CONTENTS 

 CHAPTER I AN OVERVIEW of disturbance and forest 



HEALTH IN OREGON AND WASHINGTON 2 



Introduction 2 



Forest Health Defined 2 



What Is at Stake 2 



Assessing Forest Health 2 



This Report 5 



Sources of Information 5 



Scientific References and Names 5 



Changes In Forest Vegetation 6 



Forest Succession 6 



American Indian and Pioneer Influences 6 



Logging and Tree Farming 7 



Fire Suppression 8 



Vegetation, Past and Present 8 



Tree Mortality 1 1 



Ecological Role of Mortality 1 1 



Patterns of Mortality 1 1 



Normal Mortality 12 



Mortality Trends 12 



Weather and Its Influence On Forests 13 



Short-Term Weather Events 14 



Long-Term Weather Changes 15 



The Future 16 



Exotic Pests 16 



Problems With Exotics 16 



Introduction of Exotic Pests 18 



Reducing Introductions 19 



Control and Eradication 19 



Effects of Air Quality 19 



Ozone 19 



Lichens As Bioindicators 2 1 



Acidity of Cloud Water 2 1 



Monitoring Methods 21 



Aerial Survey 2 1 



Forest Inventory 22 



Forest Heath Monitoring Plot Network 22 



New Monitoring Technology 23 



Risk Rating 23 



