The knowledge of the effect of temperature on ecological resources under various environmental conditions is important in the agricultural management and land. use planning. The estimation method on the effect of temperature for biological activity was discussed，along with an example of predicting flowering day for fruit trees in Nagano prefecture. Daily mean temperature under various topological conditions，was estimated with the square gridtech. nique at an arbitrary point of the study area. By using estimated daily mean temperature，flowering day of apple trees (Fuji， Starking) at every grid was predicted from DTS method (the Days Transformed at the Standard Temperature)，which was derived from Arrhenius' law. The predicted values were in close agreement with the observed.Article環境科学年報11:43-52(1989)research repor
