Treesearch

Santiago, Chile has the distinction of having among the worst urban air pollution problems in Latin America. As part of an atmospheric pollution reduction plan, the Santiago Regional Metropolitan government defined an environmental policy goal of using urban forests to remove particulate matter less than 10 µm (PM10) in the Gran Santiago area. We used cost effectiveness, or the process of establishing costs and selecting least cost alternatives for obtaining a defined policy goal of PM10 removal, to analyze this policy goal. For this study, we quantified PM10 removal by Santiago's urban...

1. Amphibians are recognized both for their sensitivity to environmental perturbations and for their usefulness as cost-effective biometrics of ecosystem integrity (=system health). 2. Twenty-three years of research in headwater streams in the Klamath-Siskiyou and North Coast Bioregions of the Pacific Northwest, U.S.A., showed distinct patterns in the distribution of amphibians to variations in water temperature, % fine sediments and the amount of large woody debris (LWD). 3. Here, we review seven studies that demonstrate connections between species presence and abundance and these three...

Even as they increase the beauty of our surroundings, trees provide us with a great many ecosystem services, including air quality improvement, energy conservation, stormwater interception, and atmospheric carbon dioxide reduction. These benefits must be weighed against the costs of maintaining trees, including planting, pruning, irrigation, administration, pest control, liability, cleanup, and removal. We present benefits and costs for representative small, medium, and large trees in the Tropical region derived from models based on indepth research carried out in Honolulu, Hawaii. Average...

Investigations to determine stable or source-sink animal population dynamics are challenging and often infeasible for most species due to the time and expense of mark-recapture studies and the challenge of life histories attributes that result in low detectability and low recapture probabilities. Often, managers rely solely on occupancy or relative abundance patterns to assess a species’ sensitivity to environmental changes. Greater insight into population-level responses to environmental change can be gained by consideration of a combination of readily obtainable metrics, including...

Hyperpredation occurs when non-native prey facilitate invasive predators, which then suppress native prey. Direct impacts of introduced fish on amphibians are well studied, but the role of fish in supporting shared predators has not been considered. We present evidence for indirect effects of trout on amphibians through snake predation. Analyses of the diet, distribution and density of the Pacific coast aquatic garter snake (Thamnophis atratus) relative to the sympatric common garter snake (Thamnophis sirtalis) in the Klamath Mountains of California suggest that trout introductions...

In 1987, the Pacific Southwest Research Station (PSW) of the U.S. Department of Agriculture Forest Service (USFS) chartered a research work unit to examine outdoor recreation in the wildland-urban interface. The new work unit was established to address the needs of the increasingly diverse recreation visitors to national forests. The four forest supervisors in southern California observed that in the past, most recreation visitors were White.¹ However, that percentage was changing with an increase in diverse visitors. In particular, they noted the increasing numbers of Latino visitors....

Fire events often have a large impact on recreation and tourism, yet these issues had not been addressed from a social science perspective. To address his, the Wildland Recreation and Urban Cultures Research Work Unit (RWU) of the Pacific Southwest Research Station acquired funding through the National Fire Plan within the community assistance topic area. The three RWU scientists have developed some distinct lines of research to address the research objectives identified when acquiring the funding: examine values/attitudes and behaviors of recreation residence owners and year-round...

Rock glaciers and related periglacial rock-ice features (RIFs) are abundant yet overlooked landforms in the Sierra Nevada, California, where they occur in diverse forms. We mapped 421 RIFs from field surveys, and grouped these into six classes based on morphology and location. These categories comprise a greater range of frozen-ground features than are commonly described in rock-glacier surveys. Mapped features extended from 2225 to 3932m (modern, mean 3333 m), occurred mostly on NNW to NNE aspects, and ranged in apparent age from modern to relict (late Pleistocene). Many of the smaller...

Crown fire initiation is studied by using a simple experimental and detailed physical modeling based on Large Eddy Simulation (LES). Experiments conducted thus far reveal that crown fuel ignition via surface fire occurs when the crown base is within the continuous flame region and does not occur when the crown base is located in the hot plume gas region of the surface five. Accordingly, the focus in this article is on crown fuel ignition when the crown base is situated within the intermittent flame region. In this region, the /lame shape and height changes with time over the course of...

Both climate and plant species are hypothesized to influence soil organic carbon (SOC) quality, but accurate prediction of how SOC process rates respond to global change will require an improved understanding of how SOC quality varies with mean annual temperature (MAT) and forest type. We investigated SOC quality in paired hardwood and pine stands growing in coarse textured soils located along a 22 °C gradient in MAT. To do this, we conducted 80-day incubation experiments at 10 and 30 1C to quantify SOC decomposition rates, which we used to kinetically define SOC quality. We used these...