Treesearch

Phytoremediation is an emerging technology for remediating brownfields, landfills, and other contaminated sites. Many laboratory and field tests have demonstrated that trees and other vegetation can absorb, transform, or contain a variety of contaminants, including soft and heavy metals and volatile organics through hydraulic control, absorption, and mycorrhizal activity in the root zone. But phytoremediation can not be applied in an "off the shelf" fashion because plants grow differently on different soils, different microenvironmnets, and different types of contaminants. Site- and...

Chemical crop tree release treatments were applied to young hardwood stands at three sites in central West Virginia to evaluate the effectiveness of glyphosate as Accord (41.5% SL), imazapyr as Arsenal AC (53.1% SL) and Chopper (27.6% EC), and triclopyr as Garlon 3A (44.4% triethylamine salt SL), and Garlon 4 (61.6% butoxyethyl ester EC) using hack-and-squirt injection and low volume stem bark band application methods. American beech (Fagus grandifolia Ehrh.) was a major competitor to black cherry (Prunus serotina Ehrh.) crop trees at each site. The treatments were applied in June and...

In art galleries, one often studies a painting from various angles and distances, seeking to discover all that is possible about the method and style of the artist and what the artist is trying to communicate. In other words the observer is trying to detremine "what is behind the painting."

The optimum frequency and time of sampling required to generate comprehensive diversity indices of herbaceous species in Allegheny hardwood forests was studied. Four 8-ha sites on the Allegheny National Forest were sampled monthly from May to August in 1992 and 1993 for herbaceous layer species composition and percent cover.

Water resources in forests of the northeastern United States have been a contentious issue throughout the 20th century. The Weeks Law of 1911 recognized the needs to protect water yield and quality, and stimulated long-term interest in the relationships between forests and water. Research has provided a clear understanding of the roles of forests in hydrologic and nutrient cycling, water quality, and sedimentation, and how these roles are affected by human and natural disturbances.

Using Scots pine (Pinus sylvestris L.) in Fenno-Scandia as a case study, we investigate whether net primary production (NPP) and maintenance respiration are constant fractions of gross primary production (GPP) as even-aged mono-specific stands progress from initiation to old age. A model of the ratio of NPP to GPP is developed based on (1) the classical model of respiration, which divides total respiration into construction and maintenance components, and (2) a process-based model, which derives respiration from processes including construction, nitrate uptake and reduction, ion uptake,...

Uncertainty is an important consideration for both developers and users of environmental simulation models. Establishing quantitative estimates of uncertainty for deterministic models can be difficult when the underlying bases for such information are scarce. We demonstrate an application of probabilistic uncertainty analysis that provides for refinements in quantifying input uncertainty even with little information. Uncertainties in forest carbon budget projections were examined with Monte Carlo analyses of the model FORCARB. We identified model sensitivity to range, shape, and covariabili...

One of the first considerations in developing a strong and comprehensive urban forestry program is determining the desired outcomes from managing and maintaining vegetation in cities. Urban trees offer a wide range of potential benefits to the urban environment and society. However, there also are a wide range of potential costs and, as with all ecosystems, numerous interactions that must be understood if society is to optimize the net benefits from urban vegetation. Inadequate understanding of the wide range of benefits, costs, and expected outcomes of urban vegetation management designs...

The Hubbard Brook Ecosystem Study (HBES), begun in 1963, is a long-term effort to understand the structure, function and change in forest watersheds and associated aquatic ecosystems at the Hubbard Brook Experimental Forest in New Hampshire. Chemical analyses of streamwater and precipitation collections began in 1963, and analyses of lakewater collections began in 1967. This publication documents these collection methods, sites, and analytical techniques, providing a complete record to ensure the integrity of HBES data.

The effects of elevation, aspect, ambient air temperature, and soil moisture on soil temperature were examined in and adjacent to the Fernow Experimental Forest in West Virginia to determine the extent of frigid soils. The mean annual temperature of frigid soils ranges from 1? to 7?C at a depth of 50 cm; the difference between mean winter and mean summer temperatures exceeds 5?C. Soil temperature and moisture were measured and data on air temperature were collected at study sites on or near the Fernow from December 1994 to December 1997. Readings were taken 6 times during the year (January,...