Increasing Planting Stock Size by Family Selection in California Ponderosa Pine

Increasing Planting Stock Size by Family Selection in California Ponderosa Pine
Author: James L. Jenkinson
Publisher:
Total Pages: 16
Release: 1975
Genre: Ponderosa pine
ISBN:

Wind-pollinated families from four geographic areas in the northern Sierra Nevada were tested in the nursery. For every area, the native families differed significantly from each other in 1-year seedling height, and in 2-year height, diameter, and stem volume. Family growth was poorly correlated with family seed weight; it was independent of germination speed and seed parent stem volume. The size of planting stock can be improved and small-grade seedling production decreased by eliminating from future collections seed trees whose families show poor growth in the nursery.

Weather and Tree Growth Associated with White Fir Mortality Caused by Fir Engraver and Roundheaded Fir Borer

Weather and Tree Growth Associated with White Fir Mortality Caused by Fir Engraver and Roundheaded Fir Borer
Author: Craig D. Whitesell
Publisher:
Total Pages: 182
Release: 1974
Genre: Abies concolor
ISBN:

Ohia forest decline-its severity and rate of spread-was studied by aerial photographic techniques on a 197,000-acre (80,000-ha) portion of the island of Hawaii. In 1954, only 300 acres (121 ha) showed signs of severe decline; by 1972, the acreage of severely affected forest had increased to 85,200 acres (34,480 ha). Rate of decline and current severity were related to mean annual precipitation and to elevation. The epidemic is continuing. Some forests on other Hawaiian islands also display decline symptoms.