7. THE TREE COMPONENt

7.1 Factors of importance

The role of trees in land-use systems has already been discussed in Chapter 4.

The most important ways in which trees can contribute to production are:

• By the direct production of tree products

• By having service functions that enhance the production of other components, e.g. crops or livestock.

There are, however, other factors to be considered:

• Ease of propagation

• Taboos and beliefs related to the tree, both positive and negative

• Ease of management

• Time from planting to harvest, i.e. growth rate.

If they are to be discussed in economic terms all these factors can be divided into two groups, the positive factors (credit, representing the gross value of the production), and the negative factors (debit, representing the cost of the production).

Positive (credit)

• Value of the direct production

• Value of the service functions

• Positive intangible value (taboos and beliefs).

Negative (debit)

• Competition with other components in the system

• Cost of establishment and management

• Risks

Negative intangible value.

In addition, the time required between investment (planting) and harvest is of importance. A quick return is always desirable.