Survival of natural and planted seedlings under a shelterwood in southwest Oregon

The effects of naturally shaded microsites on\ud survival and height growth of natural and planted\ud seedlings were evaluated after an initial shelterwood\ud harvest in the eastern Siskiyou Mountains of\ud southwestern Oregon. After 2 years, the\ud probabilities of survival for planted Douglas-fir (84\ud percent) and ponderosa pine (56 percent) were\ud significantly greater than those for natural Douglas-fir (13 percent) and white fir (18\ud percent). Stress from heat and drought was the\ud greatest cause of mortality for both planted and\ud natural seedlings. Survival of natural seedlings was\ud significantly greater on shaded then on unshaded\ud microsites, but shading did not affect survival of\ud planted seedlings. Survival of planted seedlings\ud seemed to be associated with root size