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1.
The Namib is a relatively well-studied hyperarid desert. Much of the research effort was coordinated through the institutional framework of the Gobabeb Research and Training Centre, which was established in the middle of this desert fifty years ago. The initial discoveries focused on the Namib's remarkably high biodiversity and adaptations to desert conditions, analysed against the foundations of research into this desert's particular climate, geomorphology and geology. The antiquity of this desert, its extreme hyperaridity, and strong climatic gradients provided unusual windows into ecosystem drivers in arid lands, past and present. The Gobabeb Centre itself evolved to translate much of its knowledge into application and is today geared to increase this trend even further, driven by the urgent need for knowledge-based environmental management, such as ecological restoration of mining areas.The current volume collates nine papers which review a cross-section of Namib research, with special focus on projects conducted through Gobabeb. These papers concern different facets of geomorphology where Namib research has led global understanding, reviewed in three papers, and one climatological review of the moisture regime. A review of reptile research illustrates the relationship between biodiversity processes and environmental factors, which is further sharpened in a comparison of dune lizard ecology between continents. The review of botanical research in the Central Namib fittingly binds much of the accumulated knowledge of desert plants into a detailed vegetation map. A review of research on the highly variable ephemeral river systems of the Namib illustrates how academic knowledge accumulated at Gobabeb connects to applied research, which is also the topic of the final paper concerning the knowledge gaps and research needs to provide the information required for ecological restoration. 相似文献
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荒漠生态系统服务价值评估研究进展 总被引：4，自引：1，他引：3
荒漠生态系统是中国西北地区的代表性生态系统,具有不同于其他生态系统的独特结构和功能。开展荒漠生态系统服务价值评估,对干旱区的生态恢复与重建以及区域环境保护具有重要意义,有助于促进干旱区的可持续发展。把荒漠生态系统服务划分为防风固沙、土壤保育、固碳释氧、水资源调控、生物多样性保育、旅游文化等6类。在此基础上回顾与评述了相关研究,简要概括了已有研究中存在的主要问题,最后建议加强荒漠生态系统提供的独特服务的价值评估和针对特定地区开展小区域的荒漠生态系统服务价值评估等方面的研究,以及科学选取与调整价格参数。 相似文献
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塔里木河流域地处我国西北新疆,面积约102×104 km2,是我国丝绸之路经济带建设的核心区。在过去50 a里,塔里木河流域经历了大规模的水土资源开发,经济社会发展的同时,河道断流,湖泊干涸,沙漠化加剧,生物多样性受损,生态隐忧日益加剧,已威胁塔里木河流域绿洲经济发展和社会稳定,严重影响国家"丝绸之路经济带"建设。荒漠与绿洲生态国家重点实验室针对塔里木河流域的生态环境问题,开展了长期的生态监测与科学研究,基于多年监测调查数据,解析了塔里木河荒漠河岸林植被与地下水的关系,揭示了生态系统退化过程和机理,提出了塔里木河下游合理/胁迫/临界地下水位与流域生态需水量,研发提出的退化生态系统修复重建关键技术得到推广应用;提出的重点生态工程建设方案,被纳入《南疆水利规划》;提出的流域水资源管理建议被国家采纳并实施。科技支撑塔里木河流域生态修复及可持续管理,为丝绸之路经济带生态文明建设提供了重要科学依据和示范样板。 相似文献
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The hyper-arid Namib Desert is an ancient desert of great lithological diversity. Weathering plays a key role in landscape evolution in the Namib which, in spite of its aridity, has a number of sources of moisture – rainfall, fogs, dews and groundwater seepage – which enhance weathering. Among the weathering processes that have been the subject of recent study in the central Namib are salt, thermal and lichen weathering which, in often complex associations of processes, contribute to the array of small scale weathering features found on marble and granite outcrops here. At the landscape scale weathering in the central Namib is also highly interrelated with erosion and the development of geochemical sediments (calcrete, gypcrete, tufas etc), whilst weathering ‘hotspots’ are thought to be important sources of fine sediment production. Over the long term weathering has played important roles in landscape evolution here which, despite localized weathering hotspots, has been very slow for much of the Cenozoic. 相似文献
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人类土地利用的主要生态后果及其缓解对策 总被引：44，自引：13，他引：31
通过对土地利用尤其是以集约农业为主的土地利用已经产生的陆地生态系统生物侵入、生物多样性损失及碳循环、氮循环和水循环改变等生态后果的综述。主要论述了物种特性及其组成的改变对生态系统的影响及不同特性物种组成对土地利用带来的负面环境效应响应的特点。提出了在建立可持续土地利用的框架体系下,发展精确农业为特色的可持续农业和恢复重建退化生态系统等对策来调控不合理土地利用的负面环境效应。 相似文献
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本文以阿尔泰山两河源保护区采金废弃矿区为研究区,从地形、土壤、水分和地表植被4个方面出发,结合矿区现有条件,设置11种恢复措施,选取丰富度指数、优势度指数、多样性指数、均匀度指数、生物量、植被盖度、物种数及土石比等7个评价指标,采用主成分分析法,得出不同恢复措施的主成分得分及生态效益排名。结果表明,单一恢复措施,如推平、羊群驻扎、泥浆等基本上是从某一个方面来考虑生态恢复的,存在一定的缺陷,恢复效益排名比较靠后;多种措施相结合,不仅能改善土壤环境,也会引起植物群落多样性格局的变化,生态恢复效益很好;同一种恢复措施,施行年限越长恢复效果越好。 相似文献
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This review is concerned with the aeolian geomorphology of the Namib Sand Sea, part of the Namib Desert in Namibia, south-west Africa, concentrating in particular on studies made over the past 50 years. The paper covers: sand sea organisation and dune patterns; and the dynamics of individual dunes. It demonstrates that studies in the Namib Sand Sea have been important to a much wider understanding of the geomorphological development of global sand seas. 相似文献
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荒漠土壤微生物群落结构特征研究进展 总被引：3，自引：2，他引：1
荒漠生态系统占地球陆地面积三分之一,是地球化学循环中的重要部分。荒漠干旱高温、缺乏植被、UV辐射强,曾被认为是没有生命的地方。然而在这恶劣环境中却蕴含有大量的微生物资源,尤其是荒漠土壤富集了大量微生物。微生物参与和主导整个荒漠生态系统地球生物化学循环,对于调节重要生态过程、修复和稳定荒漠生态系统起到重要作用,对其的研究生态学意义突出。本文综述了国内外对荒漠土壤微生物群落结构特征、群落功能多样性以及微生物群落、微生物与植物、微生物与环境之间相互关系的研究现状,旨在充分了解荒漠土壤微生物多样性研究,总结对荒漠微生物生态认识的不足,为荒漠微生物生态研究方向提供参考。 相似文献
9.
Groundwater is a key factor controlling the growth of vegetation in desert riparian systems. It is important to recognise how groundwater changes affect the riparian forest ecosystem. This information will not only help us to understand the ecological and hydrological process of the riparian forest but also provide support for ecological recovery of riparian forests and water-resources management of arid inland river basins. This study aims to estimate the suitability of the Water Vegetation Energy and Solute Modelling(WAVES) model to simulate the Ejina Desert riparian forest ecosystem changes,China, to assess effects of groundwater-depth change on the canopy leaf area index(LAI) and water budgets, and to ascertain the suitable groundwater depth for preserving the stability and structure of desert riparian forest. Results demonstrated that the WAVES model can simulate changes to ecological and hydrological processes. The annual mean water consumption of a Tamarix chinensis riparian forest was less than that of a Populus euphratica riparian forest, and the canopy LAI of the desert riparian forest should increase as groundwater depth decreases. Groundwater changes could significantly influence water budgets for T. chinensis and P. euphratica riparian forests and show the positive and negative effects on vegetation growth and water budgets of riparian forests. Maintaining the annual mean groundwater depth at around 1.7-2.7 m is critical for healthy riparian forest growth. This study highlights the importance of considering groundwater-change impacts on desert riparian vegetation and water-balance applications in ecological restoration and efficient water-resource management in the Heihe River Basin. 相似文献
10.
Urban biodiversity is now recognized as playing a critical role in supporting global biodiversity. However, it is important to note that biodiversity is a systematic and holistic concept and prior studies have not generally focused on cross-border or multi-scale management problems. On one hand, the ecosystems of cities are interconnected with adjacent cities by natural landscapes, so they are like mosaics instead of being isolated. Urban biodiversity research demands the consideration of the continuity within an ecosystem. On the other hand, both active protection and passive restoration strategies for urban biodiversity should not only be developed by researchers or municipal government agencies, but more importantly, they should consider the real ecosystem management problems faced by multi-scale departments in order to build a practicable Pressure-State-Response (PSR) model. The solutions for these issues should be included in the analysis to form a complete and more effective urban biodiversity strategy. The study in this paper offers an answer to whether different scales of cities or districts should adopt the same biodiversity strategy; and therefore, the decision depends on whether the places are of the same importance to the global or regional ecosystem, or whether the ecological elements are connected to the adjacent cities/districts and the problems that multiple stakeholders care about. 相似文献
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Ephemeral rivers have been largely excluded from previous attempts to classify global hydrologic regimes, or to assess the role of hydrologic characteristics in regulating ecological processes and patterns in fluvial ecosystems. The Namib Desert's ephemeral rivers are amongst the most hydrologically variable fluvial systems yet described. The coefficient of variation for mean annual runoff (CVMAR) among 28 stations, representing 7 Namib rivers, averages 1.55, compared with a global mean of ∼0.45. Distinct curvilinear relationships exist among hydrologic characters and longitudinal position along the rivers. In particular, peak discharge, annual flow volume, and days of flow per annum exhibit a marked decline in the lower reaches of the rivers, after a mid-catchment peak. These longitudinal gradients exert strong controls over the composition of vegetation, invertebrate, and fungal communities; the availability and structure of various micro-habitats; and the rates of ecological processes such as decomposition. Flood pulses, although variable in their timing and magnitude, play a critical role in regulating organic matter transport and deposition, and primary and secondary production. Despite the tolerance of the biota to harsh and variable abiotic conditions, these ecosystems are highly sensitive to hydrologic alterations as water is acutely limiting for many organisms and ecological processes. Accordingly, alterations to flow regimes can quickly degrade ecological integrity. Managers must seek to maintain existing hydrologic regimes, a challenge amplified by increasing human water demand and changing regional climates. 相似文献
13.
湿地景观格局变化研究进展 总被引：45，自引：1，他引：44
湿地是自然界最富生物多样性的生态景观,具有重要的生态功能。湿地景观格局是各种生态过程综合作用的结果,具有高度的景观异质性,对景观的功能和过程有着显著的影响。湿地生态系统是世界上受威胁最为严重的生态系统之一,在自然因素和人类活动的影响下发生了大面积的转化或丧失。本文从湿地景观格局研究方法、面积变化、景观类型转化、驱动力以及动态模型、湿地景观格局指数以及湿地景观格局与气候变化之间的关系等方面综述了湿地景观格局变化的研究进展,指出湿地景观格局变化及其生态效应和高原湿地景观格局变化与气候变化之间的关系是未来研究的重点领域。 相似文献
14.
腾格里沙漠沙坡头地区固沙植被对生物多样性恢复的长期影响 总被引：36，自引：16，他引：20
地处腾格里沙漠东南缘的沙坡头人工固沙植被始建于1956年,46 a来不仅确保了包兰铁路沙漠地段的畅通无阻,而且对区域生态环境的恢复产生了巨大的影响,成为我国干旱沙漠地区交通干线荒漠化防治与生态恢复的成功模式。长期定位监测结果表明:人工固沙植被建立4~5 a后,沙丘表面物理结构初步得到稳定,并由大气降尘形成的无机土壤结皮逐渐演变形成土壤微生物结皮。荒漠藻类、苔藓和地衣等隐花植物在结皮层中得到了大量的繁衍:固沙植被建立46 a后出现藻类24种;苔藓仅有5 种,少于天然固定沙丘结皮上的种类,此外,地衣也在植被区发现,这说明固定沙丘景观逐渐趋于稳定的状态;相对于流沙区,固沙植被区近地面风速降低了 40%,土壤有机质含量增加了60%,其中氮、磷、钾等荒漠生态系统主要限制养分因子及土壤理化性质得到了改善,沙丘表层成土过程明显;土壤水分循环的时空变异驱动了植被的演变,为大量的草本的侵入和定居创造了条件;此外,对鸟类、昆虫和土壤动物及荒漠动物的生存产生了积极的影响。46 a后,固沙植被区共有鸟类 28 种,昆虫 50 种,动物 23种。生物多样性的恢复使原有的相对单一的固沙植被演变成一个结构、组成和功能相对复杂的荒漠生态系统。沙坡头地区生态环境在人为促进下的恢复为我国西部生态建设提供了科学依据。 相似文献
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中国干旱沙区的生态重建与恢复:沙坡头站60年重要研究进展综述 总被引：3，自引：2，他引：1
中国科学院沙坡头沙漠研究试验站建站60年来,服务于国家需求,推动了沙漠科学的发展。在沙害治理、沙漠生态重建与恢复、荒漠生态系统长期生态学、沙地生态水文学\,人工植被稳定性及干旱胁迫生理生态学方面取得了重要进展\.解决了在降水量小于200 mm的干旱沙漠地区植被建设的关键技术,证实了通过人为促进生态恢复是可行的,创造了人类活动(治理和利用)与沙漠自然和谐持续发展的模式;探讨了干旱沙区土壤水循环的植被调控机理,提出了生态恢复的关键技术及其应用模式;理论上探明了人工植被稳定性维持的生态学机理,提出了荒漠系统生态恢复的理论模型;揭示了荒漠生态系统碳、氮循环及其对环境因子的响应;引领了生物土壤结皮的生理生态功能及其水文学研究;拓展了干旱逆境生理生态学的研究。沙坡头站已成为国际沙漠科学与荒漠长期生态学研究的重要平台。 相似文献
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Restoring degraded landscapes in lowland Namaqualand: Lessons from the mining experience and from regional ecological dynamics 总被引：4，自引：1，他引：4
Three-quarters of a century ago diamond mining was added to livestock grazing and cereal cropping as a serious cause of landscape degradation in the north-western semi-arid region of South Africa, Namaqualand. Since that time the activities of diamond mine operators and prospectors have eclipsed all other land uses as a cause of degradation in this region. Discontinuous patches along virtually all of the 400 km of the Namaqualand coastline have been, or are currently, being mined or prospected. Prior to 1992 little was done to restore the landscapes and ecosystems to their pre-mining state, but since then legislation has placed a clear responsibility for restoration on mining operators. Implementation of ecological restoration was initially slow, but has recently gained momentum, in line with a growing awareness of environmental responsibilities amongst the global mining industry. In general, autogenic recovery of the perennial vegetation does not take place. The low annual rainfall and prevailing strong windy conditions present the greatest climatic challenges to the restoration of the flora. While the unique vegetation, and its features (e.g. poor representation of perennial species in the seedbank) present challenges to understanding the interventions that are critical in achieving ecological restoration. At the same time, climatic conditions such as the strong seasonality and low variability of rainfall, together with floristic features such as the high incidence of succulence, and the extraordinary drought tolerance of many seedlings, present opportunities for restoration. Perhaps the greatest challenges to restoration derive from the unsuitability of much of the mined overburden soils for plant growth. The nature and importance of climatic conditions, mined soils, topsoils, soil nutrients, landscaping, seedbanks, seeding, transplantation, and the interactions between these and other factors are evaluated in the context of this semi-arid environment and the prevailing mining practices. 相似文献
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湿地保护保育措施设计是江西东江源国家湿地公园规划与建设的核心。对河流湿地进行保护和保育、修复和恢复,构建良好的河流廊道生态系统,恢复其生态功能和湿地生物多样性,营造优美的湿地景观,是把东江源国家湿地公园打造成＂健康的湿地、洁净的水源、原生态的河流＂的关键。通过设计河道保洁工程、河流湿地修复与恢复工程、生态河岸带建设工程、水生生物多样性恢复工程、湿地生态滤场构建、生态缓冲控制区6大工程14个项目,对东江源国家湿地公园的湿地进行科学、系统与有效的保护。 相似文献
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荒漠植被影响土壤水文过程研究述评 总被引：39，自引：20，他引：19
简要回顾了有关荒漠植被对土壤水文过程影响的试验研究,介绍了荒漠地区土壤水文过程研究的主要方法以及基本的土壤水分平衡方程,并对特定区域土壤水分动态与植被结构之间的关系进行分析,以期对今后从事该领域的研究与管理者有所启示。由于荒漠地区土壤水文特性具有极高的变异性,因此,阐明荒漠植被区土壤水分动态,确定这一特殊生态系统内植被格局与土壤水文过程的关系,可在理论上回答雨养型人工植被建设与荒漠地区生态恢复工程中,土壤水文过程影响植被结构与格局的基础性科学问题。 相似文献
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我国土壤动物生态地理研究进展 总被引：40，自引：0，他引：40
通过回顾我国近30年来土壤动物生态地理研究的进展,概述了我国土壤动物群落多样性及生态地理分布。包括我国从热带、亚热带到温带,从森林、草地、沙漠到湿地、农田乃至城市等诸多生态系统。总结了土壤动物群落对环境的响应及其指示意义研究的相关进展,从土壤动物对环境的营造、净化及其在生态系统凋落物分解和物质循环中的作用三个方面论述了土壤动物的功能,最后介绍了土壤动物与其他生物的互作、地上地下的生态学联系、全球变化对土壤动物群落的影响等热点领域的研究现状,并提出了未来土壤动物生态地理研究的热点问题。包括分子生物技术在土壤动物分类研究中的应用;土壤动物群落多样性的功能和机理;地上与地下生态系统的交互作用;干扰、污染、生物入侵和全球变化对土壤动物群落和功能的影响等。 相似文献