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Students benefit in many ways by taking field trips to forests. Improved academic performance, increased participation in outdoor recreation, and a better grasp of natural resources management are some of the advantages. However, trips are not easy for teachers to organize and lead. Declining budgets, on-campus schedules, and standards of learning are but a few of the constraints. With this in mind we studied the use of forest field trips among high school science teachers in the Southern Piedmont of the United States. We asked them if they have ever led a field trip to a forest for instructional purposes and measured their perceived constraints, teaching characteristics, natural resources training and extra-curricular activities, and proximity of their school to a forest. Binary logistic regression was used to model the relationship between these data and whether a teacher had taken a class on a forest field trip. Teachers also were asked to comment about trip constraints. Under half had led a forest field trip and qualitative data suggest that constraints such as time, money, and standardization are significant. However, model results indicate that walking distance to a forest, confidence in teaching topics related to forests, and participation in natural resources school programs predict field trip use (chi[superscript 2] = 127.81). Findings will help develop strategies for incorporating forest field trips into secondary science curriculum.

Flood tolerance and growth rate of seedlings are often deciding criteria for wetland and riparian restoration plantings; however, these efforts often result in inadequate survival and growth of planted tree species. In an attempt to determine if parental seed source ecotype and seedling greenhouse preconditioning could influence survival and growth of two common restoration tree species, seeds from American sycamore (Platanus occidentalis L.) and willow oak (Quercus phellos L.) were collected from upland and floodplain sites in the Piedmont and Ridge and Valley regions of Virginia and were subjected to greenhouse flooding and drought preconditioning prior to field planting. American sycamore seedlings grown under normal conditions were 15 % shorter than seedlings subjected to flood preconditioning but had 13 % greater height than drought preconditioned seedlings. Preconditioning did not have a significant effect on willow oak seedling height. American sycamore seedlings sourced from dry ecotypes were 14 % taller than seedlings sourced from wet ecotypes, while willow oak seedlings sourced from wet ecotypes were 11 % taller than dry ecotype acorns. Seedlings from dry ecotype parents for American sycamore and seedlings from wet ecotype parents for willow oak may increase survival and growth of these species on marginal Piedmont agricultural sites. Adaptations observed after greenhouse preconditioning did not increase survivability or growth. Selection of seed sources from trees that exhibit good growth and vigor in landscape settings similar to the restoration area may increase the likelihood of meeting restoration goals and objectives. [ABSTRACT FROM AUTHOR]

The nature of the relationship between a property's selling price and its marketing time in the housing market remains an open question to date, despite almost 40 years of inquiry and hundreds of regressions conducted on various data sources. This study attempts to settle the long‐standing open question by examining the issue from a new perspective. We demonstrate that the true price–TOM relationship should be nonlinear and characterized by an inverted U‐shaped curve wherein the selling price increases with TOM up to a certain threshold, reflective of a positive exposure effect and decreases thereafter to reflect a negative stigma effect. This relationship is borne out in an empirical analysis using a large sample of home sales from the Hampton Roads, Virginia metropolitan area during an extended period of time. We then formulate hypotheses about the benefit of search by home sellers, which are subsequently confirmed by the empirical findings. [ABSTRACT FROM AUTHOR]

Quantification of the heterotrophic component of total soil respiration is important for estimating forest carbon pools and fluxes, and for understanding carbon dynamics associated with stand development and silvicultural management. We measured the proportion of heterotrophic respiration (R H ) to total soil respiration (R S ) in extensively managed loblolly pine ( Pinus taeda L.) stands of four age classes in the Piedmont physiographic province of Virginia. Our objectives were to evaluate the influence of stand age and seasonality on the proportion of R H to R S (R H :R S ). R H was partitioned using root exclusion cores, and both R S and R H were measured 90 days following installation of cores for five seasons. Repeated measures analysis revealed that stand age and measurement season each had a significant effect on R H :R S ( P < 0.001), but that there were no interactive effects ( P = 0.202). Mean R H :R S during the 12-month study declined with stand age, and were 0.82, 0.73, 0.59, and 0.50 for 3-year-old, 9-year-old, 18- year-old, and 25-year-old stands, respectively. Across all age classes, the winter season had the highest mean R H :R S of 0.85 while summer had the lowest of 0.55. This study provides estimates of R H :R S in managed loblolly pine systems, and demonstrates the need to consider the impact of stand age and seasonal patterns when estimating net annual carbon (C) budgets of forest ecosystems and to identify the point at which plantations switch from functioning as C sources to a C sinks. [ABSTRACT FROM AUTHOR]

We studied stormwater detention basins where woody vegetation removal was suspended for 2 years in Virginia, USA to determine if woody vegetation can control Typha populations and how early woody plant succession interacts with Typha, other herbaceous vegetation, and site factors. Distribution and composition of woody vegetation, Typha and non- Typha herbaceous vegetation biomass, and site factors were assessed at 100 plots in four basins ranging in age from 7 to 17 years. A greenhouse study examined the interaction of shade and soil moisture on Typha biomass and persistence. Principal component analysis identified an environmental gradient associated with greater water table depths and decreased elevation that favored Typha but negatively influenced woody vegetation. Elevation was correlated with litter layer distribution, suggesting that initial topography influences subsequent environmental characteristics and thus plant communities. Soil organic matter at 0-10 cm ranged from 5.4 to 12.7 %. Woody plants present were native species with the exception of Ailanthus altissima and Pyrus calleryana. In the greenhouse, shade and reduced soil moisture decreased Typha biomass and rhizome length. The shade effect was strongest in flooded plants and the soil moisture effect was strongest for plants in full sun. Typha in dry soil and heavy shade had 95 % less total biomass and 83 % smaller rhizomes than Typha in flooded soil and full sun, but even moderate soil moisture reductions decreased above- and below-ground biomass by 63 and 56 %, respectively. Suspending maintenance allows restoration of woody vegetation dominated by native species and may suppress Typha invasion. [ABSTRACT FROM AUTHOR]

Abstract: Clonal forestry offers the opportunity to increase yields, enhance uniformity and improve wood characteristics. Intensive silvicultural practices, including fertilization, will be required to capture the full growth potential of clonal plantations. However, variation in nutrient use efficiency that exists among clones could affect growth responses. Our research objective was to determine the range of growth response and stem form quality due to fertilization in clones of Pinus taeda. A split-plot experimental design was used, with the whole plots being two levels of fertilizer application (fertilizer versus control) and the split plot factor being 25 clones. Whole plot treatments were blocked and replicated four times. Six years after planting and five years after fertilizer application, a repeated measures analysis showed fertilizer-by-time and clone-by-time interactions affected volume (p <0.10). Clone-by-fertilizer interactions were observed for tree height, branch traits, and a metric of foliar display. These interactions were primarily due to scale-effect phenomena rather than rank shifts. The magnitude of fertilizer responses observed in a small number of genotypes suggests that knowledge of fertilizer responses in widely deployed genotypes, if developed prior to mid-rotation, may better optimize management of single-clone blocks. Our results further indicate that a range of possibilities exist for the design and application of clone-specific precision silvicultural systems. [ABSTRACT FROM AUTHOR]

Survival and growth of planted tree species are common indices used to evaluate success of wetland restoration efforts used to compensate for wetland losses. Restoration efforts on marginal agricultural lands have typically resulted in less than satisfactory survival and growth of desired tree species. In an attempt to determine the effects of bottomland hardwood silvicultural methods on the survival and growth of pioneer tree species, this study evaluated combinations of five mechanical site-preparation techniques (mound, bed, rip, disk, pit), four levels of planting stock (gallon, tubeling, bare root, and direct seed), and three planting aids (mat, tube, none) on the four-year survival and growth of American sycamore planted in an old field riparian area in the Piedmont of Virginia. After four growing seasons, results indicated that mounding mechanical site preparation combined with gallon (3.8 L) planting stock provided the most positive influences on mean survival (100%), height (4.72 m), and groundline diameter (9.52 cm), and resulted in the greatest aboveground dry biomass accumulation (5.44 Mg/ha/year). These treatments may be economically viable for restoration and mitigations efforts, and could offer other economic alternatives such as short-rotation woody crops, which might make restoration efforts in marginal old field areas more attractive to private landowners. [ABSTRACT FROM AUTHOR]

Cerebrovascular accidents, or strokes, and gliomas are common intraaxial brain lesions in dogs. An accurate differentiation of these two lesions is necessary for prognosis and treatment decisions. The magnetic resonance (MR) imaging characteristics of 21 dogs with a presumed cerebrovascular accident and 17 with a glioma were compared. MR imaging findings were reviewed retrospectively by three observers unaware of the final diagnosis. Statistically significant differences between the appearance of gliomas and cerebrovascular accidents were identified based on lesion location, size, mass effect, perilesional edema, and appearance of the apparent diffusion coefficient map. Gliomas were predominantly located in the cerebrum (76%) compared with presumed cerebrovascular accidents that were located mainly in the cerebellum, thalamus, caudate nucleus, midbrain, and brainstem (76%). Gliomas were significantly larger compared with presumed cerebrovascular accidents and more commonly associated with mass effect and perilesional edema. Wedge-shaped lesions were seen only in 19% of presumed cerebrovascular accidents. Between the three observers, 10-47% of the presumed cerebrovascular accidents were misdiagnosed as gliomas, and 0-12% of the gliomas were misdiagnosed as cerebrovascular accidents. Diffusion weighted imaging increased the accuracy of the diagnosis for both lesions. Agreement between observers was moderate (kappa = 0.48, P < 0.01).