Carbonaceous aerosols in PM10 and pollution gases in winter in Beijing

An intensive observation of organic carbon (OC) and element carbon (EC) in PM10 and gaseous materials (SO2, CO, and O3,) was conducted continuously to assess the characteristics of wintertime carbonaceous aerosols in an urban area of Beijing, China. Results showed that the averaged total carbon (TC) and PM10 concentrations in observation period are 30.2±120.4 and 172.6±198.3 μ/m3, respectively. Average OC concentration in nighttime (24.9±19.6 μ/m3) was 40% higher than that in daytime (17.7±10.9 μ/m3). Average EC concentrations in daytime (8.8±15.2 μ/m3) was close to that in nighttime (8.9±15.1 μ/m3). The OC/EC ratios in nighttime ranging from 2.4 to 2.7 are higher than that in daytime ranging from 1.9 to 2.0. The concentrations of OC, EC, PM10 were low with strong winds and high with weak winds. The OC and EC were well correlated with PM10, CO and SO2, which implies they have similar sources. OC and EC were not well correlated with O3. By considering variation of OC/EC ratios in daytime and night time, correlations between OC and O3, and meteorological condition, we speculated that OC and EC in Beijing PM10 were emitted as the primary particulate form. Emission of motor vehicle with low OC/EC ratio and coal combustion sources with high OC/EC ratio are probably the dominant sources for carbonaceous aerosols in Beijing in winter. A simple method was used to estimate the relative contribution of sources to carbonaceous aerosols in Beijing PM10. Motor vehicle source accounts for 80% and 68%, while coal combustion accounts for 20% and 32% in daytime and nighttime, respectively in Beijing. Averagely, the motor vehicle and coal combustion accounted for 74% and 26%, respectively, for carbonaceous aerosols during the observation period. It points to the motor vehicle is dominant emission for carbonaceous aerosols in Beijing PM10 in winter period, which should be paid attention to control high level of PM10 in Beijing effectively.     

生物炭在农业增产和污染治理中的应用

生物炭(biochar)作为重要的碳汇、土壤重要的改良剂以及污染物有效地吸附剂受到了国内外研究人员的普遍关注。在阅读近几年国内外关于生物炭在农业增产和污染方面文献的基础上,作者总结了生物炭应用规律并提出一些未来研究的展望。表述如下:生物炭具有多孔性和巨大的表面积,它能够增加土壤的持水量、增加对营养元素的吸附以减少其流失并改善土壤的结构,此外生物炭本身含有丰富的营养元素并能够缓慢释放以供作物吸收,因此生物炭能改善土壤肥力并增加农作物产量。同时,生物炭巨大的吸附功能可以降低重金属和有机污染物在土壤及污水中的活性,起到降低污染物浓度的作用。因此生物炭在农业增产和减少污染方面有巨大的潜力。但是,到目前为止,对于生物炭很多的作用机制还未搞清楚,对不同种类生物炭性状、生物质在高温热解过程中内部化学成分和结构的变化、长期定位实验以及危害方面还应加强研究。对此,研究人员应该结合当地情况,尽多的用当地主要的动植物废料来生产生物炭以达到当地农业增产和治理污染的目的;其次,增加长期定位试验,找到适合当地的生物炭种类及其生产条件;另外还应增加对我国新疆、西藏等土壤贫瘠的偏远地区的研究,使当地的土壤更大程度的被利用以改善当地人民的生活;最后,当地政府及相关部门应该加大对生物炭研究的支持,使生物炭早日被普遍运用,造福百姓。     

填埋场古细菌垂直分布格局及其与垃圾降解程度响应特征

研究了青岛市小涧西垃圾填埋场表层（3~12 m）、中上层（15~24 m）、中下层（27~36 m）和底层（39~45 m）古细菌的多样性、群落组成与垂直分布特征,以及垃圾降解程度与古细菌群落结构演替变化的响应关系.结果表明：垃圾有机质和凯氏氮含量随填埋深度增加呈降低趋势,而pH呈微弱升高趋势.填埋场中下层的古细菌群落多样性和丰度显著高于其他填埋层.在填埋层各深度上,广古菌门（Euryarcharota）为优势菌门,相对丰度达到90%以上,甲烷微菌纲（Methanomicrobia）和热源体纲（Thermoplasmata）为优势菌纲,二者相对丰度之和达84.69%~99.67%.属水平上,甲烷囊菌属（Methanoculleus）的占比在38.16%~64.46%之间变化,且与有机质相关性不显著,表明该类氢营养型产甲烷菌在垃圾中分布广泛,受垃圾降解程度影响较小.马赛球菌属（Methanomassiliicoccus）的相对丰度自表层的50%降至底层的20%,且与有机质呈显著正相关（r=0.95,p<0.05）,表明该类甲基营养型产甲烷菌的分布受有机质降解程度影响较大.以乙酸裂解产甲烷的甲烷八叠球菌属（Methanosarcina）和甲烷丝菌属（Methanothrix）在填埋场中也占有重要地位,但二者相对丰度整体低于Methanoculleus.Methanosarcina自表层至底层所占比重逐渐升高,与有机质呈显著负相关（r=-0.96,p<0.05）;而Methanothrix仅在中下层有较高的丰度,与有机质相关性不显著,主要与两种菌属对乙酸亲和性的差异有关.不同填埋深度上产甲烷菌群落结构的演替变化反映了不同类型产甲烷菌对垃圾降解产物与稳定化程度的响应.     

A Global Conservation System for Climate-Change Adaptation

Abstract:  Climate change has created the need for a new strategic framework for conservation. This framework needs to include new protected areas that account for species range shifts and management that addresses large-scale change across international borders. Actions within the framework must be effective in international waters and across political frontiers and have the ability to accommodate large income and ability-to-pay discrepancies between countries. A global protected-area system responds to these needs. A fully implemented global system of protected areas will help in the transition to a new conservation paradigm robust to climate change and will ensure the integrity of the climate services provided by carbon sequestration from the world's natural habitats. The internationally coordinated response to climate change afforded by such a system could have significant cost savings relative to a system of climate adaptation that unfolds solely at a country level. Implementation of a global system is needed very soon because the effects of climate change on species and ecosystems are already well underway .     

Risk Assessment of Inbreeding and Outbreeding Depression in a Captive‐Breeding Program

Captive‐breeding programs can be implemented to preserve the genetic diversity of endangered populations such that the controlled release of captive‐bred individuals into the wild may promote recovery. A common difficulty, however, is that programs are founded with limited wild broodstock, and inbreeding can become increasingly difficult to avoid with successive generations in captivity. Program managers must choose between maintaining the genetic purity of populations, at the risk of inbreeding depression, or interbreeding populations, at the risk of outbreeding depression. We evaluate these relative risks in a captive‐breeding program for 3 endangered populations of Atlantic salmon (Salmo salar). In each of 2 years, we released juvenile F₁ and F₂ interpopulation hybrids, backcrosses, as well as inbred and noninbred within‐population crosstypes into 9 wild streams. Juvenile size and survival was quantified in each year. Few crosstype effects were observed, but interestingly, the relative fitness consequences of inbreeding and outbreeding varied from year to year. Temporal variation in environmental quality might have driven some of these annual differences, by exacerbating the importance of maternal effects on juvenile fitness in a year of low environmental quality and by affecting the severity of inbreeding depression differently in different years. Nonetheless, inbreeding was more consistently associated with a negative effect on fitness, whereas the consequences of outbreeding were less predictable. Considering the challenges associated with a sound risk assessment in the wild and given that the effect of inbreeding on fitness is relatively predictable, we suggest that risk can be weighted more strongly in terms of the probable outcome of outbreeding. Factors such as genetic similarities between populations and the number of generations in isolation can sometimes be used to assess outbreeding risk, in lieu of experimentation. Evaluación del Riesgo de Depresión por Endogamia y Exogamia en un Programa de Reproducción en Cautiverio     

沸石吸附-生物再生活性污泥工艺对比试验研究

介绍了沸石吸附-生物再生活性污泥工艺的对比试验研究结果,试验结果表明沸石可以进行生物再生,再生后的沸石对COD、氨氮的去除效果良好,对于沸石的生物再生效果而言,缺氧/好氧工艺的效果好于单一曝气工艺.     

Postfire Logging in Riparian Areas

Abstract:  We reviewed the behavior of wildfire in riparian zones, primarily in the western United States, and the potential ecological consequences of postfire logging. Fire behavior in riparian zones is complex, but many aquatic and riparian organisms exhibit a suite of adaptations that allow relatively rapid recovery after fire. Unless constrained by other factors, fish tend to rebound relatively quickly, usually within a decade after a wildfire. Additionally, fire and subsequent erosion events contribute wood and coarse sediment that can create and maintain productive aquatic habitats over time. The potential effects of postfire logging in riparian areas depend on the landscape context and disturbance history of a site; however, available evidence suggests two key management implications: (1) fire in riparian areas creates conditions that may not require intervention to sustain the long-term productivity of the aquatic network and (2) protection of burned riparian areas gives priority to what is left rather than what is removed. Research is needed to determine how postfire logging in riparian areas has affected the spread of invasive species and the vulnerability of upland forests to insect and disease outbreaks and how postfire logging will affect the frequency and behavior of future fires. The effectiveness of using postfire logging to restore desired riparian structure and function is therefore unproven, but such projects are gaining interest with the departure of forest conditions from those that existed prior to timber harvest, fire suppression, and climate change. In the absence of reliable information about the potential consequence of postfire timber harvest, we conclude that providing postfire riparian zones with the same environmental protections they received before they burned is justified ecologically. Without a commitment to monitor management experiments, the effects of postfire riparian logging will remain unknown and highly contentious.     

When Agendas Collide: Human Welfare and Biological Conservation

Abstract:  Conservation should benefit ecosystems, nonhuman organisms, and current and future human beings. Nevertheless, tension among these goals engenders potential ethical conflicts: conservationists' true motivations may differ from the justifications they offer for their activities, and conservation projects have the potential to disempower and oppress people. We reviewed the promise and deficiencies of integrating social, economic, and biological concerns into conservation, focusing on research in ecosystem services and efforts in community-based conservation. Despite much progress, neither paradigm provides a silver bullet for conservation's most pressing problems, and both require additional thought and modification to become maximally effective. We conclude that the following strategies are needed to make conservation more effective in our human-dominated world. (1) Conservation research needs to integrate with social scholarship in a more sophisticated manner. (2) Conservation must be informed by a detailed understanding of the spatial, temporal, and social distributions of costs and benefits of conservation efforts. Strategies should reflect this understanding, particularly by equitably distributing conservation's costs. (3) We must better acknowledge the social concerns that accompany biodiversity conservation; accordingly, sometimes we must argue for conservation for biodiversity's sake, not for its direct human benefits.     

A reactor system combining reductive dechlorination with cometabolic oxidation for complete degradation of tetrachloroentylene

A laboratory sequential anaerobic-aerobic bioreactor system, which consisted of an anaerobic fixed film reactor and two aerobic chemostats, was set up to degrade tetrachloroethylene (PCE) without accumulating highly toxic degradation intermediates. A soil enrichment culture, which could reductively dechlorinate 900/zM ( ca. 150 mg/L) of PCE stoichiometrically into cis-l, 2-dichloroethylene ( cis-DCE), was attached to ceramic media in the anaerobic fixed film reactor. A phenol degrading strain, Alcaligenes sp. 115, which can efficiently degrade cis-DCE by co-metabolic oxidation, was used as inocuhim for the aerobic chemostats consisted of a transformation reactor and a growth reactor.The anaerobic fixed film bioreactor showed more than 99 % of PCE transformation into cis-DCE in the range of influent PCE concentration from 5μM to 35μM at hydraulic retention time of 48h. On the other hand, efficient degradation of the resultant cis-DCE by strain R5 in the following aerobic system could not be achieved due to oxygen limitation. However, 54% of the maximum cis-DCE degradation was obtained when 10μmol of hydrogen peroxide (H2O2 ) was supplemented to the transformation reactor as an additional oxygen source. Further studies are needed to achieve more efficient co-metabolic degradation of cis-DCE in the aerobic reactor.