THE NATURE OF BENEFITS FROM FORESTRY INVESTMENTS

Forestry is a multiple output activity. The planting of forests produces a number of joint outputs and services. Outputs can be positive, taking the form of benefits, or negative, i.e., forests may actually reduce the provision of a service compared to the displaced land use, creating a cost. Much depends on exactly where afforestation takes place. Thus:

1. an afforested area supplies trees as timber and as a source of recreational value;, depending on the ‘mix’ of trees and the treatments applied to them, in-place biological diversity may be increased compared to the number of species and/or total species biomass in the displaced land use;

2. landscape values may be increased or decreased according to the preferences of those looking at the landscape;

3. some watershed may be protected by afforestation through the prevention of soil erosion. Others may suffer from soil erosion from ploughing and road building activity;

4. water run-off may be reduced by interception to the point where surrounding areas suffer a diminution of water supply, but flood peaks may be reduced once the forest is established;

5. microclimates may be affected by afforestation, but considerable uncertainty surrounds these impacts;

6. afforestation may increase the deposition of airborne sulphur oxides and nitrogen dioxide in the forested area, but, in so doing, will reduce the transport of these pollutants to other areas.