Registered users receive a variety of benefits including the ability to customize email alerts, create favorite journals list, and save searches.
Please note that a BioOne web account does not automatically grant access to full-text content. An institutional or society member subscription is required to view non-Open Access content.
Contact firstname.lastname@example.org with any questions.
Old-growth stands within the Tionesta Research Natural Area were sampled in 1977, 1990 and 2000. Sapling growth within 25 treefall gaps was sampled all three times. Canopy trees were measured using the point-centered quarter method, with 83 points sampled all three times. Gap regeneration increased significantly in density and basal area from 1977–1990. Beech (Fagus grandifolia) significantly increased its relative gap sapling density from 68% to 91% to 94% over the 3 y. Other species decreased in absolute numbers presumably due to deer browsing. Canopy tree density remained constant and basal area increased 1977–1990 but both decreased 1990–2000. Species relative density and basal area values did not change. Mortality rates almost doubled from 1977–1990 to 1990–2000, increasing especially for smaller canopy trees. Snag densities and formation rates also increased, though not significantly, from the first to the second time interval. Beech, in particular, showed large increases in mortality, probably due to the growing impact of beech bark disease, which reached the stand about 1990. The stand seems changing to a new state with less beech in the canopy and more in the understory. Which species will replace beech in the canopy is difficult to predict.
English ivy Hedera helix L. is rapidly invading forest ecosystems in the southeastern United States, leading to a decrease in the diversity of native plant species. To determine the underlying mechanism for the loss of diversity and understand the potential for restoration of impacted habitats, we examined whether ivy had a negative effect on seed bank formation and germination. We sampled the seed bank and the summer and fall seed rains in areas with and without ivy. In addition, we determined potential allelopathic effects of ivy on germination of Coreopsis lancelota seeds. The density and species diversity of the seed bank and seed rains were not significantly different between areas with and without ivy. However, ivy led to a marginally significant reduction in the germination rate of C. lancelota seeds. Yet, the effect of ivy on germination only occurred when ivy plants were present. Germination rates did not differ in soil from areas with and without ivy. Our results suggest that native plant communities can regenerate naturally from the seed bank if English ivy were removed.
Two hundred and thirty-seven species of macrofungi and 465 species of vascular plants were identified from seven selected permanent sites. Areas of permanent sites ranged from 0.5 to 10.8 ha. No fungal species were collected from all sites and 126 (53%) were collected from only one site. Fourteen fungal species (6%) were collected each year of the study and 116 (49%) were collected only 1 y. Numbers of newly collected fungal species from the seven sites did not decrease each year of the study. Classifying fungal genera by nutritional group showed 36% of the genera collected were terricolous, 53% lignicolous, 16% ectomycorrhizal and 5% parasites. Nine plant species were collected from all sites, while 232 (50%) were collected at only one site. Fifteen plant species on the sites are on the state list of rare, threatened and endangered species. Botany Bay, a narrow moist canyon with dense vegetation dominated by Picea glauca, Ostrya virginiana, Betula papyrifera and Pinus ponderosa, had the highest fungal and plant species diversity/ha of 188 and 238, respectively. Alabaugh Canyon, a dry open woodland dominated by Pinus ponderosa and Juniperus virginiana, had the lowest fungal and plant species diversity/ha of 3.1 and 14.7, respectively. Species diversity of all plants and all fungi at the sites had a very significant correlation (r = 0.9). Regression and ANOVA showed a very significant relationship between species diversity of fungi and plants/ha (P = 0.003). In cluster and principal component analyses assemblages of plants and fungi showed different patterns of similarity.
The winged mapleleaf mussel [Quadrula fragosa (Conrad)] is a Federal endangered species. Controlled propagation to aid in recovering this species has been delayed because host fishes for its parasitic glochidia (larvae) are unknown. This study identified blue catfish [Ictaluris furcatus (Lesueur)] and confirmed channel catfish [Ictaluris punctatus (Rafinesque)] as suitable hosts. The time required for glochidia to metamorphose and for peak juvenile excystment to begin was water temperature dependent and ranged from 28 to 37 d in a constant thermal regime (19 C); totaled 70 d in a varied thermal regime (12–19 C); and ranged 260 to 262 d in simulated natural thermal regimes (0–21 C). We developed a quantitative model that describes the thermal-temporal relation and used it to empirically estimate the species-specific low-temperature threshold for development of glochidia into juveniles on channel catfish (9.26 C) and the cumulative temperature units of development required to achieve peak excystment of juveniles from blue catfish (383 C•d) and channel catfish (395 C•d). Long-term tests simulated the development of glochidia into juveniles in natural thermal regimes and consistently affirmed the validity of these estimates, as well as provided evidence for a thermal cue (17–20 C) that presumably is needed to trigger peak juvenile excystment. These findings substantiate our model and provide an approach that could be used to determine corresponding thermal criteria for early life development of other mussel species. These data can be used to improve juvenile mussel production in propagation programs designed to help recover imperiled species and may also be useful in detecting temporal climatic changes within a watershed.
Lespesia archippivora is a widespread generalist parasitoid whose hosts include monarch butterfly larvae. We report parasitism rates by this tachinid fly in wild captured monarchs, using data collected over 7 y by 77 volunteers in the Monarch Larva Monitoring Project, a North American Citizen Science Program. Data were collected in 21 U.S. states and one Canadian province, with focus sites in Wisconsin, Michigan and North Carolina. Overall, approximately 13% of monarch larvae contained tachinid flies. Parasitism rates varied by year, and this variation was, to a large extent, region-wide. For example, larvae collected in 2000–2002 throughout the Upper Midwestern U.S. suffered significantly more parasitism than those collected in 1999 or 2003–2005. There were no consistent patterns with respect to date of collection within years. The number of flies per parasitized monarch ranged from one to 10 and comparison to a Poisson distribution indicated that flies were more aggregated within hosts than expected by chance. Larvae collected during later stadia were both more likely to be parasitized and contained more flies per larva. Whereas the first pattern is likely to be the result of longer exposure to parasitoids, the latter suggests that females either respond to larger hosts by laying more eggs or that superparasitism (parasitism by more than one individual) occurs. When more than four flies emerged from a single host, their mean pupa mass was smaller, suggesting a cost to superparasitism. We report six cases of hyperparasitism by a wasp in the family Perilampidae. When three milkweed species with varying levels of cardenolides occurred in one area, monarchs found on a species with low cardenolide levels (Asclepias syriaca) were most likely to be parasitized, but those found on a species with very high levels of cardenolides (A. curassavica) showed higher levels of parasitism than those on found on the less toxic A. incarnata. Potential impacts of L. archippivora on monarch butterflies are discussed in light of these findings.
Declines of numerous Neotropical migrant birds have been attributed to habitat destruction and alteration. Forest management activities may promote changes to habitat components and, with the increase in commercial forestry in the South, information on Neotropical migrants in managed forests is needed. We examined the avian communities and habitat characteristics of four forest age classes at Ben's Creek Wildlife Management Area, a managed loblolly pine (Pinus taeda) forest in eastern Louisiana during the 2003 and 2004 summer breeding seasons. Mean species richness and relative diversity in 4–5 and 13–23 y stands were similar and greater than 7–9 y stands, and similar in 1 y stands to other age classes. Of 17 guilds (habitat, foraging and nesting) examined, relative abundance was similar across stand age only for second growth inhabitants and ground gleaning foragers. Frequency of occurrence varied across stand age for 17 of 19 species analyzed. Late-successional bird species occurred with greater frequency in 13–23 y stands, whereas occurrence of early-successional bird species was greater in 1 y and 4–5 y stands. Birds of conservation concern detected included both early- and late-successional species. Mean bird community conservation value was similar across stand age. Effects of stand age appear to benefit certain species, but are potentially costly for others. Efforts to combine management of timber and conservation of songbirds must consider both species habitat requirements and the distribution of these requirements in the landscape.
Territorial spacing is an aspect of songbird territoriality which is easily investigated, though often ignored. Cerulean warblers (Dendroica cerulea) maintain all-purpose breeding territories in eastern North American deciduous forest. Many observers have noted that cerulean warblers may breed in clusters of territories, but this information has not been determined statistically. We investigated the spatial relationships of cerulean warblers at Big Oaks National Wildlife Refuge, Madison, Indiana, during the summers of 2002 and 2003. We used a nearest neighbor analysis for the spatial placement of the centroids of cerulean warbler territories. The analysis indicated that clustering occurred in three out of the five study plots. Territories which exhibited clustered distribution had significantly higher amounts of vegetative stratification, more trees, and trees with smaller diameter than territories which were not clustered.
Understanding the relationship between wetland types and waterfowl distribution in the Great Lakes States of Wisconsin, Michigan, Illinois, Indiana and Ohio is complicated because basin specific waterfowl survey data do not exist. We used data from breeding waterfowl surveys in Michigan and Wisconsin during 1993 to 2002 and digital wetland data within buffered transect routes to develop a predictive model of mallard distribution within the 5 Great Lake States. The most parsimonious model based on AICc was used to map predictive distributions of breeding mallards. Based on the positive influence of palustrine emergent, palustrine unknown and palustrine unconsolidated shore and the negative influence of palustrine forested wetlands, the highest densities of breeding mallards were predicted in southeastern Wisconsin and southeastern Michigan. Additionally, we flew helicopter surveys in spring of 2003 to characterize wetland basins used by mallard pairs. Individual pairs were observed most often on small palustrine emergent and palustrine forested wetlands. The resulting models and maps can be used by a variety of agencies to plan conservation and management actions for mallards breeding in the Great Lakes States.
We captured female Lasiurus borealis near the Indianapolis International Airport during summers of 2003 and 2004 and radiotracked them during foraging. We obtained complete foraging data on 13 bats. A series of multi-azimuth (3–7) triangulations was used to estimate the location of each bat throughout the night. Distance based analysis was used to examine habitat use by L. borealis. Lasiurus borealis had both smaller home ranges than previously noted and smaller home ranges than other species at this location. Lasiurus borealis foraged in woodlands and over newly planted tree fields, open water, park and pasture lands more than predicted by randomly generated points and avoided highly urban areas such as commercial lands, gravel pits and transportation corridors.
Sex-biased dispersal is a specific pattern of movement whereby one sex either stays or returns to its natal group or natal area to breed while the other disperses from the natal area. Temperate vespertilionid bats are thought to exhibit the typical mammalian pattern of male-biased dispersal although relatively few studies have been conducted on this group. The northern myotis (Myotis septentrionalis) is a relatively common forest dwelling bat found in eastern North America. Despite being a common species in North America, relatively little is known about its habitat requirements and life history characteristics including dispersal patterns. Using five polymorphic microsatellite loci I found that females within localized subpopulations exhibited a higher degree of genetic structuring than males indicating female philopatry and male-biased dispersal [female FST = 0.011; male FST = −0.016; P = 0.006 (sex-biased dispersal randomization test)]. I also found a weak (FST = 0.002), but significant (P = 0.03), average fixation index for the subpopulations examined which is consistent with other studies on temperate vespertilionid bats. The presence of maternity site fidelity in M. septentrionalis may have important conservation implications since commercial and private development that thins or removes potential roost trees could have an impact on pregnant female bats that will have to incur additional costs of searching for new roosting habitat as they return from their hibernacula.
Forestry practices result in a range of levels of disturbance to forest ecosystems, from clearcutting and deferment (high disturbance) to single-tree selection cutting and unharvested forests (low disturbance). We investigated the effects of timber harvest and disturbance on small mammal species in the Allegheny Mountains of West Virginia. In 2003 and 2004, mammals were captured using Sherman box traps, individually marked, and released. We collected habitat data in 2004 to characterize macrohabitat at the stand level and microhabitat surrounding each trap. Trap success was significantly higher in disturbed habitats than undisturbed habitats for red-backed vole Myodes (Clethrionomys) gapperi (P = 0.0012) and woodland jumping mouse Napaeozapus insignis (P = 0.0221). Abundance estimated using the Jolly-Seber method was significantly higher in disturbed habitats for red-backed voles (P = 0.0001). Adult northern short-tailed shrews Blarina brevicauda (P = 0.0001) and white-footed and deer mice Peromyscus spp. (P = 0.0254) weighed more in disturbed habitats. Small mammal distribution was strongly influenced by microhabitat factors, which differed substantially within stands. Leaf litter depth was a significant microhabitat factor for four of the five species analyzed, with red-backed voles (P = 0.0001), woodland jumping mice (P = 0.0001), Peromyscus spp. (P = 0.0055), and eastern chipmunks Tamias striatus (P = 0.0007) all preferring shallow leaf litter. These small mammal species responded neutrally or favorably to disturbance, and identified favorable microhabitat features regardless of stand type.
Published accounts of fetal rates in white-tailed deer (Odocoileus virginianus (Boddaert)) indicate that litter sizes vary from one to three fawns per female deer per year and that variation is associated positively with nutrition. We report on a female deer from agricultural habitat that was carrying five fetuses (one female, four male) when it was shot on 26 Jan. 2006. The mean fetal length suggested a gestational age of 75 d. One male fetus was substantially underweight with respect to the others despite equivalent length and head measurements.
Melanic white-tailed deer are distinguished from normal white-tailed deer by having uniform black hairs on the back with subdued black hairs on the belly, a completely dark face and ears, a distinctive mid-dorsal stripe extending from the head to the apex of the tail and a tail with black dorsally and white ventrally. We report records for two melanistic white-tailed deer in Pennsylvania. A male fawn was captured in Valley Forge National Historical Park in 1999 and an adult male was harvested in Bucks County in 2002. Since at least one melanistic deer was produced in this region, there is a possibility another melanic deer will be produced in the future.
Throughout northwestern Ohio, northern Indiana, southern Michigan and western Ontario, only four records of the eastern pipistrelle (Pipistrellus subflavus) existed in the early 1980s. These individuals, three adult males and one bat of unknown sex or age, were considered to be vagrants or disoriented migrants. Between 1993 and 2006 we gathered 71 additional records of this species in the central Great Lakes basin, including reproductive females and young-of-the-year. Most were found near the eastern shore of Lake Michigan, particularly at two unusual hibernacula, Tippy Dam and Bear Cave. We speculated that modifications of Bear Cave associated with its commercialization in 1936–1940 created conditions suitable for the eastern pipistrelle to colonize this area.
This section is placed at the beginning of a manuscript and must convey everything presented: what the research was about, where, why and how it was conducted and what it means relative to the current state of knowledge. It should consist of one paragraph of 250 or fewer words (i.e., no more than 3% of length of manuscript). Abstracts always are written in the past tense, thus, the best quality abstracts are written after the remainder of the manuscript is finished. Bibliographic services publish only the title and abstract of manuscripts. When conducting a literature search, researchers may read abstracts of perhaps 100s of papers in which the titles possibly have bearing on an aspect of their work. Only if the content of the abstract seems relevant will researchers progress to reading the article from which the abstract was derived. Therefore, great care must be used to write an abstract so it correctly reflects the contents of the manuscript in a precise and concise manner that can stand alone. Furthermore, it must contain no figures, tables or references to them, or material not presented in the body of the manuscript; except for critique papers, no literature citations should be included. Also, it should not contain acronyms or jargon, even with definitions, not readily known to the general reading audience of the publication in which the manuscript will be published.