Effects of Management Treatments on Regeneration of a Geographically Disjunct, Relictual Hybrid Aspen (Populus xsmithii) Population in the Central Great Plains, USA.

Populus xsmithii is an uncommon hybrid of quaking aspen (Populus tremuloides) and bigtooth aspen (Populus grandidentata). Like its parents, Populus xsmithii is an early successional member of boreal forest communities, dependent on disturbance events that clear areas of competitive stems and spur an increase in clonal suckering. In recent years, aspen dieback has been noted across much of the western United States, a condition characterized by mortality of older stems and a lack of recruitment of suckers to maturity.

Site Preparation Drives Long-Term Plant Community Dynamics in Restored Tallgrass Prairie: A Case Study in Southeastern South Dakota.

Most tallgrass prairies have been destroyed or altered, making restoration an important component to their conservation. Our goal was to evaluate progress 12-years post-restoration at Spirit Mound Historic Prairie and determine whether the outcomes varied based on different land use and restoration histories across the site. We examined changes in plant diversity, richness, evenness, non-native species relative abundance, and community composition from 2004 to 2013.

Dynamics of plains cottonwood (Populus deltoides) forests and historical landscape change along unchannelized segments of the Missouri River, USA.

Construction of six large dams and reservoirs on the Missouri River over the last 50-75 years has resulted in major landscape changes and alterations in flow patterns, with implications for riparian forests dominated by plains cottonwood (Populus deltoides). We quantified changes in land cover from 1892-1950s and the 1950s-2006 and the current extent and age structure of cottonwood forests on seven segments (two reservoir and five remnant floodplain) comprising 1127 km (53 %) of the unchannelized upper two-thirds of the Missouri River. Riparian forest area declined by 49 %; grassland 61 %; shrubland 52 %; and sandbar habitat 96 %; while agricultural cropland increased six-fold and river/reservoir surface area doubled from 1892 to 2006.

Analysis of alprazolam by DART-TOF mass spectrometry in counterfeit and routine drug identification cases.

The high prevalence of alprazolam abuse translates to an increased workload for crime laboratories in characterizing seized tablets. These tablets may originate as diverted pharmaceuticals or counterfeited mimics, so efficient analytical techniques should provide confirmatory data while minimizing destruction of evidence. We offer the first report of a validated forensic method for confirming alprazolam tablets by direct analysis in real time-time of flight (DART-TOF) mass spectrometric analysis.

Status of the Riparian ecosystem in the upper San Pedro River, Arizona: application of an assessment model.

A portion of Arizona's San Pedro River is managed as a National Riparian Conservation Area but is potentially affected by ground-water withdrawals beyond the conservation area borders. We applied an assessment model to the Conservation Area as a basis for monitoring long-term changes in riparian ecosystem condition resulting from changes in river water availability, and collected multi-year data on a subset of the most sensitive bioindicators. The assessment model is based on nine vegetation bioindicators that are sensitive to changes in surface water or ground water.

Effects of weevil larvae on acorn use by blue jays.

 Blue jays (Cyanocitta cristata L.) are important consumers and dispersers of the nuts of oaks and other fagaceous trees in eastern North America. Acorns compose much of the jay diet, especially during the autumn when jays may consume or cache a significant portion of an acorn crop.