Characterizing Spatial Uncertainty when Integrating Social Data in Conservation Planning

Recent conservation planning studies have presented approaches for integrating spatially referenced social (SRS) data with a view to improving the feasibility of conservation action. We reviewed the growing conservation literature on SRS data, focusing on elicited or stated preferences derived through social survey methods such as choice experiments and public participation geographic information systems. Elicited SRS data includes the spatial distribution of willingness to sell, willingness to pay, willingness to act, and assessments of social and cultural values. We developed a typology for assessing elicited SRS data uncertainty which describes how social survey uncertainty propagates when projected spatially and the importance of accounting for spatial uncertainty such as scale effects and data quality. These uncertainties will propagate when elicited SRS data is integrated with biophysical data for conservation planning and may have important consequences for assessing the feasibility of conservation actions. To explore this issue further, we conducted a systematic review of the elicited SRS data literature. We found that social survey uncertainty was commonly tested for, but that these uncertainties were ignored when projected spatially. Based on these results we developed a framework which will help researchers and practitioners estimate social survey uncertainty and use these quantitative estimates to systematically address uncertainty within an analysis. This is important when using SRS data in conservation applications because decisions need to be made irrespective of data quality and well characterized uncertainty can be incorporated into decision theoretic approaches.     

Species-specific influence of group composition on collective behaviors in ants

The success of a social group is often driven by its collective characteristics and the traits of its individuals. Thus, understanding how collective behavior is influenced by the behavioral composition of group members is an important first step to understand the ecology of collective personalities. Here, we investigated how the efficiency of several group behaviors is influenced by the aggressiveness of its members in two species of Temnothorax ants. In our manipulation of group composition, we created two experimentally reconstituted groups in a split-colony design, i.e., each colony was split into an aggressive and a docile group of equal sizes. We found strong species-specific differences in how collective behaviors were influenced by its group members. In Temnothorax longispinosus, having more aggressive individuals improved colony defense and nest relocation efficiency. In addition, source colony identity strongly influenced group behavior in T. longispinosus, highlighting that manipulations of group compositions must control for the origin of the chosen individuals. In contrast, group composition and source colony did not influence collective behaviors in Temnothorax curvispinosus. This suggests that the mechanisms regulating collective behaviors via individual differences in behavior might differ among even closely related species.     

Detecting and quantifying reductive dechlorination under monitored natural attenuation conditions

Field sampling and testing were used to investigate the relationship between baseline geochemical and microbial community data and in situ reductive dechlorination rates at a site contaminated with trichloroethene (TCE) and carbon tetrachloride (CTET). Ten monitoring wells were selected to represent conditions along groundwater flow paths from the contaminant source zone to a wetlands groundwater discharge zone. Groundwater samples were analyzed for a suite of geochemical and microbial parameters; then push‐pull tests with fluorinated reactive tracers were conducted in each well to measure in situ reductive dechlorination rates. No exogenous electron donors were added in these tests, as the goal was to assess in situ reductive dechlorination rates under natural attenuation conditions. Geochemical data provided preliminary evidence that reductive dechlorination of TCE and CTET was occurring at the site, and microbial data confirmed the presence of known dechlorinating organisms in groundwater. Push‐pull tests were conducted using trichlorofluoroethene (TCFE) as a reactive tracer for TCE and, in one well, trichlorofluoromethane (TCFM) as a reactive tracer for CTET. Injected TCFE was transformed to cis‐ and trans‐dichlorofluoroethene and chlorofluoroethene, and, in one test, injected TCFE was completely dechlorinated to fluoroethene (FE). In situ TCFE transformation rates ranged from less than 0.005 to 0.004/day. In the single well tested, injected TCFM was transformed in situ to dichlorofluoromethane and chlorofluoromethane; the TCFM transformation rate was estimated as 0.001/day. The results indicate that it is possible to use push‐pull tests with reactive tracers to directly detect and quantify reductive dechlorination of chlorinated ethenes and ethanes under monitored natural attenuation conditions, which has not previously been demonstrated. Transformation rate estimates obtained with these techniques should improve the accuracy of contaminant transport modeling. © 2012 Wiley Periodicals, Inc.     

Mechanical Properties of Kenaf/Polypropylene Nonwoven Composites

With an industrial trend of going green, the use of natural fibers in polymer composites is growing rapidly, especially in the automotive industry. The objectives of this research are to investigate mechanical performance of kenaf/polypropylene nonwoven composites (KPNCs) in production of automotive interior parts, and to develop preliminary linear models for quantifying elastic range of the KPNCs under various loading conditions. Using polypropylene (PP) fiber as bonding fiber, the KPNCs were fabricated with 50/50 blend ratio by weight. Unlike the manufacturing method of fiber reinforced plastics, all KPNCs were produced by carding and needle-punching techniques and thermally bonded by a panel press with 3-mm thickness gauge. Mechanical properties of the KPNCs in terms of uniaxial tensile, open-hole tensile, tensile at different strain rates, flexural, and in-plane shear were measured instrumentally. It was found that sample which was processed at higher temperature (230?°C) but shorter time (60?s) had the best mechanical performance. KPNCs were relatively insensitive to the notch but sensitive to strain rates. The linear elastic finite element model of KPNCs agreed well with the experimental results in the valid strain range of 0?C0.5?% for uniaxial tensile test and 0?C1?% for flexural test.     

Determination of urinary lead in school children in Manzini, Swaziland, Southern Africa

Two hundred and fifty-seven urine samples collected from school children living in the Manzini region, Swaziland, were analysed for lead (Pb), using a graphite furnace atomic absorption spectrometer. The mean urine lead concentration for the urban schools ranged from 0.038–0.040 gml^–1, while that for the rural schools ranged from 0.017–0.022 gml^–1. The observed range shown by the urban schools was above the normal (for healthy humans) urine lead concentration of 0.035 gml^–1. However, the mean urine lead concentration for the rural schools was found to be lower than this value. The mean urine lead concentration for the urban schools was significantly higher than that of the rural schools. The differences in the mean urine lead concentrations for boys and girls from both urban and rural schools were found not to be significant, despite the higher values shown by the girls. The difference in lead concentrations between urban and rural schools in Manzini was thought to be due to the traffic density within the urban area.     

Are queen Bombus terrestris giant workers or are workers dwarf queens? Solving the 'chicken and egg' problem in a bumblebee species

In the social bee, Bombus terrestris, the two castes differ in size and physiology, but not in any other morphological and anatomical aspects. The size differences between the castes are the result of longer instar duration in prospective queen larvae. It appears that queen larvae are programmed to have a higher molting weight at the end of the 2nd, 3rd and 4th instars. Calculation of the growth ratio, the ratio between the logarithm of molting weight at two successive instars, revealed that queen larvae have a linear growth ratio over the entire larval development as predicted by Dyar's rule. In the worker larvae, in contrast, linearity of the growth ratio breaks after the second instar, resulting in larval molting at lower weights than expected by Dyar's rule. We therefore suggest that workers' development is abnormally shortened, either by parental manipulation or by adopting a different growth plan in response to the queen's signal.     

Toward efficient riparian restoration: integrating economic, physical, and biological models

This paper integrates economic, biological, and physical models to explore the efficient combination and spatial allocation of conservation efforts to protect water quality and increase salmonid populations in the Grande Ronde basin, Oregon. We focus on the effects of shade on water temperatures and the subsequent impacts on endangered juvenile salmonid populations. The integrated modeling system consists of a physical model that links riparian conditions and hydrological characteristics to water temperature; a biological model that links water temperature and riparian conditions to salmonid abundance, and an economic model that incorporates both physical and biological models to estimate minimum cost allocations of conservation efforts. Our findings indicate that conservation alternatives such as passive and active riparian restoration, the width of riparian restoration zones, and the types of vegetation used in restoration activities should be selected based on the spatial distribution of riparian characteristics in the basin. The relative effectiveness of passive and active restoration plays an important role in determining the efficient allocations of conservation efforts. The time frame considered in the restoration efforts and the magnitude of desired temperature reductions also affect the efficient combinations of restoration activities. If the objective of conservation efforts is to maximize fish populations, then fishery benefits should be directly targeted. Targeting other criterion such as water temperatures would result in different allocations of conservation efforts, and therefore are not generally efficient.     

Attracting retirees to apply: desired organizational characteristics of bridge employment

This research examined the impact of three organizational policies on applicant attraction of 120 older workers with an interest in bridge employment (i.e., work after formal retirement). Using a mock newspaper ad to manipulate policies, scheduling flexibility, and a targeted equal employment opportunity (EEO) statement positively influenced older workers' attraction to the organization, while opportunities to transfer knowledge had little impact. A significant and positive three‐way interaction suggested that older workers are sensitive to the strength of the overall message such that the effects of all three policies when seen together were greater than the sum of their individual effects. Copyright © 2005 John Wiley & Sons, Ltd.     

Accumulation of pollutant nitrogen in calcareous and acidic grasslands: Evidence from N flux and 15N tracer studies

Semi-natural calcareous and acidic grasslands are known to be sensitive to increased atmospheric N deposition. However, the fate of pollutant N within these systems is unknown. This paper reports on the first studies to determine the fate of added N within a calcareous and an acidic grassland subject to long-term simulated enhanced N deposition. Intact soil/turf cores were removed from field plots treated for six years with enhanced N deposition (ambient +0, +35 and +140 kg N ha^?1 year^?1). Cores were inserted into lysimeters and output fluxes of N were monitored in detail. Complete N budgets—calculated from the N flux data—showed considerable accumulation of N within the treated grasslands, up to 76% and 38% of pollutant N in the calcareous and acidic grasslands respectively. In the second study, the short-term (21 day) fate of pollutant N was determined by tracing ¹⁵N labelled ammonium nitrate (+35 kg N ha^?1 year^?1) though the acidic and calcareous lysimeters into plant, soil and leachate pools. Up to 91% and 59% of ¹⁵N was recovered in soils and vegetation of the calcareous and acidic grasslands respectively, with negligible amounts recovered in soil extractable ammonium and nitrate (<0.3%) and in leachate (<0.02%). This rapid short-term immobilisation of pollutant N supports the long-term accumulation of the element calculated from the N flux study.