In the western United States, up to 90% of quaking aspen (Populus tremuloides Michx.) is estimated to have disappeared since European settlement due to human activities. This loss poses a significant threat to many forms of biodiversity associated with aspen, including plants, birds, and mammals. However, no work has investigated native bee diversity associated with aspen. Our objectives were to: (1) describe the diversity, taxonomic composition, and sex ratios of bees in aspen stands in native bunchgrass prairie of northeastern Oregon, (2) compare bee communities in aspen with those in an adjacent grassland, and (3) document differences in floral resources associated with each habitat. We sampled native bees and quantified blooming non-anemophilous plant richness in four aspen stands and four locations in bunchgrass prairie three times during the summer. Bee abundance increased in both habitats as the summer progressed. Although taxa richness and overall abundance of bees did not differ significantly between habitats, community composition did. Bumble bees (Bombus) were more abundant in aspen stands, while sweat bees (Lasioglossum and Halictus) were more abundant in grassland locations. Four species of bumble bees were significantly associated with aspen stands and sex ratios of bumble bees were significantly more male-biased in aspen stands compared to grassland locations. Floral resources are one potential driver of observed differences between habitats. In late summer, aspen stands had higher blooming plant richness, as well as a distinctive floral community. This study suggests that conserving aspen benefits not only many plants and vertebrates, but also ecologically significant invertebrates, such as native bees.

Forest composition can shift through time in response to a variety of factors including changes in climate conditions and disturbance regimes. In many forests of eastern North America, oak (Quercus) populations are decreasing while maple (Acer) populations are increasing. Altered fire regimes over the last century are thought to be the primary driver of oak-to-maple dynamics; however, other factors may be playing an important role in this dominance transition. Our study sought to determine the community structure and disturbance history of an old-growth forest remnant in an area of western Ohio where fires were historically infrequent. To determine community structure, abundance of woody species was measured within 32 plots at four canopy strata. Dendrochronology was used to determine the disturbance history of the site and canopy accession patterns of canopy trees. We found that oaks and hickories (Carya) were important contributors to the forest canopy, but were less numerous than maples in sub-canopy layers. There was vastly higher biomass of standing dead material from oaks than from other genera. We propose that a cohort of oak and hickory dominance was initiated by a change in historical disturbance regime, and that in recent decades the stand is responding to a suite of multiple interacting ecosystem drivers, which have favored maple regeneration. In the coming decades, this forest, along with others in the region, will be faced with a new suite of interacting drivers including exotic insects, invasive plants, and climate change.

Increased hurricane frequency and intensity and residential and commercial development are contributing to loss of maritime forests, coastal hammocks, and scrub dunes. Barriers to natural regeneration necessitate active restoration. We evaluated the survival of woody species planted in ephemeral barrier island swales on Santa Rosa Island, Florida, in an effort to restore barrier island scrub and pine forest lost in recent hurricanes. Contractors planted sand live oak (Quercus geminata) on swale ridges, inkberry (Ilex glabra) on swale mid-slopes, and slash pine (Pinus elliottii) in swale depressions. Polyacrylamide gels are often used to increase transplant survival in the drought-prone, sandy environments. To assist us in evaluating the efficacy of these gels, contractors planted 10 plants with gel and 10 without for each swale, position, and woody species. We followed plant survival for 21 months and measured changes in plant height after one year. Polyacrylamide gel did not significantly affect survival of slash pine or sand live oak. Less than 25% of slash pine and sand live oak survived after 21 months. We found initial survival of inkberry was greater with than without gel, but plant death continued; and after eight weeks, we found no difference in survival for inkberry planted with and without gel. Inkberry survival declined to < 5% at the last evaluation. Changes in plant height were also not affected by Polyacrylamide gel. We do not recommend the use of Polyacrylamide gel to replace supplemental water or to replace the planting of deeply rooted plants on barrier islands.

Bog turtles (Glyptemys muhlenbergii) access saturated wetland soils and move through them to thermoregulate, find cover, and hibernate. Variability in the physical properties of the soil that affects suitability for turtle use is little understood. We identified dominant soil series and measured soil organic carbon (SOC) content and particle size in the top 18 cm of surface soils from Southwestern Virginia wetlands frequently used by bog turtles and similar wetlands not known to be used. A static cone penetrometer was used to evaluate soil strength in specific locations where bog turtles were found and adjacent random areas. Soils were poorly developed alluvium with aquic soil regimes. Levels of SOC were greater in locations with more continuous surface saturation and averaged 10% in the wettest locations. Proportions of sand, silt, and clay in wetlands were consistent with loam and silt loam textures. Levels of SOC and dominant particle sizes were not different in similarly saturated areas of wetlands that were frequently used or not known to be used by bog turtles. However, some wetlands not known to be used completely lacked areas that were always saturated. Based on penetrometer data, bog turtle use was centered on low strength soils. The physical qualities of surface soils in bog turtle wetlands result from the depositional environment and hydrology. The soil information derived from this study may assist biologists to determine whether wetlands are used by bog turtles, and also establishes reference soil conditions for use during wetland restoration projects that occur within the geographic range of the bog turtle.

To mitigate the loss of native tree species threatened by non-native pathogens, managers need to better understand the conservation status of remaining populations and the conditions that favor successful regeneration. Populations of Juglans cinerea L. (butternut), a wide-ranging riparian species, have been devastated by butternut canker, a disease caused by a non-native fungal pathogen. We assessed J. cinerea within Great Smoky Mountains National Park (GSMNP) to determine post-disease survivorship and health, recruitment history, environmental conditions associated with survival, and the extent of hybridization with a non-native congener. Monitoring records were used to locate and collect data for 207 J. cinerea trees in 19 watersheds. Tree cores were collected from a subset of individuals to assess recruitment history. We sampled vegetation plots within areas that contained J. cinerea to assess site conditions and overstory species composition of characteristic habitat. We collected leaf samples for genetic analysis to determine the frequency of hybridization. Our reassessment of monitoring records suggests that J. cinerea abundance in GSMNP has declined due to butternut canker and thirty years of poor regeneration. Populations displayed continuous recruitment following Park establishment (1934) until around 1980, after which regeneration declined drastically. Ordination analysis revealed that J. cinerea in the contemporary forest was associated with greater distance from homesites and reduced basal area of competing species. Hybrids comprised a small portion of sampled trees. The presence of healthy trees and low rate of hybridization suggest that these trees may contribute to the development of disease-resistant genotypes for future restoration efforts.

This four-year study investigated the impacts of a 2010 mast year (for red oak; Quercus rubra) and spring 2009 and 2011 prescribed fires by comparing temporal variation in tree regeneration on seven burned and unburned sites at the Mohonk Preserve in the Shawangunk Mountains of eastern New York. The overstory of all stands was dominated to varying degrees by red oak, chestnut oak (Q. montana), and red maple (Acer rubrum). Seedling density for red oak was 4267/ha in 2009 compared with 23,000/ha in 2011 as a result of the 2010 mast year. By 2012, red oak seedling density decreased to 12,714/ha, suggesting the ephemeral nature of young oak seedlings, but remained higher than pre-mast year levels. Average seedling density was 31,030/ha on the burned sites and 23,189/ha on the unburned sites and dominated by red oak followed by chestnut oak. Red oak seedling density was much higher on burned than unburned sites (mean = 19,400 versus 9578/ha, respectively), whereas chestnut oak was moderately higher on unburned sites. The results of this study suggest that while prescribed burning stimulated red oak seedling density at the Mohonk Preserve, mast year played an even larger role over the short term (which included unburned sites). Moreover, a synergistic interaction of these factors may have resulted in burned sites having the highest red oak seedling density following a mast year.

Biological invasions of non-native species are an important conservation issue because of the potential negative impacts on native plant and animal communities. One species of concern in Virginia is Japanese spiraea (Spiraea japonica L.f.). At Buffalo Mountain Natural Area Preserve (BMNAP) the spread of Japanese spiraea threatens the integrity of native high-elevation grassy balds, eastern redcedar (Juniperus virginiana L.) glades, and mafic seep communities. A prerequisite to successful management of a non-native species is knowledge about where a species has established and how it spreads. Thus, our objectives were to: (1) identify current populations of Japanese spiraea at BMNAP, and (2) characterize environmental conditions favoring the growth of Japanese spiraea. Paired-plot sampling was used to compare environmental parameters from adjacent plots with and without Japanese spiraea. Canopy cover was significantly lower in plots with Japanese spiraea compared to plots without Japanese spiraea (t = 1.76, P = 0.02), suggesting Japanese spiraea is more successful in establishing in higher light environments. At BMNAP, lower canopy cover reflected historical disturbances such as old power line cuts or roads. Although Japanese spiraea is not currently invading the grassy balds or eastern redcedar glades at the Buffalo Mountain summit, existing populations pose an immediate threat to the mafic seeps at the base of the mountain. Regular monitoring and mapping will be important to prevent Japanese spiraea from hindering conservation goals.

Fire history is an important aspect of the natural disturbance pattern of many types of forested ecosystems. Nonetheless, many forests and corresponding management plans lack quantitative information on fire interval, frequency, and seasonality. This project examined the fire history at Price Mountain, Virginia, using fire scar samples and tree-ring analyses from live tree chronologies. Additionally, this project investigated the fire scarring potential of two little-studied species, black gum (Nyssa sylvatica) and sourwood (Oxydendrum arboreum), as well as described the age-structure of the current stand. We hypothesized that fire frequency would be high prior to the fire suppression era, given the proximity to an historical railroad track at the base of the mountain and susceptibility to lightning due to elevation. Six major fire years occurred between 1861 and 1925 at an average interval of 14 years, followed by a period of no fires. Two-thirds of the fires burned early in the season. There was an initial establishment of sourwood and chestnut oak (Quercus prinus) from 1930–1940 as well as another establishment peak between 1950 and 1960 after a major logging event. Pine (Pinus pungens and Pinus rigida) species established between 1870 and 1930. Reconstructed fire history and age structure informs land managers that repeated fires occurred in this Appalachian ridge top forest and that modern forest structure is in part the legacy of historic fires and fire suppression.

Species extinction is the major biodiversity crisis in the twenty-first century. Today, anthropogenic activities are causing extinction of many species of ecological and economic importance. Arunachal Pradesh, home of high biodiversity and endemism, has many species facing tremendous stress which are on the verge of extinction. Taxus wallichiana, an endangered tree species distributed in temperate forests, has the anti-cancerous chemical Paclitaxel (Taxol®). It has other important uses in Ayurveda, Tibetan, and Unani medicine. Currently, Taxol is recognized as the most effective drug for a variety of cancers. Owing to its high economic demand, unsustainable extraction, and over-harvesting, the species ranked in the endangered category and is at risk of extinction in Arunachal Himalaya. Regeneration from seed is very poor due to a long dormancy period (nearly 18 months) and it is slow to reach maturity in nature. Moreover, consumption of fruits by birds, monkeys, rats, etc., is causing regeneration failure. A very few populations survive in isolated pockets and they will become extinct in the near future if proper conservation measures are not initiated. Conservation measures either by in situ or ex situ, with community participation, can be undertaken. In situ conservation can be exercised by establishing sanctuaries, parks, reserve forests, etc. Ex situ conservation could be practiced by cultivating the species in gardens, parks, and also by tissue culture techniques. Furthermore, mass awareness and motivation of local people for large scale cultivation and preparation of bonsai to a certain height to harvest the leaves without damaging the whole tree may reduce pressure on wild populations. This may meet the market demand as well as conserve the species and will boost the rural economy while also providing employment opportunity for the local inhabitants.

Pondberry (Lindera melissifolia) is an endangered plant species that occurs in seven southern states. It is a rhizomatous, clonal shrub that usually grows in colonies and has numerous stems with few branches and drooping leaves that give off a spicy odor when crushed. Pondberry is dioecious, with small yellow flowers that bloom in spring and have scarlet drupes that mature in late summer or fall. The species grows in low areas within bottomland hardwood forests in the western part of its range and on the margins of limestone sinks and wet depressions in pine forests in the eastern part. Pondberry has probably always been a rare species, but its distribution and abundance have been affected by habitat destruction and alteration, such as timber cutting, clearing of land, and local drainage or flooding of wetlands. Until recently research on pondberry has been sparse; but because of proposed flood control measures for the area in which the species occurs in Mississippi, interest in research has increased. This review will be helpful to land managers and scientists because it provides information about all known current research on the species.

We report the status of alien species on Isla de Cedros, Mexico, and analyze the information from different years that together with a collaborative effort between academic biologists, Mexican governmental agencies, and local individuals has resulted in major information about the alien species on this island. We also report species richness of distinct endemic mammal species and the presence of feral dogs (Canis lupus familiaris Linnaeus), which is the principal problematic situation in this “Marine Priority Region.” The possible origin of feral dogs could be the migratory movement of stray dogs to find food in the inner part of the island, first moving to garbage dumps, reproducing in the area, and later hunting goats (Capra aegagrus hircus Linnaeus) in packs. The combination of the high density of stray dogs, urban and industrial food garbage dumps, and the large number of marine resources scattered along the seashore made ideal conditions for the establishment of feral dog packs that are affecting native species. The island does not have any natural mammal predator, but the presence of feral species, dogs and cats (Felis silvestris catus Schreber), could disturb the occurrence of endemic fauna as it has happened on other islands in the world.