CALPUFF and AERMOD model validation study in the near field: Martins Creek revisited

This paper describes a near-field validation study involving the steady-state, U.S. Environmental Protection Agency (EPA) guideline model AERMOD and the nonsteady-state puff model CALPUFF. Relative model performance is compared with field measurements collected near Martins Creek, PA-a rural, hilly area along the Pennsylvania-New Jersey border. The principal emission sources in the study were two coal-fired power plants with tall stacks and buoyant plumes. Over 1 yr of sulfur dioxide measurements were collected at eight monitors located at or above the two power plants' stack tops. Concurrent meteorological data were available at two sites. Both sites collected data 10 m above the ground. One of the sites also collected sonic detection and ranging measurements up to 420 m above ground. The ability of the two models to predict monitored sulfur dioxide concentrations was assessed in a four-part model validation. Each part of the validation applied different criteria and statistics to provide a comprehensive evaluation of model performance. Because of their importance in regulatory applications, an emphasis was placed on statistics that demonstrate the model's ability to reproduce the upper end of the concentration distribution. On the basis of the combined results of the four-part validation (i.e., weight of evidence), the performance of CALPUFF was judged to be superior to that of AERMOD.     

The corporate impact of addressing social issues: a financial case study of a project in Peru

Large, multinational resource development projects can affectmany aspects, including social, economic and ecological realities, in the regions where they operate. Social and environmental issues that are usually ignored in such projectsare increasingly affecting the financial future of multinationalcorporations in negative ways. In this article, we advance the argument that corporations can successfully manage these issuesand that if they choose to view these management efforts as an investment rather than an expense, they may well acquire a competitive advantage over companies that do not. We describe asa case study the Camisea natural gas and condensates developmentproject in Peru, operated by Shell Prospecting and Development Peru (SPDP). Camisea is one of the first projects anywhere inthe world to conduct a detailed analysis of key industry-relatedsocial issues and the processes, required investment and financial impact of managing them. The Camisea example supportsthe argument that addressing social and environmental concerns makes financial sense. In present value terms, the benefit ofmanaging these concerns was expected to surpass the cost investment by approximately US$50 million.     

Characterizing species co-occurrence patterns of imperfectly detected stream fishes to inform species reintroduction efforts

Species reintroduction efforts can improve the recovery of imperiled species, but successful implementation of this conservation strategy requires a thorough understanding of the abiotic and biotic factors influencing species viability. Species interactions are especially understudied, in particular by omitting the effect of imperfect detection on negative, neutral, or positive associations within a community. Using repeat surveys from 5 southern Ontario, Canada, Great Lakes tributaries, we quantified species co-occurrence patterns with the eastern sand darter (ESD) (Ammocrypta pellucida), listed as federally threatened, and characterized how imperfect detection during sampling can influence inference regarding these relationships. We used a probabilistic framework that included 3 approaches of increasing complexity: probabilistic co-occurrence analysis ignoring imperfect detection; single-species occupancy models with subsequent co-occurrence analysis; and 2-species occupancy models. We then used our occupancy models to predict suitable sites for potential future reintroduction efforts while considering the influence of negative species interactions. Based on the observed data, ESD showed several positive associations with co-occurring species; however, species associations differed when imperfect detection was considered. Specifically, a negative association between ESD and rosyface shiner (Notropis rubellus) was observed only after accounting for imperfect detection in the Grand River. Alternatively, positive associations in the Grand River between ESD and northern hogsucker (Hypentelium nigricans) and silver shiner (Notropis photogenis) were observed regardless of whether imperfect detection was accounted for. Our models predicted several potential reintroduction sites for ESD in formerly occupied watersheds with high levels of certainty. Overall, our results demonstrate the importance of investigating imperfect detection and species co-occurrence when planning reintroduction efforts.     

Effects of two sterol-inhibiting fungicides on populations of pest and beneficial arthropods on apple

This research demonstrated that sterol-inhibiting fungicides alter the population structure of some pest and beneficial arthropods in apple orchards. Orchard populations of European red mite, Panonychus ulmi (Koch) (Acarina: Tetranychidae); the predacious mite, Typhlodromus caudiglans Schuster (Acarina: Phytoseiidae); the spotted tentiform leafminer, Phyllonorycter blancardella Fabr. (Lepidoptera: Gracillariidae); the leafminer parasite Pholetesor ornigis Weed (Hymenoptera: Braconidae); the green apple aphid, Aphis pomi DeGeer (Homoptera: Aphididae); white apple leafhopper, Typhlocyba pomaria McAtee (Homoptera: Cicadellidae); Campylomma verbasci Meyer (Hemiptera: Miridae); chalcids, primarily Sympiesis sericeicornis Nees (Hymenoptera: Chalcididae), were monitored for two growing seasons in a McIntosh apple orchard that had received applications, at 2-week intervals, of two sterol-inhibiting fungicides, bitertanol and flusilazole. High rates of flusilazole were associated with increased numbers of European red mite and decreased numbers of predacious mite species, particularly T. caudiglans. Trees receiving a high rate of bitertanol had fewer European red mites and predacious mite species. Fungicides did not influence spotted tentiform leafminer oviposition or the number of leafminer larvae in May and June 1985. However, in September 1985 there were fewer leafminer pupae in plots treated with the two lower rates of flusilazole and more larvae in plots treated with the high rate of bitertanol, relative to trees sprayed with captan. In 1986, there were more leafminer eggs in plots treated with the low rate of bitertanol compared with captan and non-sprayed trees. However, by 24 June, all treatments showed similar levels of leafminer larvae and pupae. Populations of P. ornigis were generally higher in trees treated with flusilazole in both years. Numbers of aphids and mullein bug were higher in trees treated with flusilazole relative to non-sprayed and captan-treated trees. Chalcid populations were higher in bitertanol-treated trees. Fungicides had no apparent effect on populations of white apple leafhopper.     

A female-specific attractant for the codling moth,<Emphasis Type="Italic"> Cydia pomonella</Emphasis>, from apple fruit volatiles

Host plant-derived esters were investigated as potential female-specific attractants for the codling moth (CM), Cydia pomonella (L.), a key pest of apples worldwide. The behavioural effects of single and combined volatile compounds and of a natural odour blend were examined using olfactometry and wind-tunnel bioassays. The apple-derived volatile butyl hexanoate attracted mated females while it was behaviourally ineffective for males over a dosage range of more than three orders of magnitude in olfactometer assays. Female CM preferred this kairomone to the headspace volatiles from ripe apples. Both no-choice and choice trials in the wind-tunnel suggested that female moths might be effectively trapped by means of this compound. In contrast, headspace volatiles collected from ripe apple fruits as well as a blend containing the six dominant esters from ripe apples were behaviourally ineffective. A female-specific repellency was found for the component hexyl acetate in the olfactometer, but this ester had no significant effect in the wind-tunnel. Butyl hexanoate with its sex-specific attraction should be further evaluated for monitoring and controlling CM females in orchards.     

Continuous growth facilitates feeding and reproduction: impact of size on energy allocation patterns for organisms with indeterminate growth

Body size has great influence on feeding, reproduction, and ecological importance. This study measures growth, reproduction, and feeding for several northeastern Pacific intertidal invertebrates that have indeterminate growth. In all species studied, linear size (length, diameter) showed asymptotic growth fit by the von Bertalanffy growth function, supporting the notion that less energy is allocated to growth with age because of increased reproduction. However, these same species displayed a continuous, roughly linear increase in volume with age. Both reproductive output and food intake were shown to scale proportionally with volume. This indicates that some species with indeterminate growth do not reduce energy allocation to growth with age but instead display continuous volumetric growth that facilitates increases in feeding rate and reproductive output with age and size. A simple allometric model is proposed to describe constant volumetric growth rates and linear increases in reproduction with age.