Treesearch

Leisure preferences and open space needs were explored within a discrete, homogeneous ethnic community: the Chinese Americans of Chicago's Chinatown. Face-to-face interviews and focus group discussions were used to identify outdoor leisure patterns and preferences, in general, and with respect to new park development being planned for the community. Findings show that although some popular activities are no different from what might be expected for the mainstreum Anglo American population, the meaning and significance of these activities have clear and unique ties to Chinese culture....

The effect of soil warming on CO2 and CH4 flux from a spruce-fir forest soil was evaluated at the Howland Integrated Forest Study site in Maine, USA from 1993 to 1995. Elevated soil temperatures (~5 °C) were maintained during the snow-free season (May-November) in replicated 15 × 15-m plots using electric cables buried 1-2 cm below the soil surface; replicated unheated plots served as the control. CO2 evolution from the soil surface and soil air CO2 concentrations both showed clear seasonal trends and significant (P < 0.0001) positive exponential relationships with soil temperature. Soil...

Several hypotheses about the relationships among individual tree growth, tree leaf area, and relative tree size or position were tested with red spruce (Picea rubens Sarg.) growing in uneven-aged, mixed-species forests of south-central Maine, U.S.A. Based on data from 65 sample trees, predictive models were developed to (i) estimate the amount of foliage held by individual trees from sapwood cross-sectional area and (ii) define the relationship between stem volume growth and three variables: total foliage area, relative position in the stand, and the degree of past suppression. A model...

More than 400 species of exotic phytophagous insects have become established on native and introduced woody plants in North America. About 5 percent of these invasives have well-recognized, severe ecological impacts on the trees and ecosystems that they occupy. For the others, very little is known about their influence on natural processes. However, evidence suggests that all may irrevocably change their respective, invaded ecosystems. In the worst cases, the exotics insects have become the "final straw" causing their adopted host plants to fall into perennial decline-death spirals.

Interest in the species of Eastern Black Walnut (Juglans nigra L.) for commercial nut production continues to increase. During the past several years interested growers have intensified tree care and evaluated several varieties and selections. It is believed that we have arrived at an economically viable threshold for commercial nut production. While we are operating with a strong level of cautious enthusiasm we believe that we are witnessing the emergence of a new industry.

Discusses temporary options for crossing streams and wetland soils with forest harvesting and transportation equipment. Reviews the available literature on the environmental effects of temporary crossings. Provides an overview of regulations pertaining to temporary crossings for several jurisdictions in the Great Lakes Region.

Presents methods for synthesizing information from existing biomass literature for estimating biomass over extensive forest areas with specific applications to Maine. Tables of appropriate regression equations and the tree and shrub species to which these equations can be applied are presented as well as biomass estimates at the county and state level.

Increased rates of litter decay due to projected global warming could substantially alter the balance between C assimilation and release in forest soils, with consequent feedbacks to climate change. This study was conducted to investigate the effects of soil warming on the decomposition of red spruce (Picea rubens Sarg.) and red maple (Acer rubrum L.) foliar litter at Howland, ME. Experimentally increased Oa horizon soil temperatures (increase of 4-5°C) were maintained during the snow-free season from 1993 through 1995 in replicated 15 by 15 m plots using heat-resistance cables. For red...

The Ultimate Grading and Remanufactming System (UGRS) is an advanced computer program for grading and remanufacturing lumber. It is an interactive program that will both grade lumber according to NHLA rules and remanufacture it for maximum value. UGRS is written to run under Microsoft Windows 3.0 or later updates and provides a sophisticated graphical user interface. UGRS displays boards that have been digitally described in a computer file (x-y coordinates) showing the board outline and defects along with pertinent grading and remanufacturing infmmation. Potential applications include: 1)...

The effect of 2 formulations of Bacillus thuringiensis subsp. kurstaki (Foray 48B and Dipel 8AF) was evaluated on 42 species of native Lepidoptera in laboratory bioassays using instars that are present in the field at the time of gypsy moth suppression applications. Mortality was significant for 27 of the 42 species evaluated against Foray 48B, and 8 of 14 species evaluated against Dipel 8AF. Susceptible species were noted in 5 of 6 families assayed—Papilionidae, Nymphalidae, Geometridae, Lasiocampidae, Satumiidae, and Noctuidae. The 1 species treated in the Lymantriidae family was not...