Riparian reference condition: Using regional plant composition to guide functional improvements in the City of Austin

This technical report focuses on ways to restore riparian habitat within specific Austin creeks. This study is designed to serve as a template for restoration efforts with other urbanized creeks (Waller).As a result of an expanding and rapidly urbanizing metropolitan area, the riparian vegetation communities of Austin-area streams continue to diverge further from their natural state. In an effort to maintain the ecological function and the natural character of Austin watersheds, the City of Austin Watershed Protection Department has identified a need to characterize an archetype, or background condition of Edwards Plateau and Blackland Prairie riparian communities for use as a template for both benchmarking and target for stream restoration projects. Species composition, spatial arrangement and physical attributes of vegetation communities for 12 sites located in both smaller and larger watersheds were characterized using multiple belt-transects. Multivariate analyses including detrended correspondence analysis (DCA), analysis of similarity (ANOSIM), and similarity percentage (SIMPER) were performed by Community Analysis Package software (Seaby and Henderson 2007). Results show that there was a significant difference in plant community composition in all compared drainage areas and ecoregions for both ground cover and overstory communities (p<0.05). The analysis of similarity showed that the samples should be grouped by ecoregion and location within the watershed for overstory and ground cover communities. Recommended vegetation templates are presented as a guide for comparison to other riparian communities in the Austin area, and also a reference point for restoration of degraded systems. These quantitative species distribution lists are an important resource for riparian ecologists in this region.Waller Creek Working Grou

Shell-model studies of the astrophysical rp reaction 29P(p, y)30 S

We present results for levels in 30S (the mirror nucleus of 30Si) that are used for the 29P(p,γ ) rp reaction rate calculations. The resonance energies used in the reaction rate calculations are based on recent measurements which extend the excitation energy spectrum. The levels are checked against results from the isobaric mass multiplet equation and the binding energies of the T = 1 analog states. Where the analog states are not known the levels are calculated with two-body interactions that use the sd-shell interactions USDA and USDB as the charge-independent parts, with a Coulomb, charge-dependent, and charge-asymmetric Hamiltonian added. The γ -decay lifetimes and 29P to 30S spectroscopic factors are also calculated with the same interactions, and together with experimental information on the levels of excited states are used to determine the 29P(p,γ )30S reaction rates.Web of Scienc

Implications for the 1s0d shell of the new two-body interactions USDA and USDB

The new Hamiltonians USDA and USDB for the sd-shell are used to calculate M1 and E2 moments and transition matrix elements, Gamow-Teller beta decay matrix elements and spectroscopic factors for sd-shell nuclei from A=17 to A=39. The results are compared with those obtained with the older USD Hamiltonian and with experiment to explore the interaction sensitivity of these observables. Predictions up to high energies are also tested for 26Mg in a number of cases

Environmental Gradients in Old‐Growth Appalachian Forest Predict Fine‐Scale Distribution, Co‐occurrence, and Density of Woodland Salamanders

Woodland salamanders are among the most abundant vertebrate animals in temperate deciduous forests of eastern North America. Because of their abundance, woodland salamanders are responsible for the transformation of nutrients and translocation of energy between highly disparate levels of trophic organization: detrital food webs and high‐order predators. However, the spatial extent of woodland salamanders’ role in the ecosystem is likely contingent upon the distribution of their biomass throughout the forest. We sought to determine if natural environmental gradients influence the fine‐scale distribution and density of Southern Ravine Salamanders (Plethodon richmondi) and Cumberland Plateau Salamanders (P. kentucki). We addressed this objective by constructing occupancy, co‐occurrence, and abundance models from temporally replicated surveys within an old‐growth forest in the Cumberland Plateau region of Kentucky. We found that Plethodon richmondi had a more restricted fine‐scale distribution than P. kentucki (mean occupancy probability [] = 0.737) and exhibited variable density, from \u3c250 to \u3e1000 individuals per hectare, associated with increased soil moisture and reduced solar exposure due to slope face. While more ubiquitously distributed ( = 0.95), P. kentucki density varied from \u3c400 to \u3e1,000 individuals per hectare and was inversely related to increased solar exposure from canopy disturbance and landscape convexity. Our data suggest co‐occurrence patterns of P. richmondi and P. kentucki are influenced primarily by abiotic conditions within the forest, and that populations likely occur independently and without evidence of biotic interaction. Given the critical role that woodland salamanders play in the maintenance of forest health, regions that support large populations of woodland salamanders, such as those highlighted in this study—mesic forest stands on north‐to‐east facing slopes with dense canopy and abundant natural cover, may provide enhanced ecosystem services and support the stability of the total forest