The rust fungus, P uccinia psidii , is a devastating pathogen of introduced eucalypts ( E ucalyptus spp.) in Brazil where it was first observed in 1912. This pathogen is hypothesized to be endemic to S outh and C entral A merica and to have first infected eucalypts via a host jump from native guava ( P sidium guajava ). Ten microsatellite markers were used to genotype 148 P . psidii samples from eucalypts and guava plus five a...

There is growing understanding that recent deterioration of the Black Sea ecosystem was partly due to changes in the marine physical environment. This study uses high resolution 0.25° climatology to analyze sea surface temperature variability over the 20th century in two contrasting regions of the sea. Results show that the deep Black Sea was cooling during the first three quarters of the century and was warming in the last 15...

The introduction of nonnative invasive species (NNIS) into the United States has had tremendous impacts on the nation's commercial and urban forest resources. Of principal concern are the effects of NNIS on forest composition, structure, function, productivity, and patterns of carbon sequestration. In 2006, the Society of American Foresters commissioned an ad hoc team to prepare a white paper on the effect of NNIS on America's...