Canopy development, XXXX exchange and @entity505 balance of a modeled agroforestry tree.

@entity515 @entity2101 @entity505 @entity734 @entity3363
We developed a whole-canopy @entity515 exchange simulation model to study effects of pruning on the @entity505 balance of trees. Model inputs include global short-wave radiation, photosynthetic @entity2101 ( @entity2101 ), air temperature, time series of the development of canopy diameter, height and total leaf area during the simulation period and local geographical and atmospheric parameters. Canopy structure is derived stochastically from the time series of canopy development and growth functions of individual phytoelements. The @entity2101 incident on a phytoelement is computed from the average gap frequency of the canopy and the binary random probability of sunflecks on the phytoelement. Instantaneous @entity515 assimilation rate of each phytoelement is computed from @entity2101 and phytoelement age. Assimilation rates are integrated over space and time to estimate whole-canopy @entity515 assimilation. The model was used to study @entity505 balance in five sources of the leguminous agroforestry tree Erythrina poeppigiana (Walpers) O.F. Cook during two 6-month pruning intervals. The canopy description appeared to be realistic. According to the simulations, cumulative assimilation did not provide enough @entity505 for tree growth until two months after pruning, indicating @entity734 of tree growth on reserve @entity3363 . The two most productive sources, which had the most open canopies, were the most dependent on reserve @entity3363 after pruning.
