5种喀斯特生境植物叶片解剖结构特征

对我国喀斯特地区几种不同生活型植物——常绿植物桂花(Osmanthus fragrans Lour.)、竹叶椒(Zanthoxylunarmatum DC),落叶植物红背山麻杆(Alchornea trewioides Muell.),草本植物石上莲(Oreocharis benthamii Clark var.reticulata Dunn),草本植物单枝竹(Monocladus saxatilis Chia,Fung et Y.L.Yang)的叶片形态解剖特征(叶片厚度、气孔密度、气孔结构等)进行了观察和测量,发现差异较大:竹叶椒角质层较厚,红背山麻杆的叶片较厚,单枝竹叶片上下表皮均有气孔,桂花气孔密度最高,石上莲的气孔纵径最长.结果表明:1)喀斯特生境植物存在着普遍的抗旱功能性解剖结构,用以适应喀斯特地区的特殊干旱气候;2)不同生活型植物对干旱选择的策略不同.表3参20     

国际金融危机背景下中国服务贸易的开放

近年来我国服务贸易保持着稳健发展,逐步跻身全球服务贸易大国行列.国际金融危机对我国服务贸易的发展既是严峻挑战,又带来了新的发展机遇.本文就在国际金融危机背景下,中国服务贸易面对机遇和挑战将如何开放提出了几点对策.     

基于旅游资源评价的吉林省旅游发展格局研究

科学评价旅游资源是制定旅游开发策略的前提.在系统分析吉林省自身旅游资源特征以及在东北三省中所处优劣势的基础上,探讨当前旅游资源的状况对吉林省旅游业产生的影响,针对性地提出“一心两域”的吉林省旅游发展格局模式.     

我国环境事件生发机理的Logistics回归分析

以近年来我国发生的有影响力的100个环境事件为研究对象,通过多元Logistics回归方法。利用环境污染生境、污染主体特征、污染物特征、对象敏感性、社会敏感性、治理难度和治理效果7类变量23类观测指标解析了影响环境事件发生的显著因素。以此为基础,分别给出了控制和预防大概率小损失、大概率大损失、小概率小损失和小概率大损失环境事件发生的政策建议。     

Investigation and Long-Term Monitoring of Phragmites australis Within Virginia's Constructed Wetland Sites

Phragmites australis Trin., and/or aggressive species, Typha spp. Tidally influenced wetlands that have subtidal perimeter ditches have significantly less (P < 0.05) P. australis in the wetland interior than those without perimeter ditches. Fractured regression analyses show that 6 years after construction, P. australis invasion can be extensive. Linear regression analysis suggests that, if conditions remain favorable for P. australis colonization, constructed wetlands could be overrun in 40 years.     

Lactation patterns of pinnipeds are not explained by optimization of maternal energy delivery rates

Within pinnipeds, phocids and otariids show differing maternal care strategies. Phocids rear young out of body stores in a yearly cycle with a single stay ashore when the mother fasts while lactating, whereas otariids provision their young by repeated foraging trips to sea alternating with brief stays ashore where they suckle their young. In a previous optimality model, these differences have been interpreted as adaptations based on differing energy requirements of large (phocid) and smaller (otariid) species, and the time budget of the large elephant and the much smaller Antarctic fur seal were correctly predicted. Our refined model—extended to pinniped species of all sizes—predicts lactation strategies to shift from attendance cycles to 1-year cycles with increasing body mass and provides an explanation for the finding that phocid pups are weaned at lower relative mass than otariid pups. However, other predictions do not correspond to empirical findings. In particular, the model does not explain the behavior of large otariids and small phocids. Thus, maternal metabolic requirements alone appear insufficient to explain observed lactation patterns. In the light of our results, we discuss more generally the scope and limitations of optimality models when applied in a comparative framework to a group of related species.     

Toward an integrated analysis of mitigation and adaptation: some preliminary findings

Between 1999 and 2003, the Oak Ridge National Laboratory (ORNL) made a preliminary effort to integrate an analysis of mitigation and adaptation to climate change impact vulnerabilities in two ways: top-down and bottom-up. This paper briefly describes these early experiments and summarizes their findings, both about climate change vulnerability reduction and about the challenges of integrated analysis, expanding upon results previously reported [Wilbanks et al. (Environment 45/5:28–38, 2003); ORNL (Integrated analysis of mitigation and adaptation as responses to concerns about impacts of global climate change, ORNL Working paper 2003); ORNL and CUSAT 2003; Wilbanks 2005]. The U.S Government’s right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged     

湖北省森林资源发展问题刍议

湖北省具有发展森林资源的良好条件，但目前的森林覆盖率不高，林种结构不合理，森林生产力相当低。应在保护和经营好现有森林资源的基础上，以扩大森林面积和提高森林质量为中心，统筹规划，合理布局，增加投入，加速发展，科学经营，永续利用，不断提高其经济、社会、生态效益，造福于人民。     

湖北省水患防治对策研究

湖北省的洪涝灾害受全球尺度和流域尺度的多种因素的影响。全球尺度因素是指全球性的气候异常，流域尺度因素是指不利的自然条件和人类对自然环境与自然资源的不合理开发利用等方面。现阶段所采用的治水对策，即生态措施和工程措施，存在明显的局限性，不能彻底根治水患。通过系统分析湖北省水患原因和治水对策，提出以洪涝灾害承灾区的受因人口和受因财产的总数定量地表示洪涝灾害灾情的指标，该指标与灾情的对应关系明确且简明易得，为治水对策提供了更合理的依据。在此基础上，论述了“提高洪涝灾害承灾区的城市化水平、鼓励抗洪新技术和新机制的开发利用以及加强溃堤后的应对策略研究”等治水对策的必要性、合理性和可行性。     

我国水产科学研究状况及发展战略浅谈

根据我国的国情，内陆水体水产学的研究重心应从发展渔业转移到保护水质上来，这种转移是与国际潮流相一致的，也是符合国民经济需求和民族长远利益的，必须努力促进这个学科方向的转移，并通过科学导向将我国水产开发的重点转向海洋，给我们的子孙后代留下了赖以生存的清洁水源。