Carbon sequestration and soil microbes in purple paddy soil as affected by long-term fertilization

Soil organic carbon (SOC) sequestration impacts on food security and climate change and may be affected by soil microbes in fertilized croplands. A 12-year field experiment under the rice–wheat system was used to evaluate the effect of the long-term fertilization on the SOC accumulation, culturable soil microbes, and their interaction in purple paddy soil. Results showed that varied fertilizations resulted in a significant increase of the SOC content and stock in the plow layer, as well as rise in populations of major soil microbes, including bacteria, actinomycetes, and fungi compared with no fertilization. Soil with combined application of chemical NPK fertilizer and organic amendment (pig manure or rice straw return) on average had the highest organic carbon content and stock, amounts of bacteria, actinomycetes, and fungi, which were 7.8%, 5.8%, 75.8%, 130.5%, and 16.2% higher than the NPK fertilization alone. Fertilization differentially altered populations of the functional anaerobic bacteria in paddy soil. With the combined application of chemical NPK fertilizer and organic amendment, soil displayed higher amounts of anaerobic cellulolytic bacteria, anaerobic fermentative bacteria, hydrogen-producing acetogen, methanogenic bacteria, denitrifying bacteria, and sulphate-reducing bacteria than that with the NPK fertilization alone or no fertilization. Populations of all three major soil microbes showed significantly positive correlations with the SOC content, indicating their interaction was of mutual promotion. Data suggest that the combined application of the NPK fertilizer with organic amendment especially by the rice straw return is recommended to sustain the soil biological fertility and mitigate the emission of the greenhouse gas by the SOC sequestration in purple paddy soil.     

黄河三角洲自然保护区秋冬季水鸟群落组成与生境关系分析

于2014年10月至2015年1月采用样线调查法对黄河三角洲自然保护区秋季迁徙期和越冬期水鸟群落结构进行调查研究,调查共包括8条样线40个观测点.结果表明:(1)秋季迁徙期共记录水鸟6目14科54种,国家Ⅰ级保护鸟类5种,国家Ⅱ级保护鸟类8种;越冬期共记录水鸟5目7科31种,国家Ⅰ级保护鸟类1种,国家Ⅱ级保护鸟类4种.(2)2个时期雁形目水鸟种类和数量均占优势,豆雁(Anser fabalis)、斑嘴鸭(Anas poecilorhycha)、赤膀鸭(Anas strepera)和绿头鸭(Anas platyrhynchos)为优势物种,丹顶鹤(Grus japonensis)、东方白鹳(Ciconia boyciana)和大大鹅(Cygnus cygnus)等珍稀水鸟也有一定的种群数量.(3)秋季迁徙期水鸟种数、数量和ShannonWiener多样性指数多于或高于越冬期.(4)5种典型生境之间水鸟种类和数量存在差异,天然水域是水鸟群落的主要分布区.(5)自然生境内的水鸟种数、数量和Shannon-Wiener多样性指数一般多于或高于人工生境.相似性分析结果表明,自然生境之间水鸟群落结构相似程度高于人工生境.     

石墨相氮化碳光催化剂的制备、改性及其在水处理中的应用

作为典型的非金属半导体光催化剂,类石墨相氮化碳(g-C3N4)由于具有物理化学性质稳定、能带结构适宜、制备成本低廉等优势,近年来受到广泛关注.本文综述了石墨相氮化碳的基本结构特性、常用制备方法以及结构改性策略,对其在水处理中的应用进行了总结,并对g-C3N4未来的发展趋势进行了展望,以期为氮化碳新材料开发及其在水处理方...     

关于焦化行业CO2排放核算方法的探讨

本文分析了适用于焦化行业通用CO₂排放核算方法,在此基础上结合我国焦化行业工艺和原料的特征,采用排放因子法和物料衡算法等两种方法对10家典型焦化企业CO₂排放进行核算。结果表明:物料衡算法能很好地反映不同类型焦化企业的排放特征;排放因子法对我国独立焦化企业存在碳排放量系统性高估的可能。为此,建议我国焦化企业可借鉴德国焦化企业的碳核算经验,采用碳平衡法对不同类型的焦化企业(单元)的碳排放量进行核算,并完善相关的统计和监测技术。     

Water quality modelling of the river Yamuna (India) using QUAL2E-UNCAS

This paper describes the utility of QUAL2E as a modelling package in the evaluation of a water quality improvement programme. In this study, QUAL2E was applied to determine the pollution loads in the river Yamuna during its course through the national capital territory of Delhi, India. The study aimed at examining the influence of different scenarios on river water quality. Four different pollution scenarios were analysed besides the 'business as usual' situation. The study revealed that it was necessary to treat the discharge from drains to the river Yamuna and diversion of a substantial load to the Agra canal for further treatment was also essential. It was also established through this study that maintaining a flow rate of more than 10 m(3)/s in the river could also help preserve the river's water quality. To clearly display the model outcomes and demarcate polluted zones in the river stretch, model results were interfaced with a Geographical Information System (GIS) to produce cartographic outputs. In addition, uncertainty analysis in the form of first-order error analysis and Monte Carlo analysis was performed, to realise the effect of each model parameter on DO and BOD predictions. The uncertainty analysis gave satisfactory results on simulated data.     

The integrated project AquaTerra of the EU sixth framework lays foundations for better understanding of river-sediment-soil-groundwater systems

The integrated project "AquaTerra" with the full title "integrated modeling of the river-sediment-soil-groundwater system; advanced tools for the management of catchment areas and river basins in the context of global change" is among the first environmental projects within the sixth Framework Program of the European Union. Commencing in June 2004, it brought together a multidisciplinary team of 45 partner organizations from 12 EU countries, Romania, Switzerland, Serbia and Montenegro. AquaTerra is an ambitious project with the primary objective of laying the foundations for a better understanding of the behavior of environmental pollutants and their fluxes in the soil-sediment-water system with respect to climate and land use changes. The project performs research as well as modeling on river-sediment-soil-groundwater systems through quantification of deposition, sorption and turnover rates and the development of numerical models to reveal fluxes and trends in soil and sediment functioning. Scales ranging from the laboratory to river basins are addressed with the potential to provide improved river basin management, enhanced soil and groundwater monitoring as well as the early identification and forecasting of impacts on water quantity and quality. Study areas are the catchments of the Ebro, Meuse, Elbe and Danube Rivers and the Brévilles Spring. Here we outline the general structure of the project and the activities conducted within eleven existing sub-projects of AquaTerra.     

Wood carbon content of tree species in Eastern China: interspecific variability and the importance of the volatile fraction

Data on the mass density and carbon content of tree organs, and in particular stem wood, are essential for accurate assessments of forest carbon sequestration. However most available data, including that for East Asia, has neglected the volatile C fraction. Wood samples were collected and assayed for C content from 14 native tree species in Jilin Province, NE China. C content showed statistically significant variation among species, ranging from 48.4% to 51.0%. The volatile C fraction was non-negligible, averaging 2.2%, and showed high variation among species. As found in prior studies, wood C content was appreciably higher in conifer than hardwood (angiosperm) species (50.8+/-0.1% vs. 49.5+/-0.2%, respectively). Wood carbon density (gC/cm(3)) showed very high inter-specific variation, due mainly to differences in wood specific gravity. Our analyses, in conjunction with recently published data from North America, indicate a global mean value of 47.5+/-0.5% wood C content exclusive of volatile C; the widely used 50% figure corresponds more closely to total wood C inclusive of the volatile fraction. Failure to include volatile C or to use species- or higher-taxon-specific C content values in forest C assessments is likely to introduce biases on the order approximately 4-6%. In addition, the stocks and flows of the volatile C fraction in wood are in themselves an important and sorely neglected aspect of forest C processes likely to be strongly impacted by harvests and other management practices.     

The effects of sediment-laden waters on irrigated lands along the lower Yellow River in China

Expansion of irrigation in the Yellow River (Huang He in Chinese) Basin of China is a major accomplishment of the post-revolutionary period in China. Irrigation reliance on the Yellow River was anticipated to not only supply greater reliability of water for crops, but also to improve the productivity of aeolian, saline and alkali soils because of the high sediment loads in the river. Irrigation expansion also was a significant factor in affecting human modification of the landscape ecosystem in the lower reaches of the Yellow River. Based on field investigation and sampling of the amount and distribution of used suspended sediment load in irrigated areas, this paper analyzes the impact of the suspended sediment on soil texture, fertility and salinity and the consequences to the landscape ecosystem. Results indicate that soil quality has indeed been improved through irrigation and related deposition of sediment, but some local problems created by long periods of irrigation should not be ignored in the future.     

A Social Analysis of the Bioinvasions of Dreissena polymorpha in Spain and Hydrilla verticillata in Guatemala

Human agency plays a key role in the processes of biological invasions. This comprises not only the human role in the configuration of driving forces or in the perception of the impacts, but also the conceptualization of alien species themselves as an environmental problem. This paper examines different stakeholders' positions in bioinvasion processes at different scales, and it looks at their relevance for the management of invasive species. It compares two cases: the invasion process of Dreissena polymorpha in the Ebro River in Spain and the case of Hydrilla verticillata in Lake Izabal, Guatemala. Our results are structured according to impacts and to management options. The discussion focuses on the relevance of incorporating the different stakeholders' interests and values in the analysis and management of biological invasions. Although social analysis of stakeholders' positions is necessary in order to foster management actions, it also reveals conflicts on the relevant criteria and on the very definition of invasive species.     

Criteria for the Assessment of Sustainable Water Management

Pressure on the world’s water resources is increasing, restraining social and economic development in many countries, and threatening ecological values in others. In order to manage water resources in a more sustainable manner, new planning methodologies/processes for river basin management need to be developed. This study attempts to construct a set of useable normative criteria for the analysis and evaluation of such processes. The criteria were designed as a response to the lack of deductive approaches in the evaluation of methodologies and working procedures used in the context of river basin management, making it possible to highlight their potential for sustainable development. The criteria are based on the twin concepts of participation and integration. These concepts function as well-established dimensions of both sustainable development and sustainable river basin management, and they are of significant methodological relevance. A synthesis of the key aspects connected to the two concepts is undertaken, based on a broad literature review. Focus is laid on how in methodological terms, and in relation to regional water management, to achieve participation and integration in a decision-making or planning process. The criteria are concerned with how knowledge and values are integrated into the planning process and how commitment, legitimacy, or acceptance for the resulting plan is generated.