A huge spider will always make you jump. It was hiding underneath the bark of a dead alder tree, only exposed because I knocked if off randomly. It was about the size of a casino chip. Though I rarely see big nasties, I run into spiders all the time. You constantly have spiders on you while your doing forestry work (with the exception of winter). Inspired, I used the internets, and came across this gem:
Study of the arthropod inhabitants of the Coniferous Biome of the montane Pacific Slope, in cooperation with D.L. Dahlsten, University of California, Berkeley, and R.R. Mason, USDA Forest Service, La Grande, Oregon, revealed that the arboreal spider fauna of the Pacific Northwest is not diverse. Of the more than 500 samples taken from the 15 most abundant tree species throughout this three-State region (more than 100,000 spiders), only 55 species ever constituted more than 5 percent of the total spider population at any site. Most arboreal spiders in this region belong to about 30 abundant, widespread species; only about 150 species were ever collected.
Interesting no doubt. So 150 species is apparently not diverse! Id like to see this study in the coastal douglas-fir, spruce, and oakwoodland forest types.