依靠生态自然修复能力 加快吉林省水土流失治理步伐

新时期吉林省水土保持生态建设面临着严峻的挑战。依靠生态自然修复能力恢复生态，是改善生态环境，加快水土流失治理的一项有效措施，分析了依靠生态自然修复能力恢复生态的理论依据及实践依据，提出搞好水土资源调查，统一规划，加大水土保持监督执法力度，正确处理治理与预防保护的关系是生态自然恢复的重要保证措施。     

新时期黄河流域水土保持战略目标的转变与发展对策

[目的] 遵循黄河流域生态保护和高质量发展国家战略（简称“黄河国家战略”）赋予黄河流域水土保持工作的新使命,分析黄河流域水土保持面临的重大挑战,旨在为黄河流域生态建设的高质量发展提供参考。[方法] 基于“黄河国家战略”的需求,结合长期的野外考察和学术研究成果,对新时期黄河流域水土保持发展战略目标的转变进行了重点分析和探讨。[结果] 新中国成立以来,通过70 a余的持续治理,黄河泥沙显著减少,流域生态环境明显好转,但目前仍存在一些问题：①空间治理不均衡,局部地区水土流失依然严重;②人工植被系统空间结构雷同化,生态系统不稳定;③缺乏景观格局优化配置,难以有效解决黄土高原生态系统由“绿”变“稳”的问题;④生态治理的功能性机制性问题凸显,影响水土保持的可持续发展。新时期的水土保持肩负着高质量发展根基的新使命,其本身也面临着战略定位和发展方式的转变,以及传统理论内涵和理念更新的重大挑战。因此,迫切需要研究严重制约生态治理效益与生态经济协同发展提质增效的关键技术难题,以及促进新时期黄河流域水土保持事业发展的对策。[结论] “黄河国家战略”的实施必将大大推进黄河流域水土保持事业的发展。黄河流域生态治理研究应着力解决高质量发展中生态保护治理的一系列关键科技问题,将水土保持战略目标由低标准大面积治理转向精致和精准治理,提升水土保持在推动黄河流域高质量发展中的地位和作用。     

水土保持在发展农村生产力中的地位与作用

水土保持作为农业长远发展的重要条件,在发展农村生产力中的特殊地位与作用表现为:水土保持为保护国土资源,从根本上改善生态环境和农业生产条件,保护和发展生产力发挥着无法替代的功能。     

三峡库区水土流失及其防治对策

三峡库区水土流失治理是事关库区生态环境改善的成败和三峡工程长久安全运行的大事。三峡库区水土保持生态建设必须走“保护与治理”相结合之路 ,主要对策是尽快制定《三峡库区水土保持条例》 ,加快水土流失治理步伐 ,增加水土保持专项投入等     

新形势下合川区水土保持工作思路

党的十八大报告把生态文明建设摆在中国特色社会主义总体布局五位一体的高度,体现了保护生态环境的重要性.合川“双百城市”的目标定位和“五城联创”的战略举措对全区城市水土保持工作和区域水土保持生态环境建设也提出了更高的要求.面对新形势和新要求,提出了合川区水土保持工作应该坚持预防和治理“两条腿并行”的思路.     

依靠生态自然修复能力加快吉林省水土流失治理步伐

新时期吉林省水土保持生态建设面临着严峻的挑战。依靠生态自然修复能力恢复生态 ,是改善生态环境 ,加快水土流失治理的一项有效措施。分析了依靠生态自然修复能力恢复生态的理论依据及实践依据 ,提出搞好水土资源调查、统一规划、加大水土保持监督执法力度、正确处理治理与预防保护的关系是生态自然恢复的重要保证措施     

水保生态建设农民投资投劳问题探讨

农村实行税费改革并取消“两工”后,水土保持生态环境建设的投入面临严峻的考验。在困境面前,山东省莱芜市莱城区各级政府及有关部门,积极探索,大胆改革,在“一事一议”制度基础上,通过“四荒”、有林地经营管理权和小型水利水保工程使用权拍卖,激活了水保发展活力,调动了群众积极性,拓宽了水土保持投资渠道,解决了水土保持生态环境建设的投资投劳问题,加快了治理速度,保证了治理效果。     

对当前水土保持监督工作的几点思考

水土保持监督管理，对保护水土资源和生态环境，加快水土流失防治，增强全民的水土保持法制意识，发挥了重要作用，但也存在着一些新的问题，结合大同市水土保持监督工作的实践，就城市水土保持如何加强，转变管理方式使治理项目后续管理步入正轨，水土保持动态监测网络建立，水土保持监督机构如何依法行使其管职能等方面，提出了新的 见解。     

汉江源头流域水土保持现状的调查与思考

在调查汉江源头流域水土保持现状的基础上，认识水土流失造成的危害，分析水土流失形成的原因，提出治理水流失的措施体系，为实施“生态环境的保护与建设”战略，为再造“山川秀美”西部地区奠定基础。     

黄土高原水土流失治理前后生态环境变化特征

生态环境改善是水土保持治理成效的重要体现。研究表明：黄土高原水土流失治理后，植被覆盖率显著提高，生态环境明显改善。物种数量及丰富度显著增加，种群间建立了新的生态平衡关系。建议：进一步开展黄土高原水土保持重点治理区生物多样性变化研究，制定生物多样性监测技术标准体系，完善生物多样性保护相关政策制度，为黄土高原地区生态环境改善效果和水土保持有效性评估奠定基础。     

Use of a 6-steps microcosm for studying a wastewater discharge in a freshwater ecosystem: a multidisciplinary study

An experimental microcosm has been designed for simulating and studying impacts of a wastewater treatment plant (WTP) discharge on a freshwater/sediment ecosystem. The study was focused on the changes in biodiversity of benthic populations, especially bacteria and oligochaetes. Effluents were discharged in the Saône river, near Lyon (France) from a small treatment plant which treated domestic raw water by an activated sludge process. Freshwater and sediments were sampled in the Saône river upstream of the discharge point and placed in microcosms. Following the WTP discharge, physicochemical parameters of the overlying water column and sediments exhibited only a slight change, as compared to a reference. Characterization of the sediment bacterial populations was conducted with the Biolog and API systems. Strain identification and interpretation of data was difficult using thesetwo systems. Bacterial taxa in the sediments increased slightly below the WTP discharge. Gram negative strains dominated in the effluents, but G+ and G- bacteria were balanced in the sediments. Pseudomonas sp. and Bacillus sp., were the dominant strains. Invertebrate populations indicated an effect of the WTP discharge, with increasing of pollution resistant strains (Tubificidae) and disappearance of pollution intolerant strains such as Limnodrilus udekemianus and Quistadrilus multicoetosus. Taken as a whole, biological parameters indicated an environmental changes despite only slight changes in the physicochemistry of water. This experimental microcosm has proven to be a useful tool for studying impact of wastewater discharge on benthic populations.     

Determination of ochratoxin a with a DNA aptamer

This work describes the identification of an aptamer that binds with high affinity and specificity to ochratoxin A (OTA), a mycotoxin that occurs in wheat and other foodstuffs, and a quantitative detection method for OTA based on the use of this aptamer. Aptamers are single-stranded oligonucleotides selected in vitro to bind to molecular targets. The aptamer selected in this work exhibited a dissociation constant in the nanomolar range and did not bind compounds with structures similar to OTA such as N-acetylphenylalanine or warfarin. The aptamer bound with a 100-fold less affinity to ochratoxin B. The selected aptamers could be used for the determination of ppb quantities of OTA in naturally contaminated wheat samples. Further work is ongoing to broaden the application demonstrated here with the development of sensors, affinity columns, and other analytical systems for field and laboratory determination of this toxin in food and agricultural products.     

Structural characteristics of clay-dominated soils of a marsh and a palaeosol in a crossed diagram

Although the shrink‐swell phenomenon of clays has been thoroughly studied, the in situ relation of the shrinkage curve to the structure profile is rarely presented from the shrinkage limit to the liquid limit. We studied the consolidated structure of clay‐dominated (<2 μm) soils formed on ‘pseudo‐liquid’ marsh sediments in the ‘Marais de l’Ouest’ (France). The profiles were studied in a grassland field and in a sunflower field from unsaturated surface soils down to deeper, saturated, levels characterized by a very large water content (100% by weight). The consolidation states were quantified recording cone resistance (Qd) profiles using a dynamic penetrometer in successive seasons. These Qd profiles were compared with the associated wet density and gravimetric water‐content profiles. Two consolidation depths were evident, the surface soil and a 130‐cm deep palaeosol. The seasonal Qd profiles demonstrate the partial irreversibility of the consolidation peaks associated with the surface soil and with the palaeosol. The shrinkage properties were established through drying curves of undisturbed test samples. In the void ratio (e)‐water content (W) and water content (W)‐saturation index (Sr) diagrams, the profiles as a whole exhibit only one clay soil behaviour from their pseudo‐liquid to plastic to solid states. Each Qd profile is represented by a hyperbolic curve in the e/Qd diagram. Represented in a (e – W – Qd —Sr) crossed diagram, the vertical evolution of the successive profiles shows the soil structure behaviour from the initial pseudo‐liquid sediment to the consolidated soil. A simple cone resistance recording associated with gravimetric water‐content profiles, characterizes the evolution of structural layers of soils for the seasonal drying‐wetting cycles, for the over‐consolidation associated with the palaeosol, and also for the effect of ploughing.     

Impact of a ski basin on a mountain watershed

The input of heavy metals by automobile exhaust pollution associated with the ski basin activities is the primary concern of this paper. Stream, snowpack and lichen samples were collected and analyzed for Pb, Zn, and Cu. Some lichen samples were also analyzed for Ca, Mg, Na, K, Fe, and Mn, as well as Pb, Zn, and Cu. Snowpack samples from roadside areas demonstrated increased levels of Pb and Cu in comparison to areas up to 180 m from the road, but heavy metal levels at more remote areas were comparable to roadside levels. In all snow samples the heavy metals associated with the particulate matter was the major form of all inputs. Heavy metals in streams were also highly correlated with the particulate matter content. Heavy metal inputs to the watershed were greater than stream export, indicating an accumulation of heavy metals by the system. The forest canopy appears to be the major factor in the accumulation of heavy metals, probably due to better interception and impaction of the particulate matter by the canopy.     

Macrokinetic grounds for a model of microbial growth on a substrate with a single major component

The dependency of experimental microbial growth data on the concentration of a major substrate component in phase space follows the law of a deformed bell curve and, until now, has not had a widely accepted rational. In the present work, a theoretical equation of this dependency at a fixed time was derived from the equation of the dependency of growth on time for a single concentration of a major component, which was previously obtained using a non-stationary non-equilibrium approach. The validity of the equation was established by comparison to experimental data from an independent source. The equation allows one to find intervals in the phase space of the dependency of growth on the initial concentration of the major component of the substrate that qualitatively vary by sign (plus or minus) and direction (increasing or decreasing) of the change of: a) growth, b) rates, and c) acceleration of its change in response to the change in the concentration of a major component of the substrate.     

The Control of a Small Dam in Nutrient Inputs to a Hypertrophic Estuary in a Mediterranean Climate

A two-year study was carried out in the lower part of the Palmones River to describe the role of a small dam controlling the nutrient fluxes to the estuary. Results showed an important spatial heterogeneity in the nutrient content and water properties of lowland catchment due to the effects of the small dam and the effluents of a sewage treatment work. Taking into account the values of hydraulic retention time, the dam could be considered as an optimally dimensioned pre-dam. Therefore, it removed on average more than 25% of total phosphorus (TP) while no net removal was obtained for TN during the studied period. Palmones River exported 11.3 TonsP year^?1 of TP and 72.1 TonsN year^?1 of TN to the estuary showing important seasonal differences. Less than 10% from the total amount of nutrient was exported during low flow conditions, while in four months with important flooding events, the percentage of total nitrogen exported exceeded 64%.     

脆弱刚毛藻对水体中三种苯系物的去除效果

采用L934正交设计法,研究了脆弱刚毛藻[Cladophora fracta (Dillw.) Kuetz.]对水体中3种苯系物苯、甲苯和二甲苯的去除作用.结果表明,脆弱刚毛藻对苯、甲苯和二甲苯的去除率分别为46.6写,13.6%和7.4 Yo.分析不同处理条件对脆弱刚毛藻对苯去除率的影响,各因素极差值大小依次为:温度>处理时间>藻体重量,温度是影响去除笨效果的主要因素.在刚毛藻去除甲苯的实验中,各因素R值大小依次为处理时间>藻体重量>温度,主要影响因素是处理时间.而对于二甲苯,藻体重量则是最主要的因素.     

Using a Numerical Model to Track the Discharge of a Wastewater Treatment Plant in a Tidal Estuary

Along the coast of Maine, USA, there are numerous wastewater treatment plants that discharge their treated effluents into a river estuary which is shared by commercial fishing and shellfish harvesting. Occasionally, there can be failures or bypasses of treatment plants that lead to untreated or partially treated sewage flowing into shellfish harvesting waters. To prevent any toxic contamination of harvested shellfish, a prohibitive zone is established around the treatment plant where shellfish harvesting is prohibited. The U.S. Food and Drug Administration has conducted numerous dye studies on both coasts of the USA to determine these prohibitive zones, based on the guidelines of the National Shellfish Sanitation Program. In May 2010, the FDA conducted such a dye study at the Yarmouth, Maine wastewater treatment plant. The results are compared with a numerical coastal model that provides the velocity field for the currents around the treatment plant. This model includes a diffusion equation to simulate dye dispersion from a point source which is used to determine the prohibitive zone. The numerical model shows good correlation with the FDA dye study report and establishes a prohibitive zone for commercial harvesting in keeping with that of the FDA study. The benefits of the numerical model include sampling at thousands of locations simultaneously, seasonal changes in river volumes, and changes in plant discharge volumes.