Landscape Influences on Headwater Streams on Fort Stewart,Georgia, USA

Military landscapes represent a mixture of undisturbed natural ecosystems, developed areas, and lands that support different types and intensities of military training. Research to understand water-quality influences of military landscapes usually involves intensive sampling in a few watersheds. In this study, we developed a survey design of accessible headwater watersheds intended to improve our ability to distinguish land–water relationships in general, and training influences, in particular, on Fort Stewart, GA. We sampled and analyzed water from watershed outlets. We successfully developed correlative models for total suspended solids (TSS), total nitrogen (TN), organic carbon (OC), and organic nitrogen (ON), which dominated in this blackwater ecosystem. TSS tended to be greater in samples after rainfall and during the growing season, and models that included %Wetland suggested a “build-and-flush” relationship. We also detected a positive association between TSS and tank-training, which suggests a need to intercept sediment-laden runoff from training areas. Models for OC showed a negative association with %Grassland. TN and ON both showed negative associations with %Grassland, %Wetland, and %Forest. Unexpected positive associations were observed between OC and equipment-training activity and between ON and %Bare ground + Roads. Future studies that combine our survey-based approach with more intensive monitoring of the timing and intensity of training would be needed to better understand the mechanisms for these empirical relationships involving military training. Looking beyond local effects on Fort Stewart streams, we explore questions about how exports of OC and nitrogen from coastal military installations ultimately influence estuaries downstream.     

Study on the dynamics of algal bloom and its influence factors in Tolo Harbour, Hong Kong.

In this paper, the semi-enclosed bay named Tolo Harbour and Channel in Hong Kong, which was frequently attacked by red tides, was used as a case study. Data sets related to marine water quality, river nutrients, and meteorological conditions recorded between 1988 and 1999 were chosen for statistical analysis. A multivariate analysis showed that algal growth, represented by the chlorophyll a concentration, had obvious spatial and temporal variations in the study area. The chlorophyll a concentration had a consistently decreasing trend from the inner part of the Harbour and surface waters to the outer part and bottom waters. The temporal variations had a markedly seasonal variation with high bioproductivity in spring and winter. There were long-term fluctuations in the chlorophyll a concentration with a high-low-high pattern in the study period. Nutrients and hydrological and meteorological conditions were important factors of algal bloom. Besides nitrogen, which was the most critical factor of algal bloom for the whole water body, total phosphorus in the surface waters and phosphate (PO4) and silica (SiO2) in the bottom waters also showed strongly positive or negative correlations with the chlorophyll a level. For the meteorological conditions, global solar radiation was the key factor of massive algal bloom in the study period, while rainfall and wind direction were the most important factors of seasonal variation.     

Identification methods of key contributing factors in crashes with high numbers of fatalities and injuries in China

Objectives: In China, serious road traffic crashes (SRTCs) are those in which there are 10–30 fatalities, 50–100 serious injuries, or a total cost of 50–100 million RMB (U.S.$8–16 M), and particularly serious road traffic crashes (PSRTCs) are those that are more severe or costly. Due to the large number of fatalities and injuries as well as the negative public reaction they elicit, SRTCs and PSRTCs have become of great concern to China during recent years. The aim of this study is to identify the main factors contributing to these road traffic crashes and to propose preventive measures to reduce their number.

Methods: 49 contributing factors of the SRTCs and PSRTCs that occurred from 2007 to 2013 were collected from the database “In-depth investigation and analysis system for major road traffic crashes” (IIASMRTC) and were analyzed through the integrated use of principal component analysis and hierarchical clustering to determine the primary and secondary groups of contributing factors.

Results: Speeding and overloading of passengers were the primary contributing factors, featuring in up to 66.3 and 32.6% of accidents, respectively. Two secondary contributing factors were road related: lack of or nonstandard roadside safety infrastructure and slippery roads due to rain, snow, or ice.

Conclusions: The current approach to SRTCs and PSRTCs is focused on the attribution of responsibility and the enforcement of regulations considered relevant to particular SRTCs and PSRTCs. It would be more effective to investigate contributing factors and characteristics of SRTCs and PSRTCs as a whole to provide adequate information for safety interventions in regions where SRTCs and PSRTCs are more common. In addition to mandating a driver training program and publicization of the hazards associated with traffic violations, implementation of speed cameras, speed signs, markings, and vehicle-mounted Global Positioning Systems (GPS) are suggested to reduce speeding of passenger vehicles, while increasing regular checks by traffic police and passenger station staff and improving transportation management to increase income of contractors and drivers are feasible measures to prevent overloading of people. Other promising measures include regular inspection of roadside safety infrastructure and improving skid resistance on dangerous road sections in mountainous areas.     

An experimental investigation of the bioacoustics of cowbird song

Summary Female cowbirds (Molothrus ater ater), maintained in isolation from males during the breeding season, respond to the playback of male song with copulatory postures. They respond to some songs more than to others. Cowbird song potency can thus be operationally defined by the proportion of copulatory postures a song elicits across multiple playbacks. The purpose of the present study was to explore whether song potency changes with distance in the field. No field recordings elicited high levels of responding by the females. When songs of known high potency are systematically degraded, the results indicate that female cowbirds are sensitive to small changes in signal to noise ratio and to atmospheric attenuation. The data suggest that cowbird song potency degrades very rapidly with transmission distance in the field.     

Soil chemical changes resulting from irrigation with water co-produced with coalbed natural gas

Land application of coalbed natural gas (CBNG) co-produced water is a popular management option within northwestern Powder River Basin (PRB) of Wyoming. This study evaluated the impacts of land application of CBNG waters on soil chemical properties at five sites. Soil samples were collected from different depths (0-5, 5-15, 15-30, 30-60, 60-90, and 90-120 cm) from sites that were irrigated with CBNG water for 2 to 3 yr and control sites. Chemical properties of CBNG water used for irrigation on the study sites indicate that electrical conductivity of CBNG water (EC(w)) and sodium adsorption ratio of CBNG water (SAR(w)) values were greater than those recommended for irrigation use on the soils at the study sites. Soil chemical analyses indicated that electrical conductivity of soil saturated paste extracts (EC(e)) and sodium adsorption ratio of soil saturated paste extracts (SAR(e)) values for irrigated sites were significantly greater (P < 0.05) than control plots in the upper 30-cm soil depths. Mass balance calculations suggested that there has been significant buildup of Na in irrigated soils due to CBNG irrigation water as well as Na mobilization within the soil profiles. Results indicate that irrigation with CBNG water significantly impacts certain soil properties, particularly if amendments are not properly utilized. This study provides information for better understanding changes in soil properties due to land application of CBNG water. These changes must be considered in developing possible criteria for preserving fragile PRB ecosystems.     

Composition and Toxicity of Residual Bunker C Fuel Oil in Intertidal Sediments After 30 Years

In 1970, approximately 2000 m³ of Bunker C crude oil impacted 300 km of Nova Scotia’s coastline following the grounding of the tanker Arrow. Only 10% of the contaminated coast was subjected to cleanup, the remainder was left to cleanse naturally. To determine the long-term environmental impact of residual oil from this spill event, samples of sediment and interstitial water were recovered in 1993, 1997 and 2000 from a sheltered lagoon in Black Duck Cove. This heavily oiled site was intentionally left to recover on its own. Visual observations and chemical analysis confirmed that substantial quantities of the weathered cargo oil were still present within the sediments at this site. However, direct observations of benthic invertebrate abundance suggest that natural processes have reduced the impacts of the residual oil. To confirm this hypothesis, sediment and interstitial water samples from Black Duck Cove were assessed with a comprehensive set of biotests and chemical assays.Residual oil in the sediments had limited effect on hepatic CYP1A protein levels and mixed function oxygenase (MFO) induction in winter flounder (Pleuronectes americanus). No toxicity was detected with the Microtox solid phase test (Vibrio fischeri). Significant sediment toxicity was detected by the amphipod survival test (Eohaustorius estuarius) in four out of the eight contaminated sediments. Interstitial water samples were deemed non-toxic by the Microtox 100% test (Vibrio fischeri) and the echinoid fertilization test (Lytechinus pictus). Sediment elutriates were also found to be non-toxic in the grass shrimp embryo-larval toxicity (GSELTOX) test (Palaemonetes pugio).Recovery at this contaminated site is attributed to natural processes that mediated biodegradation and physical removal of oil from the sediments. In support of the latter mechanism, mineralization experiments showed that all test sediments had the capacity for hexadecane, octacosane and naphthalene degradation, while chemical analysis confirmed that the Bunker C oil from the Arrow had undergone substantial biodegradation.     

太湖流域北部潜在洪涝风险区分析及影响评估

太湖流域历来遭受严重的洪涝灾害,并且近年来有不断加重的趋势。本文选择太湖流域北部的无锡市作为典型研究地区,研究其洪涝的危险性并进行潜在损失评估。人类活动,包括修筑圩区、森林破坏、人口增长、城市化等,对这个地区的洪涝形势有较大的影响;自然条件的变化使河道水位升高,洪涝历时缩短,洪峰增高。本文选择不同回归年(2,5,10,20,50年),结合地理信息系统分析模型,计算了潜在洪涝危险区域和洪涝损失,主要结论为:(1)人类活动已经改变了自然的洪涝形势,增大了汇流和洪涝;(2)洪涝危险区与降雨中心有关;(3)筑圩成功地保护了圩内的土地,缩短了洪涝历时,增高了圩外河道的洪涝水位;(4)经济发展使洪涝损失增加。     

5,11-Dimethylheptadecane and 2,5-Dimethyl-heptadecane: Sex pheromone components of the geometrid moth,Lambdina fiscellaria fiscellaiia

Dedicated to Marshall Noble who worked over 20 years as a volunteer in support of research at Simon Fraser University