DESCRIPTIONS OF THE PLOT OVERSTORY STANDS 



Measurements revealed that the structural and ecological values of the predominantly 

 ponderosa pine overstory stands varied among the plots and, to a lesser degree, within 

 the plots. These values substantiated the long-observed variability of mature ponderosa 

 pine stands in mountainous western Montana. Here, rapidly changing topography is 

 responsible for complex mosaics of plant habitats that not only produce innumerable 

 combinations of vegetation habitat types within relatively small areas but also varia- 

 tions in the productive capabilities of plants within these types (fig. 2). The differ- 

 ing combinations of descriptive values represented by the plot stands undoubtedly are 

 repeated many times in stands of mature ponderosa pine throughout western Montana. It 

 is almost certain, too, that many pine stands in this geographic area possess combina- 

 tions of values not represented by the plot stands. 



Forest Cover and Vegetation Habitat Types 



Of the 35 plots used to sample ponderosa pine stand conditions, only six contained 

 stands that represented the Society of American Foresters' interior ponderosa pine 

 forest cover type (S.A.F. Type 237) in which ponderosa pine is strongly climax. This 

 may indicate the relative sparseness of this type of pine stand in western Montana.^ 

 Most of the remaining plot stands represented the Society's ponderosa pine--larch-- 

 Douglas-fir forest cover type (S.A.F. Type 214) wherein ponderosa pine is strongly serai. 



The plot stands represented several of the Daubenmires' vegetation habitat types. 

 Although these types were developed from vegetation mosaics in eastern Washington and 

 northern Idaho, current ecological studies indicate that some of them containing sig- 

 nificant amounts of ponderosa pine are to be found in limited amounts in western 

 Montana.^ Among them are the Finns ponderosa/ Fes tuoa idahoensis (ponderosa pine/ 

 Idaho fescue) , Finns ponderosa/Agropyron spiaatum (ponderosa pine/b luebunch wheatgrass) , 

 Pinus ponderosa/Furshia tvidentata (ponderosa pine/bitterbrush) , and the Finns ponderosa/ 

 Symphorioarpos albns (ponderosa pine/snowberry) types in which ponderosa pine is climax. 



'^Robert D. Pfister, Research Forest Ecologist, and Peter F. Stickney, Research 

 Range Ecologist, Forestry Sciences Laboratory, Missoula, Montana. Personal communica- 

 tion . 



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