Plant disease can be seen as a symptom of an unhealthy ecosystem rather than as the problem. Consider the natural role of fungi and other microorganisms, insects, fire and other factors and their interactions in forest and rangeland ecosystems.
Plant pathogens can cause mortality of individual plants as well as shifts in the composition of plant communities. At the same time, pathogens can help maintain plant species diversity.
Will the condition actually harm the tree, shrub or grass plant? Is it likely to cause economic or aesthetic damage? There are instances where a condition can run its course without assistance or with some minimal attention including pruning, fertilization or site amendments.
Review all available control methods and follow all local, state and federal regulations that apply. Evaluate the benefits and risks of each treatment and choose the best solution with the least negative environmental impact. The challenge, when using pesticides, is to pick the one that will cause the least harm to non-target organisms in the forest or landscape.
Plants can be damaged by fungi, bacteria, viruses, parasitic plants and nematodes.
- Armillaria root rot, U. S. Forest Service
- Aspen and Poplar Leaf Spots
- Bacterial Wetwood
- Common Forest Insects and Diseases
- Cytospora Canker
- Diseases and Insects of Aspen
- Honeylocust Diseases
- Mistletoes in Colorado Conifers
- Pinyon Pine Diseases and Insects
- Sycamore Anthracnose
- Thousand Cankers disease
- White pine blister rust, U.S. Forest Service
A major threat to high elevation white pines and their ecosystems is a non-native fungus (Cronartium ribicola) that causes white pine blister rust. All of the North American white pines are susceptible to the rust.
Almost all of the five-needle pines in the Rocky Mountain Region, including limber, whitebark, and Rocky Mountain bristlecone pine, are primary hosts of limber pine dwarf mistletoe. See the CSU factsheet on mistletoes.
The Field Guide to the Insects and Diseases of the Rocky Mountain Region from the U. S. Forest Service is a complete resource of pests found in the region.