Sustainability of rice production systems: an empirical evaluation to improve policy

An evaluation is needed to monitor the progress of sustainable development (SD) in rice production systems. The purpose of this study is to provide policy inputs, examine the sustainability of rice production, and determine major policy areas. A requisite set of 12 indicators of three dimensions of SD, namely economic, was generated by employing an assemblage of top–down and bottom–up approaches. The data were gathered from farm households’ survey as well as in-depth discussion with stakeholders from the regions that represent irrigated, rain-fed lowland, rain-fed upland, flood-prone, and saline-prone rice-growing ecosystems in Bangladesh. By constructing composite indicators, the results revealed that 44 % of rice growers were economically viable, environmentally sound, and socially developed. The irrigated rice production system was found to be the most sustainable. The path analysis measured the contribution of the indicators to the index, and results highlighted that rice growers’ knowledge, skills, and social networks development, improving land productivity, and integrated nutrient management were essential for promoting sustainable rice production. However, the study findings suggest that pluralistic (i.e., government and non-government) agricultural advisory services can serve as an engine of transition to rice production sustainability in which a multi-year planning and strategy formulation are crucial besides investing in the modernization of extension services. Overall and ecosystem-specific policy implications that emerged from the findings of this study are outlined.     

Tie them up tight: wrapping by Philoponella vicina spiders breaks, compresses and sometimes kills their prey

We show that uloborid spiders, which lack the poison glands typical of nearly all other spiders, employ thousands of wrapping movements with their hind legs and up to hundreds of meters of silk line to make a shroud that applies substantial compressive force to their prey. Shrouds sometimes break the prey’s legs, buckle its compound eyes inward, or kill it outright. The compressive force apparently results from the summation of small tensions on sticky lines as they are applied to the prey package. Behavioral details indicate that wrapping is designed to compact prey; in turn, compaction probably functions to facilitate these spiders’ unusual method of feeding. This is the first demonstration that prey wrapping by spiders compacts and physically damages their prey, rather than simply restraining them.     

建设海峡西岸高效持续农业示范区的基本思路与技术对策——以福建省龙海市为例

本文以福建省龙海市为例,分析了龙海市农业发展优势与存在的问题,提出了建设海峡西岸高效持续农业示范区的基本思路与技术对策     

Institutional Arrangements for Flood Hazards in Malaysia: An Evaluation Using the Criteria Approach

Institutional aspects of flood hazards significantly affect their outcomes in Malaysia. Institutional arrangements to deal with floods include: legislative activity, organisational structures, attitudes and sub-culture, and policies and instruments. When assessed in terms of four specific criteria, institutional aspects of flood hazards are found to be largely inadequate. Disaster reduction programmes are over-dependent on a reactive approach based largely on technology and not even aimed at floods specifically. Structual flood reduction measures are the predominant management tool and, although the importance of non-structural measures is recognised, thus far they have been under-employed. Current laws and regulations with regard to flood management are also insufficient and both the financial and human resources of flood hazard organisations are generally found to be wanting. Finally, economic efficiency, equity and public accountability issues are not adequately addressed by institutional arrangements for flood hazards.     

Modeling distribution changes of vegetation in China under future climate change

Climatic change will result in great changes in vegetation. In this paper, a biogeographical model, the BIOME1, was used to predict potential vegetation distribution in China under climate change. Firstly, the BIOME1 was validated according to the climate–vegetation relationships in China. Kappa statistics showed that the validated BIOME1 was able to capture the geographical patterns of vegetation more accurately. Then, the validated BIOME1 was used to predict the distribution of vegetation of China under two climatic scenarios produced by a Regional Circulation Model, RegCM2/CN. The simulation results showed obvious northward shifts of the boreal, temperate deciduous and evergreen and tropical forests, a large expansion of tropical dry forest/savanna and reduction of tundra on the Tibetan Plateau. Three vulnerable regions sensitive to climate changes are pointed out, i.e., Northern China, the Tibetan Plateau and Southwestern China (mainly Hengduan Mountains in Yunnan Province and west of Sichuan Province). In recent decades, China has experienced dramatic industrialization and population growth, which exert strong pressure on the environment of China. The consequences of climate changes warrant more attention for maintaining a sustainable environment for China.     

持续农业的新发展--生态农村的建设

本文分析了现今农村影响农业持续发展的因素 ,提高建立高产优质高效生产体系以及提高资源利用率的技术措施和优化物质循环转化环节等三项生态村建设的必备条件与对策。阐述了全村总体型和家庭生态型二种建设模式的基本原理与设计原则 ,并详细介绍了城郊型生态村 ,山区型生态村 ,庭院型生态村模式。     

气相色谱法用ECD测定有机磷农药

选用固定液选择得当的色谱柱，采用ECD检测器测定有机磷农药的寒冷含量，能得到理想的测定效果。     

Copper uptake by four Elsholtzia ecotypes supplied with varying levels of copper in solution culture

The effects of copper (Cu) on the yield and Cu uptake of three ecotypes of Elsholtzia splendens and one of Elsholtzia argyi were studied using solution culture. Three Cu concentrations were compared: 0.31 (control), 50 and 100 micromol L(-1). Although E. argyi took up more Cu in the aboveground parts, typical visual symptoms of Cu toxicity appeared when the plants grew in 50 and 100 micromol Cu L(-1). In contrast, plants from all three populations of E. splendens showed high Cu tolerance and substantial shoot Cu accumulation of 58-144 mg kg(-1). Shoot Cu concentrations were about 16-27 times higher than root Cu concentrations. Root-to-shoot ratio of the E. argyi ecotype was halved when Cu was supplied at a level of 100 mg L(-1) compared to the control (0.31 mg L(-1)) but the ratio increased by 6-47% in the three E. splendens ecotypes. The increase in root-to-shoot ratio in E. splendens may be a mechanism by which the plants can tolerate high Cu concentrations. There were few differences in morphology among the three E. splendens ecotypes in response to added Cu. The results are discussed in relation to the possible use of E. splendens as a pioneer species in the phytostabilization of Cu-contaminated soils.     

中国水利水电工程开发与区域可持续发展

本文论述了中国水利水电工程开发与区域可持续发展的关系,并提出了中国实现可持续的水利水电工程开发的主要对策。     

活性炭纤维在机动车尾气净化中的研究与应用展望

机动车尾气净化控制的一个难点在于冷启动阶段,此时由于温度较低,催化剂尚未完全起作用,导致排出的污染物浓度较高。阐述了活性炭纤维的基本特性,特别是其低温吸附与催化性能对NO和CO的转化作用,讨论了活性炭纤维作为机动车尾气净化材料所需的改性及方法,并展望了其应用前景。