Function, Formation and Control of Heartwood and Extractives

Abstract

The events of plant cell division and cell enlargement have received much attention. On the other hand, the changes during maturation as well as the onset of cellular senescence, which are less easily observed, have received comparatively little attention. When the aging processes in the cells of a living tree are studied, they are found to be much more complex, as these processes occur at different time intervals with different cells and in different dimensional spaces. Moreover, there are severe experimental difficulties in observing the processes and changes in the inner sapwood. Furthermore the environment acting on a tree is complex and constantly changing and the response of the tree to the environment is equally complex and similarly changing.