Influence of climate change on agricultural land-use potential: Adapting and updating the land capability system for Scotland

Land capability systems have been designed to evaluate and communicate biophysical constraints on land use, including climatic limitations. By grading land quality, the resulting information is particularly relevant for planners and managers, and for land valuation. Higher-grade land is more flexible and has more options for land use. Using Scotland as a case study, a widely-used land capability system was adapted to investigate the influence of recent and future climate change on land-use potential. The adapted method was applied to both interpolated gridded weather station data and to future climate change scenarios derived from the HadRM3 climate model. At a national scale, differing regional patterns of land capability were recognised, with changes in these patterns occurring in recent decades and projected to occur on a more substantial scale into the future. In general, climate change is acting to enhance land-use potential in Scotland, mainly in the drier east, while the west remains constrained by its wetter climate. These results demonstrate the key control directed by soil moisture values on land-use options, in addition to temperature change. Shifts in land-use potential have implications for both strategic resource planning and for developing anticipatory climate change adaptation actions. The land capability assessment highlights not only potential changes in agriculture and other productive land uses, but also repercussions for biodiversity and terrestrial carbon stocks. Various amendments are suggested to the land capability procedures to reflect existing or emerging climate-related issues that were not considered necessary in the original system, notably excessive soil moisture deficits.