|Abstract or Summary
- Reforestation of certain areas of southwestern Oregon has become a serious problem. Reforestation failures are evident in numerous clear-cut stands, but failures are also noted in various partially-cut stands. The Dead Indian Plateau, approximately twenty miles east of Ashland, Oregon, has many areas where this is evident. This study investigated rodents, drought, cattle, and differences between clear-cut and canopied areas as factors associated with poor seedling survival. Four plantations were established on the plateau in the spring of 1975, and data were obtained through two growing seasons. Three species, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco.), white fir (Abies concolor (Cord. and Glend. (Lindl. )), and ponderosa pine (Pinus poriderosa Dougi. ex Loud.) were planted on each plantation in a split-split plot experimental design. Both containerized and bare-root stock of each species were used. Survival and growth were tallied throughout the study, then subjected to analyses of variance. There were several significant differences. Canopied areas had better survival than open areas. Bare-root stock survived better than container-grown stock. Ponderosa pine had much better survival than Douglas-fir or white fir in the clear-cut areas. Caging effectively protected seedlings from rodent damage, as there were significant caged s.uncaged survival differences in clear-cut areas. There also were significant species -fencing and species -caging interactions. Growth data for all species and all plantations were analysed for canopied areas only. (Excessive mortality precluded several clear-cut growth analyses.) Plantation #2 had significantly better growth than the other plantations. Caged seedlings grew much better than uncaged. Container-grown Douglas-fir and white fir grew significantly better than bare-root stock. With this many significant interactions, it is apparent that no single factor was associated with seedling survival and growth on. the Dead Indian plantations. The most apparent survival difference was between open and canopied plots. Absence of overs tory canopy cover was related to seedling mortality. This was largely due to a combination of growing season frosts and gophers. Damage from these factors was limited under a canopy cover. For satisfactory survival, seedlings should be planted under a forest cover. Later, after seedlings are large enough to withstand severe frosts, the canopy can be removed. The superior growth of containerized Douglas-fir and white fir under overstory canopies indicates that these stock types may be underplanted on severe sites in the Dead Indian area where shelterwood harvesting is practiced. Further study should be conducted to substantiate this conclusion. Superior survival of bare-root ponderosa pine in the open indicates that it may be preferred for planting on clearcut sites in the study area. Other frost hardy and drought resistant species should also be investigated for suitability in clear-cut areas. This includes Douglas-fir stock with induced frost hardiness.