The forestlands of Montana from the headwaters for a number of major river basins. These river systems supply large quantities of high quality water that nurtures some of the West's best fisheries and is used for irrigation, livestock water, as well as for domestic, recreational and industrial purposes. These same lands supply the logs that sustain the forest products industry, an important component of Montana's economy. Of Montana's total land area (93 million acres), 17 coniferous tree species cover about 22.5 million acres (Montana Logging Association). Of these 17 species, there are 11 conifer species of commercial value:
1. Douglas-fir - Pseudotsuga menziesii
2. Lodgepole pine - Pinus contorta
3. Ponderosa pine - Pinus ponderosa
4. Western white pine - Pinus monticola
5. Grand fir - Abies grandis
6. Subalpine fir - Abies lasiocarpa
7. White spruce - Picea glauca
8. Engelmann spruce - Picea engelmannii
9. Western hemlock - Tsuga heterophylla
10. Western red cedar - Thuja Plicata
11. Western larch - Larix occidentalis
Forests on the east side of the Continental Divide are dominated by ponderosa pine (p-pine) and Douglas fir and are associated with the many isolated mountain ranges like the Snowies, Belt, and Bears Paw mountains.
West of the Continental Divide, in western Montana, many more species are present including western larch, lodgepole pine, western white pine, grand fir, alpine fir, Englemann spruce, western hemlock and western red cedar. This abundance of species is mostly due to Pacific weather systems that are inter-cepted by high mountains that in turn deliver enough moisture for tree growth. Generally, forests across
Montana can be separated into four basic forest species zones:
- Douglas-fir (32%)
- Lodgepole pine (21%)
- Spruce and fir (15%)
- Ponderosa pine (12%)
These zones are created by differences in temperature, moisture, elevation, and soil. Tree species are adapted to specific conditons, although some tree species have a greater ability to varying conditions. Similarly, these species are more or less adapted to varying types of disturbances.
Identifying and managing the pests that infest
Montana’s forests, forest nurseries, and seed orchards can be difficult and time consuming. There are more than 1300 diseases and insect pests common on conifer trees in the northern and central
Rocky Mountains. Of these, only about 10% account for most of the reported cases of damage. In addition, there is other animal damage and abiotic injuries that are often encountered.
