Treesearch

The daily activity of some predators is correlated with the activity pattern of their prey. If capture efficiency varies as a function of prey activity, a predator that synchronizes its foraging activity with the time of day that prey are most vulnerable should capture more prey, and at lower cost, than a predator that initiates foraging at random. Mink, Mustela vison, and weasels, M. erminea and M. nivalis, were presented with an opportunity to maximize their intake in similar circumstances in the laboratory. An animal's ability to synchronize its foraging activity with the time of day...

Larvai of Lacinipolia patalis (Grote) (Lepidoptera: Noctuidae) were discovered in Douglas-fir (Pseudotsuga menziessi [Mirb.} Franco) cones collected from the Louisiana-Pacific Corporation's Little River Seed Orchard near Trinidad Head in Humboldt County, CA (elevation 91 m) during the fall of 1985. Previous surveys have not reported this noctuid from Douglas-fir cones (Keen 1958; Tietz 1972; Furniss and Carolin 1977; Hedline et al. 1980; Ruth 1980; Schowalter et al. 1985). Its usual hosts are blackberry and loganberry (Rubus spp.) and roses (Rosa spp.); it normally feeds on foliage and, to...

Mixed-conifer forests are the largest vegetation type in California, covering more than 13 million acres (Barbour and Major 1977). This type, the Sierra Nevada Mixed Conifer (Society of American Foresters Forest cover type 243, Tappeiner 1980) dominates mid-elevations of the Sierra Nevada's western slopes. The extent of the mixed-conifer type and the amount of timber harvested from the west slopes of the Sierra Nevada emphasize the need for accurate growth and yield prediction methods for this area.

Estimates of forest growth (increment) are used for evaluating productivity of land and to project growing stock into the future. Since volume is the accepted parameter for measuring forest growth (Spurr 1952), estimates of periodic volume increment for individual trees on inventory plots form the basis for appraising the productivity of the land and timber.

Economic efficiency and risk have long been considered during the selection of fire management programs and the design of fire management polices. The risk considerations was largely subjective, however, and efficiency has only recently been calculated for selected portions of the fire management program. The highly stochastic behavior of the fire system and the high degree of interaction among its components make it difficult to model analytically. Without fairly advance quantitative models, estimating the risk and efficiency consequences of fire management alternative was impossible.

Palau is an archipelago of high and low islands located in the western Caroline Islands. The largest island in the group is the heavily forested high island of Babelthuap. Knowledge of the soils and the extent and composition of Palau's vegetation, including the forests, is needed for land-use planning. To fill this need, a formal agreement was drawn up between the High Commissioner of the Trust Territory of the Pacific Islands, and twoagencies of the U.S. Department of Agriculture—the Soil Conservation Service and the Forest Service. Vegetation maps of Palau are a product of this agreement...

When planted in sheltered sites in northern California, only 49% of black walnut (Juglans nigra L.) and 58% of black cherry (Prunus serotina Ehrh.) survived for 15 years, and 20% of northern red oak (Quercus rubra L.) survived for 10 years. The black walnut trees averaged 0.6 inches diameter at breast height (dbh) and 5.4 feet in height when measured at 15 years; the black cherry trees averaged 2.1 inches dbh and 20.3 feet in height. The northern red oak seedlings taller than breast height averaged 1.0 inch dbh and 3.8 feet in height. In northern California, only the black cherry shows any...

Truk is one of the four States of the Federated States of Micronesia (FSM). Knowledge of the extent and composition of its vegetation, including forest land, is needed for land-use planning. To fill this need, a formal agreement was drawn up between the High Commissioner of the Trust Territory of the Pacific Islands and two agencies of the U.S. Department of Agriculture-the Soil Conservation Service and the Forest Service, to map the vegetation of Truk. Three vegetation maps were prepared by the Forest Service in cooperation with the Government of the State of Truk, for land-use planning...

The soils and vegetation of the Caroline high islands, Federated States of Micronesia, are being mapped by the U.S. Department of Agriculture's Forest Service and Soil Conservation Service. By the end of 1987, vegetation maps and reports on Kosrae, Pohnpei, Yap, four Truk Islands, and Palau are expected to be available. To compare soil types with vegetation types, vegetation maps were laid onto soils maps of these islands. There may be correlation with individual vegetation species and soil acidity, but no clear correlation was apparent between strongly acid soils and broad vegetation...