Treesearch

Tree shade reduces summer air conditioning demand and increases winter heating load by intercepting solar energy that would otherwise heat the shaded structure. We evaluate the magnitude of these effects here for 254 residential properties participating in a utility sponsored tree planting program in Sacramento, California. Tree and building characteristics and typical weather data are used to model hourly shading and energy used for space conditioning for each building for a period of one year. There were an average of 3.1 program trees per property which reduced annual and peak (8 h...

The Sacramento Municipal Utility District's (SMUD) shade tree program will result in the planting of 500,000 trees and has been found to produce net benefits from air conditioning savings. In this study we assume three scenarios (base, highest, and lowest benefits) based on the SMUD program and apply Best Available Control Technology (BACT) cost analysis to determine if shade trees planted in residential yards can be a cost effective means to improve air quality. Planting and maintenance costs, pollutant deposition, and biogenic hydrocarbon emissions are estimated annually for 30 years...

The objective was to investigate and compare methods for quantifying the concentrations of different plastics in stock samples. Five types of plastics were added to clean, bleached, hardwood pulp stock. The plastics concentrations in the stock samples were 0.10%, 0.50%, 1.0%, and 2.0 %, based on the oven-dried weight of the pulp. Samples were processed and analyzed by four quantification methods: image analysis, screening, passage through a hydrocyclone, and vacuum flotation. Screening was the most efficient and reliable method for quantifying plastics. Application: As recyclers delve...

Productive soils form the foundation for productive forests. But unfortunately, the significance of soil seems lost to modem society. Most of us are too far removed from the natural factors of production to appreciate the multiple roles of soil. Nor is its worth recognized well by many forest managers who too often see soil only in its capacity for logging roads and trafficability. Thus, the Santiago Declaration is a milestone marking the significance of soil in sustainable forestry. Soil-based indicators of sustainable forestry listed in the Santiago Declaration are described in a generic...

Educating, interpreting for, and communicating with wilderness visitors is necessary to promote appropriate low-impact wilderness recreation. The Angeles National Forest is located northeast of Los Angeles and is surrounded by a large and ethnically diverse population that provided a potentially ethnically diverse sample ofwilderness visitors for the purpose of this study. This study assessed the types of visitors coming to the Cucamonga, San Gabriel, and Sheep Mountain Wildernesses on the Angeles National Forest and provided a basis for understanding their behavior, attitudes, and needs...

The reliance on signs as a mode of agency communication with visitors requires an examination of message presentation and content in order to evaluate message impact and effectiveness. This paper reports on a system¬atic evaluation of signs and messages at 42 recreation areas in California and Arizona. A number of factors, including type of site, managing agency, density of message locales, sign attributes, and message content, were ex¬amined. Messages addressing depreciative activities, and how those mes¬sages were framed, were of particular interest. The vast majority of messages...

Multiple use area management is of particular interest to both outdoor and urban planners due to an increase in and diversity of users. These areas pose special management challenges due to the diverse and potential conflicting interests involved. Diverse users are frequently excluded from management decisions, however. Further, when visitor input is solicited, it is typically in response to researcher driven. management options. In addition, visitors are often artificially segmented by activity type alone, discounting participation in multiple activities or related identities. This...

For decades, managers have seeded burned slopes with annual grass in an attempt to increase postfire plant cover and reduce the accelerated hillslope erosion, runoff, and debris flows that typically occur during the first winter after fire. In California, annual ryegrass (Lolium multiflorum) was commonly used for this purpose. Critics argue that ryegrass and other seeded grasses suppress native plant regeneration and increase the risk of early reburn. Similar to other researchers, we found that cover of native herbaceous plants was reduced on seeded sites compared to unseeded areas in the...

Prior to the early 1900s, there were no mangroves in the Hawaiian Archipelago. In 1902, Rhizophora mangle was introduced on the island of Molokai, primarily for the purpose of stabilizing coastal mud flats. This species is now well established in Hawaii, and is found on nearly all of the major islands. At least five other species of mangroves or associated species were introduced to Hawaii in the early 1900s, and while none has thrived to the degree of R. mangle, at least two have established self- maintaining populations (Bruguiera gymnorrhiza and Conocarpus erectus). Mangroves are highly...