Noteworthy Collections: Virginia and North Carolina
ABSTRACT Two species of sunflower (<em>Helianthus grosseserratus</em> and <em>H. rigidus</em>) were investigated to determine phenological, habitat, and morphological separation between them. The two species had overlapping distributions across a habitat gradient and also over- lapped in flowering times, although <em>H. rigidus</em> flowered earlier than <em>H. grosseserratus</em>. The two species achieved their maximum abundance on different portions of a topographic gradient, with <em>H. rigidus</em> being more abundant than <em>H. grosseserratus</em> on upper and middle slopes and <em>H. grosseserratus</em> being more abundant on lower slopes and depressions. The two species had relatively distinctive morphologies.
ABSTRACT Mean phytoplankton cell concentrations and cell volumes are given for four stations sampled during October and December in the Elizabeth River. <em>Skeletonema costatum</em> is a dominant species, with other diatoms, cryptomonads, and cyanobacteria (< 3 μm) forming the most characteristic and dominant assemblages. In comparison to studies made over 20 years ago, diatoms and cryptomonads have remained dominant, with an increased presence of smaller sized diatoms and phytoflagellates.
ABSTRACT During two growing seasons, the monthly biomass was determined for the dominant plants at three tidal marshes within the lower Pearl River basin, Louisiana. There were differences between the two growing seasons in ecological dominance and production. Ten species (<em>Spartina patens</em>, <em>Sagittaia lancifolia</em>, <em>Phyla nodiflora</em>, <em>Peltandra virginica</em>, <em>Vigna luteola</em>, <em>Saururus cernuus</em>, <em>Polygonum sagittatum</em>, <em>Panicum gymnocarpon</em>, and <em>Eleocharis</em> spp.) accounted for 98% of the marsh productivity. Using the Smalley method, net aboveground primary production was 1241 g/m2/yr for the freshwater marsh, 1745 g/m2/yr for the intermediate salinity marsh, and 2259 g/m2/yr for the brackish marsh. The peak total biomass for the freshwater marsh was 1205 g/m2, for the intermediate marsh it was 1103 g/m2, and for the brackish marsh it was 3089 g/m2. By summing the annual live standing biomass for each species, primary production estimates for each marsh site were lower than those calculated by the Smalley method: 1190
ABSTRACT Nickel concentrations were measured in leaves of canopy and subcanopy trees from two nickeliferous areas in western North Carolina. Over and downslope from the Buck Creek ultramafic body in Clay County, the geometric mean of Ni concentrations is 250 μg/g in leaf ash, and only 3 out of 22 values are less than 100 μg/g. The geometric mean from trees growing over the surrounding mafic rocks is 65 μg/g, and only one value exceeds 100 μg/g. Results from the Webster-Addie district in Jackson County are less consistent, but in one oak species higher Ni values occur in samples taken over or near the ultramafic rocks. The more complete Buck Creek results suggest that differences in Ni concentrations between species are less important than differences between plants in nickeliferous and non-nickeliferous areas. The ability of plants to assimilate nickel provides a potential prospecting tool for this element in humid temperate
ABSTRACT The original Southern Mixed Hardwood Forest data gathered by Elsie Quarterman and Catherine Keever for their paper on the forests of the southeastern United States Coastal Plain were reanalyzed using ordination techniques not available in 1962. When importance percent of the broadly distributed successional species <em>Pinus taeda</em> was deleted, detrended correspondence analysis produced an interpretable ordination of 27 stands. <em>Fagus grandifolia</em> is concentrated at the opposite end of an X axis from <em>Quercus hemisphaerica</em> Bartr. (= <em>Q. laurifolia</em> of Quarterman and Keever), with soils sandier and with lower available minerals at the <em>Q. hemisphaerica</em> end. <em>Carya glabra</em> and <em>Liquidambar styraciflua</em> concentrations overlap both of the above species. <em>Quercus alba</em> and <em>Carya tomentosa</em> are concentrated on the lower (drier?) end of the Y axis, with <em>Magnolia grandiflora</em> on the upper half of that axis and <em>Pinus glabra</em> at the extreme upper end. <em>Quercus falcata</em> and <em>Q. stellata</em> are concentrated at
ABSTRACT Although logging and homesteading were widespread in the Great Smoky Mountains (prior to the acquisition of the land by the National Park Service), few parkwide studies of historical anthropogenic disturbance have been completed. Based on a disturbance history summary map developed primarily from archival records, the type and extent of historical land use were tabulated, on a parkwide and, also, on a major watershed basis. Human-related disturbances were categorized as corporate logging (40%), concentrated settlement (9%), diffuse disturbance (21%), big trees with diffuse disturbance (8%), and miscellaneous disturbances (3%). Twenty percent of the Park was considered high in virgin forest attributes. The attributes chosen to define virgin forest in this study were, for a given area, the absence of written records concerning historical human impacts on the forest and the absence of any mapped record of human land use. The discussion focuses on key characteristics of each disturbance category
ABSTRACT Changes over the last 25 years in a Clingman’s Dome fir-spruce stand are quantified. Balsam woolly adelgid induced mortality of Fraser fir has resulted in a 47% decrease in live basal area of fir. Fir remains the dominant species comprising 57% of the stand basal area, and exhibits abundant recruitment. Minor increases in red spruce density and basal area are evident despite reports of radial growth reductions in spruce at this site.