However, results have then been applied to potential impacts of climatic change, notably upon land suitability and agri-ecological assessments These have generally used resource-rating schemes to assign land parcels to broadly defined suitability or agri-ecological classes (e.g. Brklacich and Curran, 1994). Rating schemes have frequently used comparisons of basic climatic requirements, such as growing period or moisture supply, for broad categories of agricultural production in relation to specified shifts in selected climatic properties.