RELATING CARBON ALLOCATION PATTERNS TO TREE SENESCENCE IN METROSIDEROS FORESTS

The ratios of carbohydrate sink to source in the shoot systems of mature and juvenile Metrosideros polymorpha trees in Hawaii were compared, testing a prediction of the pipe model theory that this ratio is proportional to height, thus explaining the synchrony of forest decline in even-height stands. The volume of inner bark was found to be about one-half as great as the volume of sapwood in mature trees, but is likely to be responsible for a disproportionate part of total aboveground respiration. -from Author