Acid deposition contributes to forest health concerns at high elevation sites in Great Smoky Mountains National Park (GSMNP). Bark samples were taken from living trees at three study sites: Abies fraseri and Picea rubens from high elevation sites near the Clingman's Dome area of Tennessee; Juniperus virginiana and Quercus alba at low elevation sites at GSMNP in the Cades Cove area and also at Pertle Springs (PS), Missouri. All trees were climbed using the doubled rope climbing method and sampled for bark at approximately 3 m increments up to 12 m. A total of 162 laboratory moist chamber cultures were prepared in Petri dishes using bark samples representing all tree species, then measured for pH, and examined for myxomycete plasmodia and fruiting bodies. Thirty-four myxomycete species were observed and identified from cultures of tree bark from GSMNP that included two new records, Physarum auriscalpium and a possible new species of Trichia. Thirty species represent new records for the state of Missouri; most notable were Clastoderma microcarpum, Licea inconspicua, Physarum synsporum, and Macbrideola declinata. Data were analyzed using Nonmetric Multidimensional Scaling, Multi-response Permutation Procedure, and Indicator Species Analysis ordinations. Juniperus virginiana had the highest mean bark pH at 6.76 and also the highest species diversity, and Picea rubens had the lowest mean bark pH at 3.72; both had distinctive assemblages of myxomycete species. Abies fraseri had the lowest species diversity with no observed species. Myxomycete species diversity appears to decrease at higher elevations with aerial pollutants adversely impacting Abies fraseri.

Forest canopy and subcanopy data were collected from and compared among five disjunct bottomland hardwood forests in the Lower Mississippi Alluvial Valley, each with known occurrence of a population of the federally endangered shrub Lindera melissifolia. All study sites are cut-over forests, underlain by hydric soils, and have a seasonal high water table. Canopy and subcanopy species are similar among sites, but species differ in relative importance, and flood tolerant tree species exceed that of flood intolerant species. Distribution of L. melissifolia colonies within each study site was not associated with mean tree density or d.b.h. Forest composition and structure at each study site reflect hydrologic regime, topography, historical disturbance, and an absence of recent disturbance. Results of this study provide a quantitative description of bottomland forests that currently sustain L. melissifolia populations. This information may be utilized for development of forest management plans aimed at ensuring continued sustainability of existing L. melissifolia populations and assessing other bottomland hardwood forests for potential reintroduction of this endangered species.

Wild hyacinth (Camassia angusta) is a perennial species native to mesic prairies of the midwestern and south-central United States. In Illinois, the only extant population of this state-endangered species is in a small section of degraded black-soil prairie along a railroad track right-of-way south of Elwin, Macon County. The objectives of this study were to determine the population status, seed production, and effects of scarification and stratification on germination of C. angusta. The population was surveyed from 1990 to 2007. A survey of other plant species present was conducted in 1999. The site consisted of approximately 75% native and 25% exotic species. The number of flowering stems of Camassia angusta fluctuated significantly (28 to 169 plants) during the course of this study. Prescribed spring burns and a construction equipment disturbance may be partially responsible for these fluctuations. A large percentage of undeveloped fruit, resulting in low seed production (<3,000), as well as low seed germination (8%), may be responsible for this population's inability to increase consistently in number of individuals.

The palmettos Serenoa repens and Sabal etonia are foundation species in many peninsular Florida vegetative associations. We monitored survival and growth of palmetto seedlings using two cohorts found in different vegetative associations. Mixed-species cohorts containing both Serenoa repens and Sabal etonia were individually tagged in 1989 and have been monitored until 2008. One cohort (N  =  100 seedlings) is in an “inopina-phase” scrubby flatwoods and a second cohort (N  =  78 seedlings) is in a “wiregrass-phase” flatwoods. The sand substrates at both sites are nutrient-poor Entisols that show rapid permeability, low available-water capacity, and acidic pH. In addition to experiencing seasonal and variable annual precipitation patterns, these cohorts endured a severe and prolonged drought during 1999–2001 as well as an intense fire at the height of this drought. Seedlings showed remarkable survivorship, with 57% of the flatwoods cohort and 35% of the scrubby flatwoods cohort surviving from 1989 until 2008. In spite of their high survival, the seedlings experienced minimal height and crown width increases during the 19-year study. Height increase from 1989 to 2008 for the flatwoods cohort was a modest <0.5 cm per year and that of scrubby flatwoods was ∼0.3 cm per year. Serenoa repens and Sabal etonia seedlings show extraordinary persistence and tolerance but at a cost of exceptionally slow growth rates. These data suggest that: (1) the transition from seedlings to reproductive palmettos in nutrient-poor Florida uplands takes multiple decades; and, (2) the restoration of palmettos as foundation species in disturbed sites will require effort.

The negative ecological impact of invasive plant species has been widely reported in recent years. Herbarium specimens can allow for the study of spatiotemporal spread of invasive species in order to understand distribution characteristics and patterns which can then be utilized for management decisions. In this study, three common wetland invasive plant species (Phragmites australis, Lythrum salicaria and Rorippa nasturtium-aquaticum) were chosen and analyzed via two previously published methods to determine the historic rate and pattern of spread as well as to identify periods of invasiveness. Performance of these methods varied in scale with a general, area-corrected approach covering the entire southeastern United States and an associate species-corrected method covering smaller, regional areas of dense historical specimen collection. Results showed positive spread over time for these three species in both methods; however, periods of invasiveness did not coincide between the two methods. The use of two different methods and the subsequent comparison of results show the importance of sampling bias correction, scale selection, and adequate sample sizes for spatiotemporal analyses of plant distributions using herbarium records.

Wet prairies in the Southeast consist of floristically diverse grass-sedge ecosystems that are conspicuously lacking in woody species because of seasonal soil saturation and frequent fire. They occupy a landscape position between mesic, pyrogenic pine savannas and hydric swamps and marshes. Wet prairies are recognized wherever they occur on broad expanses of land; however, many go unrecognized or are mistaken for ecotones where they occupy strips of land that narrowly separate pine savannas from more deeply inundated wetlands. Such spatially narrow wet prairie in west-central Florida was characterized in terms of its plant species composition and abundance, soils, and elevations relative to the saw-palmetto line (border with pine savanna), the cypress strand line (border with deeper wetlands), lichen line (maximum inundation following major storm events), and taper points on cypress buttresses (wet season normal pool). Wet prairie ranged horizontally from 1.5 to 30 m wide (mean 12.7 ± 3.9 m) and vertically up to 24 cm in elevation (mean 13 ± 6.7 cm) relative to its cypress strand line and saw palmetto line, respectively. The mean elevation of taper points varied from place to place from 3 to 15 cm above the saw palmetto line, indicating shallow wet-seasonal inundation. Soils were mostly hydric (71%), level, very poorly drained, sandy, and contained a spodic horizon. The wet prairie plant community was characterized by 97 species (25 grasses, 16 sedges, 51 forbs, and 5 shrubs—all Hypericum spp.) of which 76 species were K-strategists and 21 r-strategists. The mean number of species per m² was 12.3 ± 3.3.

The requirement for heat shock to break physical dormancy of hard seeds is a widely known strategy for recruitment in fire maintained ecosystems. Despite extensive work by fire ecologists in the southeastern United States, heat shock response has been demonstrated for only a few eastern North American temperate species. In this study germination responses to dry and wet heat were investigated for three species with physical dormancy: Galactia regularis (Fabaceae), Lupinus perennis (Fabaceae), and Rhus copallinum (Anacardiaceae). Control, wet heat (1 min boiling), and dry heat (10 min at 60, 70, 80, 90, 100, and 110°C) treatments were independently applied in the laboratory. Maximum germination occurred at 80°C for G. regularis and L. perennis and was significantly greater than both control and boiling treatments. For R. copallinum, maximum germination occurred at 90°C for all populations investigated and was significantly greater than the control group in three of four populations. Heat shock germination may play a larger role in post fire recruitment in the flora of the eastern United States than currently recognized.

Sandhill Research and Education Center is located on 215 ha of greenspace in South Carolina. The Center is now surrounded by suburban development. Although located within the Sandhills region and within the historic range of the Longleaf Pine Forest, agriculture has been the predominant land use during the last century. With development pressure and an interest in transitioning from agriculture to ecological restoration, a baseline inventory of the flora was initiated to provide further guidance to administrators. This survey delineates six plant community types (Swamp Tupelo, Sand Hickory, Blackjack Oak, Turkey Oak, Field, and Utility Right-of-Way) and reports a total of 328 species in 237 genera and 100 families. It adds two state records (Lespedeza virgata and Lotus corniculatus), 38 county records, and several noteworthy species.