The General Land Office (GLO) survey records of the Ashley County, Arkansas, area were analyzed for natural attributes including forest composition and structure, prairie communities and aquatic and geomorphological features. Almost 13,000 witness trees from at least 23 families were extracted from the surveys. Most (68% of the total) witness trees were black oak (Quercus velutina), pine (Pinus spp.), post oak (Q. stellata), white oak (Q. alba), hickory (Carya spp.) and sweetgum (Liquidambar styraciflua), with 60% of the taxa having fewer than 20 individuals and 26% represented by a single tree. Witness trees were usually moderate sized with very few small or large individuals noted. The distribution of presettlement grasslands, bottomland forests and upland mixed pine/hardwood forests was approximately mapped across the study area. Catastrophic disturbances mentioned in the GLO records included windthrow, floods, fire, timber harvest and earthquakes. Even during this early period, European settlers were altering the Ashley County landscape with trails, homes, farms, cotton gins and small-scale land clearing. Other notable ecological features in these survey records included large woody debris, wetlands, unique terrain conditions and wild game.

The purpose of this paper is to provide quantitative fire history information from a historically unique region, the oak barrens of the Interior Low Plateau Ecoregion. We sampled 27 post oak (Quercus stellata Wangenh.) trees from the Boone Creek watershed in southern Indiana. The period of tree-ring record ranged in calendar years from 1654 to 1999 and fire scar dates (n = 84) ranged from 1656 to 1992. The mean fire interval for the period 1656 to 1992 was 8.4 y and individual fire intervals ranged from 1 to 129 y. The average percentage of trees scarred at the site was 19% or about 1 in 5 trees sampled. No significant relationship was identified between fire years and drought conditions however, variability in the fire record coincided with Native American migrations and Euro-American settlement periods. Temporal variability in the fire record illustrates not only the dynamic nature of anthropogenic fire regimes but also the importance of humans in culturing presettlement barrens communities.

Few data are available that compare long-term changes in burned and unburned prairie remnants in the eastern part of the tallgrass prairie region. To assess effects on species richness and composition, in 1996 we resampled three dry and four dry-mesic sand prairie remnants that were originally sampled in 1976. Three of these sites were managed with burning over the 20 y period and four were not, allowing a comparison of temporal change among burned and unburned sites. Mean richness of native species per plot increased only in burned sites and declined only in unburned sites. In contrast, richness of alien species increased only in unburned sites and declined only in burned sites. In unburned dry-mesic sand prairies, an increase in the alien grasses Bromus inermis and Poa pratensis was accompanied by a decline in the native grasses Schizachyrium scoparius and Stipa spartea, and the forbs Echinacea pallida, Helianthus rigidus and Coreopsis palmata. Railroad rights-of-way prairies bordering agricultural fields were most vulnerable to invasion of alien grasses. These findings underscore the need to use fire to prevent invasion of alien grasses and to maintain native species richness and composition of prairie.

Annual brome grasses, Bromus japonicus and B. tectorum, are common exotic plants in the northern mixed grass prairies of North America. As annuals, the bromes die following seed set in late spring, creating a functional difference between them and native perennial grasses because perennials continue to maintain live shoots into the summer and root systems throughout the year. Our objective was to investigate how this functional difference alters ecosystem properties over the growing season, including soil moisture content, quantity of plant biomass, litter accumulation and aboveground litter decomposition. We conducted an experiment in which the annual bromes were removed from treatment plots to compare with adjacent reference plots. While this experiment served as a direct test for brome impacts, observational plots also were sampled to determine if impacts were apparent in an unmanipulated system. A litter bag experiment was conducted to evaluate impacts of brome grasses on decomposition. Experimental removal of brome grasses led to more biomass both above- and belowground at the end of the growing season, and high brome observational plots averaged 28% less aboveground biomass and 40% less belowground biomass than low brome plots. In contrast, removal of brome grasses did not produce a consistent impact on soil moisture content between sites or among months, and none of measurable impacts from the removal experiment were significant in the observational study. Bromes slowed decomposition of aboveground litter at both sites. However, the overall impact on litter accumulation was only significant at one site, where brome removal reduced surface litter in the latter half of the growing season and high brome observational plots averaged 36% more litter than low brome plots. This study demonstrates how the brome functional type alters several properties in an ecosystem traditionally dominated by perennial grasses.

Plateau live oak (Quercus virginiana var. fusiformis) is thought to act as a nurse plant to other woody species in the upland savannas of the Edwards Plateau of central Texas; however, little is known of the nature, extent and duration of this facilitation. We tested the hypothesis that spatial asymmetry exists in the composition of the understory woody plant community associated with live oak trees that would indicate facilitative effects of the oak canopy on understory microclimate. The central live oaks in 20 discrete tree-shrub clusters sampled at a location in the eastern Edwards Plateau were relatively large and possessed a dense understory of 5 to 11 species of shrubs and small trees. Both adult and juvenile woody plants were nonuniformly distributed around the central live oak with significantly more individuals and species found in the northern than southern halves of clusters. No statistical differences were found between northern (NE vs. NW) or southern (SE vs. SW) quadrants or between eastern and western sides. Similar patterns were found for total cover (canopy and basal diameter) of adults and density and cover of Juniperus ashei, the dominant understory species. Neither the degree of this asymmetry or extent of understory development (i.e., total shrub density or species richness) was related to the size of the central live oak. Results are consistent with the hypothesis that microclimate modification by the live oak overstory is an important and perhaps persistent mechanism of facilitation in these woody clusters. These findings also suggest that processes structuring these live oak clusters differ from those of other tree-shrub clusters in subtropical savannas in this general region.

General Land Office survey records of 1838–1846 were used to reconstruct the pre-European settlement vegetation along a soil moisture gradient in the Huron National Forest of northeastern lower Michigan. These data were compared to current forest data. Jack pine (Pinus banksiana), red pine (P. resinosa) and white pine (P. strobus) dominated fire-prone presettlement dry and dry-mesic sites on coarse-textured soils of glacial outwash plains and moraines. Hemlock (Tsuga canadensis), beech (Fagus grandifolia), sugar maple (Acer saccharum) and white pine were most important on presettlement mesic sites on medium-textured soils of moraines and kame and kettle topography. Presettlement wet-mesic sites were dominated by hemlock, white pine and aspen (Populus spp.). White cedar (Thuja occidentalis) and tamarack (Larix laricina) dominated presettlement wet sites on organic soils of outwash plains. Important presettlement forest types included: jack pine (41%), mixed conifer–northern hardwood (22%), lowland conifer (15%) and mixed pine (14%).

Tree species composition has substantially changed on dry-mesic to wet-mesic sites over the last 150 y. White pine and hemlock have significantly declined in abundance. Oak (Quercus spp.), sugar maple and aspen currently dominate dry-mesic to wet-mesic sites. Important current forest types include: jack pine (32%), aspen–white birch (Betula papyrifera; 16%), oak (16%) and northern hardwood (8%). Today's forests have smaller trees and higher tree densities than forests in the presettlement era. Widespread logging, altered fire regimes and other anthropogenic disturbances since European settlement have interacted with physical factors to produce today's forests.

Prairie restoration has the potential to sequester nitrogen (N) and atmospheric carbon (C) in the soil, but the capability of a site to respond positively to prairie restoration depends on numerous factors such as soil parent material, topography and time. Soil bulk density in the top 10 cm and C and N concentrations at several intervals to a depth of 1 m were measured in a tallgrass prairie topochronosequence at fine- and coarse-textured soil locations to evaluate the role of texture, slope and ecosystem age in controlling C and N sequestration following cessation of cultivation and subsequent prairie restoration. Soil C and N concentrations, contents and C:N ratios were significantly greater in fine-textured soils compared to sites with coarse-textured soil. Soil texture generally did not explain variations in the amounts or rates of C and N sequestration in the restored prairies. Soil surface bulk density was significantly correlated with slope, but not ecosystem age, at sites with coarse-textured soil. Within the limits of this study, neither slope nor ecosystem age were correlated to bulk density at sites with fine-textured soil. Soil C content in the top 25 cm increased significantly as ecosystem age increased for the restored and remnant prairies at the fine-textured location, but not at the coarse-textured location. Results demonstrate that a combination of soil parent material, topography and time since cessation of cultivation control the content and accumulation of C and N following prairie restoration. In the context of this study, the bottom line is that significant C sequestration was not achieved, given the current level and types of restoration management, within two and a half decades following conversion of cultivated cropland to prairie.

In vitro culture of mycotrophic leaf-bearing seedlings of federally threatened Platanthera praeclara Sheviak and Bowles, a terrestrial orchid native to the midwestern prairies, is reported for the first time. Symbiotic germination was evaluated to: (1) determine need for cold moist stratification to enhance seed germination and seedling development and (2) identify the mycobionts that support in vitro germination and development. Germination was improved by exposing seeds to both 4- and 6-mo stratification periods; whereas seeds without stratification failed to germinate in a pilot study. Pretreatment of seeds with 6 mo of stratification combined with inoculation with mycorrhizal fungus derived from a seedling (Ceratorhiza sp., UAMH 9847) supported development of higher stage protocorms and some leaf-bearing seedlings of P. praeclara. Protocorms with developing leaf primordia were also obtained by coinoculation with strains of Epulorhiza and Ceratorhiza. Fungi derived from mature P. praeclara plants failed to promote seedling development to advanced growth stages. Results indicate that in vitro development of P. praeclara is best supported when stratified seeds are cultured with fungi isolated from young seedlings.

Seasonal activity of 24 species of ground-occurring, forest Coleoptera in northern Wisconsin and the Upper Peninsula of Michigan was assessed using pitfall traps during the spring and summer of 1996 and 1997. Overall, species richness, abundance and diversity remained relatively constant throughout the season, although species composition varied considerably. Trap catch of seven species was greatest from early May to late June: Calosoma frigidum Kirby, Carabus nemoralis Müller, Platynus decentis (Say), Pterostichus adstrictus Eschscholtz, P. mutus (Say), P. pensylvanicus LeConte and Sphaeroderus lecontei Dejean. Two species, Carabus sylvosus Say and Nicrophorus sayi Laporte, showed both early and late peaks in trap catch. Trap catch of eight species was greatest from early July to late August: Calathus ingratus Dejean, Synuchus impunctatus (Say), Pterostichus melanarius (Illiger), Pterostichus tristis (Dejean), Geotrupes bayli Jekel, Nicrophorus defodiens Mannerheim, N. tomentosus Weber and Oiceoptoma noveboracensis Forster. Implications for studies that assess impacts of forest management practices on beetle biodiversity are discussed.

Little is known regarding the impact of stream drying on community structure and habitat selection of lotic crayfish. Crayfish community structure was measured through quantitative sampling of riffle, run and pool habitats in 15 intermittent and 21 permanent streams in the Spring River watershed in the Ozark Plateau region of northern Arkansas and southern Missouri. MANOVA was used to determine whether stream permanence, habitat and crayfish size affect crayfish density and ANOVA was used to determine the effect of stream permanence and habitat type on species richness. Canonical Correspondence Analysis was used to determine the relationship between environmental variables and crayfish relative densities. Four crayfish species were collected: Orconectes marchandi, O. punctimanus, O. ozarkae and Cambarus hubbsi. Overall, crayfish densities were significantly greater in intermittent streams than in permanent streams with density of O. marchandi and O. punctimanus significantly greater in intermittent streams than in permanent streams. Densities of O. ozarkae and C. hubbsi did not differ significantly between the two stream types. Large individuals of O. punctimanus and O. ozarkae were found in significantly greater densities than small individuals. There was a significant relationship between crayfish relative density and abiotic environmental variables for permanent streams, but not for intermittent streams. In permanent streams, percent gravel, substrate diversity and mean current velocity were among the most important factors in determining crayfish density. Taxa mobility and predation risk are likely explanations for observed patterns of crayfish density.

Surprisingly few studies have empirically compared genetic variation between central and peripheral populations of vertebrates, even though such populations are considered very important to evolutionary theories of anagenetic and cladogenetic change. This study assesses levels of microsatellite variability within and between populations of eastern collared lizards (Crotaphytus collaris collaris) sampled in three regions: the central part of its range and at the northeastern periphery in the southwestern and northeastern Ozarks. As expected, central populations possessed significantly higher within-population variability than peripheral populations, whereas the two peripheral subregions did not differ significantly from one another. Estimates of subdivision (F_st) differed significantly among all three regions in the following order: central < southwestern Ozark region < northeastern Ozark region. Estimates of subdivision between specially sampled populations separated by no more than 10 km indicated effective panmixia at the local level in the central region, historically high rates of localized dispersal in the southwestern Ozarks with recently imposed isolation and dominance of drift at all spatial scales in the northeastern Ozarks. These differences in regional population structure are consistent with regional differences in time of occupation by collared lizards, time and duration of forestation and latitudinal effects.

We surveyed forest songbirds during migration in bottomland hardwood forest stands and managed cottonwood (Populus deltoides) plantations in northeast Louisiana and west-central Mississippi between 24 March and 24 May 1996 and 1997. We detected more bird species in bottomland hardwood stands than in cottonwood stands. Within hardwood stands, we detected more individuals in stands subjected to uneven-aged timber harvest than in unmanaged stands. Early in migration, avian species composition was similar in both forest types, being comprised mainly of short-distance migrants. Bird species composition in these forest types became increasingly disparate as long-distance neotropical-nearctic migrants arrived. Ten bird species were characteristic of bottomland hardwood forests, whereas eight different species were characteristic of managed cottonwood plantations. Because these two forest types supported different bird communities, both forest types provide important inland stopover habitat during migration. Silvicultural management of bottomland hardwood forests that increases their understory vegetation will provide forested habitat for a more species rich and abundant population of songbirds during migration.

Woodland habitats are scarce in the northern Great Plains and were historically concentrated along river corridors. Over the past century, riparian habitats in this area have been much reduced, but new woodland habitats in the form of farmstead woodlots and shelterbelts have appeared. We used mist net sampling and point counts to document richness and abundance of Neotropical migrant birds in farmstead woodlot habitats during spring and fall migrations (1996–1997) in southeastern South Dakota. A total of 668 individuals of 30 Neotropical migrant species (excluding the taxa Coccyzus, Troglodytes, Mimidae, Icterus and Pheucticus, in which migratory and non-migratory individuals were difficult to distinguish) was captured in 4342 net hours (using 9-m, rather than the standard 12-m mist nets) in spring. The corresponding fall totals (again using 9-m nets) were 3250 net h, 231 individuals and 29 species. If fall captures in a ragweed (Ambrosia trifida) patch occurring within the woodlot are included, however, the fall totals were 5107 net h, 1211 individuals and 29 species. Overall densities of Neotropical migrants from point counts were 1302 birds · km⁻² in spring and 898 birds · km⁻² in fall. Capture and point count data followed similar phenologies, with peak abundance during mid-May in spring and late August-early September in fall. Both methods indicated seasonal abundance differences for some species, with Swainson's thrush (Catharus ustulatus) and blackpoll warbler (Dendroica striata) more abundant in spring. Orange-crowned (Vermivora celata), Nashville (V. ruficapilla) and Wilson's (Wilsonia pusilla) warblers were more abundant in fall. Captures within the woodlot were evenly distributed among different microhabitats during spring migration, but fall captures occurred disproportionately in scrubby edge-related microhabitats, especially in ragweed, suggesting that seasonal shifts in microhabitat selection may occur within woodlots. Density and capture rate data were similar to previously reported values for riparian habitats in this area. Thus, a diverse assemblage of Neotropical migrants occurs in woodlots during migration, suggesting that woodlots are regularly used as stopover sites and supplement available natural woodland habitats along river corridors.

Rio Grande wild turkeys (Meleagris gallopavo intermedia) were trapped in Oklahoma and released in northeastern South Dakota during the early 1970s. Based on wintering counts, this population peaked at over 1000 birds in the mid 1980s, but steadily declined to <200 in 1996. This decline prompted the introduction of eastern wild turkeys (M. g. silvestris), which were indigenous to southeastern South Dakota, as a replacement subspecies. We compared nest site characteristics of translocated eastern wild turkeys with those of established Rio Grande wild turkeys. Over a 2 y period we radio-marked 23 eastern females, and 21 Rio Grande females. Eastern females initiated 45 nests, whereas Rio Grande females initiated 41 nests. Vegetation type selection for nest sites (e.g., woodland, grassland and shrub) did not differ between Rio Grande and eastern wild turkeys (P = 0.96). However, turkey nest sites (subspecies pooled) differed from paired reference sites by having: (1) more nest sites directly under shrubs (P < 0.001) within woodlands and shrublands, (2) more trees within 1 m of the nest bowl (P = 0.001) in woodlands and (3) greater cover above the nest bowl (P = 0.007) within grasslands and shrublands. Frequency of vegetation types selected by female wild turkeys of both subspecies as nest sites differed (P = 0.001) from the frequency of vegetation types randomly sampled. Although shrub vegetation types were least available, females selected shrub vegetation types (primarily western snowberry [Symphoricarpos occidentalis]) for the majority (53%) of nest initiations. Other nests were divided between woodlands (27%) and grasslands (20%). Nest success was not correlated with vegetation type.

We assessed the spatial independence of fisher (Martes pennanti) detections at sooted aluminum track plates deployed in northwestern California during 1994 and 1995. We used six track plates with 1 km spacing to form a 5 km segment. We estimated the probability of detecting fishers using program CAPTURE. We evaluated temporal and spatial relations among track plates within each six-station segment using nonlinear regression and a randomization test. Estimated probabilities of initially detecting a fisher (capture) were 0.04 and 0.07, and probabilities of subsequent detection (recapture) were 0.36 and 0.3 in 1994 and 1995, respectively. A nonlinear regression of mean number of detections per segment on time had an upper asymptote of 1.22 indicating that detections at stations did not increase linearly through time. We found that on 25 of 30 segments, the observed data were likely to occur under the null hypothesis of no dependency. The segments with potential spatial dependencies were characterized by low numbers of detections (≤4 out of a possible 66) and did not effect conclusions. We viewed the results of the randomization test and the regression as evidence that fisher detections at track plates were not dependent upon previous detections at neighboring track plates. However, because individual fishers were not marked, we could not assess independence with respect to individual animals. When using between-station distances similar to those evaluated in this study, individual track plates are appropriate sampling units for indexing populations, assessing trends or for future investigations of habitat use.

Body-composition dynamics in meadow voles (Microtus pennsylvanicus) were examined by noninvasive EM-SCAN® methods for 12 mo. At the population level, body mass and fat-free mass varied seasonally with highs in spring and summer and lows in autumn and winter. In autumn and winter, losses in body mass and fat-free mass occurred in individual adults (40 g summer body mass), whereas voles maintained 2–3 g of lipid mass year-round, equating to 4% body fat in summer and 7% body fat in winter. Thus, changes in body composition were primarily due to changes in fat-free mass and not changes in lipid mass. Voles may rely more on energy sparing (reduction in fat-free mass and body mass) than on energy storing as a primary means of overwinter survival. Compared with results from more northern populations of arvicoline rodents, the lesser change in total body mass observed in this study suggests a latitudinal influence on seasonal change, possibly due to reduced environmental circumstances.

We examined the efficacy of four track plate enclosure designs for monitoring the abundance of small and medium-sized mammals along 10 streams in New York State. Box size and clarity of view through the box were evaluated as factors affecting visitation. We checked track plate stations weekly from September 1999 to March 2000. Eleven mammalian species or species groups visited the track plate stations. Raccoons (Procyon lotor) (P = 0.020) and feral cats (Felis catus) (P = 0.008) visited large enclosures significantly more than small enclosures. Feral cats visited clear-view enclosures significantly more than obstructed-view enclosures (P = 0.025). Enclosure size and view did not significantly affect visitation by other species; however, a large box with a clear view was the most effective design.

Bird populations and habitat structure were compared between three commercially thinned and three unthinned western hemlock (Tsuga heterophylla) stands to assess short-term effects of commercial thinning on breeding bird communities. Thinning reduced the density of small trees and snags (≤30 cm dbh), but did not affect the density of large trees or snags (>30 cm dbh). The overstory canopy was more open and cover of forbs, grasses and seedlings was higher in thinned than unthinned stands. Winter wrens (Troglodytes troglodytes), dark-eyed juncos (Junco hyemalis), chestnut-backed chickadees (Parus rufescens) and red-breasted nuthatches (Sitta canadensis) were more abundant in thinned than unthinned stands, but total bird density did not differ between thinned and unthinned stands. Commercial thinning thus enhances habitat conditions for some bird species while having minimal effects on other bird species.

Previous research has indicated fewer host-specific ectoparasites on woodrats of the eastern United States as compared to western woodrat species. The Allegheny woodrat (Neotoma magister) is a species of conservation concern that is associated with rocky habitats in the Appalachian and Interior Highland regions in the eastern United States. We examined Allegheny woodrat flea parasites in the core of the distribution to further elucidate patterns of ectoparasite host specificity in woodrats of the eastern United States. Of 346 fleas collected from 62 Allegheny woodrats, all but 1 were identified as Orchopeas pennsylvanicus. The single exception was a male Epitedia cavernicola, which represents only the second collection of this species from West Virginia. Unlike the eastern woodrat (Neotoma floridana), which hosts a variety of generalist flea parasites, Allegheny woodrats in our study were host to only 2 flea species, both of which are host specific to woodrats. We suggest that flea host specificity may be related to the specific habitat requirements of this species.

The tarsal region of white-tailed deer (Odocoileus virginianus) is an important source of socially significant odors. Because the tarsal provides a suitable environment for microbial growth, we identified bacterial species recovered from the tarsal tufts of 120 hunter-harvested deer to determine if differences occurred between the sexes or among age classes that could be important in odor production. Females tended to have a lower abundance of bacteria on the tarsal tufts (P = 0.06). Bacterial abundance did not differ among age classes of males, and an increase in tarsal staining did not correlate with greater bacterial abundance. Of the 62 species of bacteria identified, Hafnia alvei was recovered most commonly, occurring on 29% of the tarsal tufts. Bacillus was the most common genus isolated, occurring on 91% of the tarsal tufts. Bacterial composition differed among individuals, consistent with the hypothesis that odor production may result from bacterial action on urinary products.

We sampled a variety of wetlands in the Nebraska sandhills at Valentine National Wildlife Refuge. Significantly more individuals of painted turtles (Chrysemys picta) occurred in lakes and open waters than in marshes or small ponds, and the opposite was true for Blanding's turtles (Emydoidea blandingii). Besides this marked difference in habitat use, 46% of the captured E. blandingii in pond/marsh habitat were juveniles, but only 31.6% in lakes and open water. Current information suggests that marshes and small ponds are important habitat for juvenile turtles, especially Emydoidea blandingii.