Relationship between heavy metal concentrations of herbaceous plants and soils at four Pb-Zn mining sites in Yunnan, China

This paper studied the relationship between heavy metal concentrations of herbaceous plants and soils at four Pb-Zn mining sites in Yunnan, China. 50 herbaceous plant samples of 9 plant species from 4 families and 50 soil samples were collected and then ana1yzed for the tota1 concentrations of Pb, Cd, and Zn. The results showed that the average concentrations of Pb, Cd, and Zn in soil samples were 3772.83, 168.81, and 5385.65 mg/kg, respectively. The average concentrations of Pb, Cd, and Zn were 395.68, 28.14, and 1664.20 mg/kg in the shoots, and 924.12, 57.25, and 1778.75 mg/kg in the roots, respectively. Heterospecific plants at the same site and conspecific plants at various sites had different average levels of Pb, Cd, and Zn, both in the shoots and the roots. Enrichment coefficients of Pb, Cd, and Zn were greater than 1 in 2, 3, and 9 herbaceous plant samples, respectively. Translocation factors of Pb, Cd, and Zn were greater than 1 in 10, 17, and 25 herbaceous plant samples, respectively. In all 50 samples, the concentrations of Pb, Cd, and Zn between the shoots and the roots, the shoots, and the soils, and the roots and the soils had significant positive relationships.     

Impact of domestic sewage on fresh water body

In the present study various (physico-chemical) factors were assessed over a period of two years (from February 2002 to January 2004) to note the chemistry and quality of tank water in Bhalki town of Bidar. Physico-chemical factors like pH, dissolved oxygen, magnesium, chlorine, nitrite, sulphates and chemical oxygen demand were found with maximum concentration during summer season. Similarly, during monsoon season free carbon dioxide, alkalinity hardness, calcium, phosphate, silicon, total solids and biological oxygen demand; and in winter season organic matter were recorded. The concentrations viz., pH, hardness and nitrite were more compared to the potable water standard of WHO. The correlation matrix and dendrogram of physico-chemical factors have been computed and analysed. The positive co-relation coefficient observed between pH and magnesium, dissolved oxygen and hardness, free carbondioxide and calcium, alkalinity and nitrite, alkalinityand phosphate, alkalinity and biological oxygen demand, hardness and calcium, hardness and magnesium, magnesium and chlorine, nitrate and phosphate, nitrite and biological oxygen demand, phosphate and organic matter; and silicon and chemical oxygen demand. The dendrogram confirms chlorine, pH, hardness, silicon, total solids and sulphates are the key factors of the change in the chemistry of water body     

Nanosensors and nanobiosensors in food and agriculture

The food and agriculture sector controls the economic growth of a developing country. The food industries have practices of growing crops, raising livestock and sea foods, food processing and packaging, regulating production and distribution with quality and safety. The process control and monitoring quality are crucial steps. Here we review nanosensors and nanobiosensors as alternative of classical quantification methods. Nanoscale dimensions of metal nanoparticles, metal nanoclusters, metal oxide nanoparticles, metal and carbon quantum dots, graphene, carbon nanotubes, and nanocomposites expand the sensitivity by signal amplification and integrate several novel transduction principles such as enhanced electrochemical, optical, Raman, enhanced catalytic activity, and superparamagnetic properties into the nanosensors. The electrochemical nanosensors, optical nanosensors, electronic nose and electronic tongue, nanobarcode technology, and wireless nanosensors have revolutionized the sensing in food and agriculture sectors with multiplex and real-time sensing capabilities. Despite previous success stories of the remunerative health sector, the approaches are transferred subsequently to food and agriculture sector; with potential application in detection of food contaminants such as preservatives, antibiotics, heavy metal ions, toxins, microbial load, and pathogens along with the rapid monitoring of temperature, traceability, humidity, gas, and aroma of the food stuff.     

Geochemical baselines of heavy metals in the sediments of two large freshwater lakes in China: implications for contamination character and history

The aim of this study was to estimate the geochemical baseline concentrations of various heavy metals in the surface sediments of two large freshwater lakes in Taihu and Dianchi, China, and to assess the character and history of heavy metal contamination around the two lakes. Heavy metal concentrations in the sediments were obtained by field surveys and were supplemented with published data. The statistical methods of cumulative frequency and normalization were employed to obtain the baselines. The respective baseline concentrations for As, Sb, Hg, Co, Cr, Cu, Ni, Pb and Zn were 9.92, 1.67, 0.14, 22.62, 100.56, 31.63, 31.97, 33.05 and 97.01?mg/kg, respectively, in Taihu, and 24.60, 4.29, 0.25, 36.78, 135.68, 90.05, 50.76, 73.56 and 208.76?mg/kg, respectively, in Dianchi. The baseline concentrations of these heavy metals in Lake Taihu were equivalent to the pre-industrial concentrations determined from lakes in Sweden and Europe. Conversely, those in Lake Dianchi were much higher than the pre-industrial values. Li, Fe, Sc, Ti, V and Al were found to be the suitable reference elements for normalization, and one of these elements could be used to predict the baseline concentrations of heavy metals except Hg. Most of the heavy metals had one inflexion, and only Cu and Pb in Taihu, Sb, Pb and Zn in Dianchi, were found to have two inflexions in the cumulative curves, suggesting remarkable anthropogenic inputs of Cu and Pb in Taihu, Sb, Pb and Zn in Dianchi, which are generally consistent with the respective industrial structure around Taihu and Dianchi.     

AQUATOX: Modeling environmental fate and ecological effects in aquatic ecosystems

AQUATOX combines aquatic ecosystem, chemical fate, and ecotoxicological constructs to obtain a truly integrative fate and effects model. It is a general, mechanistic ecological risk assessment model intended to be used to evaluate past, present, and future direct and indirect effects from various stressors including nutrients, organic wastes, sediments, toxic organic chemicals, flow, and temperature in aquatic ecosystems. The model has a very flexible structure and provides multiple analytical tools useful for evaluating ecological effects, including uncertainty analysis, nominal range sensitivity analysis, comparison of perturbed and control simulations, and graphing and tabulation of predicted concentrations, rates, and photosynthetic limitations. It can represent a full aquatic food web, including multiple genera and guilds of periphyton, phytoplankton, submersed aquatic vegetation, invertebrates, and fish and associated organic toxicants. It can model up to 20 organic chemicals simultaneously. (It does not model metals.) Modeled processes for organic toxicants include chemodynamics of neutral and ionized organic chemicals, bioaccumulation as a function of sorption and bioenergetics, biotransformation to daughter products, and sublethal and lethal toxicity. It has an extensive library of default biotic, chemical, and toxicological parameters and incorporates the ICE regression equations for estimating toxicity in numerous organisms. The model has been implemented for streams, small rivers, ponds, lakes, reservoirs, and estuaries. It is an integral part of the BASINS system with linkage to the watershed models HSPF and SWAT.     

3 forest simulation model

The 3 forest simulation model is a process model of tree growth, carbon and nitrogen dynamics in a single-species, even-aged forest stand. It is based on the model. Major changes include the computation of sun angle and radiation as a function of latitude and day of the year, the closed-form integration of canopy production as a function of day and hour, the introduction of tree number, height, and diameter as separate state variables, and different growth strategies, mortalities, and resulting self-thinning as function of crowding competition.The tree/soil system is described by a set of nonlinear ordinary differential equations for the state variables: tree number, base diameter, tree height, wood biomass, nitrogen in wood, leaf mass, fine root mass, fruit biomass, assimilate, carbon and nitrogen in litter, carbon and nitrogen in soil organic matter, and plant-available nitrogen. The model includes explicit formulations of all relevant ecophysiological processes such as: computation of radiation as a function of seasonal time, daytime and cloudiness, light attenuation in the canopy, and canopy photosynthesis as function of latitude, seasonal time, and daytime, respiration of all parts, assimilate allocation, increment formation, nitrogen fixation, mineralization, humification and leaching, forest management (thinning, felling, litter removal, fertilization etc.), temperature effects on respiration and decomposition, and environmental effects (pollution damage to photosynthesis, leaves, and fine roots). Only ecophysiological parameters which can be either directly measured or estimated with reasonable certainty are used. 3 is a generic process model which requires species- and site-specific parametrization. It can be applied to deciduous and coniferous forests under tropical, as well as temperate or boreal conditions.The paper presents a full documentation of the mathematical model as well as representative simulation results for spruce and acacia.     

treedyn3 forest simulation model

The treedyn3 forest simulation model is a process model of tree growth, carbon and nitrogen dynamics in a single-species, even-aged forest stand. It is based on the treedyn model. Major changes include the computation of sun angle and radiation as a function of latitude and day of the year, the closed-form integration of canopy production as a function of day and hour, the introduction of tree number, height, and diameter as separate state variables, and different growth strategies, mortalities, and resulting self-thinning as function of crowding competition.The tree/soil system is described by a set of nonlinear ordinary differential equations for the state variables: tree number, base diameter, tree height, wood biomass, nitrogen in wood, leaf mass, fine root mass, fruit biomass, assimilate, carbon and nitrogen in litter, carbon and nitrogen in soil organic matter, and plant-available nitrogen. The model includes explicit formulations of all relevant ecophysiological processes such as: computation of radiation as a function of seasonal time, daytime and cloudiness, light attenuation in the canopy, and canopy photosynthesis as function of latitude, seasonal time, and daytime, respiration of all parts, assimilate allocation, increment formation, nitrogen fixation, mineralization, humification and leaching, forest management (thinning, felling, litter removal, fertilization etc.), temperature effects on respiration and decomposition, and environmental effects (pollution damage to photosynthesis, leaves, and fine roots). Only ecophysiological parameters which can be either directly measured or estimated with reasonable certainty are used. treedyn3 is a generic process model which requires species- and site-specific parametrization. It can be applied to deciduous and coniferous forests under tropical, as well as temperate or boreal conditions.The paper presents a full documentation of the mathematical model as well as representative simulation results for spruce and acacia.     

Ecotypes diversity in autumn olive (Elaeagnus umbellata Thunb): A single plant with multiple micronutrient genes

Elaeagnus umbellata, a member of the Elaeagnaceae family, is native to Pakistan, China, India, Korea, and Japan. It is found commonly at altitudes ranging from 1200 to 2100 m and thrives on eroded and degraded land due to its ability to fix nitrogen. The plant also grows under variable pH (4-8) and drought, and is used locally as fuel wood, fencing, fodder, basket making, and shelterbelts. The fruit of the plant is well known for its essential nutrients and medicinal compounds such as vitamins, minerals, essential fatty acids, carotenoids (lycopene), soluble solids, and sugars. Medicinally, it is widely believed to protect against myocardial infections, pulmonary infections, and various forms of cancers. Ten ecotypes from variable microclimatic conditions were investigated for their morphological, molecular and biochemical diversity improvement and commercialization purposes. Comparisons and disabilities indicated significant variability in terms of morphological (plant height, number of branches, thorn size and number, leaf area, fruit size, 100 fruit weight, and yield), molecular (SDS-PAGE), and micro- and macronutrient (vitamin C, Fe, mg, P, Na, K, essential oils, and sugar) bases among the ecotypes. This variability will be helpful in developing commercial varieties of the plant utilizing the conventional techniques of selection and hybridization for economic activities. The plant has ample quantities of multiple micronutrients, thus indicating their expression through a powerful promoter at one place (fruit mesocarp). Efforts to identify and isolate the micronutrient genes (vitamin A, C, E, and Fe), the deficiency of which causes malnutrition and disabilities within the population of developing countries. Micronutrient genes have also been initiated for their characterization and future transformation into staple food crops for stable bio-fortification.     

Ecotypes diversity in autumn olive (Elaeagnus umbellata Thunb): A single plant with multiple micronutrient genes

Elaeagnus umbellata, a member of the Elaeagnaceae family, is native to Pakistan, China, India, Korea, and Japan. It is found commonly at altitudes ranging from 1200 to 2100 m and thrives on eroded and degraded land due to its ability to fix nitrogen. The plant also grows under variable pH (4–8) and drought, and is used locally as fuel wood, fencing, fodder, basket making, and shelterbelts. The fruit of the plant is well known for its essential nutrients and medicinal compounds such as vitamins, minerals, essential fatty acids, carotenoids (lycopene), soluble solids, and sugars. Medicinally, it is widely believed to protect against myocardial infections, pulmonary infections, and various forms of cancers. Ten ecotypes from variable microclimatic conditions were investigated for their morphological, molecular and biochemical diversity improvement and commercialization purposes. Comparisons and disabilities indicated significant variability in terms of morphological (plant height, number of branches, thorn size and number, leaf area, fruit size, 100 fruit weight, and yield), molecular (SDS-PAGE), and micro- and macronutrient (vitamin C, Fe, mg, P, Na, K, essential oils, and sugar) bases among the ecotypes. This variability will be helpful in developing commercial varieties of the plant utilizing the conventional techniques of selection and hybridization for economic activities. The plant has ample quantities of multiple micronutrients, thus indicating their expression through a powerful promoter at one place (fruit mesocarp). Efforts to identify and isolate the micronutrient genes (vitamin A, C, E, and Fe), the deficiency of which causes malnutrition and disabilities within the population of developing countries. Micronutrient genes have also been initiated for their characterization and future transformation into staple food crops for stable bio-fortification.     

Influence of lead on growth and nutrient accumulation in canola (Brassica napus L.) cultivars

Canola (Brassica napus L.) is commonly used as a hyper-accumulator for phytoextraction of heavy metals from soil and water. Like many other heavy metals, lead (Pb) contaminates soil, water and air and thus it is a great problem. This study was conducted to investigate toxic effects of Pb on growth and nutrient uptake in four canola cultivars. Each of four cultivars of canola (Con-II, Con-III, Legend and Shiralee) was subjected to four levels of Pb (0, 30, 60 and 90 mg Pb kg(-1) of soil) from lead chloride [PbCl2]. Due to Pb toxicity, plant growth was adversely affected and relatively a severe reduction in root biomass (45.7%) was recorded. The Pb accumulation increased both in shoot and root, the highest being in root. The uptake of different nutrients, i.e., N, P, K, Ca, Mg, Zn, Cu and Mn was reduced (38.4, 32.8, 33.1, 49.6, 7.78, 52.0, 42.6 and 45.9%, respectively) in the shoots and that of N, Fe, Zn, and Cu in the roots (48.5, 33.2, 24.3 and 44.8%, respectively) of all canola cultivars. The root K, P, Zn and Mn and shoot P, Mg and Fe contents were less affected, the concentration of Pb, Ca and Mg in roots of all cultivars. Among canola cultivars Con-II and Con-III performed better than Legend and Shiralee in terms of growth (26.03%) and nutrient accumulation. Overall, plant growth and nutrient accumulation in the canola cultivars was hampered due to the presence of Pb.     

Recognizing reflexivity among conservation practitioners

When deciding how to conserve biodiversity, practitioners navigate diverse missions, sometimes conflicting approaches, and uncertain trade-offs. These choices are based not only on evidence, funders’ priorities, stakeholders’ interests, and policies, but also on practitioners’ personal experiences, backgrounds, and values. Calls for greater reflexivity—an individual or group's ability to examine themselves in relation to their actions and interactions with others—have appeared in the conservation science literature. But what role does reflexivity play in conservation practice? We explored how self-reflection can shape how individuals and groups conserve nature. To provide examples of reflexivity in conservation practice, we conducted a year-long series of workshop discussions and online exchanges. During these, we examined cases from the peer-reviewed and gray literature, our own experiences, and conversations with 10 experts. Reflexivity among practitioners spanned individual and collective levels and informal and formal settings. Reflexivity also encompassed diverse themes, including practitioners’ values, emotional struggles, social identities, training, cultural backgrounds, and experiences of success and failure. Reflexive processes also have limitations, dangers, and costs. Informal and institutionalized reflexivity requires allocation of limited time and resources, can be hard to put into practice, and alone cannot solve conservation challenges. Yet, when intentionally undertaken, reflexive processes might be integrated into adaptive management cycles at multiple points, helping conservation practitioners better reach their goals. Reflexivity could also play a more transformative role in conservation by motivating practitioners to reevaluate their goals and methods entirely. Reflexivity might help the conservation movement imagine and thus work toward a better world for wildlife, people, and the conservation sector itself.     

芽胞杆菌属(Bacillus sp.)10株细菌混合制剂对4种作物出苗及苗期生长的影响

以10株具有促生及抑制病害的芽胞杆菌属菌株(Bacillus sp．)的培养物，按不同比例配制成5个混合剂型细菌制剂．A、B、C、D剂型播种时接种不结球小白菜30d后，株高、叶片数、根长和干重分别增加7．8％、6．2％、9．4％和13．8％，除C处理的株高与对照差异不显著外，其余均达显著水平．接种A和B剂型显著提高豌豆出苗率，出苗9d时两菌剂处理的地上和地下部干重分别平均提高92．3％和183．3％，并发现5株供试菌株对引起豌豆病害病原菌有明显的抑菌作用．以A、B、E三个剂型菌悬液培养水稻种子4d时，各处理的平均芽长提高33．3％，根长提高16．0％，培养25d时株高、根数和地上部干重平均分别提高16．0％、9．5％和22．7％，均达显著水平．B剂型的培养物培养小麦27d时发现对株高、叶片数和植株干重的影响都不显著，但对根数和根重有显著的促进作用．综合分析认为，A菌剂最有利于供试作物出苗和苗期生长，其次为B剂型．表5参17     

浅水体浮萍污水净化系统的除氮途径

以稀释的猪场厌氧污水为供试水样,少根紫萍为供试生物材料,对夏、冬2季浅水体浮萍污水净化系统TN、NH4 -N和NOx--N(NO2--N与NO3--N之和)的去除途径进行了试验研究。结果表明,在夏季气温条件下,TN通过气态氨挥发、浮萍系统吸收/吸附NH4 -N和NOx--N得以去除,3途径去除的N分别占TN去除量的30.5%、15.9%和53.6%;NH4 -N通过气态氨挥发、浮萍系统吸收/吸附和硝化反应得以去除,3途径去除的N分别占NH4 -N总去除量的33.1%、17.3%和49.6%;NOx--N则完全通过浮萍系统吸收/吸附得以去除。在冬季气温条件下,TN通过气态氨挥发和浮萍系统吸收/吸附NH4 -N得以去除,2途径去除的N分别占TN去除量的31.7%和68.3%;NH4 -N通过气态氨挥发、浮萍系统吸收/吸附和硝化反应得以去除,3途径去除的N分别占NH4 -N总去除量的28.9%、69.5%和1.6%;而水体中的NOx--N含量始终保持稳定。     

Geochemistry of the barkinite liptobiolith (Late Permian) from the Jinshan Mine,Anhui Province,China

This paper discusses the geochemistry and mineralogy of the barkinite liptobiolith of the Late Permian age from the Jinshan Mine, Guangde County, Anhui Province, China. Samples were examined using inductively coupled plasma-mass spectroscopy, X-ray fluorescence, cold-vapor atomic absorption spectrometry, ion-selective electrode, sequential chemical extraction, scanning electron microscopy equipped with energy-dispersive X-ray, and optical microscopy. The coal is a medium-ash and high-sulfur resource. Minerals in the coal are composed of kaolinite, pyrite, calcite, and quartz. Pyrite and calcite are derived from seawater during peat accumulation. Quartz in the coal is of authigenic origin. Part of the kaolinite is from a land-source region, and part occurs as cell-fillings and is of authigenic origin. The results also indicate that the barkinite liptobiolith contains some toxic elements in high concentrations. Elements including Li, Be, Si, Sc, Ti, V, Cr, Fe, Ga, Se, Y, Zr, Mo, the rare earth elements (REEs), W, Hg, Tl, Pb, Th, and U in the coals are enriched in the barkinite liptobiolith. Results of sequential chemical extraction showed that Li, Sc, Ti, Cr, Y, Zr, REEs, and Th in the coal mainly occur as silicates, while Be and W are related to organic matter. Pyrite is the dominant source of S, Mo, Hg, Tl, and Pb. Gallium only occurs in silicate, and U and V occur both in organic and silicate associations.     

大别山多枝尖山区林下植物种间联结性研究

采用通过X2统计量检验,共同出现百分率（AC）和和联结系数（PC）3个指标分别分析了多枝尖山区林下主要植物的种间联结特征。结果表明：13个灌木植物中满山红Rhododendron mariesii和山霉Rubus corchorifolius、粉花绣线菊Spiraea japonica之间、映山红Rhododendron simsii与箬竹Arundo donax以及满山红和映山红之间正联结极显著性（P〈0.01）,而菝葜Smilax china和满山红、菝葜和五味子Schizandrae fructus、绿叶胡枝子Lespedeza buergeri和三桠乌药Lindera obtusiloba,绿叶胡枝子和映山红、满山红和五味子之间呈正联结达到显著水平（P〈0.05）;17个草本植物中林荫千里光Senecio nemorensis和苔草Carex sp之间负联结极显著（P〈0.01）,冷水花Pilea cadiere与苔草以及芒草Miscanthus sp和求米草Oplismenus undulatifolius之间负联结达到显著水平（P〈0.05）,冷水花与堇菜Viola verecunda以及野青茅Deyeuxia arundinacea、求米草与委陵菜Potentilla chinensis3个种对间呈正联结极显著（P〈0.01）。多枝尖山区林下灌木和草本植物的种间联结性较为松散,物种的生态习性、群落环境、群落演替进程和上层植物的影响等因素可能是形成该区种间联结特征的主要原因。     

Methods to prepare biosorbents and magnetic sorbents for water treatment: a review

Access to drinkable water is becoming more and more challenging due to worldwide pollution and the cost of water treatments. Water and wastewater treatment by adsorption on solid materials is usually cheap and effective in removing contaminants, yet classical adsorbents are not sustainable because they are derived from fossil fuels, and they can induce secondary pollution. Therefore, biological sorbents made of modern biomass are increasingly studied as promising alternatives. Indeed, such biosorbents utilize biological waste that would otherwise pollute water systems, and they promote the circular economy. Here we review biosorbents, magnetic sorbents, and other cost-effective sorbents with emphasis on preparation methods, adsorbents types, adsorption mechanisms, and regeneration of spent adsorbents. Biosorbents are prepared from a wide range of materials, including wood, bacteria, algae, herbaceous materials, agricultural waste, and animal waste. Commonly removed contaminants comprise dyes, heavy metals, radionuclides, pharmaceuticals, and personal care products. Preparation methods include coprecipitation, thermal decomposition, microwave irradiation, chemical reduction, micro-emulsion, and arc discharge. Adsorbents can be classified into activated carbon, biochar, lignocellulosic waste, clays, zeolites, peat, and humic soils. We detail adsorption isotherms and kinetics. Regeneration methods comprise thermal and chemical regeneration and supercritical fluid desorption. We also discuss exhausted adsorbent management and disposal. We found that agro-waste biosorbents can remove up to 68–100% of dyes, while wooden, herbaceous, bacterial, and marine-based biosorbents can remove up to 55–99% of heavy metals. Animal waste-based biosorbents can remove 1–99% of heavy metals. The average removal efficiency of modified biosorbents is around 90–95%, but some treatments, such as cross-linked beads, may negatively affect their efficiency.

     

武汉月湖水体主要元素与浮游植物的PCA与CCA分析

通过2007年1—12月对武汉月湖不同的取样点进行监测,并选择汉江琴台段水域作为研究对照,调查了月湖水体硅藻、蓝藻与水体主要元素的种类,采用PCA、CCA分析法探讨了月湖水体硅藻、蓝藻与水体元素种类的关系。结果表明:月湖水体中所含元素全年监测出28种;汉江琴台段水域中所含元素全年监测出27种。经PCA分析表明,月湖水体中累计贡献率较大为磷(P)、砷(As)、铁(Fe)、铜(Cu)、锰(Mn);汉江琴台段水域累计贡献率较大为硅(Si)、锑(Sb)、镉(Cd)、钒(V)、钡(Ba)、Ag(银)、钼(Mo)。月湖水体中蓝藻密度大于硅藻,汉江琴台段水域硅藻密度大于蓝藻。经CCA分析表明,月湖硅藻密度与硒(Se)、锶(Sr)、银(Ag)、Ba、铝(Al)呈正相关关系;月湖蓝藻密度与P、Cu、铬(Cr)呈正相关关系,月湖蓝藻密度与镁(Mg)、镍(Ni)、钙(Ca)、锌(Zn)、硫(S)呈负相关关系。CCA分析中,汉江琴台段硅藻密度与铅(Pb)、硼(B)、As、Cr、Zn、Al、Cu、Mn、Fe、P呈负相关关系,汉江琴台段硅藻密度与Mo、Ca、钴(Co)、V、Sr、Ag呈正相关关系;汉江琴台段蓝藻密度与钠(Na)、S、Mg、Ni、钾(K)呈负相关关系。月湖水体缺乏可溶硅(dissolved silicon,DSi),硅藻会提升对其他元素(Se、Sr、Ag、Ba、Al)的吸收能力,这些元素会起到缺乏元素(Si)近似的作用,替代性可能出现。水中各种元素的组态是导致月湖浮游植物群落发生演变的重要原因之一。     

Contributions of paraecologists and parataxonomists to research,conservation, and social development

Citizen science has been gaining momentum in the United States and Europe, where citizens are literate and often interested in science. However, in developing countries, which have a dire need for environmental data, such programs are slow to emerge, despite the large and untapped human resources in close proximity to areas of high biodiversity and poorly known floras and faunas. Thus, we propose that the parataxonomist and paraecologist approach, which originates from citizen‐based science, is well suited to rural areas in developing countries. Being a paraecologist or a parataxonomist is a vocation and entails full‐time employment underpinned by extensive training, whereas citizen science involves the temporary engagement of volunteers. Both approaches have their merits depending on the context and objectives of the research. We examined 4 ongoing paraecologist or parataxonomist programs in Costa Rica, India, Papua New Guinea, and southern Africa and compared their origins, long‐term objectives, implementation strategies, activities, key challenges, achievements, and implications for resident communities. The programs supported ongoing research on biodiversity assessment, monitoring, and management, and participants engaged in non‐academic capacity development in these fields. The programs in Southern Africa related to specific projects, whereas the programs in Costa Rica, India, and Papua New Guinea were designed for the long term, provided sufficient funding was available. The main focus of the paraecologists’ and parataxonomists’ activities ranged from collection and processing of specimens (Costa Rica and Papua New Guinea) or of socioeconomic and natural science data (India and Southern Africa) to communication between scientists and residents (India and Southern Africa). As members of both the local land user and research communities, paraecologists and parataxonomists can greatly improve the flow of biodiversity information to all users, from local stakeholders to international academia.     

The impact of urban land expansion on soil quality in rapidly urbanizing regions in China: Kunshan as a case study

At a stage of rapid economic development and urbanization in China, most cities are faced with serious problems caused by environment deterioration such as pollution, space press, afforestation degradation, and disordering. Kunshan City, one of the most economically vigorous regions in China, has suffered a more prominent conflict between urbanization and environmental safety. In this paper, urban land expansion in Kunshan City in the Yangtze River Delta was measured with reference to the Landsat data recorded in 1982, 1991, 1995, and 2003 and change in land-use pattern in 1981, 1991, 1995, and 2004 as well as that in nutrients in soils of different purposes between the periods were analyzed to study the effect of urban land-use expansion on soil characteristics. To get a better understanding of soil nutrients, heavy metal content, and pollution, on-the-spot investigation, sampling and laboratory analysis were all conducted, and the geo-accumulation factors and revised Nemerow comprehensive index method were adopted for evaluation of the findings. The results show that the content of organic matter, total nitrogen, rapidly available nitrogen, and available phosphorus in the soil (except available potassium) all increased, and the average content of As, Cd, Cr, Cu, Pb, Ni, Hg, Se, and Zn prove to be 8.61, 0.12, 83.53, 32.49, 29.93, 30.45, 0.27, 0.24, and 93.3 mg kg⁻¹, respectively, showing degradation in soil quality.     

深圳市内某河表层沉积物重金属含量及污染评价

2008年11月,从广东省深圳市内某河采集9个(0—5cm)表层沉积物样品,分析其Cu,Cd,Cr,Pb,Zn,Ni,As和Hg的含量和前6种元素的形态分布,并采用潜在生态风险指数法进行污染评价.结果表明,沉积物中Cu和Zn的含量普遍较高,为5.27—1865mg.kg-1和198.4—1275mg.kg-1,其次是Cr,Ni和Pb,为54.39—908.7mg.kg-1、31.3—445.5mg.kg-1和11.63—814.9mg.kg-1,As,Cd和Hg的含量较少;Cd的残余晶格态、Cr的铁/锰氧化态和残余晶格态、Cu的有机结合态和残余晶格态,以及Ni,Pb和Zn的铁/锰氧化态为各元素的主要存在形态;沉积物中Cd和Cu的潜在生态风险普遍较大,9个样品中6个达到Cd极强生态危害,4个达到Cu很强生态危害,有5个样品的重金属混合污染潜在生态风险达到极强生态危害.