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U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Native Forest Pathogens

Tree diseases are a normal part of nature and one of many ecological factors that help keep the hundreds of thousands of living plants and animals in balance with one another. However, native forest pathogens can destroy roots by reducing water and nutrient uptake. They can cause cankers which are diseases of the bark, or cause wilt diseases that reduce the flow of water to the leaves or needles. They can cause leafspots and defoliation that reduce the tree's carbohydrate reserves increasing the likelihood of not surviving a hard winters. Understanding the disease cycles of these pathogens and uncovering weak linkages helps improve their control and management.

Forest Health Protection provides funding, technical assistance, and technology development to support native forest pathogen study on Federal and non-federal lands, tribal, state, and National Forest System lands. Forest Health Protection specialists help to identify causal organisms and provide pathology expertise and recommend prescriptive treatments for managing their damaging impacts. Through these efforts we maintain, enhance, and restore healthy forest conditions and explore links between ecosystem health and pest conditions by integrating disturbance considerations in forest planning and management.

Cedar apple rust photo

Cedar apple rust. Photo by Dr. Bruce D. Moltzan, USDA Forest Service


Armillaria root rot photo

Photo by Dr. Bruce Moltzan, USDA Forest Service

Armillaria Root Rot

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Swiss needle cast photo

Photo by USDA Forest Service - North Central Research Station

Swiss Needle Cast

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Sycamore anthracnose photo

Photo by Joseph OBrien, USDA Forest Service

Sycamore Anthracnose

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