Treesearch

Banana poka vines (Possifloro mollisrimo) and kikuyu pass (Pennirerurn clondestinum) can limit koa(Acacia koa) reforestation in Hawaii. Performance of planted koa seedlings was studied in relation to type of site preparation: broadcast spraying of Roundup herbicide at three rates (2.02, 4.05, and 6.07 kg active ingredient per hectare) and hand scalping vegetation from each planting spot. One year after planting, survival and growth of koa seedlings were significantly greater in plots sprayed with a heavy dose of Roundup than in control plots. Ten year survival and height were significantly...

Polymorphic site index curves were developed from stem analysis data of 194 dominant red fir trees in California and southern Oregon. Site index was based on breast-height age and total tree height, with a base age of 50 years at breast height. Site index curves for breast height ages 10 to 160 years are presented for approximate estimates of site index. For more precise estimates, tabular vaiues of total tree height as a function of breast-height age and site index are given. Guidelines for selection of site trees and application of the site curves are discussed.

Dates were obtained between February 1969 and October 1979 on the seasonal occurrence, habitat association, reproductive phenology, and relative abundance of avifauna at two study sites in the chaparral community of the San Gabriel Mountains of southern California. The purpose of the study was to collect information on bird species use of this habitat and to document changes in the bird community over a 30-year period. During the study, 128 species representing 36 families were noted: 99 in lower elevation(914 to 1280 m) chaparral and 110 at a higher elevation (1400m)chaparral yellow pine...

The within-cone distribution of Megastigmus spermotrophus Wachtl (Hymenoptera: Torymidae), the Douglas-fir seed chalcid, infesting Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] cones from north-central France was compared with that in samples from California. Results indicate that the mid-region of cones was more intensively utilized by seed chalcids in France than in California, whereas in the northwestern United States the mid-region is characteristically occupied by dipteran and lepidopteran species. This difference in distribution may explain the large discrepancy in infestation...

California black oak (Quercus kelloggii) exceeds all other California oaks in volume, distribution, and altitudinal range. Yet this deciduous hardwood has had little sustained commercial use and almost no management, even though its wood closely resembles that of its valuable, managed, and heavily used counterpart-northern red oak (Quercus rubra)-in the Eastern United States. First collected in 1846 near Sonoma, CA, the species was not named until 1857 when John Newberry called it kelloggii in honor of Albert Kellogg, a pioneer California botanist and physician. In later botanical works,...

Soil ammonification, nitrification, and N mobility were studied for 1 yr in three Sierra Nevada (USA) mixed-conifer stands to examine the long-term influence of timber harvesting on soil N dynamics. Clearcutting had a persistent effect on soil N mineralization, detectable by in situ incubation but not by conventional low-tension lysimetry. Mineralization rates were greater in 5- and 17-yr-old regenerated clearcuts than in an adjacent 100-yr-old uncut forest. Annual rates of N mineralization averaged 12 kg ha−1 for the uncut forest, and 49 and 31 kg ha−1 for the 5- and 17-yr-old clearcuts,...

Growth of ponderosa pine (Pinus ponderosa) was monitored for 24 years after planting at five different square spacings (6, 9. 12, 15, and 18 ft) in the presence or absence of competing brush on the westside Sierra Nevada. Spacing strongly influenced both mean dbh and basal area/ac. In plots maintained free of brush, diameters ranged from 5.1 in. at the 6-ft spacing to 11.4 in. at the 18-ft spacing after 24 years. Over all spacings, brush reduced mean dbh by 20% and basal area/ac by 37%. Projections of mean dbh suggest that yield losses resulting from brush competition depend on the...