The Pinus-Symphoriaarpos and Pinus-Phy so carpus habitat types are the most produc- 

 tive of the six types in which ponderosa pine is the climax tree. Dwarfmistletoe , a 

 threat in the drier types, is absent in these two. Inconsistency of seed production 

 and droughty summers are difficulties shared with the pine-grass habitat types. Under- 

 growth dominated by brush species is a problem not encountered in the grass-dominated 

 associations. The brush cover discourages regeneration in two ways. It is a physical 

 deterrent during planting and competes with young seedlings for water and nutrients. 

 Burning removes the physical obstacle temporarily, but these species regenerate promptly 

 from subterranean organs and dormant seeds in the soil surface. Therefore, mechanical 

 site preparation that removes the brush and exposes mineral soil for a longer time is 

 necessary for planting or prompt natural regeneration. 



Clearcutting is the most appropriate reproduction cutting method if timber produc- 

 tion is the primary goal. It alleviates the problem of undergrowth of brush, the 

 primary difficulty in reproducing pine in these types. On a clearcut, mechanical site 

 preparation is easier, either by itself or used with fire or chemicals, and thorough 

 site preparation is essential to prompt regeneration. In addition, clearcutting allows 

 trees in the new stand to grow where they grow best--in the open. 



Seed-tree and shelterwood systems are successful if properly applied. The ground 

 should be prepared, exposing mineral soil, shortly before seedfall from a good cone 

 crop. Once established, trees in the young stand will survive and grow satisfactorily 

 for at least 20 to 30 years, so immediate removal of the overstory is not necessary. 

 Growth of the young trees will be faster, however, if the overhead shade is removed. 



Selection management with a long rotation is possible under the conditions recom- 

 mended for the ponderosa pine-grass habitat types. That is, cuttings should be care- 

 fully designed to develop age classes needed for the future. Selection management 

 should be used only when the primary objective is to maintain a continuous stand of 

 timber for an esthetic environment or for site protection, and timber production is 

 only a secondary objective. 



Serai Position 



Ponderosa pine loses its position as a climax species when moisture becomes 

 adequate for Douglas-fir to reproduce successfully. Then ponderosa pine becomes a 

 serai tree in a series of habitat types in which Douglas-fir is the climax species. 

 The Pseudotsuga-Symphorioarpos and Pseudotsuga-Physoaavpus types have characteristics 

 similar to the associations of ponderosa pine with the same shrub unions. The choice 

 of cutting methods for ponderosa pine in these stands is complicated somewhat by the 

 presence of other tree species with different silvical requirements and disease and 

 insect problems . 



Douglas-fir, western larch, and lodgepole pine are common associates of ponderosa 

 pine in Douglas-fir habitat types. Douglas-fir is the most shade-tolerant species in 

 this group, western larch and lodgepole pine are intolerant species, and ponderosa 

 pine is intermediate in tolerance. Therefore, silvically, each species is favored by 

 different methods of cutting. 



The choice of method depends largely on the species to be featured in management 

 of the stand. In turn, the choice of species is strongly influenced by disease and 

 insect problems that commonly arise in these habitat types. Dwarfmistletoe infections 

 are severe and frequent in Douglas-fir, western larch, and lodgepole pine, but they do 

 not attack ponderosa pine on these habitats. Spruce budworm (Choristoneura fumiferana) 

 commonly attacks Douglas-fir and occasionally western larch. Larch casebearer 

 [Coleophova laricella) severely defoliates western larch throughout the region. In 

 addition, bark beetles sometimes cause extensive mortality in Douglas-fir, ponderosa 



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