森林生态系统研究中几个重要方面的进展

本文对森林生态系统研究中几个重要方面的进展进行了综述,包括森林细根生物量与生产力、调落物、粗死木质残体和森林降水化学等。对今后这些方面研究中的重点内容与趋势进行了评述。     

基于区域植被类型评估的气候变化对中国森林生态系统的影响

基于中国知网(CNKI)和学术Google主题词为“气候变化”与“森林”的科技文献,根据全国范围的不同区域植被类型,运用整合分析方法就气候变化对森林生态系统的影响进行了系统评估,结果表明:在观测到的影响中,各个区域植被类型的树木物候、森林生产力与森林火灾方面的影响趋势大体相同,但森林地理分布影响趋势存在一定的差异;在预计的可能影响中,各个区域植被类型的树木物候、森林生产力、森林碳储量、森林火灾方面的影响趋势大体相同,但森林地理分布、森林结构方面的影响存在一定的差异.最后对现有研究的不足及未来研究方向等进行了讨论和展望.     

中国城市森林研究现状及发展趋势

工业的发展与人口剧增使城市环境不断恶化 ,引起人们对生活空间质量日益关注与重视。城市森林作为解决城市环境问题的有效途径而得到广泛研究。为推进城市森林的进一步研究 ,本文阐明了城市森林的概念、性质、分类及范围 ,并从城市森林的研究方法、结构、功能、维护管理与规划建设等几方面 ,对我国城市森林的研究现状、存在的问题及发展趋势进行了探讨。     

森林生态系统水文调节功能及机制研究进展

本研究从森林生态系统的水文过程出发,介绍了其相关概念及发展史,总结了目前森林生态水文学的研究成果,对森林生态系统不同界面层(林冠层、枯落物层及土壤层)的水文过程、影响因素及生态水文模型等方面的国内外研究进展进行了系统的阐述,同时也对森林生态系统的水土保持、水质净化和物质循环过程进行了归纳和总结。目前的研究还需要从以下几方面加以深入:(1)森林生态系统不同界面层(林冠层、枯落物层及土壤层)功能性状与环境因子对流域水分储蓄、循环、入渗与产流过程的影响及其机理;(2)森林生态系统水土保持、水质净化、元素循环三者之间耦合机制方面的研究;(3)森林生态系统的水文过程与能量流动、物质循环之间的相互关系;(4)在时间尺度和流域尺度上研究森林生态系统生态水文过程的变化情况。因此,今后的研究应加强对森林生态系统多学科、多尺度的综合研究,同时要结合现代高新技术方法来研究不同植被类型的功能性状对水文过程的影响及其机制,为森林生态系统的管理提供科学依据。     

森林康养:概念内涵、产品类型和发展路径

健康中国战略已经上升为国家战略,健康产业将在中国快速发展。森林康养作为健康产业的重要组成部分,是近几年才在中国出现的新事物,正处在不断摸索前进中的起步阶段。在分析现有森林康养定义的基础上,对森林康养的概念、功能和科学内涵进行了阐释,并从消费对象、产品内容、建设主体等方面对森林康养产品进行了分类。对森林康养发展的基本路径进行了设计,加强森林康养产业发展的宏观统筹,构建良好的森林康养发展机制,打造特色森林康养产品、建设森林康养综合体,加强科研监测和人才队伍建设,构建完善的配套设施、提供优质的森林康养服务,加强宣传和营销、提升森林康养品牌知名度。最后,从森林康养内涵和外延研究、森林康养试点示范、森林康养基地与现有森林旅游实体或保护地关系、森林康养基地建设评价、森林康养发展与森林保护关系等方面进行了讨论。     

露水河林业局森林多目标经营规划设计

改变单一经营目标的传统森林经营方式,进行森林多目标经营,综合发挥森林的生态、社会与经济功能是我国林业发展的一个新阶段。如何从一个生产单位的角度出发,统筹森林利用和保护相关的社会、经济及环境等各方面,进行多目标规划和决策,是林业研究和实践中的重要命题。以长白山区露水河林业局为例,探讨了森林多目标经营的必要性,设计了森林多目标经营的规划设计体系,从群落生境分析、发展类型设计、林分作业设计以及生命周期经营计划设计等方面对露水河林业局森林多目标经营进行了规划设计,以期为我国开展森林多目标经营提供借鉴和手段支撑。     

沿海地区森林风害研究综述

从导致森林风害的因素、风害对沿海森林生态系统的影响、风害评估方法、降低森林风害的经营管理措施等方面,综述了风害与沿海森林生态系统关系的研究成果和不足。我国未来应加强在不同尺度下沿海森林结构与功能关系、局域和区域尺度下各类生物/非生物因素与森林风害的关系以及森林风害预测评估模型的构建等3方面的研究。     

基于遥感技术的森林健康研究综述

遥感技术可以有效完成复杂时空尺度海量信息的收集处理,其与森林健康研究的交叉、融合大大提高了复杂时空尺度上森林健康研究的表达能力.目前,森林健康遥感研究正处于各学科交叉、融合、调整,由静态向动态、单一向复杂、零散向系统转变的关键发展时期,但缺乏对森林健康问题的全面考量、逻辑安排和系统的顶层设计.在把握森林健康活力、组织结构和恢复力核心理念的基础上,从森林资源调查、森林生态功能评估、森林健康风险控制和森林植被参数提取四个方面构建和丰富基于遥感技术森林健康研究体系,对国内外森林健康遥感研究进行综述.通过对以上研究内容的总结分析,明确基于遥感技术的森林健康研究各领域的研究进展,及其在理论、技术和应用方面的不足.分析认为:(1)未来应加强森林生态和遥感技术重大基础理论研究,以明确森林结构、过程、功能与遥感数据之间的耦合关系;(2)发展完善新型遥感技术、遥感数据解译算法与软件工具,提高遥感数据的精确度、利用率和利用效率;(3)提升森林健康遥感研究成果的科技转化水平,推进快速分析评价与辅助决策功能研究,指导相关森林健康经营活动和科学研究的开展,以及林业政策的制定.     

森林生态质量评估方法研究进展

森林具有水源涵养、气候调节、环境净化、水土保持、生物多样性保护等方面的生态功能, 开展森林生态质量评估对了解全球碳循环、能量循环和气候变化具有重大意义。文章在介绍森林生态质量概念和研究方法的基础上, 从森林生物量、森林生产力和森林结构三个综合性指标对森林生态质量评估进行分析与总结。着重陈述了评估指标体系构建、评估数据获取和关键的生态参数估算等方面的见解, 探讨了目前森林生态质量评估中存在的主要问题, 展望其发展前景, 包括评估指标统一标准化问题、高质量的数据、森林生存环境的影响、多源遥感数据获取森林水平、垂直结构参数的应用以及森林生态质量与生态功能的相互作用等。     

城市林木树冠覆盖研究进展

随着城市化进程的加快以及人们对由此产生的大量环境问题认识的不断加深,城市森林受到了越来越多的关注,它被越来越多的普通市民和科学家看做是有效解决城市环境与生态问题的最根本途径.在城市森林的维护、规划与建设过程中,城市林木树冠覆盖被认为是城市森林最重要的结构与功能衡量指标.针对我国城市森林研究与实践起步较晚的现实需求,从城市林木树冠覆盖的概念、分类与评价、城市林木树冠覆盖与城市森林服务功能、城市林木树冠覆盖的研究方法和城市林木树冠覆盖率与城市森林规划等4个方面,对国内外城市林木树冠覆盖研究的现状进行了评述.指出了该方面研究的未来趋势包括4个方面,首先,城市林木树冠覆盖研究,已经与城市的生态建设和日常生态、生产管理紧密结合.其次,高分辨率(米级以下)卫星影像在城市森林树冠调查与制图过程中的应用越来越普遍.第三,像面向对象的影像解译方法与激光雷达(LIDAR)等新技术将会得到更广泛的使用.第四,为了最终实现城市森林建设规划能够落地的目标,在城市森林建设的规划实施决策过程中,计算机辅助人工智能的应用将会普及.     

花粉管中的微丝和微管

对花粉管中的微丝和微管研究的几个问题的进展进行了综述, 包括微丝和微管在花粉管中的分布;微丝和微管在花粉管胞质流动、细胞器运动以及花粉管生长中的作用等几个方面。并对今后这些方面研究的重要问题进行了论述。     

Cloning,stem cells,and the current national debate: incorporating ethics into a large introductory biology course

Discussing the ethical issues involved in topics such as cloning and stem cell research in a large introductory biology course is often difficult. Teachers may be wary of presenting material biased by personal beliefs, and students often feel inhibited speaking about moral issues in a large group. Yet, to ignore what is happening "out there" beyond the textbooks and lab work is to do a disservice to students. This essay describes a semester-long project in which upperclass students presented some of the most complex and controversial ideas imaginable to introductory students by staging a mock debate and acting as members of the then newly appointed President's Council on Bioethics. Because the upperclass students were presenting the ideas of real people who play an important role in shaping national policy, no student's personal beliefs were put on the line, and many ideas were articulated. The introductory audience could accept or reject what they were hearing and learn information important for making up their own minds on these issues. This project is presented as an example of how current events can be used to put basic cell biology into context and of how exciting it can be when students teach students.     

Controversial issues in the management of multiple pregnancies.

The management of multiple pregnancies represents a true challenge for all sub-specialties concerned with perinatal medicine. Many issues were neglected over the years merely because they were rare and therefore considered not sufficiently important to merit clinical trials. This paper discusses a personal selection of controversial issues, such as multifetal pregnancy reduction of triplets and twins, special cases in multifetal pregnancy reduction, need for invasive genetic studies, management of twin-twin transfusion, discordant fetal conditions, the definition of "term" in multiples, and the controversy about the mode of delivery.     

How do learning issues relate with content in a problem-based learning pathophysiology course?

The relation between learning process and content coverage is becoming increasingly important for the understanding of the effects of problem-based learning (PBL) on students' learning. In our medical school, PBL is used as a major educational strategy in the discipline of pathophysiology. A computer program was developed allowing students to register learning issues identified as needed during tutorial sessions and learning issues stated as covered during the individual study periods. In our study, we compared "planned" (learning issues identified during PBL sessions) and "accomplished" learning issues (covered after the independent study periods) identified by pathophysiology students from three consecutive years. We found that the planned learning issues raised during tutorial sessions related to the issues effectively accomplished during the independent study and that their number grew stepwise from basic to preclinical to clinical sciences. Pathophysiology was, globally, the most mentioned discipline. Moreover, the most mentioned disciplines from the basic, preclinical, and clinical areas were physiology, histopathology, and internal medicine, respectively. The single-discipline approach did not limit the student's capacity to identify and cover learning issues beyond the objectives of pathophysiology.     

Priority issues in continuing medical education show sensitivity to change in Canadian health care.

The degree and scope of significant change in health care expectations, roles and delivery patterns in Canada have been widely documented. In 1988 the Sub-Committee on Research of the Standing Committee on CME [continuing medical education], Association of Canadian Medical Colleges, conducted a survey to determine whether those responsible for the CME portion of the medical school curriculum are changing their perceptions to keep pace with the changes in health care. The results were compared with those of a similar survey done in 1983. In both surveys people directly responsible for delivery of formal CME were asked to identify and rank research needs in CME. The response rates were very high. The CME issues identified in the two surveys had changed considerably, with entirely new issues being identified in 1988 and the emphasis placed on issues having changed. The identification of factors that promote or inhibit application of new knowledge by practising physicians was of lowest importance in 1983 and of primary importance in 1988, and comparison of the cost-effectiveness of CME methods was an important issue in 1983 and among the least important in 1988. The noted changes mirror developments in Canada''s health care milieu.     

城市森林研究进展与发展战略

城市是一个以人类活动为中心的社会．经济．自然复合生态系统,城市森林是城市生态系统重要的组成部分,是城市生态系统健康和城市可持续发展的基础和保障,具有重要的生态服务功能。本文阐述了城市森林产生的背景、概念、范围和国内外的研究现状,以及当前城市森林研究的热点问题,最后提出了城市森林的发展战略。     

Legal and public policy issues in DNA forensics

Since the 1980s, when DNA markers for identifying biological samples were first developed, the use of DNA evidence to convict defendants and to exonerate the wrongfully accused and wrongfully imprisoned has greatly increased. But the increase in databanks for storing DNA information on individuals convicted of certain crimes raises important legal and ethical issues on the use, collection and storage of DNA evidence. These issues have been the subject of a recent US National Commission, which will, hopefully, broaden public discourse about the future uses of DNA forensic technology.     

Risk assessment for inherited susceptibility to cancer: a review of the psychosocial and ethical dimensions

The objective of this study was to conduct a broad-based systematic review of social, ethical, and legal considerations associated with genetic cancer risk assessment technologies (CaRATs). This paper focuses on psychosocial and ethical issues. Search results were limited to papers published in English, French, or German from January, 1990, to May, 2003. A quality assessment tool was developed and applied to retrieved papers. Application of the quality assessment tool resulted in 77 of 247 qualitative and quantitative primary research papers being reviewed and synthesized. A broad range of issues were addressed and grouped into content areas. Despite a large literature addressing psychosocial and ethical issues associated with CaRATs, many existing studies are not adequate to inform decision-makers and stakeholders. Careful policy analysis, as in some of the economic analyses reviewed here, is important to bridge this gap.     

动物毒素及相关药物研究进展

动物毒素是指有毒动物毒器分泌的毒液中,结构和功能丰富多样的蛋白质和多肽,其具有高活力、高结构多样性、高专一性等特点, 是药物开发的重要资源。综述了动物毒素药物的特点以及进入临床药物和候选药物分子的研究进展,同时分析了我国动物毒素类药物研发 中需要重视的问题。