Treesearch

We quantified fire severity patterns within intermittent stream drainages in a recently burned area of the central western Cascades, Oregon. Aerial photographs were used to estimate post fire live canopy cover within streamside and upland zones on the southeast and southwest-facing slopes of 33 watersheds. Live canopy cover did not differ significantly between streamside and upland zones in the watersheds. Fire severity data obtained from aerial photographs were highly correlated with fire severity data obtained in the field in six of the watersheds, confirming that aerial photograph...

The sale, scope, and complexity of natural resource and environmental issues have dramatically increased, yet the urgency to solve these issues often requires immediate information that spans disciplinary boundaries, synthesizes material from a variety of sources, draws inferences, and identifies levels of confidence. Although science information and knowledge are only one consideration in natural resource decisions, credible science information is increasingly necessary to gain public support and acceptance. But what are the appropriate roles for science and scientists versus managers and...

We developed a species- and location-specific database of published ecophysiological variables typically used as input parameters for biogeochemical models of coniferous and deciduous forested ecosystems in the Western United States. Parameters are based on the requirements of Biome-BGC, a widely used biogeochemical model that was originally parameterized for the forests of the Pacific Northwest. Several other ecosystem models, including Century 5, Daycent, TEM, and PnET, also use some of the inputs described here. This database provides a compendium of ecophysiological data for the...

This report focuses on economic trends since the 1970s in rural southeast Alaska. These trends are compared with those in the Nation and in nonmetropolitan areas of the country to determine the extent to which the economy in rural southeast Alaska is affected by regional activity and by larger market forces. Many of the economic changes occurring in rural southeast Alaska, such as the decline in the manufacturing sector, are reflections of broad-scale changes in the greater U.S. economy. Other changes, such as the increase in nonwage income as a percentage of total income, have been...

We determined δ13C values associated with canopy gross and net C02 fluxes from four U.S. sites sampled between 2001 and 2002. Annual mean, flux-weighted δ13C values of net ecosystem C02 exchange (NEE) were estimated for four contrasting ecosystems (three forests and one grassland) by analyzing daytime flask measurements collected at the top of canopies. Combining δ13C values associated with respiratory and net (respiration minus photosynthesis) fluxes, we demonstrate a method for estimating whole-canopy photosynthetic discrimination against 13C (ΔA) in terrestrial ecosystems directly from...

Clearcutting has been the primary timber management practice in southeast Alaska forests since large-scale commercial forestry began in the 1950s. The dense, even-aged conifer stands that subsequently develop, however, may have undesirable consequences for some nontimber resources, most notably fish and wildlife. Red alder is frequently established in these young-growth conifer stands and appears to provide different forest structural attributes and improved biodiversity that may mitigate some negative effects of harvesting. However, to date, it has been unclear what the ecological...

We studied six pine plantations in coastal South Carolina to determine the influence of clearcutting with corridor retention on small mammal abundance, richness, and diversity. Small mammals were live-trapped in recently clearcut stands that retained pine corridors 100 m in width and in adjacent pine plantations, 20--23-years-old. We compared small mammal communities between harvested stands with corridors and non-harvested pine stands. We captured 1158 small mammals, representing 844 unique individuals and seven different species in 94,080 trap nights. Rodent abundance, richness, and...

The Early Warning System is a pheromone-based trapping system used to detect outbreaks of Douglas-fir tussock moth (DFTM, Orgyia pseudotsugata) in the western United States. Millions of acres are susceptible to DFTM defoliation, but Early Warning System monitoring focuses attention only on the relatively limited areas where outbreaks may be developing. During 20+ years of monitoring, the Early Warning System provided warnings of 1-3 years for seven of nine outbreaks. No warnings were provided for two outbreaks because of inadequate density and distribution of" Early Warning System plots in...

Red tree voles are one of the least understood small mammals in the Pacific Northwest, because they live in the forest canopy and are difficult to sample using conventional trapping methods. We examined the distribution and relative abundance of tree voles in different regions of Oregon based on their occurrence in diets of northern spotted owls. We identified the skeletal remains of 2,954 red tree voles in regurgitated pellets collected from 1,118 different spotted owl territories. Tree voles were found in the diet at 486 territories. They were most common in the diet in the central and...

We describe local, regional, and annual variation in diets of northern Spotted Owls (Strix occidaatalis caurina) in Oregon based on 24497 prey collected at 1118 owl territories in 1970-2003. The sample included 91.5% mammals, 4.3% birds, 4.1% insects, and 0.1% other prey. The diet included 2131 species, including 49 mammals, 41 birds, 3 reptiles, 1 frog, 1 crayfish, 1 scorpion, 2 snails, and 33 species of insects. On average, 91.9 ± 0.3% (SE) of prey in the diet were nocturnal animals, 3.3 ± 0.2% were diurnal, and 4.8 ± 0.2% were active both day and night. Of the prey captured, 50.5 ± 0.8%...