高尔夫球场农药化肥对水环境的影响和对策

通过对某高尔夫球场运营过程中化肥和农药施用的分析，用简化模型计算了一般情况下和最不利情况下化肥、农药对地面水环境的影响，提出控制农药化肥污染的对策措施。     

Loss of Large Predatory Sharks from the Mediterranean Sea

Abstract:  Evidence for severe declines in large predatory fishes is increasing around the world. Because of its long history of intense fishing, the Mediterranean Sea offers a unique perspective on fish population declines over historical timescales. We used a diverse set of records dating back to the early 19th and mid 20th century to reconstruct long-term population trends of large predatory sharks in the northwestern Mediterranean Sea. We compiled 9 time series of abundance indices from commercial and recreational fishery landings, scientific surveys, and sighting records. Generalized linear models were used to extract instantaneous rates of change from each data set, and a meta-analysis was conducted to compare population trends. Only 5 of the 20 species we considered had sufficient records for analysis. Hammerhead ( Sphyrna spp.), blue ( Prionace glauca ), mackerel ( Isurus oxyrinchus and Lamna nasus ), and thresher sharks ( Alopias vulpinus ) declined between 96 and 99.99% relative to their former abundance. According to World Conservation Union (IUCN) criteria, these species would be considered critically endangered. So far, the lack of quantitative population assessments has impeded shark conservation in the Mediterranean Sea. Our study fills this critical information gap, suggesting that current levels of exploitation put large sharks at risk of extinction in the Mediterranean Sea. Possible ecosystem effects of these losses involve a disruption of top-down control and a release of midlevel consumers.     

对化工园区标准化管理体系应用实践的认识

随着全球经济一体化步伐的加快,中国的化工企业已呈现各种化工园区集聚发展的态势。化工园区作为地区化工行业集聚区域,也是一个地区工业经济发展的重要载体,已逐渐成为推动区域经济快速增长的重要支撑。本文分析了国内外先进化工园区管理模式及经验,总结了目前国内化工园区管理中存在的问题,通过借鉴国内外先进化工园区管理模式及成功经验,分析提出解决化工园区环境管理问题的建议,以期为改善园区管理现状、促进化工园区科学发展提供理论依据。     

Assessing the strength of climate and land-use influences on montane epiphyte communities

Epiphytes, air plants that are structurally dependent on trees, are a keystone group in tropical forests; they support the food and habitat needs of animals and influence water and nutrient cycles. They reach peak diversity in humid montane forests. Climate predictions for Central American mountains include increased temperatures, altered precipitation seasonality, and increased cloud base heights, all of which may challenge epiphytes. Although remaining montane forests are highly fragmented, many tropical agricultural systems include trees that host epiphytes, allowing epiphyte communities to persist even in landscapes with lower forest connectivity. I used structural equations models to test the relative effects of climate, land use, tree characteristics, and biotic interactions on vascular epiphyte diversity with data from 31 shade coffee farms and 2 protected forests in northern Nicaragua. I also tested substrate preferences of common species with randomization tests. Tree size, tree diversity, and climate all affected epiphyte richness, but the effect of climate was almost entirely mediated by bryophyte cover. Bryophytes showed strong sensitivity to mean annual temperature and insolation. Many ferns and some orchids were positively associated with bryophyte mats, whereas bromeliads tended to establish among lichen or on bare bark. The tight relationships between bryophytes and climate and between bryophytes and vascular epiphytes indicated that relatively small climate changes could result in rapid, cascading losses of montane epiphyte communities. Currently, shade coffee farms can support high bryophyte cover and diverse vascular epiphyte assemblages when larger, older trees are present. Agroforests serve as valuable reservoirs for epiphyte biodiversity and may be important early-warning systems as the climate changes.     

ESTIMATION OF LONG-TERM DISCHARGE STATISTICS BY REGIONAL ADJUSTMENT1

ABSTRACT: A regional adjustment relationship was developed to estimate long-term (30-year) monthly median discharges from short term (three-year) records. This method differs from traditional approaches in that it is based on site-specific discharge data but does not require correlation of these data with discharges from a single hydrologically similar long-term gage. The method is shown to be statistically robust, and applicable to statistics other than the median.     

Validation of the UK Met. Office’s name model against the ETEX dataset

The ETEX 1 data set has been used to assess the performance of the UK Met Office’s long-range dispersion model NAME. In terms of emergency response modelling the model performed well, successfully predicting the overall spread and timing of the plume across Europe. However, in common with most other models, NAME overpredicted the observed concentrations. This is in contrast with other NAME validation studies which indicate either no significant bias or a tendency to underpredict concentrations. This suggests the reasons for overpredicting are specific to the ETEX situation. Explanations include inadequate vertical diffusion or transport, possible venting by convective activity, and experimental errors. An assessment of a range of advection schemes of varying complexity indicated no clear advantage, at present, in using more sophisticated random walk techniques at long range, a simple diffusion coefficient based scheme providing some of the best results. A brief look is also taken at a simulation of the more problematical ETEX 2 release.     

Toxicity and Repellency of Hot Pepper Extracts to Spider Mite,Tetranychus urticae Koch

Increasing concern about persistence and environmental impact of synthetic pesticide residues require development of biodegradable and environmentally safe alternatives. The potential of using fruit extracts of hot pepper as alternatives to synthetic acaricides for controlling the two-spotted spider mite, Tetranychus urticae Koch, is explored in this study. Twenty-four Capsicum accessions (Solanaceae) were screened for their toxicity and repellency to the spider mites. Crude extracts from fruits of C. chinense, C. frutescens, C. baccatum, C. annuum, and C. pubescens were prepared in methanol and tested for their acaricidal properties. Spider mite mortality was greatest (45%) when fruit extract of accession Grif-9169 (C. annuum) was used. Results from diving board bioassays indicated that mites avoided filter paper strips treated with hot pepper extracts from accessions PI-596057 (C. baccatum), PI-195299 (C. annuum), and Grif- 9270 (C. annuum). This investigation suggests that methanolic extracts of these three accessions may have a great potential for repelling spider mites and should be field-tested on a large-scale to assess their value in managing populations of spider mites, which could reduce reliance on synthetic acaricides. An attempt was made to correlate repellency with chemical constituents of fruit extracts of the most repellent accessions to identify chemical sources of repellency. Capsaicin and dihydrocapsaicin, the pungent components of pepper fruit, were not correlated with toxicity or repellency, indicating that these are not likely related to the toxicity or repellency of the pepper fruit extracts. Other, unidentified chemicals are likely responsible for toxicity and repellency to the two-spotted spider mite     

Screening differentially expressed genes in an amphipod (Hyalella azteca) exposed to fungicide vinclozolin by suppression subtractive hybridization

Vinclozolin, a dicarboximide fungicide, is an endocrine disrupting chemical that competes with an androgenic endocrine disruptor compound. Most research has focused on the epigenetic effect of vinclozolin in humans. In terms of ecotoxicology, understanding the effect of vinclozolin on non-target organisms is important. The expression profile of a comprehensive set of genes in the amphipod Hyalella azteca exposed to vinclozolin was examined. The expressed sequence tags in low-dose vinclozolin-treated and -untreated amphipods were isolated and identified by suppression subtractive hybridization. DNA dot blotting was used to confirm the results and establish a subtracted cDNA library for comparing all differentially expressed sequences with and without vinclozolin treatment. In total, 494 differentially expressed genes, including hemocyanin, heatshock protein, cytochrome, cytochrome oxidase and NADH dehydrogenase were detected. Hemocyanin was the most abundant gene. DNA dot blotting revealed 55 genes with significant differential expression. These genes included larval serum protein 1 alpha, E3 ubiquitin-protein ligase, mitochondrial cytochrome c oxidase, mitochondrial protein, proteasome inhibitor, hemocyanin, zinc-finger–containing protein, mitochondrial NADH-ubiquinone oxidoreductase and epididymal sperm-binding protein. Vinclozolin appears to upregulate stress-related genes and hemocyanin, related to immunity. Moreover, vinclozolin downregulated NADH dehydrogenase, related to respiration. Thus, even a non-lethal concentration of vinclozolin still has an effect at the genetic level in H. azteca and presents a potential risk, especially as it would affect non-target organism hormone metabolism.     

Seasonal Flushing of Pollutant Concentrations and Loads in Urban Stormwater1

Schiff, Kenneth C. and Liesl L. Tiefenthaler, 2011. Seasonal Flushing of Pollutant Concentrations and Loads in Urban Stormwater. Journal of the American Water Resources Association (JAWRA) 47(1):136‐142. DOI: 10.1111/j.1752‐1688.2010.00497.x Abstract: Despite broad observations of first flush within storms, the scientific understanding of seasonal flushing remains incomplete. Seasonal flushing occurs when initial storms of the season have greater concentrations or loads than storms later in the season. The goal of this study was to census stormwater concentrations and loads from an arid, urban watershed to quantify seasonal flushing. Samples were collected every 15 min during the 1997‐1998 wet season from the Santa Ana River and analyzed for total suspended solids. Initial storms of the season generated event mean concentrations 3‐10 times the event mean concentration of storms later in the season. Cumulative flow‐weighted mean concentrations were calculated as the season progressed. Early season storms discharged only 6% of the annual volume, but influenced flow‐weighted mean concentrations well past the midpoint of the wet season. Mass‐based estimates also indicated a disproportionate load in the early portion of the year; over 52% of the annual load was discharged in the first 30% of the annual volume from the highly urbanized lower watershed. Other stormwater pollutants, including six trace metals (Cd, Cr, Cu, Pb, Ni, Zn), were highly correlated with total suspended solids and also exhibited a significant seasonal flush.     

A metapopulation approach of the dynamics of arthropods from Mediterranean-type ecosystems

In this paper we developed a general stage-structured, Leslie-type model, suitable to simulate dynamics of soil arthropods under typical Mediterranean conditions. In order to explore arthropods’ life-history strategies in relation to enhanced spatial heterogeneity of the Mediterranean ecosystems, metapopulation characteristics were considered and different habitat quality regimes, in terms of dominant microclimatic conditions, were taken into account. Environmental stochasticity in temperature and humidity was incorporated into the model, and an elasticity analysis was conducted to quantify contribution of different life-history traits to metapopulation growth rate. The application of the model revealed well-known life-cycle characteristics of Mediterranean arthropods, such as seasonally fluctuating population sizes and skewing phenologies, a fact that confirms models’ reliability. Furthermore, the model seems able to elucidate controversial points of the animals’ life-cycle development, such as the long-term maintenance of populations in the field and the underlying mechanisms related to the adjustment to the specific features of the Mediterranean ecosystem. Subpopulations inhabiting various microsites display different dynamics and the interaction between these subpopulations, via dispersion, seems to be able to ensure stochastic equilibrium for the system. Dispersal appears to play a decisive role, allowing arthropods to conform to spatial severities and habitats fragmentation, rescuing individuals and recolonizing previously extinct habitats.