Raphael and others 



Chapter 18 



Landscape-level Analysis of Habitat in Washington 



Table 7 Water Resource Inventory Area (WRIA) basin characteristics: landscape pattern indices and proportion of basin area in cover classes, 

 Washington Department of Natural Resources serai stage data (Green and others I993) 1 



1 See figure 1 for locations of each basin; table excludes fragments of WRIA basins 38, 39, and 45 along western boundary of range. 



2 LS = late serai 



Resources and 0.9 million ha (18 percent) by the National 

 Park Service. Based on the WDNR classification, private 

 and state lands are predominantly mid-serai and other forest, 

 whereas National Forest and Park Service lands are 

 predominantly late-serai (fig. 3). An analysis based on the 

 WDFW classification (fig. 4) shows a similar distribution of 

 forest age classes among land managers. However, the amount 

 of late-serai forest (old growth and large sawtimber) is much 

 lower than that estimated from the WDNR classification. 

 This difference reflects the elevation cutoff (3200 feet) used 

 by the WDFW (table 2). 



The WRIA basin is too large an area relative to the 

 number of surveys conducted within each basin (fig. 1) to 

 detect relationships among landscape pattern variables and 

 detection rate. Analysis of smaller basins with greater sampling 

 intensities may help to clarify what, if any relationship exists 

 between broad landscape pattern and likelihood of murrelet 

 detection. However, the description of amount and config- 



uration of forest vegetation within river basins given here 

 may help to determine those areas in Washington that are in 

 need of closer examination at finer scales of analysis and 

 with greater surveying effort. 



Site-Level Analysis 



Stand Characteristics 



Most (59 percent) of the Marbled Murrelet survey sites 

 were centered within the various other forest categories 

 (WDFW forest-cover map). Most of the remaining sites 

 were located within old-growth stands (table 8). The 

 proportion of sites within the various forest-cover classes 

 differed significantly among detection classes (chi-square = 

 40.2, P = 0.000). Patch area did not differ significantly 

 among occupied, detected or undetected sites, nor did it 

 differ among forest-cover classes (table 9). Survey sites 

 averaged 30.6 km from nearest saltwater; mean distance did 

 not significantly vary among occupied, detected, and un- 



USDA Forest Service Gen. Tech. Rep. PSW-152. 1995. 



185 



