Treesearch

Globally, the environment is changing and deteriorating as greenhouse gases such as carbon dioxide (CO2) and tropospheric ozone (03) continue to increase at a rate of about 1% per year (Keeling et al. 1995, Chameides et al. 1995). The increase in these gases is directly related to anthropogenic activities (Chameides et al. 1995, Mooney et al. 1991) and is likely inducing subtle but substantial changes in the earth's surface temperatures and weather (Cha 1997; Martin 1996). In addition, anthropogenic activities have been linked to decreasing levels of stratospheric O3 and concomitant...

When wetland restoration includes re-establishing native plant taxa as an objective, an understanding of the variables driving the development of plant communities is necessary. With this in mind, we examined soil and physiographic characteristics of depressional wetlands of three vegetation types (cypressgum swamps, cypress savannas, and grass-sedge marshes) located in a fire-maintained longleaf pine ecosystem in southwestern Georgia, USA. Our objective was to establish whether plant community development in these wetlands is controlled primarily by hydrogeomorphic features or by different...

A distinctly American Romantic view of nature emerged during the 1800's. It was motivated by concerns that core American values were being degraded by the replacement of the wild frontier with industrialization and urbanization, and by concerns that a shallow and materialistic society was being created by the rationalism and utilitarianism of modernism (Oelschlaeger, 1991; Oravec, 1996). Romanticism celebrates wil, untrammeled nature as a holy temple where one finds God, learns moral lessons, and retreats from civilization. Nature has value because it is beyond human control, undisturbed...

In the past two decades, ecological restoration has moved from an obscure and scientifically suspect craft to a widely practiced and respected profession with considerable scientific knowledge and refined on-the-ground practices. Concurrently, forest restoration has become a valued skill of forestry professionals and a popular goal for forest management. Politics and conflicting human valuse, however, continue to confound and derail even some of the most well-intended efforts to restore forest ecosystems. Restoration projects exist within a social context, and they must therefore produce...

The language we use to describe nature matters. It is used by policy analysts to set goals for ecological restoration and management, by scientists to describe the nature that did, does, or could exist, and by all of us to imagine possible and acceptable conditions of environmental quality. Participants in environmental decision making demand a lot of the language and terminology used to discuss nature.We expect it to be precise and valid (i.e., we expect it to allow accurate scientific descriptions of the environment and of environmental quality). We also expect it to be powerful and fair...

Following a major disturbance event in forests that removes most of the standing vegetation, patterns of fine root growth, mortality, and decomposition may be altered from the pre-disturbance conditions. The objective of this study was to describe the changes in the seasonal and spatial dynamics of fine root growth, mortality, and decomposition that occur following removal of standing forest vegetation. Four upland temperate deciduous forest stands in southern Indiana, USA were chosen for this study. The ages of the stands, as represented as the number of growing seasons since forest...

Process models are powerful research tools for assessing the effects of multiple environmental stresses on forest plantations. These models are driven by interacting environmental variables and often include genetic factors necessary for assessing forest plantation growth over a range of different site, climate, and silvicultural conditions. However, process models are usually detailed and present complex modelling challenges that require innovative computing approaches. The authors have developed a hierarchical, parallel computing strategy for modelling forest plantations growing under...

Fragmentation of the land means changes in the vegetative cover. This alone has caused significant and wide spread physical and water quality changes to the streams and rivers in the central and upper Midwest. Removal of the forest canopy that changes land use to "open" conditions: agricultural, urban, or rights of way, is sufficient to initiate and prolong in-channel stream erosion and sedimentation for more than a Century. The comparison between cropland and forestland, shows the loss of forest cover will cause nearly annual, bankfull, peak flows to double or triple. The processes...

We used a spatially explicit landscape model, LANDIS, to simulate the effects of five management alternatives on a 3216 ha forest landscape in southeast Missouri, USA. We compared management alternatives among two intensities of even-aged management with clearcutting, uneven-aged management with group selection harvest, a mixture of even- and uneven-aged management, and no harvesting. Anticipated disturbances by windthrow and wildfire were included in the 100-year simulations across the landscape. The uneven-aged, even-aged long rotation, and mixed harvest regimes were similar to one...

Managing public forest collaboratively requires an understanding of differences between and similarities among diverse stakeholder groups. The Minnesota Contextual Content Analysis (MCCA) computer program was used to analyze text obtained from World Wide Web sites expressing the views of seven diverse stakeholder groups involved in forest planning and managemnet. Stakeholder groups wer found to share a practical orientation toward achievement of goals, but had important differences in the emphasis they placed on a set of more specific concepts. MCCA was found to be potentially useful tool...