Lidar quantification of bank erosion in Blue Earth County, Minnesota

Sediment and phosphorus (P) transport from the Minnesota River Basin to Lake Pepin on the upper Mississippi River has garnered much attention in recent years. However, there is lack of data on the extent of sediment and P contributions from riverbanks vis-à-vis uplands and ravines. Using two light detection and ranging (lidar) data sets taken in 2005 and 2009, a study was undertaken to quantify sediment and associated P losses from riverbanks in Blue Earth County, Minnesota. Volume change in river valleys as a result of bank erosion amounted to 1.71 million m over 4 yr. Volume change closely followed the trend: the Blue Earth River > the Minnesota River at the county's northern edge > the Le Sueur River > the Maple River > the Watonwan River > the Big Cobb River > Perch Creek > Little Cobb River. Using fine sediment content (silt + clay) and bulk density of 37 bank samples representing three parent materials, we estimate bank erosion contributions of 48 to 79% of the measured total suspended solids at the mouth of the Blue Earth and the Le Sueur rivers. Corresponding soluble P and total P contributions ranged from 0.13 to 0.20% and 40 to 49%, respectively. Although tall banks (>3 m high) accounted for 33% of the total length and 63% of the total area, they accounted for 75% of the volume change in river valleys. We conclude that multitemporal lidar data sets are useful in estimating bank erosion and associated P contributions over large scales, and for riverbanks that are not readily accessible for conventional surveying equipment.     

Transport and retention of Cryptosporidium parvum oocysts in sandy soils

A series of miscible-displacement experiments was conducted to examine the retention and transport behavior of oocysts in natural porous media. Three soils and a model sand were used that differed in physical and geochemical properties. Transport behavior was examined under various treatment conditions to help evaluate retention mechanisms. Significant retention of oocysts was observed for all media despite the fact that conditions were unfavorable for physicochemical interactions with respect to DLVO theory. The magnitude of retention was not influenced significantly by alterations in solution chemistry (reduction in ionic strength) or soil surface properties (removal of soil organic matter and metal oxides). On the basis of the observed results, it appears that retention by secondary energy minima or geochemical microdomains was minimal for these systems. The porous media used for the experiments exhibited large magnitudes of surface roughness, and it is suggested that this surface roughness contributed significantly to oocyst retention.     

Identification of Swamp Deer (<Emphasis Type="Italic">Cervus duvauceli duvauceli</Emphasis> Cuvier) Potential Habitat in Jhilmil Jheel Conservation Reserve,Uttarakhand, India Using Multi-Criteria Analysis

The present study aims to identify the potential habitat for swamp deer (Cervus duvauceli duvauceli Cuvier) in Jhilmil Jheel Conservation Reserve in the Uttarakhand province of India using multi-criteria analysis. The study area represents one of the last remnant habitats of the flagship species, the swamp deer in Uttarakhand, which is considered as vulnerable. The study showed that only 6.08% of the study area (225 km²) was highly suitable to suitable for the swamp deer. An area of 135.52 km² (60.23%) turned out to be moderately suitable. Within the officially designated Conservation Reserve (area 37.84 km²), 10.91% (4.13 km²) area was found highly suitable to suitable, while 74.19% (28.07 km²) happens to be moderately suitable. Only 14 km² area, which was found as suitable habitat for swamp deer falls short of the space required by a population of 134 animals. The problem could be mitigated if the agricultural land (2.47 km²) adjacent to the Jhilmil Jheel is brought under the Reserve management. This would provide additional area to meet the fodder requirement. The study brings out a particularly grim situation with limited options for conservation and management of the swamp deer in the Indo-Gangetic plains. It also emphasizes the role of geospatial techniques in quick appraisal of habitat attributes and identification of potential sites for protected areas.     

拟开发场地的土壤重金属污染调查与评价实践

土壤污染调查乃"土壤修复"的前期。在某市郊拟开发建设的场地,按8个点分三层采集了24个土壤样品,用原子吸收光谱法测定样品中汞、铅、镉、铜、锌、镍、铬等7种重金属元素的含量,汞呈现对数正态分布,其他元素为正态分布,各元素在土壤层水平分布状态和垂直分布水平的差异性不显著,锌含量水平现状值在《土壤环境质量标准》GB15618-1995二级标准的指标限值内,汞、铅、镉、铜、镍、铬含量水平现状值均在土壤环境质量一级标准的指标限值内,且各元素浓度水平现状值均与场地所在区域土壤背景值一致。由此,本调查的场地土壤环境现状没有受到铅、汞、镉、铜、锌、镍、铬金属元素污染。     

Homegardens as a Multi-functional Land-Use Strategy in Sri Lanka with Focus on Carbon Sequestration

This paper explores the concept of homegardens and their potential functions as strategic elements in land-use planning, and adaptation and mitigation to climate change in Sri Lanka. The ancient and locally adapted agroforestry system of homegardens is presently estimated to occupy nearly 15 % of the land area in Sri Lanka and is described in the scientific literature to offer several ecosystem services to its users; such as climate regulation, protection against natural hazards, enhanced land productivity and biological diversity, increased crop diversity and food security for rural poor and hence reduced vulnerability to climate change. Our results, based on a limited sample size, indicate that the homegardens also store significant amount of carbon, with above ground biomass carbon stocks in dry zone homegardens (n = 8) ranging from 10 to 55 megagrams of carbon per hectare (Mg C ha⁻¹) with a mean value of 35 Mg C ha⁻¹, whereas carbon stocks in wet zone homegardens (n = 4) range from 48 to 145 Mg C ha⁻¹ with a mean value of 87 Mg C ha⁻¹. This implies that homegardens may contain a significant fraction of the total above ground biomass carbon stock in the terrestrial system in Sri Lanka, and from our estimates its share has increased from almost one-sixth in 1992 to nearly one-fifth in 2010. In the light of current discussions on reducing emissions from deforestation and forest degradation (REDD+), the concept of homegardens in Sri Lanka provides interesting aspects to the debate and future research in terms of forest definitions, setting reference levels, and general sustainability.     

Insights into the dissolution and the three-dimensional structure of insensitive munitions formulations

Two compounds, 2,4-dinitroanisole (DNAN) and 3-nitro-1,2,4-triazol-5-one (NTO) are the main ingredients in a suite of explosive formulations that are being, or soon will be, fielded at military training ranges. We aim to understand the dissolution characteristics of DNAN and NTO and three insensitive muntions (IM) formulations that contain them. This information is needed to accurately predict the environmental fate of IM constituents, some of which may be toxic to people and the environment. We used Raman spectroscopy to identify the different constituents in the IM formulations and micro computed tomography to image their three-dimensional structure. These are the first three-dimensional images of detonated explosive particles.     

Sexual difference in PCB congener distributions of burbot (Lota lota) from Lake Erie

Concentrations of 86 congeners of polychlorinated biphenyls (PCBs) were determined for 25 adult female and 25 adult male burbot (Lota lota) from Lake Erie. Significant differences in mean proportions of total PCB concentration between males and females ages 14–17 were found for 26 congeners. Males generally had higher mean proportions of hexachloro congeners, whereas females had higher mean proportions of more highly chlorinated congeners. In contrast, only four congeners exhibited differences between males and females ages 6–13 in mean proportions of total PCB. Therefore, the sexual difference in PCB congener distribution widened for older burbot. Males ages 14–17 also had higher proportions of certain hexachloro congeners than the other three demographic groups (males ages 6–13, females ages 6–13, and females ages 14–17) we examined. The reverse was true for more highly chlorinated congeners. The results supported a previous hypothesis that older male burbot spent a substantial amount of time feeding in the vicinity of mouths of rivers with sediment contaminated with PCBs. However, additional studies are needed to clarify and corroborate this apparent “hot spot” effect, such as seasonal movements, spatial distributions, and diet of burbot; and PCB congener distributions of various species of prey fishes captured at various locations throughout the eastern basin of Lake Erie and at different locations in the contaminated rivers.     

Development and application of LC–APCI–MS method for biomonitoring of animal and human exposure to imidacloprid

Imidacloprid (IMI) is a relatively new neuro-active neonicotinoid insecticide and nowadays one of the largest selling insecticides worldwide. In the present study a LC–APCI–MS based method was developed and validated for the quantification of imidacloprid and its main metabolite 6-chloronicotinic acid (6-CINA) in urine and hair specimens. The method was tested in biomonitoring of intentionally exposed animals and subsequently applied for biomonitoring of Cretan urban and rural population.     

Effects of nitrogen application rate and a nitrification inhibitor dicyandiamide on methanotroph abundance and methane uptake in a grazed pasture soil

Methane-oxidizing bacteria (methanotrophs) in the soil are a unique group of methylotrophic bacteria that utilize methane (CH₄) as their sole source of carbon and energy which limit the flux of methane to the atmosphere from soils and consume atmospheric methane. A field experiment was conducted to determine the effect of nitrogen application rates and the nitrification inhibitor dicyandiamide (DCD) on the abundance of methanotrophs and on methane flux in a grazed pasture soil. Nitrogen (N) was applied at four different rates, with urea applied at 50 and 100 kg N ha^?1 and animal urine at 300 and 600 kg N ha^?1. DCD was applied at 10 kg ha^?1. The results showed that both the DNA and selected mRNA copy numbers of the methanotroph pmoA gene were not affected by the application of urea, urine or DCD. The methanotroph DNA and mRNA pmoA gene copy numbers were low in this soil, below 7.13?×?10³ g^?1 soil and 3.75?×?10³ μg^?1 RNA, respectively. Daily CH₄ flux varied slightly among different treatments during the experimental period, ranging from ?12.89 g CH₄ ha^?1 day^?1 to ?0.83 g CH₄ ha^?1 day^?1, but no significant treatment effect was found. This study suggests that the application of urea fertilizer, animal urine returns and the use of the nitrification inhibitor DCD do not significantly affect soil methanotroph abundance or daily CH₄ fluxes in grazed grassland soils.