The prediction and selection of climatological data for ecological purposes in Great Britain.
A principal component analysis of climatological data for England, Scotland and Wales was described. Daily data for 68 stations for 1960 to 1969 inclusive were used. After correction of errors, 3-monthly means were calculated, which formed the basis for the Penman calculation of potential evapotranspiration. A principal component analysis was carried out on the 3-monthly means, the interpretations of which are discussed. Predictive equations were calculated for values of the significant components and for the main variables, using stepwise regressions. These enabled values to be estimated for any site in the country, based on grid coordinates and topographical variables. The estimated values provided useful input to ecological studies. Analysis of variance showed that annual differences were generally unimportant as a source of variation, compared with quarters and stations, so that results of the study should apply satisfactorily outside the period covered by the data.