Estimated species richness data used in study of UK Ecological status

UK species occurrence data were collated from the Biological Records Centre (BRC). Data were gathered for 11 taxonomic groups (Columns 2 to 12; Bees, Birds, Bryophytes, Butterflies, Carabidae, Hoverflies, Isopoda, Ladybirds, Moths, Grasshopper and Crickets, and Vascular plants) at the 10km2 scale (hectad; column 1) over two separate time periods: 1970 to 1990 and 2000 to 2013 (i.e. there are two separate datasets, one for each time period). Bird species occurrence data for the breeding birds of the UK were acquired from the British Trust for Ornithology (BTO). We used data corresponding to the two time periods defined above, taken from the bird atlases of 1976 and 2001-2011 respectively. Separate analyses were undertaken for both time periods within each taxonomic group. For each hectad we compiled a species list and calculated species richness. We then calculated the estimated species richness by applying a recently developed method (Frescalo) to account for the variation in recorder effort within different hectads. The Frescalo program estimates species richness at a given location according to the set of species occurring in a neighbourhood of the 100 most similar hectads from the 200 nearest hectads. The proportion of a suite of common benchmark species from this neighbourhood list that have been recorded in the focal hectad is used to assess the recording intensity of this focal hectad, and this is used to scale the 'raw' observed species richness towards the neighbourhood maximum accordingly. We ran Frescalo using the Sparta package in the program R. Neighbourhoods were defined according to biological similarity using either vascular plant data or land cover type: all datasets were analysed using the vascular plant weights files embedded within the Frescalo program, with the exception of the vascular plants dataset which for which biological similarity between hectads was defined using land cover type in order to avoid circularity. For this we used the 2007 ITE Land Cover Map.

Related datasets

UK ecological status map version 2