Quantitative analysis of carbon balance for reproduction in woody species.

The carbon balance in reproductive organs over the whole reproductive period was estimated for 20 woody species on the basis of the published data on the final dry weight and CO(2) exchange of reproductive organs. The relationship between net respiration and dry weight growth was formulated by a linear function with a negative y-intercept. From this linear relationship, linear relations of dry weight growth and net respiration to net translocation were derived. The size dependence of net respiration showed that the net respiration changed from negative to positive as the final dry weight of the reproductive organ exceeded 0.481 g. The cost for translocation per unit dry weight was much lower in the species with small reproductive organs (<0.481 g) because of their photosynthetic contribution to the weight growth. The relation of dry weight growth/net translocation ratio to net translocation was expressed as a hyperbolic function. The dry weight growth/net translocation ratio remained at 0.650, in the higher range of net translocation, irrespective of woody species.