小尺度上蜜蜂传粉服务与耕地利用集约水平之间权衡关系研究

传粉作为重要的生态系统服务之一,对维持野生植物群落和粮食生产至关重要。近年来随着全球农业投入迅速增加,耕地利用集约化程度大幅提高,昆虫传粉能力受到严重影响。由于全世界约2/3的主要粮食作物依赖传粉服务,因此传粉服务的下降将威胁着全球粮食安全。然而,传粉服务与耕地利用集约水平的相互关系有待在全球各地区进行进一步验证,尤其在中国这种农业大国。以鄱阳湖滨湖区典型村落为研究对象,基于高精度土地利用数据、传粉蜜蜂生物物理数据、区域社会经济以及实地调研数据,采用InVEST模型、GIS分析工具、数理统计和回归分析方法。定量揭示小尺度上耕地集约利用与蜜蜂传粉服务之间的权衡关系。结果显示:(1)研究村落2000年和2013年蜜蜂传粉服务丰度平均值分别为0. 127和0. 108,期间下降幅度为15. 50%。总体上,研究村落蜜蜂传粉服务有较明显的削弱。(2)受退耕还林、退田还湖以及耕地撂荒等因素的综合影响,研究村落耕地利用区域减少了37. 66 hm~2,约占村落土地总面积的13. 55%。但由于农药、化肥、机械以及劳动力等投入的增加,该村各耕地利用类型的集约度分值均有大幅度提高,增幅均高达2倍以上。(3)耕地利用集约度变化与蜜蜂传粉服务变化回归系数为-0. 164,两者呈负相关关系,也即两者之间存在此消彼长的权衡关系。研究村落耕地利用集约度的提高削弱了蜜蜂传粉服务功能。     

Household preferences and willingness to pay (WTP) for freshwater quality improvement in Pakistan’s Swat River Valley

This two-part study investigates household preferences and willingness to pay (WTP) for water quality improvement of the Swat River in Pakistan. First, a four-point Likert scale was used to rank preferences for water quality benefits without using any financial metric. Results show that households have comparatively strong preferences for non-use benefits. Second, a contingent valuation question was designed to determine WTP for adopting a management plan developed exclusively for water quality improvement in the Swat River. The estimated annual mean WTP per household for water quality improvement is $2.40 when donating to an NGO. Generalizing this value to households living in Swat Valley would generate up to $544,000 per year. The present value aggregate benefit for 15 years would be sufficient to cover the present value of aggregate costs to adopt the management plan. A mandatory program that would require paying for the management plan generates half the WTP compared to the voluntary plan, but is still sufficient to cover costs and may be more feasible than a voluntary program because payment is assured.     

Plasticity in metamorphic traits of <Emphasis Type="Italic">Rana kukunoris</Emphasis> tadpoles: The interactive effects of food level and rearing temperature

Larval amphibians are particularly likely to encounter variation in rearing temperature and resource availability due to variation in aquatic breeding habitats. In this study, plasticity in growth rates, larval mass, larval period, and size at metamorphosis were examined in Rana kukunoris Nikolskii, 1918 under different combinations of temperature and food level. Larval period and larval body mass was sensitive to food level, and varied with temperature. Tadpoles metamorphosed at an older age at low temperature than those reared at warm temperature. Food level was a significant affect on larval period at low temperature, but not at warm temperature. Mass was heavier for tadpoles reared at low temperatures than those reared at warm temperatures. The effect of food level depended on temperature, because larvae reared at low temperature that were offered a high food level achieved a larger size than larvae offered a low food level, but this did not occur at warm temperature. Therefore, we suggest that high food availability at low temperature prolonged developmental periods, thus larvae are larger as metamorphs than those reared at warm temperatures.     

Climate change adaptation strategies for transportation infrastructure in Prince George,Canada

Transport infrastructure is particularly vulnerable to climate impacts as it is designed for long operational lives, and both episodic and seasonal conditions contribute to deterioration, disruption and unsafe incidents. There are some examples of adaptation in transportation design, but many communities do not have the capacity to incorporate climate change considerations into infrastructure planning and management. Researchers worked closely with the City of Prince George, in Central British Columbia, Canada, to build on existing work and explore how the City could plan, design, and maintain roads and other structures to account for climate change. A local steering committee was formed, and created and evaluated 23 potential research topics. Two focus areas were selected for further investigation and explored during a workshop with practitioners, researchers, consultants and other representatives. The workshop precipitated an investigation of projected impacts of climate change on road maintenance and road safety, and plans to explore alternative paving techniques. Outcomes of the case study provide insights regarding climate change and local transportation infrastructure, including: how researchers can engage with local experts to explore adaptation; issues local governments perceive as important; and barriers communities face as they attempt to address vulnerabilities.     

Twentieth century droughts and agriculture: Examples from impacts on soybean production in Kentucky,USA

Drought is a significant natural hazard that slowly evolves over time. Because of its character, drought is difficult to monitor and impacts are often poorly documented. Agriculture is one of the most sensitive sectors that are prone to drought. The objective of this research is to assess the impacts of drought on soybean production and revenue in Kentucky. Soybeans are one of Kentucky’s most important commodities. In this study, impacts of 1930–1931, 1940–1942, 1952–1955, 1987–1988, 1999–2000, and 2007 droughts were considered. It was found that over the recent years, up to 56 % of the revenue from soybeans was lost due to drought. During the first half of the twentieth century, revenue loss reached up to 77 %. This research is valuable to the general public as well as planners and policy makers. Proper documentation of impacts of past droughts will help identify drought vulnerabilities and results in better risk management and mitigation.     

MnO_2/Al_2O_3吸附草甘膦及微波紫外耦合降解再生工艺

以掺混煅烧法制备Mn O2/Al2O3,并对草甘膦进行吸附,将吸附态草甘膦置于微波紫外耦合系统中进行降解和再生。研究并给出了Mn O2/Al2O3的最佳制备条件、最佳吸附条件和微波紫外耦合降解再生的最佳工艺参数。Mn O2/Al2O3最佳制备条件为Mn O2质量分数15%,煅烧温度500℃,煅烧时间2 h。在常温下,Mn O2/Al2O3对草甘膦的最大吸附量为75 mg/g。微波紫外耦合系统最佳工艺参数为功率500 W,时间25 min,空气量0.06 m3/h。在此操作条件下,Mn O2/Al2O3的再生率达到85%,并且可以多次再生利用,草甘膦最终降解产物为二氧化碳、氮氧化物、磷酸和水,矿化率为65%。     

Fe~(3+)和Cu~(2+)对饮用水氯消毒副产物三卤甲烷形成的影响

为了研究水中存在Br-的情况下,Fe3+和Cu2+对三卤甲烷(THMs)的生成及CHCl3、CHBr Cl2、CHBr2Cl、CHBr34种消毒副产物相对分布的影响,以腐殖酸模拟氯消毒过程中的前体物进行实验。结果表明,在p H为6、7和9 3种条件下,Fe3+抑制了THMs的生成,p H=6时只有CHCl3生成量随着Fe3+浓度的增加逐渐减少,其余3种消毒副产物均在增加,p H=7时4种消毒副产物浓度均减小并在Fe3+浓度为2 mg/L时生成量最低,p H=9时的生成趋势与p H=6时类似。Cu2+能促进THMs的生成,在p H为6、7和9时,当加入0.5 mg/L Cu2+时,THMs总量分别增加了16.7%、22.6%和2.5%,随着p H增加,THMs总量增加。在3种p H环境中,Cu2+对THMs生成的影响大于Fe3+,在偏酸性环境中,Fe3+影响THMs生成,产生的致癌风险高,当金属离子浓度为2.5 mg/L时,致癌风险相差最高为15%,在中性和偏碱性环境中,Cu2+影响THMs生成,产生的致癌风险高。     

密相塔半干法烟气脱硫塔内加湿降温及其对脱硫效率的影响

为了实现密相塔半干法脱硫工艺的精确加湿进一步提高系统脱硫效率,利用推导出的传热传质计算方法,得到烟气温度降低和加水量的关系.结合3组密相塔半干法工程实际数据,发现理论计算值和实测值误差区间仅为2.9％ ～5.4％.通过选取河北某钢厂210 m2烧结烟气密相塔半干法脱硫项目实际在线检测数据,发现循环脱硫灰含湿量为3％的系统脱硫效率整体高于含湿量为5％和4％的样品,最大值达93.56％.通过粒度分析、扫描电镜、X射线衍射及差热-热重对2种不同含湿量的循环脱硫灰进行表征,结果表明,含湿量为3％的循环脱硫灰较含湿量为5％的样品粒径小、比表面积大,无团聚现象,物相分析还证实相对于含湿量为5％样品,其Ca(OH)2和结晶水含量少,几乎都是CaSO4和CaS03干态物质,因此脱硫反应进行彻底,脱硫效率较高.     

纳米晶粒TiO2多孔微球的制备及其光催化性能的研究进展

介绍了纳米晶粒TiO2多孔微球的主要制备方法、主要参量及表征、光催化性能研究进展,指出了纳米晶粒TiO2多孔微球制备过程的技术关键与基本参量的功能。针对目前存在的问题,提出了今后的主要研究方向,并展望了纳米晶粒TiO2多孔微球在水处理领域的应用前景。