Abstract
1. Calculating the variation of dry matter weight in orchardgrass population after cutting by eqs.(4) and (8), we compared the calculated values with observed values. dw=α(1-e^<-at>)・W・dt…(4)[numerical formula] α and a are constants which indicate the variation of photosynthesis in plant community after cutting. n and m are constants which indicate the variation of respiration rate of plant after cutting. r is a constant which indicates the mean respiration rate of plant. W_0 is a constant which indicates the dry matter weight at cutting. 2. The values which were calculated by eqs.(4) and (8) approximately agreed with the observed values. The adaptation of eq, (4) was especially good. But it was considered that the area of application of eq.(8) would be broader than that of eq.(4) in the case of estimating the amount of dry matter production and analysing the dry matter production because the decision of constants and calculation were easy in eq.(8) 3. We examined the method of decision of each constant, which was necessary in the case of calculating the amount of dry matter production and analysing the dry matter production by eq.(8) under many caltivating conditions.
