8 



NORTH AMERICAN FAUNA 70 



and most of the southern part of the county occupied by the Siskiyou 

 Mountains. 



Three plant communities occupy the remainder of the county : 

 Mixed Conifer Forest. — Abies, Pinus, and Pseudotsuga are domi- 

 nant trees in the Mixed Conifer Forest occupying an elevational range 

 of 762 to 1,372 m. Pseudotsuga menziesii occurs in most locations 

 (Fig. 4). Most of the area has been heavily logged. Pinus ponderosa, 

 Pseudotsuga menziesii, Libocedrus decurrens, Pinus jeffreyi (Siskiyou 

 Mountains), Thuja plicata, Arbutus menziesii, Quercus garryana, Q. 

 kelloggii are dominant species. Quercus spp. occurs with Pinus pon- 

 derosa in the lower elevations and most commonly in the extreme 

 southeastern region of the county. Mixed forest of Pinus spp., 

 Pseudotsuga menziesii, Tsuga heterophylla, Abies grandis, A. nobilis, 

 and A. concolor are dominant from about 1,219 to 1,372 m (Fig. 5). 

 Pinus ponderosa and P. lambertiana (mostly secondary growth) 

 associated with Pseudotsuga menziesii are dominant along the Upper 

 Rogue River between Shady Cove to Prospect and east of Union 

 Creek. Pinus lambertiana and Pseudotsuga menziesii are dominant 

 from Prospect to Union Creek. 



Fig. 4. Pseudotsuga menziesii on the western slope of the Cascade Mountains in 



Mixed Conifer Forest. 



