Community forests have not escaped the 

 insect and disease outbreaks plaguing the ru- 

 ral forests. Many conifers like Douglas-fir and 

 ponderosa pine are found in both rural and 

 urban areas, and so too are the insects and 

 diseases that afflict them. Management of the 

 recent pandora moth outbreak in central Or- 

 egon, for example, not only concerns the 

 Deschutes National Forest, but also the city 

 of Bend — though on a different scale. Descrip- 

 tions of the more important insects and dis- 

 eases of urban forests follow. 



Disturbance Agents In Urban Settings 

 Fire and windthrow are a potential 

 threat to homes in forested areas — Homes, 

 increasingly being built at the urban-forest 



interface, are at risk of being destroyed or dam- 

 aged by wildfires or falling trees. Trees with 

 internal decay or root disease (such as lami- 

 nated root rot) are particularly susceptible to 

 Avindthrow or breakage during wind or ice 

 storms. Thinning or removal of groups of trees 

 to accommodate house construction may also 

 lead to windthrow during storms; the remain- 

 ing trees are often unstable because of height- 

 to-diameter ratio and altered wind patterns. 

 Home owners need to know that managing the 

 vegetation around their homes is essential to 

 protect their lives and prevent property dam- 

 age. Where vegetation is not properly man- 

 aged, the costs of fire protection and storm 

 clean-up increases for neighbors, the commu- 

 nity, and public agencies. 



Root rot disease often creates hazards when 

 houses are built in forests (top). Removal of 

 hazardous trees can be costly and unsightly 

 (bottom). 



Removing or thinning trees during home 

 construction can cause remaining trees to be 

 unstable and prone to windthrow. 



Urban— 61 



