Growth patterns and annual growth cycle of Acacia karroo Hayne in relation to water stress. II. The annual use and replenishment of non-structural carbohydrates in relation to phenological development.

Abstract

The use and replenishment of carbohydrate reserves in Acacia karroo is closely related to the successive events of the annual growth cycle. Acacia karroo displayed the rapid and substantial decline in non-structural carbohydrates typical of deciduous woody species. In addition, each time shoot, leaf or reproductive organs grew rapidly, reserves declined. Replenishment begins soon thereafter when the recently emerged leaves are still very small. Water stress does not change the pattern of use and replenishment. However, increasing water stress does slow replenishment down. This probably delays the beginning of the next growth event as well as the growth of organs already initiated.

Keywords: acacia karroo; botany; carbohydrates; development; growth cycle; growth patterns; leaves; reproductive organs; reserves; south africa; water stress; woody species