Treesearch

This paper is a review of research in Chicago that linked analyses of vegetation structure with forest functions and values. During 1991, the region's trees removed an estimated 5575 metric tons of air pollutants, providing air cleansing worth $9.2 million. Each year they sequester an estimated 315 800 metric tons of carbon. Increasing tree cover 10% or planting about three trees per building lot saves annual heating and cooling costs by an estimated $50 to $90 per dwelling unit because of increased shade, lower summertime air temperatures, and reduced neighborhood wind speeds once the...

Reducing overstory density is a commonly recommended method of increasing the regeneration potential of oak (Quercus) forests. However, recommendations seldom specify the probable increase in density or the size of reproduction associated with a given residual overstory density. This paper presents logistic regression models that describe this relation for a forest in the Ozark Highlands of Missouri that has been managed for 40 years by the single-tree selection system. In general, density of oak reproduction of a given size increases with decreasing residual stand basal area. However, the...

This paper describes results from field studies and simulation that can be used to estimate the yarding cost for the Koller K300 cable yarder. Yarding costs can be estimated for clearcuts and light and heavy thinnings in eastern hardwoods. Yarding costs can be estimated with a handheld calculator, or the data can be incorporated into stump-to-mill desktop PC and mainframe computer programs. The results can be a valuable tool for loggers, managers, and planners considering the use of small- to medium-size cable yarders to extract timber from eastern hardwood stands.

The gypsy moth, Lymantria dispar, will soon become established in much of the Midwest. If an outbreak with extremely high population levels of this serious defoliator is allowed to occur in the Chicago area, what kind of damage can be expected? A model for defoliation, refoliation and mortality was developed based on the number of trees and associated leaf biomass for each tree species classified according to its attractiveness to or probability of infestation by gypsy moth. Data for eight land uses in the Chicago metropolitan area were used in the model. Vacant lands, institutional lands...

We evaluated the influence of protracted low-level nitrogen (N) fertilization on 29 morphological, physiological, or chemical parameters measured on mature red spruce (Picea rubens Sarg.) growing within 10 study plots on Mount Ascutney, Vermont. For 8 consecutive years prior to this study, each plot received one of five treatments: 0, 15.7, 19.8, 25.6, or 31.4 kg N?ha-1?year-1. In comparison to plant material from control plots, trees that received N fertilization had fewer but longer and heavier needles, and higher rates of shoot water loss than trees from control plots. N fertilization...

Annual territory occupancy by Flammulated Owls (Otus flammeolus) in Colorado was evaluated from 1981-1996. Fourteen territories occurred within a 452 ha study area. Each year, three to six territories were occupied by breeding pairs and three to seven were occupied by unpaired males. Territories were occupied by breeding pairs a mean of 5.1 years (not necessarily consecutive) and by unpaired males a mean of 3.9 years (not necessarily consecutive). Territories most consistently occupied by breeding pairs contained the highest percentage of old (200-400 years) ponderosa pine/ Douglas-flr,...

The forest cover of Champaign County, in east-central Illinois, was mapped from 1993 aerial photography and entered in a geographical information system database. One hundred and six forest patches cover 3,380 ha. These patches have a mean area of 32 ha, a mean perimeter of 4,851 m, a mean perimeter to area ratio of 237, a fractal dimension of 1.59, and a mean nearest neighbor distance of 620 m. However, only 480 ha can be considered interior forest. These results are compared with results of previous landscape level studies of Illinois, and the implications of these results for conservatio...

The Illinois Plant Information Network (ILPIN), a species-based database on the flora of Illinois, is useful for assessing botanical diversity in Illinois and surrounding states. All known vascular plant taxa from Illinois (more than 3,200) are included. It contains county distributions (totaling nearly 90,000) for each taxon and information on the taxonomy, ecology, biology, and ecodistribution of each. Summary maps and tables on Illinois flora are generated easily, that include the number of taxa by county or subsets such as number of threatened and endangered species, number of exotics,...

Preliminary field trials using red oak logs from trees dying from oak wilt disease were successful in eliminating oak wilt fungus from sapwood after fumigation with sulfuryl fluoride for 72 h under tarp. These results support earlier laboratory data on the fungitoxicity of sulfuryl fluoride as a potential replacement for methyl bromide of exported red oak veneer logs. However, not all other microorganisms were completely eradicated from oak sapwood at the treatment levels used in this trial.

Forest trees are constantly exposed to various types of natural and anthropogenic stressors. A major long-term goal of our research is to develop a set of early physiological and biochemical markers of stress in trees before the appearance of visual symptoms. Six red spruce (Picea rubens Sarg.) stands from the northeastern United States were selected for collection of soil and foliage samples. All of the chosen sites had soil solution pH values below 4.0 in the Oa horizon but varied in their geochemistry. Some of these sites were apparently under some form of environmental stress as...