Treesearch

Thomas et al. (1) address a question of great scientific interest: have pollution reductions mandated by the Clean Air Act improved forest health and productivity? Although answers to this question are of great importance, various aspects of this work limit its ability to address this question.

Climate change in the 21st Century is projected to cause widespread changes in forest ecosystems. Climate-FVS is a modification to the Forest Vegetation Simulator designed to take climate change into account when predicting forest dynamics at decadal to century time scales. Individual tree climate viability scores measure the likelihood that the climate at a given location and at a given point in time is consistent with the climate recorded for species’ contemporary distribution. These viability scores are input into Climate-FVS. A web-based service is available for providing this input...

Thirty active harvesting operations were part of a harvest and utilization study conducted in West Virginia in 2008. Data were collected on roundwood product and residue yields obtained from trees of different sizes, species, and qualities. This study was modeled after studies conducted on a regular and frequent basis by the Forest Inventory and Analysis unit in the Southern Research Station. Of the total volume harvested during this study, 88 percent was utilized and 12 percent was considered unutilized. Of the hardwood logging residue measured, 56 percent was from nongrowing-stock...

The regional ice storm of early January 1998 was a widespread disturbance for millions of acres of forest in northeastern New York, northern New England, and southern Quebec. Tree crowns were partially or totally lost as stems snapped and branches broke with the weight of the deposited ice. We tracked the effect of crown injury on a large sample of northern hardwood trees within the storm footprint. Comparisons of tree survivorship from 5 to 15 years after the storm showed that paper birch was most sensitive to storm impact followed by yellow birch. Root-rot disease present prior to the...

Goldspotted oak borer, Agrilus auroguttatus Schaeffer (Coleoptera: Buprestidae), is a new invasive species in southern California, USA. The extent of the host range of this insect is not known, but this knowledge will have a major impact on assessment of the risks that this pest poses to oaks [Quercus spp. (Fagaceae)]. We conducted laboratory tests to determine the potential suitability of native and ornamental oak species for larvae and adults of A. auroguttatus. We infested 179 cut logs (from 163 different trees) with eggs or larvae, measured neonate survival and, after 5 months, counted...

The U.S. Appalachian-Cumberland highland consists of about 62.3 million acres in portions of Alabama, Georgia, North Carolina, Tennessee, Kentucky, and Virginia; and is divided into five sections - Blue Ridge Mountains; Interior Low Plateau; Northern Ridge and Valley; Southern Ridge and Valley; and Cumberland Plateau and Mountains. Appalachian-Cumberland forests provide a multitude of ecological services and societal benefits. This publication presents results from the Southern Forest Futures Project specific to the Appalachian- Cumberland subregion, along with associated challenges to...

The challenge of observing interactions between plant pathogens, their hosts, and environmental heterogeneity across multiple spatial scales commonly limits our ability to understand and manage wildland forest epidemics. Using the forest pathogen Phytophthora ramorum as a case study, we established 20 multiscale field sites to analyze how host-pathogen-environment relationships vary across spatial scales of observation in a wildland pathosystem. We developed statistical models of disease intensity across five nested levels of spatial aggregation, from an individual host through four...

Quantifying regional evapotranspiration (ET) and environmental constraints are particularly important for understanding water and carbon cycles of terrestrial ecosystems. However, a large uncertainty in the regional estimation of ET still remains for the terrestrial ecosystems in China. This study used ET measurements of 34 eddy covariance sites within China and adjacent regions to examine the performance of the revised Remote Sensing-Penman Monteith (RS-PM) model over various ecosystem types including forests, grasslands, wetlands and croplands. No significant systematic error was found...

In California, fire regimes and related ecosystem processes have been altered by land use practices associated with Euro-American settlement, and climate warming is exacerbating the magnitude and effects of these changes. Because of changing environmental baselines, restoration of narrowly defined historical conditions may no longer be an attainable or sustainable long-term management goal, but comparisons between historical and current fire regimes can assist managers in prioritizing areas for ecological restoration and other management actions. Fire return interval departure (FRID)...

Understanding sources of streamflow and nutrient concentrations are fundamental for the assessment of pollutant loadings that can lead to water quality impairments. The objective of this study was to evaluate the discharge of three main tributaries, draining different land uses with karst features, as well as their combined influences on total nitrogen (TN) and total phosphorus (TP) levels in reservoir-like embayment (R-E) on a stream entering Lake Marion, South Carolina. From 2007-2009, hydrology, TN, and TP data were collected from the 1,555-ha Chapel Branch Creek (CBC) watershed. In...