Modeling Siberian ibex (Capra sibirica) occupancy in Ikh Nart Nature Reserve, Mongolia

As the world becomes increasingly populated, humans continue to modify habitats to suit their needs. Mongolia is one of many Asian countries currently undergoing human-induced landscape change, namely in the form of increased grazing pressure on the land by domesticated animals. There is uncertainty as to how wildlife will be impacted by this change. The Siberian ibex (Capra sibirica) is an ungulate classified as IUCN Near Threatened in Mongolia and an important species for tourism. I developed an occupancy model for the species based on radio- telemetry locations (n = 920) collected in Ikh Nart Nature Reserve, then estimated the effect of habitat reductions as expected under increasing levels of grazing. I developed 13 candidate models that include combinations of habitat and human variables, and used model selection techniques to evaluate the best-supported model in the set. The model with the most support indicated that rocky outcrop, open plain, and their interaction best described ibex occupancy. Average occupancy was 5.7% across the northern Ikh Nart landscape, 7.4% within the borders of the reserve, and 17.4% within the reserve’s core protected area. Simulations showed that in the absence of open plain habitat, average occupancy declined to 1.9%, 2.1%, and 5.0% respectively in these areas. The results provide a description of how landscape factors shape the distribution of the species. Because livestock grazing is concentrated in open plain habitats, these results may be used to inform decision-making about ibex conservation in the region

Molybdenum, Ruthenium, and the Heavy r-process Elements in Moderately Metal-Poor Main-Sequence Turnoff Stars

The ratios of elemental abundances observed in metal-poor stars of the Galactic halo provide a unique present-day record of the nucleosynthesis products of its earliest stars. While the heaviest elements were synthesized by the r- and s-processes, dominant production mechanisms of light trans-ironic elements were obscure until recently. This work investigates further our 2011 conclusion that the low-entropy regime of a high-entropy wind (HEW) produced molybdenum and ruthenium in two moderately metal-poor turnoff stars that showed extreme overabundances of those elements with respect to iron. Only a few, rare nucleosynthesis events may have been involved. Here we determine abundances for Mo, Ru, and other trans-Fe elements for 28 similar stars by matching spectral calculations to well-exposed near-UV Keck HIRES spectra obtained for beryllium abundances. In each of the 26 turnoff stars with Mo or Ru line detections and no evidence for s-process production (therefore old), we find Mo and Ru to be three to six times overabundant. In contrast, the maximum overabundance is reduced to factors of three and two for the neighboring elements zirconium and palladium. Since the overproduction peaks sharply at Mo and Ru, a low-entropy HEW is confirmed as its origin. The overabundance level of the heavy r-process elements varies significantly, from none to a factor of four, but is uncorrelated with Mo and Ru overabundances. Despite their moderate metallicity, stars in this group trace the products of different nucleosynthetic events: possibly very few events, possibly events whose output depended on environment, metallicity, or time.Comment: Accepted April 2, 2013, for publication in the Astrophysical Journal Letters (7 pages, 3 figures

Precaution: principles and practice in Australian environmental and natural resource management

Precaution: principles and practice in Australian environmental and natural resource management by Deborah Peterson, was presented as the Presidential Address to the 50th Annual Australian Agricultural and Resource Economics Society Conference, Manly, New South Wales, 8 - 10 February 2006. Since the late 1980s, the concept of precaution has been incorporated into numerous international agreements and laws, as well as in domestic statutes and policies in many countries. This paper examines the international emergence of the concept and its application in Australia. Despite rapid growth in adoption of the so-called "precautionary principle," the concept remains highly controversial, and its success in terms of improving environmental and natural resource management has been questioned. This paper argues that implementation guidelines are essential to ensure that precautionary decision making is consistent with good decision making principles, and to avoid unnecessary costs and the potential for perverse outcomes. Economists have an important role in contributing to these guidelines and in developing techniques for incorporating uncertainty into decision making. The views expressed in this paper do not necessarily reflect those of the Australian Government or the Productivity Commission.Resource /Energy Economics and Policy,

Precaution: principles and practice in Australian environmental and natural resource management

Since the late 1980s, the concept of precaution has been incorporated into numerous international agreements and laws, as well as in domestic statutes and policies in many countries. This paper examines the international emergence of the concept and its application in Australia. Despite rapid growth in adoption of the so-called ‘precautionary principle’, the concept remains highly controversial, and its success in terms of improving environmental and natural resource management has been questioned. A common misconception is that the principle prescribes action. In fact, internationally accepted definitions are about decision-making processes. This paper argues that implementation guidelines are essential to ensure that precautionary decision-making is consistent with good decision-making principles, and to avoid unnecessary costs and perverse outcomes.environment, natural resource management, precautionary principle, uncertainty, Environmental Economics and Policy, Resource /Energy Economics and Policy,