Lodgepole Pine at Crater Lake: History and Management of the Forest Structure

 VII. Plant Communities in Lodgepole Pine Forest

 

Eleven communities were defined in the lodgepole pine forest. These communities are named after the apparent climax tree species and dominant shrubs and herbaceous species. A key for the identification of the communities in the field accompanies this report as Appendix B. The general distribution of these communities is shown in a type map (Appendix C). We strongly urge that the map be used only for general orientation and that the key be used when deciding management policies for any particular location in the field.

In general, we found that no one community can be said to result entirely from man’s activities, though some types apparently prospered as a result of the numerous fires that accompanied the white ‘ s arrival in the area. One community appears to have experienced fairly frequent ground fires, as well as quite severe fires. Contrary to the popular belief that lodgepole pine is usually seral, we have found three communities where lodgepole pine is the only tree even in old stands, and is reproducing in large numbers.

Brief community descriptions are given below. Accompanying data are presented in Appendices E, F and G. Included in these descriptions are what we believe to be the disturbance histories and the consequences of a fire at the present time. For more complete community description and the facts upon which this summary is based the reader is referred to Robert Zeigler’s Masters Thesis. The number in parentheses beside the community name corresponds to the number of the community on the type map (Appendix C).

(1) Incense Cedar/Manzanita

This community is found on steep rocky slopes along Annie Creek Valley. The vegetation includes sparse forest with numerous herbs and shrubs growing among the rocks. Ages indicate that the fires that probably infrequently burned this type likely originated in lodgepole stands downslope from it.

(2) Lodgepole Pine/Bitterbrush/Sedge

Stands of this type are found in the northeast quarter of the Park between Sharp Peak and Desert Creek at elevations between 1650 m and 1750 m. The herbaceous vegetation is similar to community 3, with the addition of a shrub layer of bitterbrush and, to a lesser extent, rabbitbrush goldenweed. These generally open stands are composed of almost pure lodgepole pine. The apparent successful reproduction by lodgepole pine in the absence of fire, and that all charcoal is from lodgepole pine, indicate that this community is a true lodgepole climax.

There is evidence of past mountain pine beetle activity, though litter accumulation is still fairly light. Because of the patchy nature of the ground cover, light ground fires were probably not extensive. Fairly infrequent intense fires probably recycled the stand after heavy fuel buildup. Most of the areas occupied by this community are probably incapable of supporting either kind of fire at present.

(3) Lodgepole Pine/Sedge-Needlegrass

This community is found on flat areas and depressions with deep pumice and/or scoria deposits at elevations from 1570 m to 2000 m. The largest examples are in Pumice Flat, around the Pumice Desert and on the west side of Sand Creek. The ground vegetation in this type is characteristically depauperate, consisting mainly of a sparse, patchy cover of sedges and grasses. There are very few, if any, shrubs. Though there may be some hemlock and white pine near other communities, lodgepole pine is usually the only tree species present in all layers. Therefore, this community is considered a true lodgepole climax.