EFFECTS ON WILDLIFE 



COVER-TYPE CHARACTERISTICS 



The vegetation analysis indicates that current 

 conditions differ from those that characterized 

 the analysis area historically. Mixed-conifer 

 types (often with shade-tolerant species) have 

 generally increased at the expense of fire- 

 associated lodgepole pine and fire-resistant 

 western larch. This has probably benefited 

 some species that are adapted to forests domi- 

 nated by grand fir, but hurt species for which 

 lodgepole pine or western larch-donninated 

 forests provide appropriate niches. The shade- 

 tolerant species generally provide better snow 

 intercept than do the shade intolerants, thus 

 favoring wildlife species that have trouble 

 with deep snow. Conversely, shade 

 intolerants, notably western larch, can harbor 

 heart rot without weakening the entire tree, 

 thus providing excellent raw materials for 

 cavity-dependent species. Western white pine 

 and any species dependent on western white 

 pine have declined; the project area is no 

 exception. 



STAND-AGE CHARACTERISTICS 



A decrease in fire influences during this 

 century and a stimulation of regeneration 

 through logging has resulted in an abundance 

 of trees 20 to 100 years old in the understory 

 and midstory, while logging has decreased the 

 size and density of older trees. Many stands in 

 the project area are classified as being 150 

 years old or older because of the age of these 

 remaining mid-sized trees (less than 20 inches 

 dbh), but these stands have generally been 

 sanitized by logging and have few snags, little 

 coarse woody debris, and less defect than 

 average stands in these age classes. Thus, 

 species such as the brown creeper {Certhia 

 mericana) and winter wren {Troglodytes troglo- 

 dytes), which thrive in older forests, and any 

 species dependent on cavities have probably 

 not done so well. 



PATCH CHARACTERISTICS 



Wildlife species that occupy large home ranges 

 or do not easily cross inhospitable habitats can 



be sensitive to the spatial configuration of 

 appropriate habitat. Thus, patch size and 

 connectivity can influence wildlife population 

 dynamics. Additionally, some species are 

 adapted to taking advantage of the diversity of 

 habitats that occur near patch edges, such as 

 where a closed-canopy forest abuts a recently 

 burned, younger forest. Other species are 

 adversely affected by the presence of edge, or 

 by the presence of animals that thrive near 

 edges, and thrive only near the interior of 

 relatively homogeneous patches. Patch shape 

 is correlated with how much edge a patch has, 

 given a constant area. 



The vegetation analysis indicated that patch 

 size has generally decreased since 1900. Patch 

 shape among stands has also evidently be- 

 come less complex, although some of the 

 decrease in patch size and decrease in patch 

 complexity may be an artifact of the inventory 

 system. Size and complexity may simply 

 reflect to some degree an inventory system 

 that now divides areas along boundaries that 

 are not based on stand characteristics (owner- 

 ships, streams, and roads) and boundaries due 

 to finer subdivisions based on better knowl- 

 edge of dominant species, age, and stocking. 

 The abundant regeneration has softened edges 

 so there are few sharp (high-contrast) edges, 

 minimizing habitat for edge species and 

 maximizing the benefit to forest interior 

 species. The minimum mapping unit size 

 from the 1930s' inventory was 40 acres, 

 whereas our SLI maps down to a minimum 

 size of 5 acres. This difference in technique 

 results in more patches of smaller mean size 

 even for a forest otherwise unchanged. 



SPECIAL HABITATS 



Several areas within the project area are 

 noteworthy for wetlands. There are several 

 lakes, shorelines, and marshes that provide 

 habitat for nnink {Mustela vison), eagles, loons, 

 ospreys, amphibians, and other wildlife 

 species associated with mesic (wet-site) plants. 

 Besides the obvious lakes and their shorelines, 

 there is a large, wet, sedge meadow in the 

 southeast portion of Section 8 and forested wet 

 areas across the middle of Sections 7 and 8. 



mM4r 



Stillwater State Forest • Beaver Lake Timber Sale Project 



