levels, mammalian and avian predators probably 

 exhibit minor effects on population reductions 

 (Torgensen 1994). Therefore, maintenance of 

 habitats for insectivorous birds and mammals is 

 important for long-term forest health. 



EXISTING CONDITION- COARSE FILTER 



The project area contains 6 stands in mature age 

 classes in the mixed-conifer and western larch/ 

 Douglas-fir covertypes. These areas received a 

 variety of timber harvests (see CEA, Part 7 for 

 detailed information), which affected the presence 

 and attrition of deadwood. Currently, the area is 

 experiencing disease infections and insect 

 infestations, especially by larch mistletoe, 

 Douglas-fir bark beetles, and flathead 

 woodborers. Therefore, the project area in 

 general, and the proposed units in particular, 

 consist of clumped distributions of snags and log 

 piles, along with scattered deadwood throughout 

 the stands. 



DNRC collected large tree data in Proposed Units 

 1 , 2, and 4 to verify the units' old-growth status 

 (Green et al 1992). No plot data were collected in 

 proposed Unit 3. The large trees in the proposed 

 units are primarily Douglas-fir and western larch, 

 while the understory is primarily grand fir. Fifth- 

 acre plots were used to estimate large tree 

 densities. Sampling determined that proposed 

 Units 1 and 4 met the minimum old-growth 

 definition {Green et al 1992) with an average of 

 1 5 and 1 7.7 trees per acre over 21 inches dbh, 

 respectively. In proposed Unit 2, many of the 

 large trees in this stand are currently dead 

 resulting from insect and disease vectors. The 

 remaining large live tree density in 

 proposed Unit 2 averages 5.0 trees per 

 acre, which is half of the tree density that 

 is required to meet the old-growth 

 definition. Ocular estimates in proposed 

 Unit 3 indicated that the unit did not meet 

 the minimum old-growth definition. 



2-43) found in old-growth stands (Green et. al 

 1992) and lies between the mean densities found 

 by Harris (1998) on uncut plots (18.3 snags per 

 acre) and cut plots (9.8 snags per acre) sampled 

 in the warm, moist habitat group. However, the 

 number of large and very large snags greatly 

 exceeds those reported in Harris (1998), while 

 small and medium snags are underrepresented 

 (TABLE A-1 - CURRENT SNAG-DENSITY AND 

 SIZE-CLASS DISTRIBUTION COMPARED TO 

 THOSE THAT WOULD BE EXPECTED UNDER 

 HISTORICAL CONDITIONS REPORTED BY 

 HARRIS [1998]). The abundance of large and 

 very large snags is primarily due to the effects of 

 insects and diseases in these stands, while the 

 underrepresentation of medium to small snags 

 could be due to the sampling design. Obviously 

 cull snags, nontarget species (grand fir, 

 Engelmann spruce), and staubs of less than 20 

 feet tall were not counted. Since many of the 

 smaller snags are nontarget species and tend to 

 deteriorate much quicker than larger snags, many 

 of the smaller snags were not included in the data 

 set. Because of these reasons, the snag density 

 estimates are expected to underestimate the 

 existing and retention densities, especially in the 

 smaller size classes. 



TABLE A-1 - CURRENT SNAG-DENSITY AND 

 SIZE-CLASS DISTRIBUTION COMPARED TO 

 THOSE THAT WOULD BE EXPECTED 

 UNDER HISTORICAL CONDITIONS 

 REPORTED BY HARRIS (1998) 



A more complete sampling of the 



proposed harvest units occurred to 



quantify timber volume. In addition, data 



on the snags and live trees proposed for 



harvesting and the snags planned for 



retention were tallied. An average of 12.1 



snags per acre occur on all proposed 



units. Presently, snag densities are consistent 



with what would be expected under historic 



conditions. The current density approximates the 



mean snag density of 1 5 snags per acre (range 



Page C-2 



Wildlife Analysis 



