The redheaded pasture cockchafer, Adoryphorus couloni (Burmeister) (Scarabaeidae: Dynastinae: Pentodontini) is a pest of semi-improved and improved pastures in south-eastern Australia. It is a native species that has adapted to managed pastures, and despite many years of research in attempts to control it, this species still causes major economic damage, especially to perennial dairy pastures in south-eastern Australia. This is a review of available information on A. couloni and identifies some basic information gaps that require addressing: correct identification of the main pasture beetles, more accurate detection and monitoring methods, and better information on its biology and ecology, especially its feeding behaviour in soil.
Summary Severe droughts have been associated with regional‐scale forest mortality worldwide. Climate change is expected to exacerbate regional mortality events; however, prediction remains difficult because the physiological mechanisms underlying drought survival and mortality are poorly understood. We developed a hydraulically based theory considering carbon balance and insect resistance that allowed development and examination of hypotheses regarding survival and mortality. Multiple mechanisms may cause mortality during drought. A common mechanism for plants with isohydric regulation of water status results from avoidance of drought‐induced hydraulic failure via stomatal closure, resulting in carbon starvation and a cascade of downstream effects such as reduced resistance to biotic agents. Mortality by hydraulic failure per se may occur for isohydric seedlings or trees near their maximum height. Although anisohydric plants are relatively drought‐tolerant, they are predisposed to hydraulic failure because they operate with narrower hydraulic safety margins during drought. Elevated temperatures should exacerbate carbon starvation and hydraulic failure. Biotic agents may amplify and be amplified by drought‐induced plant stress. Wet multidecadal climate oscillations may increase plant susceptibility to drought‐induced mortality by stimulating shifts in hydraulic architecture, effectively predisposing plants to water stress. Climate warming and increased frequency of extreme events will probably cause increased regional mortality episodes. Isohydric and anisohydric water potential regulation may partition species between survival and mortality, and, as such, incorporating this hydraulic framework may be effective for modeling plant survival and mortality under future climate conditions. Contents Summary 1 I. Introduction 2 II. Consequences of vegetation mortality 3 III. Global patterns of mortality 3 IV. Hypotheses on mechanisms of drought‐related mortality 4 V. Evidence for hypothesized mechanisms 5 VI. Implications of future climate on hypothesized mortality mechanisms 13 VII. Conclusions 15 Acknowledgements 15 References 15
This report describes accomplishments for the two-year project investigating temporal dynamics of glacial ice and snow meltwater, rainfall and base flow contributions to stream flow of Dinwoody Creek in the Wind River Range of western Wyoming. The primary objectives were to 1) characterize diurnal, seasonal and interannual variation in the isotopic composition of water in Dinwoody Creek, 2) quantify the contribution of baseflow and surface runoff to stream discharge using isotopic methods, and 3) partition the surface runoff component of stream discharge into that derived from glacial melt, snowmelt, and summer precipitation. This project involved a collaboration among the University of Wyoming Stable Isotope Facility, directed by the project PI (Williams), Dr. Jessica Cable of the Department of Botany and Dr. Kiona Ogle of the Departments of Botany and Statistics. Dr. Cable led the field and laboratory studies and statistical modeling and will be the primary author of a forthcoming journal article describing the findings from this project to be submitted in June 2009 to Hydrological Processes. Dr. Cable was supported part time as a postdoctoral student on this project and was mentored by Drs. Williams and Ogle. Dr. Ogle provided valuable leadership on the statistical modeling used to partition stream flow and quantify the contribution of glacier meltwater. We estimated the fractional contribution of glacier melt water to flow in Dinwoody Creek on seasonal and interannual time scales. The stable isotope composition of water (oxygen-18 and deuterium) from the Dinwoody Creek watershed and glacier system was determined on a temporally intensive scale in 2007 and 2008. Field sampling of the primary contributors to streamflow, namely snow melt, glacier melt, rain, and baseflow, were collected during the summers of 2007 and 2008. Stream samples were collected every 48 h over the entire melt season from mid-April to late October using an automated stream sampler placed beside an unimpaired USGS gauging station low in the watershed. The data were analyzed with a hierarchical Bayesian framework that allowed integration of temporal and spatial autocorrelation in the isotope data. Glacial melt contributed a significantly large proportion to stream flow in a low flow year (2007) and when stream flow was low during a high flow year (early and late summer 2008). In 2008, a large and persistent snowpack and associated melt dominated stream flow in the middle of the summer. Summer rainfall had minimal contribution to streamflow. Our findings strongly support the assertion that loss of alpine glaciers in the Wind River Range with climate warming will substantially reduce streamflow, but only during periods when snowmelt contributions are low.
