Evaluating multispecies landscape connectivity in a threatened tropical mammal community

Habitat corridors are important tools for maintaining connectivity in increasingly fragmented landscapes, but generally they have been considered in single‐species approaches. Corridors intended to facilitate the movement of multiple species could increase persistence of entire communities, but at the likely cost of being less efficient for any given species than a corridor intended specifically for that species. There have been few tests of the trade‐offs between single‐ and multispecies corridor approaches. We assessed single‐species and multispecies habitat corridors for 5 threatened mammal species in tropical forests of Borneo. We generated maps of the cost of movement across the landscape for each species based on the species’ local abundance as estimated through hierarchical modeling of camera‐trap data with biophysical and anthropogenic covariates. Elevation influenced local abundance of banded civets (Hemigalus derbyanus) and sun bears (Helarctos malayanus). Increased road density was associated with lower local abundance of Sunda clouded leopards (Neofelis diardi) and higher local abundance of sambar deer (Rusa unicolor). Pig‐tailed macaque (Macaca nemestrina) local abundance was lower in recently logged areas. An all‐species‐combined connectivity scenario with least‐cost paths and 1 km buffers generated total movement costs that were 27% and 23% higher for banded civets and clouded leopards, respectively, than the connectivity scenarios for those species individually. A carnivore multispecies connectivity scenario, however, increased movement cost by 2% for banded civets and clouded leopards. Likewise, an herbivore multispecies scenario provided more effective connectivity than the all‐species‐combined scenario for sambar and macaques. We suggest that multispecies habitat connectivity plans be tailored to groups of ecologically similar, disturbance‐sensitive species to maximize their effectiveness. Evaluación de la Conectividad de Terrenos Multiespecie en una Comunidad Tropical de Mamíferos     

Critical Limits for Hg(II) in soils, derived from chronic toxicity data

Published chronic toxicity data for Hg(II) added to soils were assembled and evaluated to produce a data set comprising 52 chronic end-points, five each for plants and invertebrates and 42 for microbes. With end-points expressed in terms of added soil Hg(II) contents, Critical Limits were derived from the 5th percentiles of species sensitivity distributions, values of 0.13 μg (g soil)⁻¹ and 3.3 μg (g soil organic matter)⁻¹ being obtained. The latter value exceeds the currently recommended Critical Limit, used to determine Hg(II) Critical Loads in Europe, of 0.5 μg (g soil organic matter)⁻¹. We also applied the WHAM/Model VI chemical speciation model to estimate concentrations of Hg²⁺ in soil solution, and derived an approximate Critical Limit Function (CLF) that includes pH; log [Hg²⁺]_crit = −2.15 pH −17.10. Because they take soil properties into account, the soil organic matter-based limit and the CLF provide the best assessment of toxic threat for different soils. For differing representative soils, each predicts a range of up to 100-fold in the dry weight-based content of mercury that corresponds to the Critical Limit.     

Prospecting at conspecific nests and exploration in a novel environment are associated with reproductive success in the jackdaw

Consistent behavioural differences between individuals of the same population (“personality” variation) might arise if individuals follow different life-history strategies. Thus, it would be important to determine how personality variation relates to behaviours potentially associated with life-history strategies, such as those related to the use of information about the state of the environment. Little is, however, known about how personality is associated with information use and reproductive success. We tested whether wild social jackdaws, Corvus monedula, show consistent behavioural differences in their exploratory behaviour (in a novel environment in the lab and in their reaction towards a novel object in the wild) and prospecting behaviour (number of visits to conspecific nests). We furthermore examined whether these behavioural traits are linked with each other and predictors of reproductive success. Breeding jackdaws were consistent in their exploratory behaviour within, and in their prospecting behaviour between, years. Exploratory behaviour in the novel environment was correlated with the latency to approach a novel object in the wild but not with the frequency of prospecting at conspecific nests. Highly exploratory males and females and frequently prospecting males produced fewer fledglings than less exploratory individuals or less prospecting males, respectively. We discuss the importance of consistent individual differences in exploration and information sampling on individual fitness.     

Types of Fabric Filter Installations

The basis for evaluating fabric filters is examined. Properly applied and maintained fabric filters perform at highly satisfactory efficiency levels.     

Soluble carbohydrates in bean leaves transformed into oxidant-tolerant tissues by EDU treatment

Improved gas-liquid chromatography techniques were used to evaluate the effects of EDUa on soluble leaf carbohydrates in $\text{Phaseolus vulgaris}$ L. ‘Bush Blue Lake 290’. This snap bean cultivar is normally rather sensitive to 0₃ but becomes highly tolerant when treated systemically with EDU. Less than 24 h is required to induce the resistance. Standardized trifoliate leaves from EDU-treated and control plants were sampled 48 h after treatment. Additional plants were sampled 48 h after treatment. Additional plants were exposed to 0₃ one day after EDU soil application to assess the plant tolerance induced. The optimal dose required to enhance oxidant tolerance was 50 mg/pot.Major sugars in both EDU-treated (0₃-tolerant) and untreated (0₃-sensitive) leaves were glyceraldehyde, erythritol, fructose, glucose and sucrose. $\text{Myo}$-inositol, ribose and arbitol were present in lesser or trace amounts. EDU-treatment resulted in significant increases (35–62%) in all soluble carbohydrates except glyceraldehyde and $\text{myo}$-inositol. Implications relating to plant tolerance, to oxidants and stress-induced senescence are discussed.     

On-road measurement of vehicle tailpipe emissions using a portable instrument

A study design procedure was developed and demonstrated for the deployment of portable onboard tailpipe emissions measurement systems for selected highway vehicles fueled by gasoline and E85 (a blend of 85% ethanol and 15% gasoline). Data collection, screening, processing, and analysis protocols were developed to assure data quality and to provide insights regarding quantification of real-world intravehicle variability in hot-stabilized emissions. Onboard systems provide representative real-world emissions measurements; however, onboard field studies are challenged by the observable but uncontrollable nature of traffic flow and ambient conditions. By characterizing intravehicle variability based on repeated data collection runs with the same driver/vehicle/route combinations, this study establishes the ability to develop stable modal emissions rates for idle, acceleration, cruise, and deceleration even in the face of uncontrollable external factors. For example, a consistent finding is that average emissions during acceleration are typically 5 times greater than during idle for hydrocarbons and carbon dioxide and 10 times greater for nitric oxide and carbon monoxide. A statistical method for comparing on-road emissions of different drivers is presented. Onboard data demonstrate the importance of accounting for the episodic nature of real-world emissions to help develop appropriate traffic and air quality management strategies.     

新型循环流化床硝化-反硝化启动试验研究

利用新型循环流化床进行清水实验及硝化、反硝化启动试验研究,考察了系统对有机物和氮的去除效果,并分析了曝气量对系统启动的影响.结果表明,将输送床和传统流化床工艺进行有机结合,技术上可行,可以在系统内不同区建立缺氧、好氧条件,通过硝化和反硝化作用完成脱氮.     

Development of probabilistic emission inventories of air toxics for Jacksonville, Florida, USA

Probabilistic emission inventories were developed for 1,3-butadiene, mercury (Hg), arsenic (As), benzene, formaldehyde, and lead for Jacksonville, FL. To quantify inter-unit variability in empirical emission factor data, the Maximum Likelihood Estimation (MLE) method or the Method of Matching Moments was used to fit parametric distributions. For data sets that contain nondetected measurements, a method based upon MLE was used for parameter estimation. To quantify the uncertainty in urban air toxic emission factors, parametric bootstrap simulation and empirical bootstrap simulation were applied to uncensored and censored data, respectively. The probabilistic emission inventories were developed based on the product of the uncertainties in the emission factors and in the activity factors. The uncertainties in the urban air toxics emission inventories range from as small as -25 to +30% for Hg to as large as -83 to +243% for As. The key sources of uncertainty in the emission inventory for each toxic are identified based upon sensitivity analysis. Typically, uncertainty in the inventory of a given pollutant can be attributed primarily to a small number of source categories. Priorities for improving the inventories and for refining the probabilistic analysis are discussed.     

Microbial Removal of Arsenic

Bangladesh is currently the subject of the world's largest mass arsenic poisoning in history. Groundwater throughout Bangladesh and West Bengal is contaminated with naturally occurring arsenic from the alluvial and deltaic sediments that form the region's aquifers. It has been estimated that 75 million people are at risk of developing health effects associated with the ingestion of arsenic. This project focuses on the use of microorganisms such as bacteria and algae to remove arsenic from water. Arsenic in the arsenite form was used in the studies. Experiments were conducted with a common alga and wastewater bacteria. A common green algae Scenedesmus abundans was used for determining arsenic uptake in batch experiments. Results of the experiments indicated that the algae biosorption could be modeled by the conventional Langmuir isotherm model. Algae morphology studies indicated that the algae cells were impacted due to the presence of arsenic as evidenced by clumping or loss of cell clusters. The wastewater bacteria also were capable of high percent of arsenic removal. Results indicate that microbial uptake of arsenic may be a viable method of pretreatment of arsenic contaminated water. However algae and sludge disposal would pose a problem and will have to be dealt with accordingly.