我国草地退化及治理对策

本文系统地分析了我国的草地退化现状及动态变化、草地退化对草地本身的影响和对农业的危害、草地退化的原因。提出了草地保护与建设的措施。     

我国近海渔业资源可持续产出基础研究的热点问题

近海具有极其重要的生态服务功能,是众多渔业生物的关键栖息地和优良渔场,支撑着近海渔业资源的补充和可持续生产。在我国,近海渔业提供90%以上的海洋捕捞产量,是我国优质蛋白的重要来源。目前,因过度捕捞直接造成的资源量骤减、及大规模围填海工程、陆源污染和海水养殖等高强度人类活动的加剧,近海资源和环境问题日益凸显,如：富营养化导致的赤潮、水母暴发等生态灾害,湿地减少引起产卵场、育幼场碎片化或功能消失等,使得近海渔业资源的补充和可持续性严重受损。渔业资源的补充过程是海洋生物、物理作用耦合的过程,依赖复杂多样的环境驱动因子来调节和维系可持续渔业生产。而渔业种群早期生活史阶段是其生命中最脆弱、对栖息环境变化的敏感性最强的阶段,小规模环境变化也可能会对其资源补充过程产生剧烈影响。因此,渔业种群早期生活史的关键生境(产卵场、育幼场等)和过程(繁殖发育、存活生长等)对环境变化的响应机制及其资源效应的研究成为海洋生态系统演变和生物资源可持续产出前沿领域的重点和热点。作者在综合国内外相关研究动态和我国近海渔业生态系统存在的突出问题的基础上,展望并分析了关键栖息地的形成和变迁过程与机理、关键资源补充过程与机制、渔业种群对生境变化的适应性响应以及资源效应的综合评估与模型分析等研究热点,期待为我国该研究领域的发展起抛砖引玉之用。     

湖北省倒春寒发生程度评估模型

选取湖北省9个代表站历史倒春寒灾害序列资料,分析1951-2010年倒春寒过程中最大降温幅度、最低日平均气温、持续天数变化的特征,结合主成分分析法构建倒春寒评估模型,探讨湖北省倒春寒发生影响程度。结果表明：60a来,湖北3月倒春寒发生频次总体呈下降趋势,4月倒春寒频次以20世纪60、70年代最多,80、90年代明显下降,而2000-2010年又有所增加;倒春寒发生过程中,平均最大降温幅度的年代际间变化不大,但3月最大降温幅度大于4月;3、4月倒春寒过程最低日平均气温按年代比较显示,在2000-2010年有所降低,但不明显;1951-2010年,倒春寒持续天数平均为4.1d,呈不显著的下降趋势。运用评估模型对2010年4月12-15日的倒春寒过程评估表明,9个代表站中5站为中度倒春寒,4站为轻度倒春寒。     

大气中O3浓度变化对水稻影响的试验研究

本文利用OTC-1型开顶式气室对水稻进行了不同O3浓度处理,试验研究了不同O3浓度对水稻生长发育、生理过程和产品品质的影响.结果表明:当大气中O3浓度增加时,水稻的气孔阻力增加、光合作用速率下降、蒸腾速率也下降.水稻的生物量减少,产量下降,但水稻的品质有提高.     

台风暴潮对浙东沿海农田生态环境的影响及其对策

研究了1997年11号台风引起的台风暴潮对浙东沿海地区农田生态环境的影响。结果表明,受海水浸泡的影响,土壤和农用灌溉水含盐量显著升高,浸泡72h及72h以上表层土壤含盐量分别达1.27%和1.38%;在海水倒灌发生后8d农用灌溉水表层、3m、6m和10m深层水含盐量分别为2.36‰、3.22‰、3.84‰和4.03‰,尽管海水退落后各深层水含盐量有所下降,但总体仍维持在2.26‰左右,二者含盐量均远超过农业生产标准。进而提出了清理枯株、深沟翻耕、优化农作物种植结构和实施栽培管理措施等恢复受咸农田生态环境的对策。     

关于天然林保护工程及其对策的探讨

本文阐述了实施天然林保护工程的基本思路和主要目标。分析了实施天然林保护工程对森工企业的影响。提出了实施天然林保护工程的对策和措施。     

Soil C and N Content Under Evolving Landscapes in an Arid Inland River Basin of Northwest China

The state of a landscape is primarily reflected by its soil nutrients and organic matter status, which in turn are related to the type, size and number of landscape elements or patches. Evolving landscape patterns inevitably cause an evolution in ecosystem functionality. In particular, in arid regions, gained, lost and existing soil N and C pools have important ecological implications. The impacts of evolving landscapes in the middle reaches of the Heihe River basin of northwest China on soil organic C and N losses were assessed by both quantitative and computer modelling methods. In the period 1987-1997, patch transitions of the regions evolving landscapes have been predominantly characterized by a farmland expansion of 1.510³ km², and the desertification of 15.12% of existing farmlands into desert. As the result of such changes, alpine steppe and piedmont warm and desert steppe decreased by 43.9% and 2.72% respectively, whereas, plain swamp meadow and gobi and sandy desert increased by 13.2% and 10.77%, respectively. Consequently, soil organic matter and N contents decreased significantly in most landscape patches. In the study region, over these ten years, net soil organic C and N losses reached 5.30 Gg and 0.51 Gg, respectively, a pattern repeated over the entire arid inland region of northwest China, due to similar hydrological resources and patterns of regional development. Large soil C and N losses caused by landscape changes will inevitably result in significant new environmental problems.     

气候变化对畜牧业生产的影响

人类活动将导致气候变化，从而给畜牧业生产带来影响。文中从三个方面综述并分析了气候变化对畜牧业的影响：１）气候变化对草地生态系统和草地面积的影响；２）气候变化包括大气中ＣＯ_２含量增加、温度和降水的变化对草地生产力和牲畜负载力的影响；３）气候变化对家畜健康、生长和繁殖的影响。     

A review of allodiversity in Lake Naivasha, Kenya: Developing conservation actions to protect East African lakes from the negative impacts of alien species

The biodiversity of developing countries is increasingly threatened by introductions of invasive alien species. This study on the allodiversity in Lake Naivasha, Kenya reviews the pathways, establishment rates and outcomes of introduced species, and provides the basis for determining conservation actions that, if implemented, could prevent potentially harmful effects of similar events in other East African lakes. Introductions into Naivasha commenced in the 1920s with the release of a sport fish and have since produced an allodiversity of 23 species. This includes species that are no longer present (e.g., some tilapia species), presumed no longer present (e.g., the Nile perch Lates niloticus) or whose distribution is highly localised and ecologically neutral (e.g., the coypu Myocastor coypus). It also includes species that established successfully and invoked major changes in lake ecology (e.g., the red swamp crayfish Procambarus clarkii) and a species that is producing apparent economic benefits to the local population (i.e., the common carp Cyprinus carpio). The most frequent donor continents were the Americas and most species were the result of secondary introductions. The main introduction vector was active release that aimed to enhance fishery production. Alien species now dominate each main level of the lake’s food web and produce impacts that are rarely restricted to a single ecosystem service. With a few exceptions, the majority of introductions translate into socioeconomic costs that contribute to rising social conflicts and exacerbating poverty. Development of appropriate conservation management tools within a regulatory framework could help protect Naivasha from further damage and could be used elsewhere in East African lakes to ensure that subsequent introductions enhance ecosystem services without affecting biodiversity.     

从水文化的角度解读水与包头城市发展的关系

文章从水文化的角度解读水与包头的历史、水与包头城区的发展、水与包头园林景观、水与包头的人居环境、水与包头城市的未来五个方面的关系，提出努力构筑城市亲水平台，为促进包头经济跨越式发展和社会全面进步提供了强有力的支撑。