234 



TECHNICAL STATE34ENT OF 



DR. JERRY F. FRANKLIN, CHIEF PLANT PATHOLOGIST 



PACIFIC NORTHWEST FX)REST AND RANGE EXPERIMENT STATION 



FOREST SERVICE 



UNITED STATES DEPARTMENT OF AGRICULTURE 



Before the 



Subconunitee on Public Lands, National Parks, and Forests 



Committee on Energjy and Natural Resources 



United States Senate 



Concerning Forest Ecosystems and Forest Management 



February 28, I989 



Forests are complex ecosystems composed of many organisms and structures, with 

 strong linkages and interdependencies at both the stand euid landscape level. 

 Attributes of forest ecosystems can be considered under the categories of: 

 COMPOSITION, i.e., the organisms and genetic pools represented by the flora, 

 fauna, and microbes; FUNCTION, or the work that the forest does, such as 

 capturing the sun's energy through photosynthesis and its conversion to organic 

 substances including wood; and STRUCTURE, or the "pieces" of the forest and 

 their physical arrangement, such as green trees, standing dead trees (snags), 

 euid down logs. 



All forest ecosystems have these attributes, but they vary in their specifics 

 depending upon their age (successional status), history (e.g., managed or 

 unmanaged) , and site conditions. There are very significant but gradual 

 changes in forest characteristics associated with successional change; e.g., we 

 may begin with a freshly logged area which lacks trees, progress to a young 

 forest with a dense canopy and heavily shaded interior, and, eventually, into 

 the more open conditions typical of mature and old-growth forests. 



