Beach Vitex ( Vitex rotundifolia Lf.) was introduced to coastal Carolina areas in the 1980s. Since its introduction, it has become a major invasive plant problem. Beach Vitex rapidly dominates the vegetation and eliminates many native plant species on primary and secondary coastal dunes. It grows rapidly and reproduces vegetatively by rooting at the nodes. Thousands of fruits, containing one to four seeds each, are produced annually and assist in the plant's spread. Beach sand in areas dominated by Beach Vitex was found to possess hydrophobic qualities, while sand collected from areas not populated by Beach Vitex readily allowed water infiltration. GC-MS analysis of hydrophobic sand extracts showed four peaks that were absent from extracts of non-hydrophobic sand. These peaks were also present in chromatograms of water extracts of Beach Vitex fruits and leaves. Comparison of GC-MS spectra with compounds previously identified in Beach Vitex indicated that one compound was a diterpene (likely ferruginol or abietatrien-3ß-ol). The second compound is likely a flavonoid (possibly casticin, artemetin, or vitexicarpin). Two additional compounds are present at low levels and are possibly phenylnaphthalene compounds. These four compounds appear to be synthesized and incorporated into surface tissues of Beach Vitex leaves and fruits and are transferred to sand during rain events and decomposition. Further studies of Beach Vitex plant parts and beach sands are being conducted to further elucidate the possibility that these chemicals are involved in the intriguing property of sand hydrophobicity. This property may aide Beach Vitex in its competition with plants possessing less expansive root systems.
In the South Carolina Coastal Plain, intensive loblolly pine (Pinus taeda L.) plantation management, without fertilization, was sustainable through two rotations as measured by biomass accumulation. Fixed plot tree inventories and destructive tree sampling of first and second rotation sections of the same plantations were used to produce area based estimates of aboveground, oven-dry tree biomass. First rotation plots in two plantations produced 289 and 242 tonnes/ha at 34 and 36 years after establishment respectively. Second rotation plots of these same stands produced 127 to 152 tonnes/ha at 15 years after establishment. Second rotation crown biomass was 67 to 87 percent of the crown biomass of the first rotation plots at 42 to 44 percent of the age of the first rotation trees. Total aboveground biomass of second rotation plots was 44 to 61 percent of the total aboveground biomass of the first at 42 to 44 percent of the age. Biomass accumulation is at least proportional to age from the first to second rotation; thus these management procedures appear to be sustainable.
Knowing the nutrient uptake potential of plantations of fast-growing species is essential to designing land-based tertiary water treatment facilities. This study was conducted to estimate the biomass of 4-year-old, intensively managed loblolly pine (Pinus taeda) and sweetgum (Liquidambar styraciflua) plantations and to estimate the N and P contained in that biomass. The cumulative effects of competition control only and competition control, irrigation, fertilization and pest control were investigated on an abandoned peanut field in Decatur County Georgia on a Lakeland sand soil. Planted at 1,157 trees/ha, loblolly pine accumulated 57.3 mg/ha dry biomass 4 years after planting and sweetgum accumulated 26.5 mg/ha dry biomass in the maximum treatment plots. Sweetgum was more responsive to the maximum treatment with a biomass increase of 388 percent compared to a 217 percent increase in loblolly pine biomass. In the maximum treatment plots, loblolly pine accumulated 330 kg N/ha and 35 kg P/ha compared to sweetgum accumulation of 137 kg N/ha and 15 kg P/ha.
Twenty loblolly pines, growing in International Paper's maximum growth experiment at Bainbridge GA, were destructively sampled at the end of the sixth growing season. Ten trees in the control and 10 in the maximum treatment were sampled. All trees were planted at a 2.4- by 3.6-m spacing and grown with complete competition control. The maximum trees also received irrigation, fertilization, and pest control. Tree measures were basal diameter, d.b.h., height of live crown, diameter at base of live crown, and total height. Each tree was sectioned at 1-m intervals and stem diameter determined at each end. Branches were removed and height, basal diameter, and length were measured on each branch. Branches were separated into foliated and unfoliated segments and weighed green. One branch from each meter was returned to the lab to determine dry weight and foliated branch to foliage ratios. The maximum treatment trees were considerably larger (17.2 cm- d.b.h., 9.57 m tall, 0.118 m 3 stem volume to 5-cm top) than the controls (13.5 cm- d.b.h., 7.72 m tall, 0.58 m 3 stem volume), but crown lengths were similar (6.7 m maximum, 6.6 m control). In the upper 5 m of crown, leaf biomass was highly corre- lated with branch basal area (r2 = 0.697 to 0.947), and there was a constant ratio of leaf biomass to branch basal area (50.4gm per cm 2 for maximum, 50.2 gm per cm 2 for control). In general, we found a constant ratio of bole basal area to cumulative branch basal area throughout the crowns (0.94 for controls, 1.06 for maximum).
Pocosins and Carolina bays share several hydrologie and physical characteristics that distinguish them from other forested wetland types; they are nutrient-poor, typically have peat or organic substrates, and are non-alluvial. Pocosin wetlands of the southeastern Atlantic Coastal Plain are characterized by non-alluvial hydrology, strongly acid soils, and a generally dense shrub layer of species that are generally characterized by evergreen, sclerophyllous leaves. Carolina bays are isolated elliptical depressions that occur across the southeastern Coastal Plain, most abundantly in southern North Carolina and in South Carolina. They range in size from a few hectares up to several thousand hectares, and their long axis is usually, but not always, oriented in a northwest-southeast direction, with a sand rim to the southeast. The distributions of pocosins and Carolina bays overlap, but pocosins typically occur in the lower and middle coastal plain terraces, whereas bays extend further inward into the upper terraces.
Two hundred twenty seven adult (>8 mo) feral swine (Sus scrofa) trapped from April through July 1999 at three locations on a coastal South Carolina (USA) peninsula with restricted ingress and egress were tested for Brucella suis and pseudorabies virus (PRV) antibodies. Approximately 44% of the animals tested positive for B. suis antibodies and 61% tested positive for antibodies to PRV. Previous surveys (1976 and 1992) of feral swine at the same location with similar methods indicated lower seroprevalences (28% and 18% for B. suis and 0% and 19% for PRV). We also found 39% of feral swine seropositive (n=179) for Trichinella spiralis and 49% seropositive (n=181) for Toxoplasma gondii. Results of repeated sampling demonstrated that seroprevalence to pathogens can increase with time in an isolated, unhunted population of feral swine suggesting an increased risk to local domestic livestock and potentially to human health.
The Gene Ontology (GO) (http://www.geneontology.org) is a community bioinformatics resource that represents gene product function through the use of structured, controlled vocabularies. The number of GO annotations of gene products has increased due to curation efforts among GO Consortium (GOC) groups, including focused literature-based annotation and ortholog-based functional inference. The GO ontologies continue to expand and improve as a result of targeted ontology development, including the introduction of computable logical definitions and development of new tools for the streamlined addition of terms to the ontology. The GOC continues to support its user community through the use of e-mail lists, social media and web-based resources.
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