Beyond predictions: biodiversity conservation in a changing climate

Climate change is predicted to become a major threat to biodiversity in the 21st century, but accurate predictions and effective solutions have proved difficult to formulate. Alarming predictions have come from a rather narrow methodological base, but a new, integrated science of climate-change biodiversity assessment is emerging, based on multiple sources and approaches. Drawing on evidence from paleoecological observations, recent phenological and microevolutionary responses, experiments, and computational models, we review the insights that different approaches bring to anticipating and managing the biodiversity consequences of climate change, including the extent of species' natural resilience. We introduce a framework that uses information from different sources to identify vulnerability and to support the design of conservation responses. Although much of the information reviewed is on species, our framework and conclusions are also applicable to ecosystems, habitats, ecological communities, and genetic diversity, whether terrestrial, marine, or fresh water.     

Phytoremediation and Modeling of Contaminated Soil using Eastern Gamagrass and Annual Ryegrass

The effectiveness of a warm season grass (eastern gamagrass), a cool season grass (annual ryegrass) and a rotation of warm and cool season grasses in the remediation of soil freshly contaminated with trinitrotoluene (TNT) and polybrominated biphenyls (PBBs) was evaluated. A total of 96 columns were filled with a Weswood silt loam soil that was mixed with TNT and PBB compounds to a target concentration of 10 mg of each contaminant. Chemical losses during this two-year field lysimeter experiment were similar for all experimental treatments and at all depths. Although higher microbial biomass was found in the rhizosphere soil, enumeration of soil microorganisms revealed a robust population in both the bulk and rhizosphere soils and the microbial growth was not dependent on root exudates only. Microbial degradation rates in the freshly contaminated soil were more affected by soil properties and the chemical characteristics of the contaminant than the presence of roots. The field data collected from the lysimeter experiment was used to calibrate a recently developed phytoremediation model. The phytoremediation computer model successfully simulated TNT soil concentrations in the column lysimeters. The model may be a valuable tool for the selection and optimization of phytoremediation methods at contaminated field sites.     

Monthly prevalence (in 1986) of antibody titers against equine monocytic ehrlichiosis in apparently healthy horses in Illinois

The seroprevalence and seasonal trend of antibody titers against equine monocytic ehrlichiosis (Potomac horse fever) were determined in apparently healthy horses in selected areas of Illinois in 1986. Sera from 1,367 horses (6 months to 29 years old) were evaluated for the presence of antibodies against Ehrlichia risticii with indirect immunofluorescence. The majority (88%) of the horses were Thoroughbred or Standardbred racehorses. The number of horses with antibodies against E risticii was 229/1,367 (16.75%). The titers in these horses ranged from 1:10 to 1:640. As the year progressed, the number of seropositive horses (titers greater than or equal to 1:10) and the magnitude of the titers increased significantly, both reaching a maximum in July and August, respectively (P less than 0.05). A relationship between seropositivity and gender was not detected. In the year prior to sampling, 56.8% of the seropositive horses had not been ill, whereas 0.8% had diarrhea, an episode of acute abdominal pain, or laminitis. It was concluded that a large number of horses in Illinois are exposed to E risticii, that maximal exposure occurs in July, and that the most common form of the disease in Illinois is not associated with clinical signs.