Web Map Service for topsoil properties from the Countryside Survey of Great Britain, 2007 using a generalized additive model

This web map service presents modelled estimates of soil pH, carbon concentration (g kg-1), nitrogen concentration (% dry weight soil) and invertebrate density (individuals m-2) at 1km2 resolution across Great Britain. A Generalized Additive Model approach was used with Countryside Survey soil data from 2007 and including climate, atmospheric deposition, habitat, soil and spatial predictors. The models are based on data from Countryside Survey sample locations across Great Britain and are representative of 0-8cm soil depth for invertebrates and 0-15 cm soil depth for other variables. The Countryside Survey looks at a range of physical, chemical and biological properties of the topsoil from a representative sample of habitats across the UK. Loss-on-ignition (LOI) was determined by combustion of 10g dry soil at 375 degrees Celsius for 16 hours; carbon concentration was estimated by multiplying LOI by a factor of 0.55. Soil N concentration was determined using a total elemental analyser. Soil pH was measured using 10g of field moist soil with 25ml de-ionised water giving a ratio of soil to water of 1:2.5 by weight. Soil invertebrates were extracted from cores using a dry Tullgren extraction method and enumerated by microscope