Growth Index (1977 = 100) 
120 
100 
80 
60 
40 
20 
1952 
1962 
1970 
Figure 6—Softwood growth inventory index, all owners, 1952-87. 
practices can enhance the production of 
forage and browse for these animals 
while protecting fragile soils and 
watersheds. For example, range forage 
productivity is assumed to rise 0.7 
percent per year on private lands. 
The 1.7 billion acres of forest and 
range lands and water have a large but 
unmeasured capacity to supply 
opportunities for picnicking, camping, 
hiking, skiing, hunting and fishing, 
wildlife observation, canoeing, 
swimming, and most other kinds of 
outdoor recreation far in excess of 
present use. 
Forest and range lands and water also 
have the potential to foster diversity 
and increased numbers of most species 
of wildlife, including those of 
recreational and commercial 
importance and endangered or 
threatened species. 
Finally, the known mineral resources 
on these lands are substantial, and there 
are undoubtedly reserves yet to be 
discovered. Thus, there exists the 
physical potential to increase the 
productivity of the minerals resource. 
Productivity in the case of minerals 1s 
difficult to define but could be 
improved by the application of 
technologies that enhance discovery 
and by the facilitation of exploratory 
work. 
If it occurs, global climate change can 
cause major changes in the 
1977 
1987 
productivity, health, and diversity of 
forest and range ecosystems with 
associated impacts on other renewable 
resources. How the productivity and 
health of forest and range ecosystems 
will change in response to stress 
associated with changing physical and 
chemical climate components will be a 
major scientific and policy issue in the 
coming decades (fig. 8). 
In summary, the Nation’s forest and 
range lands and water have the 
physical capacity to produce much 
larger quantities of renewable resource 
products and support much higher 
levels of use. A primary objective of 
this Assessment is to identify 
opportunities for management of the 
renewable resource base. These 
