Beach dune sand hydrophobicity due to the presence of beach vitex ( Vitex rotundifolia L. f.).

Conservation and preservation concerns have led to efforts to understand mechanisms of invasiveness and the effects these mechanisms have on the environment. Vitex rotundifolia L. f. [beach vitex (BV)] was introduced as a salt-tolerant woody ground cover, but it has since become invasive on primary and secondary dunes in coastal areas of the southeastern United States. Much of its invasive potential may be the result of intense substrate hydrophobicity underneath established stands, which is believed to prohibit seedling establishment by other plants including native plant species. This research was conducted to better understand BV-induced sand hydrophobicity by carrying out dune surveys of BV-infested areas of the South Carolina coast, identifying the compounds responsible for this activity via chemical analysis, and quantifying hydrophobicity persistence by resampling sites following removal of above-ground BV. The findings indicated that sand under BV cover was significantly hydrophobic, that cuticular alkanes from leaves and fruits were responsible for this hydrophobicity, and that extreme substrate hydrophobicity persisted for >3 years following BV removal.

Increased prevalence of Brucella suis and pseudorabies virus antibodies in adults of an isolated feral swine population in coastal South Carolina.

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.