哈尔滨等几个城市气候变化的对比分析

应用距平分析和Morlet小波变换方法对哈尔滨、石家庄、武汉、广州等4个城市1951—2004年的年均气温和夏季降水进行了对比分析，结果发现，这4个城市：（1）近50多a来气温基本上都是呈逐渐升温趋势，升温幅度都在1℃以上，其中哈尔滨的气温年变化比其他3个城市剧烈；（2）气温年代际演变特征非常明显，存在10～25a尺度的变化，在20世纪80年代前期发生气候突变；（3）近50多a夏季降水变化趋势不太一致，在空间分布上表现为波列特征；（4）夏季降水年代际变化特征非常明显，都存在10a左右尺度变化；（5）降水变化趋势与气温变化趋势不一致。     

Assessing the vulnerability of rare plants using climate change velocity,habitat connectivity,and dispersal ability: a case study in Alberta,Canada

Climate change generally requires species to migrate northward or to higher elevation to maintain constant climate conditions, but migration requirement and migration capacity of individual species can vary greatly. Individual populations of species occupy different positions in the landscape that determine their required range shift to maintain similar climate, and likewise the migration capacity depends on habitat connectivity. Here, we demonstrate an approach to quantifying species vulnerabilities to climate change for 419 rare vascular plants in Alberta, Canada, based on a multivariate velocity of climate change metric, local habitat fragmentation, and migration capacity. Climate change velocities indicated that future migration requirements ranged from 1 to 5 km/year in topographically complex landscapes, such as the Alberta Foothills and Rocky Mountains. In contrast, migration requirements to maintain constant climate in relatively flat Boreal Plains, Parkland, and Grassland ranged from 4 to 8 km/year. Habitat fragmentation was also highest in these flat regions, particularly the Parkland Natural Region. Of the 419 rare vascular plants assessed, 36 were globally threatened (G1–G3 ranking). Three globally threatened species were ranked as extremely vulnerable and five species as highly vulnerable to the interactions among climate change velocity, habitat fragmentation, and migration capacity. Incorporating dispersal characteristics and habitat fragmentation with local patterns in climate change velocity improves the assessment of climate change threats to species and may be applied to guide monitoring efforts or conservation actions.     

When experts disagree: the need to rethink indicator selection for assessing sustainability of agriculture

Sustainability indicators are well recognized for their potential to assess and monitor sustainable development of agricultural systems. A large number of indicators are proposed in various sustainability assessment frameworks, which raises concerns regarding the validity of approaches, usefulness and trust in such frameworks. Selecting indicators requires transparent and well-defined procedures to ensure the relevance and validity of sustainability assessments. The objective of this study, therefore, was to determine whether experts agree on which criteria are most important in the selection of indicators and indicator sets for robust sustainability assessments. Two groups of experts (Temperate Agriculture Research Network and New Zealand Sustainability Dashboard) were asked to rank the relative importance of eleven criteria for selecting individual indicators and of nine criteria for balancing a collective set of indicators. Both ranking surveys reveal a startling lack of consensus amongst experts about how best to measure agricultural sustainability and call for a radical rethink about how complementary approaches to sustainability assessments are used alongside each other to ensure a plurality of views and maximum collaboration and trust amongst stakeholders. To improve the transparency, relevance and robustness of sustainable assessments, the context of the sustainability assessment, including prioritizations of selection criteria for indicator selection, must be accounted for. A collaborative design process will enhance the acceptance of diverse values and prioritizations embedded in sustainability assessments. The process by which indicators and sustainability frameworks are established may be a much more important determinant of their success than the final shape of the assessment tools. Such an emphasis on process would make assessments more transparent, transformative and enduring.     

海洋环境中光合色素分析方法研究与应用进展

根据国内外的文献,综述了海洋环境中光合色素分析方法的发展状况,指出了其分析方法在发展过程中创新的主要方面,并对光合色素分析在赤潮监测、藻类的化学分类及生物碳生物量和矿物质通量方面的应用进行了展望。     

改性氢氧化镁制备及其去除地下水中Cr3+性能研究

氢氧化镁作为一种可缓慢释放OH-的碱,能使多数重金属离子转换为沉淀,而且不会引起太大的pH变化.但氢氧化镁难溶于水,在含水层中的迁移能力很差.若要用于地下水重金属污染修复,需要对氢氧化镁进行改性.因此,本文利用表面活性剂对氢氧化镁粉末进行改性,合成了氢氧化镁胶体,并对改性氢氧化镁的稳定性、粒度及其对Cr3+的稳定化效果进行了分析.结果表明,复配表面活性剂改性的氢氧化镁悬浮液稳定性好,粒径小,0.6~8.4μm的颗粒占82.41%.利用改性氢氧化镁对Cr3+污染地下水进行处理,其对Cr3+的去除机理主要为沉淀反应,氢氧化镁和Cr3+反应的质量比约为1.333∶1,氢氧化镁和初始Cr3+浓度对Cr3+的去除效果都有较大的影响.     

Myrothecium verrucaria NF-08产漆酶条件的响应面法优化及粗酶染料脱色研究

以半知菌属疣孢漆斑菌Myrothecium verrucaria NF-08为供试菌,采用响应面方法优化菌株产漆酶条件,并以其漆酶粗酶进行3种结构类型6种染料的脱色试验,考察了粗酶浓度、温度和p H值对脱色率的影响.两水平析因设计、中心组合设计和验证试验结果表明:葡萄糖浓度为15.4 g·L~(-1)、蛋白胨浓度为43.3 g·L~(-1)和培养基初始p H值为6.68时,漆酶活性达到最大值(25.58±1.60)U·m L~(-1),是单因素试验(16.82 U·m L~(-1))的1.52倍,提高了52.1%.以上述发酵条件获得的M.verrucaria NF-08漆酶粗酶对3种结构类型染料均有脱色效果,排序为偶氮类优于芳甲烷类优于蒽醌类.脱色率随粗酶浓度增大(2~8 U·m L~(-1))、反应温度升高(15~35℃)而上升,随p H值上升(4~10)而下降.粗酶浓度为5 U·m L~(-1),反应温度为25℃,p H值为4时,偶氮类染料铬黑T和芳甲烷类染料碱性品红即可几乎完全脱色,脱色率分别为99.2%和94.6%.     

Current issues and uncertainties in the measurement and modelling of air-vegetation exchange and within-plant processing of POPs

Air-vegetation exchange of POPs is an important process controlling the entry of POPs into terrestrial food chains, and may also have a significant effect on the global movement of these compounds. Many factors affect the air-vegetation transfer including: the physicochemical properties of the compounds of interest; environmental factors such as temperature, wind speed, humidity and light conditions; and plant characteristics such as functional type, leaf surface area, cuticular structure, and leaf longevity. The purpose of this review is to quantify the effects these differences might have on air/plant exchange of POPs, and to point out the major gaps in the knowledge of this subject that require further research. Uptake mechanisms are complicated, with the role of each factor in controlling partitioning, fate and behaviour process still not fully understood. Consequently, current models of air-vegetation exchange do not incorporate variability in these factors, with the exception of temperature. These models instead rely on using average values for a number of environmental factors (e.g. plant lipid content, surface area), ignoring the large variations in these values. The available models suggest that boundary layer conductance is of key importance in the uptake of POPs, although large uncertainties in the cuticular pathway prevents confirmation of this with any degree of certainty, and experimental data seems to show plant-side resistance to be important. Models are usually based on the assumption that POP uptake occurs through the lipophilic cuticle which covers aerial surfaces of plants. However, some authors have recently attached greater importance to the stomatal route of entry into the leaf for gas phase compounds. There is a need for greater mechanistic understanding of air-plant exchange and the 'scaling' of factors affecting it. The review also suggests a number of key variables that researchers should measure in their experiments to allow comparisons to be made between studies in order to improve our understanding of what causes any differences in measured data between sites.     

Isolation of mesotrione-degrading bacteria from aquatic environments in Brazil

Mesotrione is a benzoylcyclohexane-1,3-dione herbicide that inhibits 4-hydroxyphenyl pyruvate dioxygenase in target plants. Although it has been used since 2000, only a limited number of degrading microorganisms have been reported. Mesotrione-degrading bacteria were selected among strains isolated from Brazilian aquatic environments, located near corn fields treated with this herbicide. Pantoea ananatis was found to rapidly and completely degrade mesotrione. Mesotrione did not serve as a sole C, N, or S source for growth of P. ananatis, and mesotrione catabolism required glucose supplementation to minimal media. LC-MS/MS analyses indicated that mesotrione degradation produced intermediates other than 2-amino-4-methylsulfonyl benzoic acid or 4-methylsulfonyl-2-nitrobenzoic acid, two metabolites previously identified in a mesotrione-degrading Bacillus strain. Since P. ananatis rapidly degraded mesotrione, this strain might be useful for bioremediation purposes.     

The variability and intrinsic remediation of a BTEX plume in anaerobic sulphate-rich groundwater

Data from long-term groundwater sampling, limited coring, and associated studies are synthesised to assess the variability and intrinsic remediation/natural attenuation of a dissolved hydrocarbon plume in sulphate-rich anaerobic groundwater. Fine vertical scale (0.25- and 0.5-m depth intervals) and horizontal plume-scale (>400 m) characteristics of the plume were mapped over a 5-year period from 1991 to 1996. The plume of dissolved BTEX (benzene, toluene, ethylbenzene, xylene) and other organic compounds originated from leakage of gasoline from a subsurface fuel storage tank. The plume was up to 420 m long, less than 50 m wide and 3 m thick. In the first few years of monitoring, BTEX concentrations near the point of leakage were in approximate equilibrium with non-aqueous phase liquid (NAPL) gasoline. NAPL composition of core material and long-term trends in ratios of BTEX concentrations in groundwater indicated significant depletion (water washing, volatilisation and possibly biodegradation) of benzene from residual NAPL after 1992. Large fluctuations in BTEX concentrations in individual boreholes were shown to be largely attributable to seasonal groundwater flow variations. A combination of temporal and spatial groundwater quality data was required to adequately assess the stationarity of plumes, so as to allow inference of intrinsic remediation. Contoured concentration data for the period 1991 to 1996 indicated that plumes of toluene and o-xylene were, at best, only partially steady state (pseudo-steady state) due to seasonal groundwater flow changes. From this analysis, it was inferred that significant remediation by natural biodegradation was occurring for BTEX component plumes such as toluene and o-xylene, but provided no conclusive evidence of benzene biodegradation. Issues associated with field quantification of intrinsic remediation from groundwater sampling are highlighted. Preferential intrinsic biodegradation of selected organic compounds within the BTEX plume was shown to be occurring, in parallel with sulphate reduction and bicarbonate production. Ratios of average hydrocarbon concentrations to benzene for the period 1991 to 1992 were used to estimate degradation rates (half-lives) at various distances along the plume. The estimates varied with distance, the narrowest range being, for toluene, 110 to 260 days. These estimates were comparable to rates determined previously from an in situ tracer test and from plume-scale modelling.