Forests Of Virginia Research Articles

Testing Habitat-Relationship Models for Forest Birds of the Southeastern United States

The bird-habitat relationships proposed by Hamel (1992) represent the most comprehensive description of habitat suitability for all birds that breed and/or winter in forests of the southern United States. These relationships were developed from compilations of published census and natural history data, field experience, and expert opinion. As such, these relationships can be considered untested models of bird-habitat associations. We tested the ability of these models to predict the distribution of 25 common breeding birds among the forest habitat types of the Southern Blue Ridge physiographic province. We used point-count survey data from national forests in Virginia, Tennessee, and Georgia to test the models. Thirteen of 25 models (52%) performed well (i.e., positive association between ranks from model predictions and ranks from the observed data) on the Tennessee data, while only 33% and 23% of the models performed well on the Georgia and Virginia data, respectively. Models for some species with distributions restricted to mid-aged to mature deciduous habitats (e.g., black-and-white warbler [Mniotilta varia] and black-throated blue warbler [Dendroica caerulescens]) and/or restricted to high elevations (e.g., veery [Catharus fuscescens]) performed well across study sites. However, models for other mature deciduous forest species did not perform as well because these species (e.g., ovenbird [Seiurus aurocapillus], scarlet tanager [Piranga olivacea], and wood thrush [Hylocichla mustelina]) tended to occur more frequently than predicted in early age classes or mixed forest types. For these species, we suggest that early-aged deciduous habitat types be considered marginal habitat (rather than unused, as defined in Hamel's publication) for these relatively widespread forest birds in the Southern Blue Ridge region. Models for habitat generalists (e.g., Carolina chickadee [Poecile carolinensis], Carolina wren [Thryothorus ludovicianus], and red-eyed vireo [Vireo olivaceus]) did not perform well. We suggest that Hamel's models be used cautiously for most birds in mature forest habitats. Further tests of these models are needed to clarify the discrepancies between the predicted and observed patterns of habitat use we observed.

Using dendrochronology to identify major ice storm events in oak forests of southwestern Virginia

Major ice storms are significant forest disturbance agents and natural hazards in east- ern North America. Studies of forest damage suggest that ice storm severity varies among topo- graphic positions, but little climatic information is available to evaluate fine-scale variations in ice storm climatology. Our study assesses the utility of tree-ring analysis for identifying fine-scale spatial patterns and long-term temporal variations in the frequency of major ice storms. We looked for ice storm signals in tree-ring chronologies of chestnut oak Quercus prinus L. and black oak Q. velutina Lam. at 2 sites in southwestern Virginia that were affected by known ice storms in 1979 and 1994. Radial growth of these species exhibits a dual response to ice storm disturbance. Trees with substan- tial canopy loss show reduced radial growth for several years following an ice storm. Other trees dis- play increased growth due to the loss of competitors. We identified thresholds of ring-width increase and decrease that distinguished ice storms from other events, permitting a preliminary attempt to reconstruct ice storm history at each of the 2 study sites. For our Gap Mountain site, ring-width chronologies spanning the period 1914-1998 record apparent signals of major ice storms in 1920, 1979, and 1994. For the Walker Mountain site, our results suggest that during the period 1901-1998 the stand was affected by major ice storms in 1918 and 1994. This study suggests that den- drochronology provides a promising method for understanding fine-scale spatial patterns of ice storm disturbance in hardwood forests.

“The little spots allow’d them”: The archaeological study of African-American yards

Yards, like buildings and more portable artifacts, are significant expressions of culture. Yet within African-American archaeology, yards have not been the focus of serious discussions addressing questions of work and leisure activities, community interactions, aesthetics, and culture change. The authors review archaeological, ethnographic, and historical evidence of yards associated with New World slave quarters and present a framework for analysis. Results of recent excavations at a slave quarter at Poplar Forest in central Virginia, occupied from ca. 1790 to 1812, are presented within the context of this framework. The archaeological study of yard spaces provides significant information about cultural meanings and uses of space.

Occurrence of Lepidoptera on Selected Host Trees in Two Central Appalachian National Forests

In 1995 and 1996, Lepidoptera larvae of 13 families were sampled by pruning foliage from canopies of maple, hickory, red oak group, white oak, and chestnut oak. The families were Arctiidae, Geometridae, Hesperiidae, Lasiocampidae, Lycaenidae, Lymantriidae, Noctuidae, Notodontidae, Nymphalidae, Papilionidae, Saturniidae, Sphingidae, and Thyatiridae. Samples were collected from 18 plots (each 200 ha), nine in the George Washington National Forest in Virginia and nine in the Monongahela National Forest in West Virginia. Sampling seasons were from May to mid-August; foliage samples were collected each week. The occurrence of Lepidoptera on host trees within the two forests was compared. A total of 131 species of caterpillars representing 13 families was collected. Most larvae were Noctuidae (47 species) and Geometridae (44 species). Of 6,743 larvae collected over both years, 57% were gypsy moth, Lymantria dispar (L.). The population of this species collapsed during the second year of the study because of the fungus Entomophaga maimaiga. Other particularly abundant species in both forests were Acronicta ovata Grote, Hyphantria cunea (Drury), Polia latex (Guénée), Melanolophia canadaria (Guénée), Alsophila pometaria (Harris), and Nadata gibbosa (J.E. Smith). Some species were found only in one forest. Larval richness and abundance were higher in May and August and the lowest numbers occurred in June and July. Abundance and richness were different for the 2 yr. Population shifts may be directly related to weather conditions or indirectly related through the effects of temperature or rainfall patterns on natural enemies, foliage chemistry, or other factors. The number of species of caterpillars collected from the host tree groups was 62 on maple, 77 on hickory; 76 on the red oak group, 75 on chestnut oak, and 66 on white oak. The abundance of larvae ranged from 14.8% collected on maple to 25.4% collected on the red oak group.

Ice Storm Damage to a Mixed Hardwood Forest and Its Impacts on Forest Regeneration in the Ridge and Valley Region of Southwestern Virginia

storms in early 1994 caused tremendous damage to the forests of southwestern Virginia. Two years later, an intensive survey was carried out at the Fishburn Forest of Virginia Tech to investigate the impacts of topography on the severity of ice damage to the forests, and to quantify the effects of ice-created gaps on forest regeneration. The random survey plots were stratified based on 15 recognized topographic categories. In each plot, gap area was measured and four small random quadrats were selected for seedling survey in both gap and non-gap understory. Species differ in their susceptibility to ice damage and change in species composition across different topographic areas. We created a community susceptibility index to evaluate forest susceptibility to ice damage. This index, calculated by weighting species composition, and their local susceptibility in the corresponding topographical category, was highly correlated to the severity of ice damage as indicated by gap size. In general, forests on steep slopes had the greatest susceptibility. Because of severe ice storms are frequent in the region, and their effects on forest turnover are topographic specific, they are likely to be a major factor in determining the dynamics of forest landscapes. Presence of gaps, gap size, and topography affected seedling density and height growth. However, the species composition in gaps did not differ from that in the non-gap understory and overstory elements were well represented in the seedling communities. This indicates that future forests may not differ from current ones. However, gap size may affect the rate of forest recovery.

Effects of seven silvicultural treatments on terrestrial salamanders

We compared the relative abundance of terrestrial salamanders before and after application of seven regeneration treatments in a low-elevation, southern Appalachian hardwood forest in southwest Virginia. Treatments included understory removal, group selection, two shelterwoods, leave-tree, clearcut, and a control. Salamander relative abundance was significantly lower after harvest on the group selection ( p=0.005), shelterwoods ( p=0.007 and p=0.015), leave-tree ( p=0.001), and clearcut treatments ( p=0.001). There was no significant difference in relative abundance during the same period on the control ( p=0.788) or understory removal ( p=0.862) treatments.

Reshaping the Ecology of Invading Populations of Hemlock Woolly Adelgid, Adelges tsugae (Homoptera: Adelgidae), in Eastern North America

Hemlock woolly adelgid, Adelges tsugae Annand (Homoptera: Adelgidae), is native to Japan where it is an innocuous inhabitant of Tsuga diversifolia Masters and T. sieboldii Carriere throughout their natural growing areas. Native adelgid populations are regulated by host resistance and natural enemies, in particular the oribatid mite, Diapterobates humeralis (Hermann) and the coccinellid beetle, Pseudoscymnus tsugae Sasaji and McClure. Invading populations of A. tsugae in western North America on T. heterophylla Sargent and T. mertensiana Carriere are mainly regulated by host resistance. However, invading populations in eastern North America attain damaging levels on T. canadensis (L.) Carriere and T. caroliniana Engelmann and are regulated mainly by weather and negative density-dependent feedback mechanisms related to host deterioration. Although A. tsugae is only passively dispersed by wind, birds, forest-dwelling mammals and humans, it is spreading at an alarming rate and is sufficiently cold hardy to threaten the existence of the two eastern hemlock species throughout their natural ranges. The current hope for suppressing invading populations of hemlock woolly adelgid in eastern North America lies with the exotic predator, P. tsugae. Extensive laboratory studies of the biology and predatory ability of P. tsugae revealed that it feeds on all life stages of its prey, that its multivoltine life cycle is well synchronized with that of the adelgid, and that it has great potential for biological control. We have reared and released nearly 130,000 adults of P. tsugae in forests in Connecticut, New Jersey and Virginia during the past four years. P. tsugae has reproduced, dispersed, overwintered and reduced densities of hemlock woolly adelgid by 47–88% in only five months on release branches at these sites. Current studies are investigating the long-term ability of P. tsugae to regulate invading populations of A. tsugae in eastern North America.

The Effects of Harvesting Practices on West Virginia's Wood Supply

Abstract The status of West Virginia's timber resource was assessed by comparing preharvest and postharvest stand structures of 99 recent harvests. Stands were classified according to silvicultural practice and their potential for production of high-quality sawlogs. Results indicate that West Virginia's forest owners focus on extracting sawtimber. Only 27 stands could sustain another commercial sawlog harvest in the current rotation. Because local demand for low-grade logs and pulpwood is increasing, in the next forest rotation there exist opportunities for landowners to abandon diameter-limit sales in favor of more productive, managed forests.

Exploratory Pollen Analysis of the Ditch of the 1665 Turf Fort, Jamestown, Virginia

Pollen analysis of subsoil, slopewash, episodic fill, plowzone, and archaeological backdirt deposits in a core from a ditch associated with the 1665 Turf (earthwork) Fort at Jamestown, Virginia, record bare, slightly weedy local conditions around 17th-century artisan dwellings on the Jamestown waterfront and register the Virginia forest in the background before construction of the fort. Goosefoot dominated the earthwork slope; close relatives of the goldenrods were initially the most prominent plants in the open-ditch period. Pollen percolation rates adjusted for plowing and applied to ragweed-type (Ambrosia-type) percentages suggest that cultivation over the ditch began ca. 1729. Cultural matrix depostition, slopewash, and pollen percolation were crticial to the preservation of this record, and serve to emphasize the importance of evaluating pollen record formation processes in cultural landscape studies.

Experimental tests of nest site competition in two Peromyscus species.

The importance of interspecific competition for nest sites between the white-footed mouse (Peromyscus leucopus noveboracensis) and the cloudland deermouse (P. maniculatus nubiterrae) were investigated in the montane forests of southwestern Virginia over 3 years. Trials were conducted for both species using large, outdoor enclosures in order to examine: (i) nest site preference in isolation and (ii) nest site selection made in the presence of potential competitors. Both species demonstrated a strong preference for arboreal nest sites when tested without competitors present. After the introduction of a heterospecific intruder, P. leucopus often shifted to a non-arboreal nest while P. maniculatus continued to use arboreal nests. Intruding P. maniculatus displaced resident P. leucopus from P. leucopus' preferred nest sites in all 3 years while intruding P. leucopus never displaced P. maniculatus. Neither species was routinely displaced in conspecific trials. Resident P. maniculatus also excluded P. leucopus from access to preferred nesting sites in all three years while P. leucopus were only able to exclude P. maniculatus in the 3rd year. Both species exhibite relatively low frequencies of exclusion in conspecific trials with the exception of P. maniculatus which excluded high proportions of conspecific intruders in the second year. We suggest that the asymmetrical advantage enjoyed by P. maniculatus in nest site selection may result from both site-specific effects and a species-specific influence on P. leucopus. Nonetheless, the intensity of such influence varied between years, perhaps as a function of population density, and did not appear to drastically influence continued coexistence of these congeners.

Impact of Group Selection Silviculture on Timber Harvesting Productivity and Cost in Appalachian Hardwood Timber Stands

Abstract Group selection is a regeneration harvest method that is being promoted by the USDA Forest Service as an alternative to clearcutting. In a group selection cut, "groups" of trees are marked and harvested in small patches dispersed in a mosaic pattern throughout the timber stand. Group selection has the potential to increase harvesting cost as compared to traditional clearcutting. Three logging systems, a skyline yarder system, a feller-buncher/cable skidder system, and a chainsaw felling/cable skidder system were studied while logging group selection timber sales in the Jefferson National Forest in Virginia. Time study data on the felling and skidding functions were recorded, as well as weekly production and cost data for each operation. Historic clearcutting production was obtained from the study loggers' records for comparison purposes. Group selection unit costs were $39.72, $14.13, and $15.33 per ton for the three systems, respectively. The study systems experienced decreases in production ranging front 17% to 52%. Most of the production decrease was due to an excessive amount of unproductive time directly resulting from the impact of the small, dispersed, multiple-harvest areas on the loggers' normal operating procedure and work flow. North. J. Appl. For. 10(4): 170-174.

Age Structure and the Maintenance of Pinus pungens in Pine-oak Forests of Southwestern Virginia

-The age structure of table mountain pine Pinus pungens Lambert was examined in three pine-oak forests in southwestern Virginia. The age distribution of P. pungens was bimodal with a major peak in the large tree age classes and a smaller secondary peak in the seedling age classes. The predominance of advanced regeneration of oaks and other gap-exploiting woody species, and the underrepresentation of P. pungens seedlings and small trees, indicates that maintenance of P. pungens in these forests is unlikely under current disturbance regimes. It is hypothesized that the P. pungens populations studied originated from seed trees left on the sites following heavy logging and fires at the turn of the century.

An Experimental Examination of Nest‐Site Segregation by Two Peromyscus Species

The role of interspecific competition for nest sites in the coexistence of the white—footed mouse (Peromyscus leucopus noveboracensis) and the cloudland deermouse (Peromyscus maniculatus nubiterrae) was experimentally investigated in the montane forests of southwestern Virginia. Radiotelemetry was used on control grids, with both species present, and reciprocal removal grids to contrast nest—site selection with and without contraspecifics present. On control grids, Peromyscus maniculatus used only arboreal nests while P. leucopus used both ground and arboreal nests. In addition, relative to P. maniculatus, those P. leucopus which did select arboreal nests, used lower cavities and trees of smaller diameter at breast height (dbh). These results provide strong evidence for vertical nest—site segregation, and confirmed observations from previous studies. Though both species demonstrated shifts in nest selection between treatments in the removal experiment, the analysis of the P. maniculatus response was statistically suspect and both responses appeared to be ecologically insignificant (that is, shifts were not towards the type of nest site used by the removed species). Additionally, home range analysis and examination of nest availability suggest that large portions of suitable habitat on each grid may not have been used and that nest sites were not a limiting resource. We suggest, therefore, that interspecific competition for nest sites was probably not important to co—existence during the course of the study.

Distribution and Ecology of Myxomycetes in Temperate Forests. II. Patterns of Occurrence on Bark Surface of Living Trees, Leaf Litter, and Dung

The moist chamber culture technique was used to study myxomycete communities associated with bark surface of living trees, leaf litter, and dung in upland forests of southwestern Virginia. Patterns...

Incidence of Chestnut Blight and Survival of American Chestnut in Forest Clearcut and Neighboring Understory Sites

In 1985 and 1987, chestnut blight incidence and survival of American chestnut sprout clusters (groups of stems sprouting from a single stump) were assessed in Virginia and west Virginia forest clearcut sites, 13-19 yr after clearcutting, and in understory sites. Overall, sprout cluster blight incidence averaged 96.3% in 17 clearcuts and 37.1% in 13 understory sites; chestnut sprout cluster survival averaged 55.7 and 94.2% in clearcut and understory sites, respectively. In the 1987 survey. (…)

Distribution and ecology of Myxomycetes in temperate forests. I. Patterns of occurrence in the upland forests of southwestern Virginia

A comparative ecological study of the Myxomycetes occurring in five different upland forest communities in the Mountain Lake area of southwestern Virginia was carried out during 1982–1986. Although the forest communities selected for study occupied different relative positions (from subxeric to mesic) with respect to an environmental moisture complex-gradient, a high degree of similarity existed among the communities for species composition of Myxomycetes. However, absolute abundance, species richness, and species diversity were higher for the more mesic communities. The seasonal pattern was for both species richness and species diversity to be exceedingly low early in the season, to increase to their highest levels in August, and then to decline throughout the remainder of the season. In general, Myxomycetes appear to be rather opportunistic organisms, occupying those microhabitats suitable for their growth and development as these become available to them. Nevertheless, considerable resource partitioning among species would seem to exist, since characteristic patterns of microhabitat occupation and sporulation phenology were noted for most species. In an effort to quantify resource partitioning, values of niche breadth and niche overlap were calculated for 39 quantitatively important species.

Focus Group Interviewing Applied to Retired West Virginia Nonindustrial Private Forest Landowners

Abstract To gain a deeper understanding of the interests and motivations of retired West Virginia forest landowners, the focus group interview technique was used with four groups of retired resident owners. This group discussion technique provided a deeper understanding of how this important group of forest landowners think. The results show that these owners display a strong sense of stewardship toward the land and a concern for their families, society as a whole, and for future generations that is not evident from the results of mail questionnaire surveys. They tend to downplay the financial aspects of timber production. A land ethic is clearly implied by their comments. They desire a sense of security and well-being from the ownership of forestland and evidence a deep feeling for nature. The results of this study show that focus group interviewing is a viable technique for gaining an understanding of important segments of the land owning population that goes beyond the information provided by mail canvasses. North. J. Appl. For. 5:198-200, Sept. 1988.

Crown architecture, light interception, and stomatal conductance patterns for sympatric deciduous and evergreen species in a forest understory

Within a mixed deciduous forest in central Virginia, daily patterns of light interception and stomatal conductance were related to crown architecture for the deciduous Asimina triloba and the evergreen Ilex opaca. For A. triloba, branches were up to 54% longer, the bifurcation ratio was 15% lower, branch internode lengths were 15% greater, and leaf angles were closer to the horizontal plane (9 vs. 22°) than for I. opaca, possibly contributing to a greater percentage of sunlit leaves for A. triloba at 1100 and 1400 (22.4 vs. 10.0 and 30.0 vs. 10.1%, respectively). Maximum stomatal conductances to water vapor diffusion were 4.0 and 4.6 mm∙s−1 for sunlit leaves of A. triloba and I. opaca, respectively. Sunlit and shaded leaf stomatal conductances were similar in A. triloba throughout the day, but in I. opaca, values for sunlit leaves were up to 1.3 mm∙s−1 greater than values measured in shaded leaves. In addition, stomatal conductances for shaded leaves of A. triloba remained approximately 1.0 mm∙s−1 greater than for I. opaca throughout most of the afternoon. Therefore, within a forest understory environment, sympatric deciduous and evergreen species may differ in crown architecture, light interception, and stomatal conductance patterns.

Succession in Loblolly Pine Plantations Converted from Second-growth Forest in the Central Piedmont of Virginia

Vegetation composition and structure were quantified in 21 pine stands converted from second-growth hardwood-pine forest at two state forests in Virginia. These stands included three replications each of seven developmental stages ranging in age from 1-22 years. Species richness and vegetation cover in the ground stratum showed the same trend: high values in stands 1-5 years of age followed by a decline from 5-15 years, at which point canopy closure was complete, and these variables were relatively stable for the next 7 years. A peak in transgressive stratum richness in the 9th year was followed by a similar decline and leveling off. Evenness (J') values over time were nearly constant for these understory strata, except in 3-year-old stands where a decline in ground stratum evenness occurred due to dominance by Andropogon virginicus. Increasing richness and evenness in the overstory stratum was due to growth of hardwoods. Trends in richness and evenness differed from the old-field successional model due to a high diversity of seeds and sprouts at the start of succession. Despite such differences, the seral stages typical of old-field succession were discernible in converted stand succession. However, they were somewhat abbreviated and masked by the abundance and variety of reproductive units and the rapid closure of the canopy by codeveloping pines and sprout hardwoods. INTRODUCTION The central Piedmont of Virginia is part of the Oak-Pine Forest Region delineated by Braun (1950). Young forests are characteristically dominated by Pinus virginiana and P. echinata and are gradually replaced during succession by an oak-hickory complex (Braun, 1950). From the 1700s to the early 1800s Piedmont lands were cleared, intensively farmed and abandoned (Gottmann, 1969). Abusive crop farming depleted soils and led to severe and extensive topsoil erosion (Culbertson, 1948; Gottmann, 1969). Much abandoned cropland reverted to native forest through succession. The end of the 19th century marked the beginning of a new period of deforestation when most of the commercially valuable forest of the Piedmont was harvested (Gottmann, 1969). Pinus taeda (loblolly pine) has been the principal species planted in the central Piedmont since the 1930s, even though it is incapable of natural regeneration throughout much of this region (S. F. Warner, pers. comm.). Up to the mid-1950s, most planting of P. taeda was in old fields. Owing to a decline in agricultural land abandonment, hardwood and pine-hardwood forests have been directly converted to P. taeda plantations at an accelerated rate. Whereas much is known about the vegetation dynamics of old-field succession in the Piedmont region of the Southeast (Crafton and Wells, 1934; Billings, 1938; McQuilkin, 1940; Oosting, 1942; Keever, 1950; Nicholson and Monk, 1974, 1975), little is known about such changes associated with the establishment and development of pine plantations on sites converted from second-growth forests. Thus, the objective of this study was to examine temporal changes in the composition and structure of vegetation in loblolly pine stands converted from such forests. 1 Present address: 435 Jackson Street, Fall River, Massachusetts 02721. 2 Present address: Department of Biology. 3Department of Biology.

Age-Structure Relationships of Trees Species in an Appalachian Oak Forest in Southwest Virginia

Ross, M. S., T. L. SHARIK, and D. WM. SMITH. (Dept. Forestry, Virginia Polytechnic Inst. and State Univ., Blacksburg, VA 24061, U.S.A.). Age structure relationships of tree species in an Appalachian oak forest in southwest Virginia. Bull. Torrey Bot. Club 109: 287-298. 1982.-The complete age and diameter structures were determined for all tree species in seven Appalachian oak stands arranged along a topographic moisture gradient in southwestern Virginia. All stands but one exhibited a prominent gap in the age distribution in the 20-40 year age classes. No gap was evident in the corresponding diameter distributions. Total and juvenile age distributions were described for selected species. Age structures differed among species, and reflected the different spatial and temporal niches which they occupy. It was hypothesized that the shape of the total age distribution in individual stands is related to the disturbance sequence, and to site through its influence on the species present. Coupling of age and diameter distributions of individual populations provided insights into the functional roles of species along the moisture gradient.