The efficacy of various coniferous stock types planted on brushy sites in the Oregon Coast Range

Graduation date: 1976The selection of planting stock is a critical step in the reforestation\ud planning process. In addition to selecting the proper seed source\ud and species for the planting site, consideration must be made for the\ud type of planting stock which will be used. The survival and growth\ud potential of various classes of seedlings is basic to the evaluation of\ud the specific properties of each type in relation to adaptation to local\ud site conditions. This study provides both specific and general\ud information for a range of seedling types.\ud Several stock types were evaluated in two separate investigations.\ud Comparisons of first-year survival were made for nine\ud different stock types including wildlings on two differently-prepared\ud sites near Eddyville, Oregon. A five-year analysis of growth and\ud survival was conducted for transplant, seedling, and container-grown\ud Douglas-fir seedlings on many different sites on International Paper Company's Hinman Tree Farm between Gardiner and Lorane,\ud Oregon.\ud An interpretation of the observed survival and growth response\ud of seedlings on the Hinman plots was facilitated by characterizing\ud each plot according to potential incoming solar radiation and recording\ud seedling damage and estimates of vegetative competition around\ud each seedling.\ud Survival of the wildlings at the Eddyville site was considerably\ud less than the survival of the nursery stock and the overall survival\ud was less on the brushy site than the burned site. In general, the\ud pattern of survival between the stock types was the same for both\ud sites.\ud An analysis of survival and growth for the seedlings on the\ud Hinman plots showed that both survival and growth are related to the\ud initial height of the seedling. Larger seedlings are vulnerable o\ud fewer adverse site factors and are, therefore, capable of better\ud survival. Seedling growth is a function of size, almost independent\ud of stock type. This relationship is consistent among vegetation\ud types with the effect of size being particularly crucial for seedlings\ud in heavy brush or areas of soil movement.\ud The greater survival and faster growth of large seedlings\ud makes them a better economic investment in the Oregon Coast Range than plugs or 2-0s of the small size classes. Greater survival\ud decreases costs per surviving tree and risks of nonstocked areas;\ud increased growth means reduced expenses for pest control because\ud of a shorter exposure to adverse site factors. Any option that\ud reduces vulnerability to pests in combination with innately shorter\ud periods to maturity increases present net worth. Increasing the size\ud of Douglas-fir stock meets these criteria with a favorable ratio of\ud benefit to cost