MULE DEER SURVIVAL AMONG ADJACENT POPULATIONS IN SOUTHWEST IDAHO

Abstract: We investigated survival and cause-specific mortality of mule deer (Odocoileus hemionus) on 3 distinct winter ranges in southwest Idaho from 1992 to 1997 to identify demographic variation and potential limiting factors based on a sample of 447 radiocollared deer. During winters 1995–1996 and 1996–1997, we modeled overwinter fawn mortality based on early winter mass, sex, activity, and habitat use variables. Annual survival rates of adult mule deer varied among the 3 adjacent study areas (χ₂² = 10.93, P = 0.004). Overwinter deer survival also varied among study areas (χ₂² = 8.00, P = 0.018), and the study area X year, study area X sex, and study area X age interactions were all significant (P ≤ 0.018). Overwinter survival differences among the study areas were not consistent over time or among sexes and ages of deer. Winter malnutrition was the main cause of mortality for both adults and fawns during the severe winter of 1992–1993, when overall survival was low. Excluding harvest, predation was the major proximate cause of deer mortality during 1993–97 when overall survival was higher. The probability of winter fawn mortality increased with lower mass (χ₂¹ = 7.38, P = 0.007), being male (χ₂¹ = 5.61, P = 0.018), smaller group sizes (χ₂¹ = 3.62, P = 0.057), and using steeper slopes (χ₂¹ = 3.05, P = 0.081). Smaller group sizes and use of steep slopes corresponded to conditions where predators were more successful. Our findings suggest that coyote (Canis latrans) predation was largely compensatory whereas mountain lion (Puma concolor) predation was apparently independent of animal condition and dependent more on deer habitat use. Early winter fawn mass was a better predictor of overwinter fawn survival than a suite of winter resource use variables, lending further support for use of fawn mass to predict winters where fawn mortality may be high. No single population in this study could be used to make reliable inferences regarding deer survival in the other populations. Survival rate measurements should be used cautiously to make inferences in populations where survival has not been directly measured.     

WINTER HABITAT SELECTION BY SITKA BLACK-TAILED DEER

Abstract: Identifying and managing Sitka black-tailed deer (Odocoileus hemionus sitkensis) habitat has been an important wildlife issue for many years on the Tongass National Forest of southeastern Alaska, USA. We evaluated habitat selection of Sitka black-tailed deer in the central portion of the region during a winter with snowfall 43% above average using telemetry relocations from 30 individuals that survived the winter. Ivlev indices for habitat selection within home ranges indicated that deer used less than expected, based on availability, north, east, and west aspects, areas >244-m elevation, noncommercial forests, and the low-timber volume stratum while selecting south aspects, areas <153-m elevation, and areas within 305 m of saltwater. Deer used less than expected moderately coarse-canopied forests in the medium- and high-timber volume strata typically found on north slopes while selecting moderately fine-canopied forest in the high-timber volume stratum on south slopes. The lower than expected use of higher volume gap-phase old growth was likely because these were on north aspects where snow accumulated and persisted due to protection from maritime storms. Point relocations suggested less use than expected in clearcuts <41 years of age, while data from 7.2-ha error polygons showed deer were neutral to clearcuts. This suggests that if deer do avoid clearcuts they remain close to the forest-clearcut edge. Of 4 habitat-mapping methods evaluated, the method that incorporated timber volume strata and a wind disturbance-related aspect had greatest utility in identifying areas selected for or used disproportionately little by deer during the deep snow winter. We found that deer exhibited marked changes in habitat use during deep snow conditions compared to a low snow winter, and we agree with previous researchers that providing habitats selected by deer during deep snowfall is an important consideration in Sitka black-tailed deer habitat management.     

Effects of temperature on the activity and kinetics of the granulovirus infecting the potato tuber moth Phthorimaea operculella Zeller (Lepidoptera: Gelechiidae)

The granulovirus infecting the potato tuber moth (PoGV) is an important biocontrol agent, especially for managing the pest in rustic potato storerooms. For efficient propagation and use of baculoviruses in pest control strategies, information on the effects of temperature on virus multiplication and activity is crucial. The interaction between PoGV infection and incubation temperature on P. operculella was studied in laboratory bioassays by determining the survival, yield of virus-infected larvae, and the kinetics of virus in vivo increase. Bioassays for LC₅₀ determination by using the egg-dip method were repeated over a period of six years in controlled incubation chambers at six constant temperatures ranging from 16 to 28 °C. Additionally, at temperatures of 17 and 24 °C the kinetics of virus development and increase in larva were assessed in destructive time-series experiments. Three different virus concentrations were used for inoculation. Control mortality was significantly temperature-dependent and was well described by a second-order polynomial function, with lowest mortality at 25 °C (20%) and highest at 16 °C (>60%). LC₅₀ values and slopes of probit-mortality curves were not significantly different between temperatures. Numbers of virus-infected larvae increased exponentially with increasing log-concentration of virus inoculum; an effect of temperature was not evident. Virus granules per larva correlated highly with larval age and larval weight. Multiple regression revealed minor direct effects of temperature on virus numbers; however, with decreasing temperature, larval weight and hence virus numbers increased. As a result, temperature is an important factor to be considered in virus-production facilities. Rearing temperature in virus-production facilities should be maintained at temperatures around 24 °C.     

Lessons Learned about Research and Management: A Case Study from a Midwest Lowland Savanna,U.S.A.

Integrating research and practice is a fundamental challenge for restoration and conservation. Scientists recognize restoration as an opportunity to test basic ecological principles, and that core scientific practices such as establishing control plots, replication, monitoring, and data management are fundamental to learning from restoration and management. However, practical constraints inherent to many projects often work against fully integrating research and management. In 2005, we had the opportunity to evaluate a lowland savanna that had been undergoing restoration by The Nature Conservancy since 1997. We used the data generated as a case study to evaluate how the restoration process might have changed had scientists been involved from the outset. Prescribed fire is the primary tool used to restore upland savanna and was chosen by The Nature Conservancy to manage the lowland savanna. In open areas dominated by Reed canary grass (Phalaris arundinacea), fire was associated with reduced cover of this highly invasive species and an increase in native species richness. However, other results suggested that management options beyond the use of fire are needed to restore this lowland savanna. In retrospect, an approach that integrated the skills of researchers and managers at the outset of the study would have altered many of the restoration goals and processes. Pretreatment data, greater replication, and systematically varying treatments could have provided a more robust assessment of treatment effects. We recognize, however, that impediments in staffing, funding, and time were barriers to following this course of action.     

Integrating Comparative Risk Assessment with Multi-Criteria Decision Analysis to Manage Contaminated Sediments: An Example for the New York/New Jersey Harbor

Current environmental challenges involve complex assessment and analysis of tradeoffs among differing criteria, expectations, and levels of certainty. Using multi-criteria decision analysis in combination with comparative risk assessment, a systematic and transparent framework can be created to integrate different types and sources of decision-relevant information. Although examples of decision analysis abound in the literature and academic efforts, its use within the practice of risk assessment and environmental management is still being established. This article provides an example of the use of decision analysis study that builds on a previous screening-level, comparative risk assessment of contaminated sediment from the New York/New Jersey harbor area. Using multi-criteria decision analysis, we explored the effect of different criteria weights, utility functions, and cost estimates on the ranking of seven contaminated sediment management alternatives. Values used in weighting decision criteria were surveyed from two interaction sessions with sediment management professionals.     

Disentangling relationships between habitat conditions, disturbance history, plant diversity, and American black cherry (Prunus serotina Ehrh.) invasion in a European temperate forest

Whether non-native plant invasions are causes, consequences, or independent of the low species diversity in recipient ecosystems remains a debated question. We tried to test these three hypotheses in the special case of the American black cherry ( Prunus serotina Ehrh.), a gap-dependent tree species, which is invading European temperate forests. We compared plant communities, soil properties, and disturbance history between P. serotina -invaded and uninvaded paired-stands in a managed mixed forest. Relationships between invasion, disturbances, plant communities, and environmental conditions were investigated using redundancy analyses with variation partitioning. Several soil characteristics differed between paired stands, but were rather components of stand invasibility than invasion effects, except for topsoil available phosphorus. The disturbance history was similar among paired stands except for the amount of storm-induced tree falls, which correlated with the invader's density. Wild boar-disturbed soil areas were more important beneath P. serotina canopies, suggesting a positive feedback on its own establishment. Overall, species assemblages in invaded and uninvaded stands were similar; their ecological inconsistency suggested a management-sustained non-equilibrium. Habitat conditions and disturbances explained most of the variation in both plant diversity and P. serotina density, the last two factors exhibiting a weak direct association. We conclude that in managed forest ecosystems where plant communities are mainly driven by non-interactive factors and immigration processes, non-native plant species can naturalize without being directly influenced by measured features of the plant community in the receiving environment on the short term.     

Autonomic resource management in virtualized data centers using fuzzy logic-based approaches

Data centers, as resource providers, are expected to deliver on performance guarantees while optimizing resource utilization to reduce cost. Virtualization techniques provide the opportunity of consolidating multiple separately managed containers of virtual resources on underutilized physical servers. A key challenge that comes with virtualization is the simultaneous on-demand provisioning of shared physical resources to virtual containers and the management of their capacities to meet service-quality targets at the least cost. This paper proposes a two-level resource management system to dynamically allocate resources to individual virtual containers. It uses local controllers at the virtual-container level and a global controller at the resource-pool level. An important advantage of this two-level control architecture is that it allows independent controller designs for separately optimizing the performance of applications and the use of resources. Autonomic resource allocation is realized through the interaction of the local and global controllers. A novelty of the local controller designs is their use of fuzzy logic-based approaches to efficiently and robustly deal with the complexity and uncertainties of dynamically changing workloads and resource usage. The global controller determines the resource allocation based on a proposed profit model, with the goal of maximizing the total profit of the data center. Experimental results obtained through a prototype implementation demonstrate that, for the scenarios under consideration, the proposed resource management system can significantly reduce resource consumption while still achieving application performance targets.

Importance of grazing and soil acidity for plant community composition and trait characterisation in coastal dune grasslands

Question: Does grazing by large herbivores affect species composition or community‐wide variation in plant functional traits? Location: Dune grasslands at the Belgian coast. Methods: Plant cover and soil data were collected in 146 plots that were randomly selected at 26 grazed and ungrazed grassland sites. Plant community composition was assessed by Detrended Correspondence Analysis and mean values of plant trait categories were calculated across the plots. Results: Differentiation of plant composition and community‐wide plant trait characteristics was largely determined by grazing, soil acidity and their interaction. In ungrazed situations, a clear floristic distinction appears between acidic (non‐calcareous) and alkaline (calcareous) grasslands. In grazed situations, these floristic differences largely disappeared, indicating that grazing results in a decrease of natural variation in species composition. At higher soil pH, a larger difference in plant community composition and community‐wide plant traits was observed between grazed and ungrazed plots. In ungrazed situations, shifts in plant functional traits along the acidity gradient were observed. Conclusions: Grazing is responsible for shifts in plant community composition, and hence a decrease in plant diversity among grasslands at opposing acidity conditions in coastal dune grasslands. Therefore, care should be taken when introducing grazing as a system approach for nature conservation in dune grasslands as it may eliminate part of the natural variation in plant diversity along existing abiotic gradients.     

Emergency relocation of a Purple Copper Butterfly colony during roadworks: Successes and lessons learned

Summary  In 2004, the Roads and Traffic Authority (RTA) undertook a road realignment project near Lidsdale in the Central Tablelands of New South Wales. However, the RTA had not detected a population of the threatened Purple Copper Butterfly within the footprint of the project. The RTA responded promptly when notified of the butterflies' presence by stopping works, and preparing and implementing a butterfly management programme. This programme included modifying the realignment (and reducing the development footprint), supplementary planting of habitat, habitat rehabilitation and translocation of individual caterpillars from within the final footprint area. These actions seem to have safeguarded the population at least in the short term; however, further active management of the site will be needed to ensure its long-term viability. The project reinforces the importance of thorough predisturbance assessment of a site at the early planning stages, and the results and observations could be particularly informative in planning for introduction, reintroduction and translocation proposals involving the Purple Copper Butterfly.