of areas. Consequently, the classification of these kinds 

 of communities provides a means of interpreting the rela- 

 tionships among existing vegetation communities. It also 

 permits identification of potential trends in vegetation 

 succession toward or away from potential natural vegeta- 

 tion, and provides for either functional or interdiscipli- 

 nary management decisions. 



A matrix (fig. 1) illustrates the relationships between 

 some existing successional communities and potential 

 natural vegetation. In the examples, each row shows 

 some successional vegetation communities that occur 

 within particular vegetation series. The left column shows 

 series that may support several existing vegetation com- 

 munities. Acreage data for appropriate cells in the matrix 

 can be provided by an inventory of existing vegetation 

 where the potential natural vegetation has been identi- 

 fied. Knowing the position of a specific successional com- 



munity within the matrix in relation to its potential enables 

 prediction of natural succession or trends resulting from 

 different management treatments. Also, it connotes 

 information about the natural biological potential of the 

 existing vegetation. Similar matrices can be developed for 

 grasslands and shrublands. 



In the context of the examples, the four principal 

 objectives are to: identify the existing natural vegetation 

 community obtained through inventory; interpret it in 

 relation to potential natural vegetation for the area; eval- 

 uate management objectives and alternatives for the area; 

 and establish management goals. For example, existing 

 vegetation of an area with grassland potential may be a 

 shrub-grass serai community. One management alterna- 

 tive may be to "hold" the existing community in its pres- 

 ent serai stage for combined wildlife-livestock-water 

 production, use, and protection. Another alternative may 





Existing Vegetation (Series) 



Potential Natural (Climax) 

 Vegetation 



Vegetation 

 Series 



Pinus 

 ponderosa 

 (Ponderosa 

 pine) 



Pseudotsuga 

 menziesii 

 (Douglas- 

 fir) 



Abies 

 grandis 

 (Grand 

 fir) 



Pinus 

 contorta 

 (Lodgepole 

 pine) 



Larix 



occidentalis 

 (Western 

 larch) 



Pinus 

 ponderosa 



Climax 



— 



— 



— 



— 



Pseudotsuga 

 menziesii 



Serai 



Climax 



— 



Serai 



Serai 



Abies 

 grandis 



Serai 



Serai 



Climax 



Serai 



Serai 



Figure 1 — The relationships between existing vegetation (cover types) 

 that may be inventoried and potential natural vegetation at the series 

 level for western Montana (after Pfister and others J 977) 



10 



