ABSTRACT: Models relating development rate to temperature were used in conjunction with indices of growing season length to evaluate the regional thermal suitability for spring wheat Triticum aestivum cultivation in Finland. Thermal suitability was computed using interpolated temperature data for the baseline period 1961-1990 over a regular 10 km grid. Confidence limits of the development model were re-interpreted as spatial uncertainties in modelled suitability. The effects of climatic warming on modelled suitability were investigated by adjusting the baseline temperatures both systematically and according to scenarios of future temperature change. Three main results were obtained: (1) the thermal suitability for spring wheat cultivation could shift northwards by some 160 to 180 km per 1°C increase in mean annual temperature; (2) in regions of present-day suitability, climatic warming shifts the timing of crop development to earlier in the year and shortens the development phases; and (3) the range of predictions of future climate imposes substantially greater uncertainty on estimates of suitability than the uncertainties of the suitability model itself.

KEY WORDS: Crop phenology models · Mapping · Spatial uncertainties · Scenarios

Published in CR Vol. 7, No. 3 (1996) on December 31
ISSN: 0936-577X. Copyright © Inter-Research, Oldendorf/Luhe, 1996