SAR dataset for British plants

The British flora is one of the best studied on Earth. As such, it provides an ideal testing ground for biodiversity estimation methods. As part of a project to assess the effectiveness of different biodiversity upscaling approaches, we calculated the species-area-relationship (SAR) for British plants, using the New Atlas of the British and Irish Flora (Preston et al. 2002) as a data source. Species richness was assessed in grids ranging from the 10 x 10 km grid published in the Atlas up to 270 x 270 km resolution. Only grid cells with >75% of area on land were considered, with grid cell locations adjusted to maximise the number of cells at each scale. The SAR was calculated both for Britain as a whole and also for a set of five regional subsets.