The Effect of Soil Moisture on the Establishment of Spruce Reproduction in British Columbia

Most of the field work has been conducted at the Aleza Lake Forest Experiment Station, in the valley of the Upper Fraser River, near the city of Prince George [British Columbia]. I. A series of twelve permanent plots (numbers 1 to 12) was established for the purpose of studying the occurrence of natural reproduction on various types of seed bed, under different densities of overwood and on northern and southern aspects. 2. A second series of four plots (numbers 17 to 20) was laid out in logged-off land for the purpose of studying the survival and growth of advance reproduction after logging and the establishment of new reproduction from marginal timber and from seed trees left after logging. 3. A third series of five plots (numbers 29 to 33 inclusive) was laid out in an experimental cutting area for the purpose of studying the effect of different methods of slash disposal on subsequent reproduction. On these plots an effort was made to determine the effect of the various disposal methods on reduction of the fire hazard. 4. A series of transects and quadrats was laid out on an experimental cutting area for the purpose of studying the establishment of reproduction on logged-off land and on exposed mineral soil, as compared with the natural moss covered humus of the spruce forest. 5. Two plots (numbers 35 and 36) were established as the basis for a study of the effect of soil moisture, aspect, light, and soil type on the germination and survival of spruce seedlings in the mature forest. In this case, seed was sown artificially, as contrasted with the work on Plots 1 to 12 where natural seedfall was relied upon. Certain phases of this study were later repeated and extended in the greenhouse of the Marsh Botanical Garden...