Production

Abstract

Among the many methods of estimating net production described in Chapter 3 only the results using the harvest method are discussed here. This represents a fairly large accumulation of data. Most of the work on the dry matter production of forests has been done from the standpoint of applied forestry. Therefore, information on the stems and to a lesser extent, the foliage of the overstorey tree layer of forest ecosystems is abundant, while measurements of production by other components such as branches, roots and understorey trees and undergrowth at the same time as overstorey tree layers is limited. Moreover, the difficulties associated with estimating death and shedding of branches and roots are such that accurate estimates of their production are few in number and doubtful in absolute value. Table 21 gives an example of a detailed measurement of net production by layers for a planted larch forest. Table 22 shows the relationships between above-ground production of the overstorey tree layer and undergrowth of many different types of forests. The proportion between the two components is very variable.