CHAPTER I. AN OVERVIEW OF DISTURBANCE 



AND FOREST HEALTH IN 



OREGON AND WASHINGTON 



INTRODUCTION 



People, livestock, insects, diseases, snow, 

 wind, fire, volcanic eruptions, earthquakes, 

 and floods are constantly disrupting forests, 

 slowing growth, and injuring or killing trees 

 and other living components of the ecosystem. 

 Disturbance is natural and necessary to for- 

 est ecosystems; without it, forests could not 

 regrow, recycle, and pass through successive 

 stages from seedlings to old growth. But, when 

 disturbance causes more continuous, severe, 

 or widespread effects than people consider ac- 

 ceptable or normal, the forest is described as 

 "unhealthy." 



Forest Health Defined 



Forest health is a human 

 concept, and people have dif- 

 ferent views about what con- 

 stitutes a healthy forest. As 

 demands on forests change 

 over time, so too will people's 

 views of forest health. Cur- 

 rently, two ideas are included 

 in most definitions of forest 

 health. 



• A healthy forest maintains 

 its function, diversity, and 

 resiliency; and 



• A healthy forest provides for 

 human needs and desires, 

 and looks the way people 

 want it to look. 



What Is at Stake? 



More than 36% of the land area in Oregon 

 and Washington is forested. Forest land in the 

 two states includes more than 18 million acres 

 of federal land (19 National Forests, 7 Indian 

 Reservations, 4 National Parks, and almost 2.5 

 million acres managed by the Bureau of Land 

 Management), more than 2.8 million acres of 

 state land, and about 16 million acres of pri- 

 vate industrial and nonindustrial forest land. 

 The residents of Oregon and Washington de- 

 pend on these forests for wood products, jobs, 

 fisheries, recreation, scenery, school funding, 

 clean water, and many other products and 

 amenities. Much of what people value about 

 the Pacific Northwest is tied to the forests. 



A healthy forest can 

 renew itself vigorously 

 across the landscape, 

 recover from a wide 

 range of disturbances, 

 and retain its ecological 

 resilience while meeting 

 current and future needs 

 of people for values, 

 uses, products, and 

 services. Adapted from: 

 Forest Health Policy, USDA 

 Forest Service. 1996. 



Assessing Forest Health 



Forest health is assessed by 

 monitoring the condition of 

 various parts of the forest. 

 Certain traits, such as tree 

 growth, crown condition, mor- 

 tality, and lichen communi- 

 ties, are good indicators of for- 

 est health. The condition of 

 these indicators is used to 

 characterize the forest as 

 healthy, unhealthy, or some- 

 thing in between. Over time, 

 monitoring shows changes in 

 forest condition. Forest eco- 

 systems age just as people do. 



Overview — 2 



