浅谈宁化县农业生态的问题及对策

宁化县农业生态工作存在的主要问题是：水土流失严重；森林植被屡遭破坏；耕地面积萎缩，地力下降；农业环境污染加重；农业气象灾害频繁。并针对此提出加强宣传教育，增强农业生态保护意识；保护和培育森林资源，搞好水土保持；切实保护耕地，防治环境污染；加强农业基本建设，增强农业抗灾能力的对策。     

环境土壤学——回顾与展望

环境土壤学是一门新兴的、土壤学和环境科学交叉融合的综合性学科，其研究重点从早期服务于农业安全生产发展至现在的土壤环境与健康，本文从土壤外源物质侵袭和土壤质量演变对土壤环境影响等方面回顾了环境土壤学发展历程。土壤污染物对土壤环境质量影响是以土壤元素背景值和环境现状调查为基础，以明确污染物形态，揭示土壤反应过程机制，评估污染效应，开展土壤环境修复工程为主线不断发展更新。土壤质量演变研究中碳、氮、硫、磷元素循环从土壤肥力和农业非点源污染的探讨拓展至土壤对全球气候变化的适应与响应；土壤退化研究则从对土壤生产力或功能丧失的研究发展至全球气候变化背景下农业发展可持续性及土壤生态功能的研究。环境土壤学在今后有四个重要发展趋势：提倡多学科交叉融合；评估全球气候变化对土壤元素循环的潜在影响；完善土壤健康评价框架中的土壤环境评价指标建立；学科发展服务于国家重大需求。     

BMPs在千岛湖流域农业非点源污染控制中的应用

农业非点源污染是最主要的一类非点源污染,也是成为构成目前水质环境恶化的一大威胁。通过对千岛湖流域农业非点源污染现状进行调查,指出非点源污染已成为千岛湖流域重要的污染来源。最佳管理措施(BMPs)通过工程措施、耕种措施和管理措施共同作用控制农业非点源污染,可以取得良好的经济环境效益。根据千岛湖流域农业非点源污染特点,针对性地提出各类非点源污染控制的最佳管理措施。     

植物基因工程对农业环境的潜在危险

植物基因是一种迅速发展的新型生物技术，在农作物育种中具有诱人的应用前景。但该技术以及转基因作物的大面积种植也存在一定的潜在危险性。文中从转基因向杂草传播、抗病毒转基因、害虫抗毒性和作物遗传资源儿方面讨论了植物基因工程对农业环境可能的不利影响，以引起有关方面的注意并采取相应的避害趋利措施。     

农业面源污染及其控制技术研究

水环境面源污染的严重性已受到国内外普遍关注，面源污染业已成为国际上水环境问题研究的活跃领域。从农业面源污染的发生机理和农业面源污染的特点出发，通过分析农业面源污染与水体环境之间的关系，探讨了农业面源污染对水环境的影响。对于面源污染的控制，最佳管理措施（BMPs）现已得到广泛应用。其中，人工湿地、前置库、缓冲带、水陆交错带、水土保持和农业生态工程等是目前研究和应用较多的农业面源污染控制技术。     

邯郸市畜禽养殖业环境现状及防治对策

目前畜禽养殖业产生的污染制约着农村环境的改善。通过对该市畜禽养殖业的环境管理现状及存在的主要环境问题进行了分析,提出了畜禽养殖业的污染防治对策,以实现农业生态系统的良性循环。     

中国水土流失的历史演变

以黑龙江省宾县县城水源地二龙山水库为例,阐述了水源污染状况,面源污染形成的过程、机理及来源和途径.分析了流域农业生产管理中的化肥和农药施用,农业生物质类废弃物利用管理和水土流失对水源污染的影响.从污染物的源头控制,迁移途径控制和水生态修复控制体系构建出发,提出了加强坡耕地农业生产管理、新农村建设工程、水土流失综合防治工程和河流廊道生态修复工程措施控制农业面源污染,实现人水和谐.     

论省级农业环境立法的必要性

土壤、水体、大气是农业生产的物质基础，但农业环境面临的生态破坏和污染给农业生产带来了巨大损失。根据社会发展进程和农业环境部门管理农业环境的职能，提出了加快省级农业环境立法的重要性。     

一种改进的土壤压实模型及试验研究

土壤压实现象普遍存在于农业生态系统中。土壤的压实效应不但会给农业生产带来不良的影响，还可能增加地表径流的产生，从而加快地表水的污染。 为了更好地研究压实土壤中的水分、溶质运移以及压实效应对农业生产及生态与环境的影响，该文在原有土壤压实模型的基础上提出了一种两参数改进模型，并以4种原状土壤为例，用离心机法对改进模型进行验证。研究结果表明：改进模型能够较好地模拟土壤的压实过程，且拟合效果好于L模型；虽然改进模型的物理意义和模型精度与Assouline的三参数模型相当，但是参数少、形式简单是改进模型的优势。同时，改进模型的提出对研究土壤水分特征曲线测定过程中的容重变化特性具有重要的参考价值。     

论环境保护与制度供给

人类经济活动不可避免地会对环境产生一定的影响。一方面，经济活动必须通过利用环境中的资源才能运行。另一方面，经济活动中排放的废弃物，也可能污染环境，造成环境质量恶化，从而制约经济的正常进行。反之，环境也会影响经济活动的良好循环。     

镉在甲壳类水生生物中的蓄积现状及赋存形态研究进展

镉（Cd）在联合国环境规划署提出的12种具有全球性意义的危害化学物质中居于首位,此类物质的污染危害主要表现在水环境中。与有机污染物不同的是,水环境中的镉不能通过水生生物降解,但会在其体内蓄积并通过食物链逐渐富集,进而对水产品质量和安全造成隐患,以及引起水环境污染和人类健康等问题,因此镉对水环境及水生生物的污染和危害引起全球范围内的广泛关注。本文整理归纳了目前镉在甲壳类水生生物中的蓄积现状及富集规律研究进展,并围绕梭子蟹和虾蛄这2种典型镉蓄积的甲壳类水生生物,论述其不同部位组织间镉蓄积的差异性问题,同时对目前关于镉形态的提取方法、定性分析和毒理学效应等相关研究进展进行了综述、分析和展望,可为甲壳类水产品中镉的形态甄别、定量分析以及不同形态镉的毒理学研究提供参考依据。     

转基因生物体对生态环境的影响及其发展趋向

转基因生物体包括转基因植物、动物和微生物。目前转基因生物体的研究主要集中于转基因植物与动物的研究。文中主要论述转基因植物对生态环境的影响及其发展趋势。对转基因植物对生态环境产生的影响和可能产生的后果进行了系统的分析，并且重点评述转基因植物对土壤生态系统及土壤微生态系统的影响及进展；对其影响的评价体系和今后的发展方向等有争议的问题进行了阐述并提出了新的思路。     

转基因生物体对生态环境的影响及其发展趋向

转基因生物体包括转基因植物、动物和微生物.目前转基因生物体的研究主要集中于转基因植物与动物的研究.文中主要论述转基因植物对生态环境的影响及其发展趋势.对转基因植物对生态环境产生的影响和可能产生的后果进行了系统的分析,并且重点评述转基因植物对土壤生态系统及土壤微生态系统的影响及进展;对其影响的评价体系和今后的发展方向等有争议的问题进行了阐述并提出了新的思路.     

逆境胁迫下植物MAPK级联反应途径研究新进展

MAPK级联反应途径是广泛存在于真核生物体内的信号传导途径,参与植物生长发育及对逆境胁迫的应答反应。目前已从植物中鉴定了多条MAPK级联反应途径以及多个MAPK级联途径激酶基因,但是对MAPK级联反应途径在逆境胁迫下作用机制的了解仍有很多不足。本文基于近年来国内外在基因组范围内对MAPK级联途径激酶基因的分析,介绍了植物基因组中MAPK级联途径激酶基因的数量和结构特点、激酶的结构特点、MAPK信号传导途径基因家族在逆境胁迫下的表达特性以及MAPK级联反应途径的研究方法等,以期为该领域的相关研究提供参考。     

Environmental fate and effects of Bacillus thuringiensis (Bt) proteins from transgenic crops: a review

This paper reviews the scientific literature addressing the environmental fate and nontarget effects of the Cry protein toxins from Bacillus thuringiensis (Bt), specifically resulting from their expression in transgenic crops. Published literature on analytical methodologies for the detection and quantification of the Cry proteins in environmental matrices is also reviewed, with discussion of the adequacy of the techniques for determining the persistence and mobility of the Bt proteins. In general, assessment of the nontarget effects of Bt protein toxins indicates that there is a low level of hazard to most groups of nontarget organisms, although some investigations are of limited ecological relevance. Some published reports on the persistence of the proteins in soil show short half-lives, whereas others show low-level residues lasting for many months. Improvements in analytical methods will allow a more complete understanding of the fate and significance of Bt proteins in the environment.     

Identification of marker genes for intestinal immunomodulating effect of a fructooligosaccharide by DNA microarray analysis

Prebiotic fructooligosaccharides are noted for their intestinal immunodulating effects, and the identification of markers for the effects is a matter of great concern. This study aimed to identify marker genes for physiological effects of a particular fructooligosaccharide (FOS) on a host animal and also to define the target of its function in the small intestine. DNA microarray technology was used to screen candidate marker genes, and comprehensive changes in gene expressions in the ileum of mice fed with FOS were investigated. One of the major physiological effects of FOS was intestinal immunomodulation. Marker genes were then identified for major histocompatibility complex classes I and II, interferon, and phosphatidylinositol metabolites. Also, the ileum was segmented into Peyer's patch (PP) and the other ileal organ (DeltaPP), and these were analyzed by quantitative RT-PCR method, with the result that the site for recognizing the FOS function was the DeltaPP rather than the PP. This is the first paper showing the markers for the physiological effects of FOS in the small intestine at gene expression level. Applying these marker genes would make it possible to clarify the mechanisms of how the administration of dietary FOS and associated changes in the intestinal environment are recognized by host organisms as well as how its immunomodulating effects are expressed in the body.     

Qualitative and quantitative detection of agricultural microorganisms expressing iturin and mop cyclase in soils

The environmental release of genetically engineered microorganisms (GEMs) to improve agriculture or remediate environmental hazards has raised concern over the fate of the organisms and their engineered genes. To detect the microorganisms released into the environment at the molecular level, Bacillus subtilis KB producing iturin and Pseudomonas fluorescens MX1 carrying the moc (mannityl opine catabolism) region from the Agrobacterium tumefaciens were employed as model microorganisms. Using specific fusion primers and the TaqMan probes, qualitative and quantitative detections of the model organisms by PCR and real-time PCR were conducted employing a small-scale soil-core device and pots during the six month period. The data indicate that the model bacteria can be easily detected by qualitative and quantitative methods in the test systems employed, and they do not give significant impacts on the other bacteria in soils on the Southern blotting analysis, although long-term observation may be needed.     

双酚A对植物影响的研究进展

双酚A(BPA),一种典型环境内分泌干扰物,也是工业生产树脂、塑料以及涂料的原料,在奶瓶、食品饮料包装、牙齿固封剂等材料中存在,因其大规模的生产和广泛使用,目前BPA在环境中已无所不在。近年来,国内外学者主要研究了BPA对动物的影响,而对植物影响的报道却相对较少。本文综述了BPA在植物体内的检测方法、对植物的影响(对种子萌发、植物地下器官、地上器官和藻类的影响等)、对植物影响的机理(对植物生长、光合作用和抗氧化系统的影响等)和植物修复等4个方面,并指出未来BPA对植物影响的研究重点,主要包括:植物代谢、细胞形貌和超微结构、矿质元素及信号转导等的研究,旨在为后续研究提供参考。     

Need for an "integrated safety assessment" of GMOs, linking food safety and environmental considerations

Evidence for substantial environmental influences on health and food safety comes from work with environmental health indicators which show that agroenvironmental practices have direct and indirect effects on human health, concluding that "the quality of the environment influences the quality and safety of foods" [Fennema, O. Environ. Health Perspect. 1990, 86, 229-232). In the field of genetically modified organisms (GMOs), Codex principles have been established for the assessment of GM food safety and the Cartagena Protocol on Biosafety outlines international principles for an environmental assessment of living modified organisms. Both concepts also contain starting points for an assessment of health/food safety effects of GMOs in cases when the environment is involved in the chain of events that could lead to hazards. The environment can act as a route of unintentional entry of GMOs into the food supply, such as in the case of gene flow via pollen or seeds from GM crops, but the environment can also be involved in changes of GMO-induced agricultural practices with relevance for health/food safety. Examples for this include potential regional changes of pesticide uses and reduction in pesticide poisonings resulting from the use of Bt crops or influences on immune responses via cross-reactivity. Clearly, modern methods of biotechnology in breeding are involved in the reasons behind the rapid reduction of local varieties in agrodiversity, which constitute an identified hazard for food safety and food security. The health/food safety assessment of GM foods in cases when the environment is involved needs to be informed by data from environmental assessment. Such data might be especially important for hazard identification and exposure assessment. International organizations working in these areas will very likely be needed to initiate and enable cooperation between those institutions responsible for the different assessments, as well as for exchange and analysis of information. An integrated assessment might help to focus and save capacities in highly technical areas such as molecular characterization or profiling, which are often necessary for both assessments. In the area of establishing international standards for traded foods, such as for the newly created Standards in Trade and Development Facility (STDF), an integrated assessment might help in the consideration of important environmental aspects involved in health and food safety. Furthermore, an established integrated view on GMOs may create greater consumer confidence in the technology.     

Copper toxicity and chemistry in the environment: a review

Copper compounds have been widely used in industrial processes and agriculture. As a result, elevated Cu concentrations can be found in certain areas of the biosphere. To better understand the toxicity of Cu to organisms it is necessary to understand the mechanism by which Cu influences biological and chemical processes in the environment. This review will examine Cu toxicity, microbial resistance mechanisms and factors influencing Cu speciation and toxicity in the environment