Cite this dataset as
Maskell, L.; Henrys, P.A.; Norton, L.; Smart, S. (2016). Model estimates of expected diversity of positive plant habitat condition indicators. NERC Environmental Information Data Centre. (Dataset). https://doi.org/10.5285/cc5ae9b1-43a0-475e-9157-a9b7fccb24e7
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This dataset is made available under the terms of the Open Government Licence 
Shapefile
This dataset was created from Countryside Survey 2007 area (x,y,u) vegetation plot data. Each plot was classified to a Broad Habitat type. In each plot the number of positive habitat indicators for the Habitat type that it was classified to were counted. These positive indicators were taken from a list of plant species characteristic of each Broad Habitat created from Common Standards Monitoring Guidance and in consultation with the Botanical Society of the British Isles (BSBI) - it has been provided with this dataset. This count was then divided by the total number of positive indicators that could have been found in that habitat type and multiplied by 100. The data was extrapolated to 1km squares across GB using a generalised additive mixed model incorporating the 1km square as a random variable to account for spatial autocorrelation between plots in the same square. A poisson distribution was specified. Co-variables used in the model are Broad Habitat (the dominant broad habitat of the 1km square), air temperature, nitrogen deposition, sulphur deposition, precipitation and whether the plot is located in an SSSI (presence or absence data).
https://orcid.org/0000-0003-4006-7755