Treesearch

The eastern hardwood resource has been shaped by a combination of human and natural disturbances. This impact on the forest resources of West Virginia has been especially dramatic. This resource has changed from a virgin forest dominated white oak, chestnut, spruce, white pine, and hemlock in the late 19th century, to one dominated by red oak in the 1950's, to today's forest with rapidly increasing volumes of yellow-poplar. This paper examines changes in the composition of West Virginia's forests based on the concept of market- based disturbance. This concept assumes that past market...

We investigated the effect of habitat loss on the ability of trees to shift in distribution across a landscape dominated by agriculture. The potential distribution shifts of four tree species (Diospyros virginiana, Oxydendron arboreum, Pinus virginiana, Quercus falcata var. falcata) whose northern distribution limits fall in the southern third of Ohio were used to assess possible distribution shift scenarios as a result of global warming. Our predictions derive from the results of simulations using (a) forest inventory based estimates of current distribution and abundance of target...

Urban forests and herbaceous open space play a vital role in the environmental and aesthetic ?health? of cities, yet they are rarely identified in land-use inventories of urban areas. To provide information on urban forests and other vegetative land cover in Illinois cities, Landsat Thematic Mapper (TM) data from June 27, 1988, were classified for the Chicago metropolitan region (9,717 km2). Ten land-cover classes were identified, including two types of forestland (occupying 5.8% of the total area), residential land with trees (14.6%) or without trees (7.8%), cropland (37.5%), two types of...

Ecotones are inherent features of landscapes, transitional zones, and play more than one functional role in ecosystem dynamics. The delineation of ecotones and environmental boundaries is therefore an important step in land-use management planning. The delineation of ecotones depends on the phenomenon of interest and the statistical methods used as well as the associated spatial and temporal resolution of the data available. In the context of delineating wetland and riparian ecosystems, various data types (field data, remotely sensed data) can be used to delineate ecotones. Methodological...

As part of the Mid-Atlantic Regional Assessment, an evaluation is being made of the impacts of climate variability and potential future climate change on forests and forestry in the Mid-Atlantic Region. This paper provides a brief overview of the current status of forests in the region, and then focuses on 2 components of this evaluation: (1) modeling of the potential impacts of climate change on tree species' distributions, and (2) a survey of how extreme weather events affect forests and forest land management in the region. The tree distribution modeling indicates that climate change...

Ridgetop pine communities of the Southern Appalachian Mountains historically have been maintained by lightning- and human-caused fires. With fire suppression for several decades, characteristic stands are entering later seral stages. They typically have an overstory of Table Mountain (Pinus pungens)and/or pitch pine (P. rigida), a midstory of chestnut oak (Quercus prinus), scarlet oak (Q. coccinea), and blackgum (Nyssa sylvatica), and a shrub layer of dense mountain laurel (Kalmia latifolia). Previous research suggests that restoration of these communities can be accomplished with the...

Scant information exists about the spatial extent of human impact on forest resource supplies, i.e., depreciative and nonforest uses. I used observations of ground-sampled land use and intrusions on forest land to map the probability of resource use and human impact for broad areas. Data came from a seven-state survey region (Alabama, Arkansas, Louisiana, Mississippi, east Oklahoma, Tennessee, and east Texas) containing 32,000 land-use plots, with detailed attribute information for about half of these plots classed as forest land. Forest land attributes included human-associated intrusions...

Fall and winter needles from pines growing near the Kostomuksha oredressing mill (KODM) were collected and studied by light microscopy. Fall needles showed symptoms of SO2 influence and no specific seasonal changes in mesophyll. The injury rates of needle surface and mesophyll showed that pollutants penetrate into the needles through stomata and cuticle. Compared to fall needles winter needles exhibited a greater number of destroyed mesophyll cells and heavy cuticle damage. The effect of the KODM pollutants is thought to reduce the tolerance of mesophyll to low temperatures. It is obvious...

In Portugal, several eucalyptus spacing trials cover a relatively broad range of experimental designs: trials with a non-randomized block design with plots of different size and number of trees per plot; trials based on a non-systematic design in which spacings were randomized resulting in a factorial arrangement with plots of different size and shape and equal number of trees per plot; trials based on a completely randomized block design with different plot sizes and different numbers of trees per plot. Limitations and advantages of these experimental designs, when applied to Portuguese...

The Urban Forest Effects (UFORE) computer model was developed to help managers and researchers quantify urban forest structure and functions. The model quantifies species composition and diversity, diameter distribution, tree density and health, leaf area, leaf biomass, and other structural characteristics; hourly volatile organic compound emissions (emissions that contribute to ozone formation) throughout a year; total carbon stored and net carbon sequestered annually; and hourly pollution removal by the urban forest and associated percent improvement in air quality throughout a year.