Seasonal carbon allocation in Heteromeles arbutifolia, a California evergreen shrub

Abstract

The seasonal patterning of carbon gain and allocation was studied in the California evergreen sclerophyll shrub, Heteromeles arbutifolia. Specifically an analysis was made of the seasonal structural allocations to stems, leaves, roots and reproductive parts as well as to functional categories of cell structure, metabolism, storage, and secondary compounds (predator protection).The differential partitioning during the various seasons is viewed in terms of the overall carbon economy of the shrub. It is suggested that not all functions can be met simultaneously, even though there is year round carbon gain, because of the heavy allocation demands to meet a particular environmental stress during a given season. For example, during the spring there is a priority allocation to the development of the canopy, apparently for competitive purposes, with little going to reproduction, storage and secondary compounds.