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61.
2株苯胺降解的分离鉴定及其降解特性研究   总被引:8,自引:0,他引:8  
任随周  郭俊  曾国驱  岑英华  孙国萍 《环境科学》2006,27(12):2525-2430
从处理印染废水的活性污泥中分离得到2株苯胺降解菌,从菌落、细胞形态、生理生化及16S rRNA基因扩增测序等方面对2株菌进行了鉴定,并比较分析2株菌在好氧与缺氧条件下的苯胺降解、偶氮染料脱色及苯胺脱氨氧化酶基因tdnQ和黄素还原酶基因(fre)的携带情况.结果表明,2株菌属于Pseudomonas属和Shewanella属,分别命名为Pseudomonas sp.AN30和Shewanella sp.DN425.AN30菌株在振荡好氧条件下72h内对250mg/L苯胺的降解率为96.1%,DN425菌株的降解率为13.8%;在静置缺氧条件下AN30菌株的苯胺降解率为39.6%,DN425菌株的降解率仅为8.6%.DN425菌株在静置缺氧条件下4h内可将初始浓度为50 mg/L的偶氮染料酸性大红彻底脱色,而AN30菌株对酸性大红不具有脱色能力.以总DNA为模板,分别用tdnQ基因和fre基因特异性引物进行扩增,2株菌均能扩增出大小分别为380bp和630bp左右的目标条带,显示2菌株均携带有苯胺脱氨氧化酶基因和黄素还原酶基因.  相似文献   
62.
华西雨屏区不同密度巨桉人工林土壤呼吸特征   总被引:9,自引:0,他引:9  
从2008-03至2009-02,采用闭合动态法(LI-6400-09)对华西雨屏区不同密度中龄巨桉人工林土壤呼吸进行了研究。结果表明:①该林分土壤呼吸具有明显的季节动态,各密度林分土壤呼吸速率最高值均出现在7月份,最低出现在1月,且密度为883株·hm-2(1.5 m×8 m)的巨桉林土壤呼吸速率最大,2 222株·hm-2(1.5 m×3 m)的最小;②2008年4、7、10月土壤呼吸速率24 h平均值均表现为883株·hm-2> 1 333株·hm-2> 2 222株·hm-2,且7月>4月>10月;③土壤微生物生物量碳氮、土壤有机质含量和10 cm根系生物量都表现出相同的趋势,即林分密度越小,土壤微生物生物量碳氮越高,草本植物越多,根系生物量越大,有机质含量越多;④温度是巨桉林土壤呼吸变异的主导因子,土壤呼吸速率与土壤温度和湿度的双因素模型优于单因素模型,两者共同解释了土壤呼吸速率月动态的78.3%~91.5%;⑤各密度林分土壤呼吸Q10值随巨桉林分密度增大而降低,大小顺序为3.65(883株·hm-2)>2.60(1 333株·hm-2)>2.55(2 222株·hm-2)。  相似文献   
63.
We formally study the determinants, magnitude and distribution of efficiency gains generated in multilateral linkages between permit markets. We provide two novel decomposition results for these gains, characterize individual preferences over linking groups and show that our results are largely unaltered with strategic domestic emissions cap selection or when banking and borrowing are allowed. Using the Paris Agreement pledges and power sector emissions data of five countries which all use or considered using both emissions trading and linking, we quantify the efficiency gains. We find that the computed gains can be sizable and are split roughly equally between effort and risk sharing.  相似文献   
64.
Protected areas (PAs) are a frequently used conservation strategy, yet their socioeconomic impacts on local communities remain contentious. A shift toward increased participation by local communities in PA governance seeks to deliver benefits for human well‐being and biodiversity. Although participation is considered critical to the success of PAs, few researchers have investigated individuals’ decisions to participate and what this means for how local people experience the costs and benefits of conservation. We explored who participates in PA governance associations and why; the perceived benefits and costs to participation; and how costs and benefits are distributed within and between communities. Methods included 3 focus groups, 37 interviews, and 217 questionnaire surveys conducted in 3 communities and other stakeholders (e.g., employees of a nongovernmental organization and government officials) in PA governance in Madagascar. Our study design was grounded in the theory of planned behavior (TPB), the most commonly applied behavior model in social psychology. Participation in PA governance was limited by miscommunication and lack of knowledge about who could get involved and how. Respondents perceived limited benefits and high costs and uneven distribution of these within and between communities. Men, poorer households, and people in remote villages reported the highest costs. Our findings illustrate challenges related to comanagement of PAs: understanding the heterogeneous nature of communities; ensuring all households are represented in governance participation; understanding differences in the meaning of forest protection; and targeting interventions to reach households most in need to avoid elite capture.  相似文献   
65.
Success of animal translocations depends on improving postrelease demographic rates toward establishment and subsequent growth of released populations. Short‐term metrics for evaluating translocation success and its drivers, like postrelease survival and fecundity, are unlikely to represent longer‐term outcomes. We used information theory to investigate 25 years of data on black rhinoceros (Diceros bicornis) translocations. We used the offspring recruitment rate (ORR) of translocated females—a metric integrating survival, fecundity, and offspring recruitment at sexual maturity—to detect determinants of success. Our unambiguously best model (AICω = 0.986) predicted that ORR increases with female age at release as a function of lower postrelease adult rhinoceros sex ratio (males:females). Delay of first postrelease reproduction and failure of some females to recruit any calves to sexual maturity most influenced the pattern of ORRs, and the leading causes of recruitment failure were postrelease female death (23% of all females) and failure to calve (24% of surviving females). We recommend translocating older females (≥6 years old) because they do not exhibit the reproductive delay and low ORRs of juveniles (<4 years old) or the higher rates of recruitment failure of juveniles and young adults (4–5.9 years old). Where translocation of juveniles is necessary, they should be released into female‐biased populations, where they have higher ORRs. Our study offers the unique advantage of a long‐term analysis across a large number of replicate populations—a science‐by‐management experiment as a proxy for a manipulative experiment, and a rare opportunity, particularly for a large, critically endangered taxon such as the black rhinoceros. Our findings differ from previous recommendations, reinforce the importance of long‐term data sets and comprehensive metrics of translocation success, and suggest attention be shifted from ecological to social constraints on population growth and species recovery, particularly when translocating species with polygynous breeding systems.  相似文献   
66.
钾素Q/I特性是表征土壤钾素状况的一个重要指标,它能同时度量土壤钾素的强度和容量.本文研究了广东不同质地水稻土Q/I特性与大田钾肥施用技术的关系.结果表明:(1)不同质地土壤的Q/1曲线差异明显,砂土类曲线较平缓.粘土类曲线较陡。(2)PBCk与土壤粘粒含量呈极显著正相关(r=0.653).(3)-△K0与作物相对百分产量呈极显著正相关(r=0.873),可作为预测当季作物需钾量的参数.(4)AR_e ̄k与土壤粘粒含量呈显著负相关(r=-0.520),AR_e ̄k的大小可作为钾肥合理分配的依据.  相似文献   
67.
In evaluating current environmental protection policy, economists often note that current regulations are more costly than necessary to meet environmental quality standards. While the a priori case is strong that current regulatory approaches are resulting in higher-than-necessary costs to attain environmental standards, there is relatively little empirical evidence to support this claim. The purpose of this paper is to supply some of the missing evidence by presenting the results of one study that assesses some of the potential savings associated with implementing economic, rather than command-and-control, regulatory approaches to abate one type of air pollution in one region of the country. Specifically, the paper examines the costs of meeting a prospective short-term standard for nitrogen dioxide under a range of alternative emissions control strategies for stationary sources of nitrogen oxide emissions in the Chicago Air Quality Control Region. The alternative strategies that are considered range from those that might result under current regulatory policy to those that economic policy approaches (such as emissions charges or marketable permits) are designed to implement. The analysis shows that the most efficient program of emissions controls may be more than an order of magnitude less costly than current regulatory strategies, and that economic approaches have additional advantages over more conventional regulatory approaches.  相似文献   
68.
Cinema offers a substantial opportunity to share messages with a wide audience. However, there is little research or evidence about the potential benefits and risks of cinema for conservation. Given their global reach, cinematic representations could be important in raising awareness of conservation issues and species of concern, as well as encouraging greater audience engagement due to their heightened emotional impact on viewers. Yet there are also risks associated with increased exposure, including heightened visitor pressure to environmentally sensitive areas or changes to consumer demand for endangered species. Conservationists can better understand and engage with the film industry by studying the impact of movies on audience awareness and behavior, identifying measurable impacts on conservation outcomes, and engaging directly with the movie industry, for example, in an advisory capacity. This improved understanding and engagement can harness the industry's potential to enhance the positive impacts of movies featuring species, sites, and issues of conservation concern and to mitigate any negative effects. A robust evidence base for evaluating and planning these engagements, and for informing related policy and management decisions, needs to be built.  相似文献   
69.
Stopping declines in biodiversity is critically important, but it is only a first step toward achieving more ambitious conservation goals. The absence of an objective and practical definition of species recovery that is applicable across taxonomic groups leads to inconsistent targets in recovery plans and frustrates reporting and maximization of conservation impact. We devised a framework for comprehensively assessing species recovery and conservation success. We propose a definition of a fully recovered species that emphasizes viability, ecological functionality, and representation; and use counterfactual approaches to quantify degree of recovery. This allowed us to calculate a set of 4 conservation metrics that demonstrate impacts of conservation efforts to date (conservation legacy); identify dependence of a species on conservation actions (conservation dependence); quantify expected gains resulting from conservation action in the medium term (conservation gain); and specify requirements to achieve maximum plausible recovery over the long term (recovery potential). These metrics can incentivize the establishment and achievement of ambitious conservation targets. We illustrate their use by applying the framework to a vertebrate, an invertebrate, and a woody and an herbaceous plant. Our approach is a preliminary framework for an International Union for Conservation of Nature (IUCN) Green List of Species, which was mandated by a resolution of IUCN members in 2012. Although there are several challenges in applying our proposed framework to a wide range of species, we believe its further development, implementation, and integration with the IUCN Red List of Threatened Species will help catalyze a positive and ambitious vision for conservation that will drive sustained conservation action.  相似文献   
70.
In an analytical model of symmetric countries with mobile capital and local or transboundary pollution we investigate whether competition in emissions taxes (or emissions caps) and capital taxes leads to efficient outcomes when governments act strategically. When they have capital taxes and emissions caps at their disposal, they refrain from taxing capital and set their caps inefficiently lax [efficient] for transboundary [local] pollution. When they have the option to tax capital and emissions, capital is subsidized [untaxed] and emissions taxes are inefficiently low [efficient] for transboundary [local] pollution. In case of transboundary pollution emissions caps are Pareto-superior to emissions taxes. That holds regardless of whether the environmental policy is applied as stand-alone policy or combined with capital tax competition.  相似文献   
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