found a gradient of increasing species richness beginning from the rural areas of Flanders over the suburban towards the urban areas. This gradient was mostly due to the higher number of alien plant species, warmth indicators and threatened species in urbanised areas. We conclude that, at least in the studied region, the effects of landscape changes on plant species diversity can be monitored and predicted on a large scale and over long periods of time using land cover data. Bottleneck in this kind of analyses remains the reliability of the land cover data and the availability and reliability of the biological data. (C) 2002 Elsevier Science B.V. All rights reserved.