Public Priorities for Rangeland Management: A Regional Survey of Citizens in the Great Basin

Healthy sagebrush communities in the Great Basin are rapidly disappearing due to invasion of non-native plants, catastrophic wildfires, and encroachment of pinyon-juniper woodlands. Land management options, including the use of prescribed fire, mechanical thinning, and herbicides can reduce the potential for wildfire and restore healthy plant communities. Public acceptance of management actions is a critical component of developing and implementing successful long-term land management plans. This study examined citizens\u27 opinions and perceptions about rangeland management in the Great Basin

Acceptance, Acceptability, and Trust for Sagebrush Restoration Options in the Great Basin: A Longitudinal Perspective

In surveys of residents in three urban and three rural locations in the Great Basin we examined the social acceptability of six management practices showing promise for restoring sagebrush-dominated rangelands. Unlike most studies of range management perceptions that have relied on single measurements, we used longitudinal data from a questionnaire mailed in 2006 to residents that were resurveyed in 2010. Overall, 698 respondents comprised the panel. Respondents\u27 self-reported levels of knowledge about the health and management of Great Basin rangelands decreased from 2006 to 2010. In both years, mean acceptance was greater for the use of prescribed fire, grazing, felling, and mowing, but relatively low for chaining and herbicide use. Overall, acceptability ratings were similar in 2006 and 2010 but individually about half of the acceptance responses differed between years. Practices were more acceptable to respondents who expressed greater concern about threats posed by inaction, except that the threat of wildfire was negatively associated with acceptance for prescribed burning. Acceptance was not significantly related to concern about overall health of Great Basin rangelands, or to self-reported knowledge level. Rural/urban residence and general attitudes toward environmental protection were sometimes influential, but more so in 2006 than in 2010. By far the best predictor of acceptance was trust in agencies\u27 ability to implement the practice. In both years respondents were more likely to judge a practice acceptable than to trust agencies to use the practice. Positive or negative change in trust level was the most significant predictor of change in acceptability judgment from 2006 to 2010. Results suggest that efforts to increase acceptance of practices among Great Basin stakeholders should focus on activities designed to build trust rather than simply providing more or better information

Effects of live-bait shrimp trawling on seagrass beds and fish bycatch in Tampa Bay, Florida

The use of live shrimp for bait in recreational fishing has resulted in a controversial fishery for shrimp in Florida. In this fishery, night collections are conducted over seagrass beds with roller beam trawls to capture live shrimp, primarily pink shrimp, Penaeus duorarum. These shrimp are culled from the catch on sorting tables and placed in onboard aerated “live” wells. Beds of turtlegrass, Thalassia testudinum, a species that has highest growth rates and biomass during summer and lowest during the winter (Fonseca et al., 1996) are predominant areas for live-bait shrimp trawling (Tabb and Kenny, 1969). Our study objectives were 1) to determine effects of a roller beam trawl on turtlegrass biomass and morphometrics during intensive (up to 18 trawls over a turtlegrass bed), short-term (3-hour duration) use and 2) to examine the mortality of bycatch finfish following capture by a trawl

Structure and Energetics of Ground-State Hypericin: Comparison of Experiment and Theory

Calculations of the energies of the ground-state un-ionized tautomers of hypericin have been performed at the RMP2/6-31G(d) level of theory, using geometries obtained with the 3-21G basis set and Hartree−Fock wave functions. It is found that only the so-called normal form is likely to be populated at room temperature and that only two of the three possible double tautomers correspond to minima on the potential energy surface. The effect of continuum aqueous solvation on the tautomer energies is negligible. The O---O distances between which the proton is transferred are reported and are consistent with that required for an adiabatic proton transfer, i.e., ∼2.5 Å. All 156 vibrational frequencies are tabulated and may be viewed at www.msg.ameslab.gov. For example, the vibrations in the range 320−660 cm-1 are coupled with O---O vibrations. The vibrations that are most clearly O---O vibrations occur in the range 400−500 cm-1. Twisting of the backbone occurs in a wide range of frequencies, from 230 to 1150 cm-1, while the motion corresponding to an inversion of the (nonplanar) backbone occur at very low frequencies, 80−150 cm-1. The results of these calculations are discussed in terms of ground-state heterogeneity of hypericin that has been invoked to explain its spectra and excited-state kinetics

Potential Energy Surfaces of SimOn Cluster Formation and Isomerization

The reaction paths for formation and isomerization of a set of silica SimOn (m = 2,3, n = 1−5) nanoclusters have been investigated using second-order pertubation theory (MP2) with the 6-31G(d) basis set. The MP2/6-31G(d) calculations have predicted singlet ground states for all clusters excluding Si3O2. The total energies of the most important points on the potential energy surfaces (PES) have been determined using the completely renormalized (CR) singles and doubles coupled cluster method including perturbative triples, CR-CCSD(T) with the cc-pVTZ basis set. Although transition states have been located for many isomerization reactions, only for Si3O3 and Si3O4 have some transition states been found for the formation of a cluster from the separated reactants. In all other cases, the process of formation of SimOnclusters appears to proceed without potential energy barriers

Structures and Fragmentations of Small Silicon Oxide Clusters by ab Initio Calculations

The structures, energies, and fragmentation stabilities of silicon oxide clusters SimOn, with m = 1−5, n = 1, 2m + 1, are studied systematically by ab initio calculations. New structures for nine clusters are found to be energetically more favorable than previously proposed structures. Using the ground state structures and energies obtained from our calculations, we have also studied fragmentation pathways and dissociation energies of the clusters. Our computational results show that the dissociation energy is strongly correlated with the O/Si ratio. Oxygen-rich clusters tend to have larger dissociation energies, as well as larger HOMO−LUMO gaps. Our calculations also show that SiO is the most abundant species in the fragmentation products