Gross annual increment

The growth of woody biomass in one year s annual increment represents the quantity of material that can be harvested without affecting the productive capacity of the forest in subsequent years. The gross annual increment (GAI) is the yearly increase in woody biomass, whereas the net annual increment (NAI) is the GAI adjusted for natural losses such as fire, insect damage and so on. The NAI is often referred to as the allowable cut . In boreal and temperate zones, the removal of woody biomass is lower than the NAI, and thus these forests are presently acting as net sinks for carbon dioxide (Figure 1.6). If all of the NAI was harvested, then the forests would no longer act as sinks for CO2, but would be in balance with the atmosphere. 

Corporations pay an income tax based upon gross earnings, as shown in Table 9-19. Most major corporations pay the federal tax rate of 34 percent on their annual gross earnings. In addition, some states have a stepwise corporate income tax rate. State income tax is deductible as an expense item before the calculation of the federal tax. If 7) is the incremental tax rate and Tr is the incremental federal tax, both expressed as decimals, then the combined incremental rate T is... 

Scenario 7, Fung et al. (1991). From table 1, Reeburgh et al. (1993). Should be considered P. 5(K)-460 — 40 Tg CH4 yr = annual atmospheric (0.9% yr ) increment. Soil consumption of atmospheric CH4 added to the gross budget as an equivalent production term. 

---