景观生态学与生物多样性保护

景观生态学的发展为生物多样性保护提供了新理论,方法和技术手段,从景观多样性与遗传多样性,物种多样性,生态系统多样性各层次生物多样性之间的相互关系及生物多样性保护的景观规划等方面评述近年来景观生态学应用于生物多样性保护的主要内容及研究进展,阐述了生物多样性动态及反馈,生物多样性保护的地理途径（ＧＡＰ分析）,景观生态安全格局,区域和大陆尺度的生态网络等一些新的概念和方法。     

区域生态安全格局:概念与理论基础

提出区域生态安全格局概念的提出 ,适应了生态系统恢复和生物多样性保护的发展需求。针对区域生态环境问题 ,通过干扰排除以及空间格局规划和管理 ,能够保护和恢复生物多样性 ,维持生态系统结构、功能和过程的完整性 ,实现对区域生态环境问题的有效控制和持续改善。区域生态安全格局的研究对象具有针对性、研究尺度具有区域性、研究问题具有系统性、研究手段具有主动性。它强调区域尺度的生物多样性保护、退化生态系统恢复及其空间合理配置、生态系统健康的维持、景观生态格局的优化、以及对社会经济发展需求的满足。它更加强调格局与过程安全及其整体集成 ,将生态系统管理对策落实到具体的空间地域上 ,实现管理效果的直观可视。相关理论 ,景观生态学、干扰生态学、保护生物学、恢复生态学、生态经济学、生态伦理学、和复合生态系统理论等为其提供了坚实的理论基础。区域生态安全格局不存在一个固定标准 ,人类对生态系统服务功能需求的不断变化是生态系统管理的根本原因。实现区域生态安全不但要以社会、经济、文化、道德、法律、和法规为手段 ,更要以其不断发展对生态系统服务功能的新需求为目标逐步进行。区域生态安全格局研究对于解决区域生态环境问题具有不可替代的作用 ,具有广阔应用前景。     

景观组成、结构和梯度格局对植物多样性的影响

植物多样性作为生物多样性研究的主要内容,一直以来受到广泛关注。近20年来,随着景观生态学的兴起和地理信息技术的发展,景观生态学与岛屿生物地理学、异质种群理论相结合,在植物多样性的保护和利用研究中得到运用。本文就在这3个理论的基础上,简述了景观组成(斑块、廊道、基质)、景观结构(斑块面积、边缘、隔离程度)和梯度格局(海拔、演替、土壤养分、干扰)对植物多样性的影响,强调了地理信息技术应用的重要性和景观层次上进行植物多样性研究的必要性。因此,在多个尺度上共同研究多个影响因子对植物多样性的复合作用,利于进一步揭示植物多样性的变化过程及其机制,有利于植物多样性的保护和利用。     

沙区植物多样性保护研究进展

沙区景观表现为沙丘和低地交错分布.沙区常具独特的植物区系,含有特有和稀有植物.沙区植物丰富度降低和特有(稀有)植物消失问题近些年已受到很大关注,被列入国际生物多样性保护计划,很多国家和地区都对此开展了专门的研究.本文以近期发表的文献为基础,从植物多样性保护问题的提出、植物多样性形成机制、植物多样性保护途径、植物多样性研究与生态学理论的发展等方面论述了沙区植物多样性保护及其研究进展.沙区植物多样性保护应注意植物多样性保护目标的地域间差异(维持沙丘上的高植物丰富度还是保护特有或稀有植物)、流沙固定-植物多样性保护间的均衡、"植物多样性保护的量(高的植物丰富度)-质(特有或稀有植物出现)"间的均衡.还应将沙丘体和丘间低地视为一个统一体,研究干扰和生境破碎化对植物多样性造成的影响.     

农业生物多样性保护的景观规划途径

农业生物多样性保护不仅关系到农业可持续发展,也是物种多样性保护的重要组成部分.近年来,生物多样性保护更加强调通过景观规划途径来实现.本文在回顾国内外关于景观结构对生物多样性影响一般性结论和研究结果的基础上,从景观、地块间、地块内3个尺度分别探讨了农业生物多样性保护的景观规划途径,并建议可以通过采取如下途径有效地保护农业生物多样性：1)在景观尺度上,维持较高比例的自然、半自然生境,注意农用地和种植作物的多样化,注重树篱等廊道生境的保护和建设;2)在地块间尺度上,构建农田边缘地带;3)在地块内尺度上,合理地规划作物种植密度、作物空间分布及采取间套作、轮作等方式.此外,大尺度景观规划途径的实施还需要诸如自然保护计划、土地利用规划及生态补偿等相关政策措施的配套与支持.     

景观生态网络研究进展

作为生态学重要的概念与方法,生态网络是景观生态学研究的热点问题,也是耦合景观结构、生态过程和功能的重要途径。景观生态网络对于保护生物多样性、维持生态平衡、增加景观连接度具有重要意义。从景观生态网络的相关理论、研究进展、研究方法模型等进行分析,并对其应用前景进行展望,主要介绍了传统景观格局分析、网络分析、模型模拟等方法的适用性与特点,并分析了景观生态网络在城市景观格局优化、自然保护区规划、生物多样性保护、土地规划等领域的应用,最后提出了研究的主要问题。     

遥感在生物多样性研究中的应用进展

随着人口的持续增长, 人类经济活动对自然资源的利用强度不断升级以及全球气候变暖, 全球物种正以前所未有的速度丧失, 生物多样性成为了全球关注的热点问题。传统生物多样性研究以地面调查方法为主, 重点关注物种或样地水平, 但无法满足景观尺度、区域尺度以及全球尺度的生物多样性保护和评估需求。遥感作为获取生物多样性信息的另一种手段, 近年来在生物多样性领域发展迅速, 其覆盖广、序列性以及可重复性等特点使之在大尺度生物多样性监测和制图以及评估方面具有极大优势。本文主要通过文献收集整理, 从观测手段、研究尺度、观测对象和生物多样性关注点等方面综述了遥感在生物多样性研究中的应用现状, 重点分析不同遥感平台的技术优势和局限性, 并探讨了未来遥感在生物多样性研究的应用趋势。遥感平台按观测高度可分为近地面遥感、航空遥感和卫星遥感, 能够获取样地-景观-区域-洲际-全球尺度的生物多样性信息。星载平台在生物多样性研究中应用最多, 航空遥感的应用研究偏少主要受飞行成本限制。近地面遥感作为一个新兴平台, 能够直接观测到物种的个体, 获取生物多样性关注的物种和种群信息, 是未来遥感在生物多样性应用中的发展方向。虽然遥感技术在生物多样性研究中的应用存在一定的局限性, 未来随着传感器发展和多源数据融合技术的完善, 遥感能更好地从多个尺度、全方位地服务于生物多样性保护和评估。     

恢复生态学研究的一些基本问题探讨

对恢复生态学的研究概况、基本概念、内涵与研究内容以及生态恢复的目标、原则、程序与技术进行了分析与探讨。指出恢复生态学应加强基础理论研究(包括生态系统的演替理论及干扰条件下生态系统的受损过程与响应机制研究等)和应用技术研究(包括土壤、水体、大气和植被恢复技术、生物多样性保护技术以及生态系统的组装与集成技术等).生态恢复与重建是指根据生态学原理,通过一定的生物、生态以及工程的技术,人为地切断生态系统退化的主导因子和过程,调整和优化系统内部及其与外界的物质、能量和信息的流动过程及其时空秩序,使生态系统的结构、功能和生态学潜力尽快地成功地恢复到原有的乃至更高的水平。     

城市景观多样性的空间尺度分析——以上海市外环线以内区域为例

景观生态学研究的就是某一空间尺度范围内的景观格局与生态过程。因为景观格局与生态过程中存在的尺度多样性 ,导致尺度成为理解景观格局和生态过程相互作用的关键 ,其已经成为景观生态学的一个重要概念 ,但是由于理论和方法的限制 ,对景观生态学的尺度研究还不够 ,特别是景观格局综合性指标在不同幅度上的变化特征和效应。在 GIS与 RS技术支持下 ,采用基准分辨率为 5 m的 SPOT遥感图像作为数据源 ,对不同幅度下的城市景观多样性的空间分布格局进行了分析 ,并进一步利用半变异函数对其空间异质性进行定量描述。结论揭示 :随着空间尺度的增加 ,景观多样性程度也不断增加 ,另外多样性的空间分布格局也具有显著变化 ,由于受城市发展历史和目前城市扩展方向的影响 ,多样性在总体上是不平衡的 ,尺度越大 ,不平衡越明显 ;不同尺度下景观多样性空间格局的变化 ,与城市景观的特点和城市景观的功能息息相关 ,不过其受经济效益和社会文化效益的影响更大 ;随着尺度增加由于掩盖了更小尺度上的变异 ,导致块金效应增强 ,空间自相关部分对系统总的变异则明显下降 ;景观多样性具有尺度依赖性 ,可以说景观多样性也是尺度的函数 ,在不同的尺度上 ,结果差异显著 ,所以在景观生态学的研究中绝对不能忽略尺度对格局的影响     

景观生态学三维格局研究进展

非生物与生物的密切交互造就了多种多样的三维景观格局,景观生态学作为研究格局和生态学过程的学科,其在三维空间的探索随着激光雷达等三维数据提取技术的完善取得了快速进步.三维数据的引入使得研究更贴近真实地表景观,研究结果与相关生态学指标具有更明显的同向趋势.这改善了传统研究缺乏生态学意义的问题.但由于研究背景不同,研究方法和研究结论仍缺乏普适性.另一方面,研究结果对尺度变化的敏感度也因三维数据量的扩大而增加,如何选择并处理适宜尺度的数据使结论更加科学,是未来需要注意并探讨的问题.未来,随着数据获取更加便捷,研究将向长时间多尺度多源数据集成化发展,除动态监测及预测外,结合景观规划设计的可持续规划和生态恢复应用也是重要的研究方向之一.     

An island biogeographical view of the successional pathway in wet dune slacks

Abstract. Wet dune slacks occur as small, naturally fragmented systems in the dune landscape, isolated from other slacks. We studied the effects of slack isolation and area on the rate and direction of primary succession in a chronosequence of dune slacks. The results indicate that important changes occur in community characteristics over a period of 50 yr. Total cover and number of species increase as a result of the endogenous succession process, during which organic matter and nutrients accumulate. Consequently, competitive interactions shift from competition for nutrients to competition for light. Local factors thus determine, at least partially, the community composition in the slack. However, differences in community composition with increasing age are smaller when the slack is more isolated or smaller, suggesting a slower succession rate and biomass accumulation. Together with a lower contribution of slow dispersing species in more isolated slacks, this indicates that species accumulation is dispersal limited and thus influenced by regional factors. The stochastic variation resulting from this dispersal limited species accumulation causes a divergent successional pathway.     

Dune slack restoration in Dutch mainland coastal dunes

The 45,000 ha Dutch dunes are relatively well protected but they suffer from severe desiccation. During the last decade a lot of knowledge has been obtained about the steering processes of eco-hydrology in dunes resulting in well-founded schemes to restore wet dune slack communities. In two case studies a large-scale restoration of the landscape was necessary. Since 1987 in the North-Holland Dune Reserve the groundwater catchment has been reduced (from 8 million m³ to 2 million m³ per year) and the resulting development monitored. In another case, large-scale intervention on 35 ha of the Amsterdam Water Supply Dunes in 1995 resulted in the restoration of active sand drift with opportunities for the establishment of pioneer vegetation. In small parts of the area, the surface has stabilised as a result of vegetation growth, but elsewhere drifting sand has spread and covered previously stable surfaces. Many wet to moist dune slacks developed and results relating to geomorphology, hydrology and vegetation are presented. Finally, in 1996 yet another project of 50 ha was carried out in the Meijendel dunes, in which infiltration ponds were removed to allow vegetation succession to develop from scratch. Results of these three case studies will be presented. If only hydrological restoration is carried out, sod-cutting was found to be necessary to restore the whole series of vegetation types of dune slacks. In two cases an area was denuded. The seed bank and surrounding slacks seem to play an important role in the success of restoration, this is especially true for the pioneer vegetation types. Future monitoring will prove whether critical (Red List) plant species will return.     

Restoration of coastal dune slacks in the Netherlands

In order to stop the continuous decline of typical dune slack communities along the Dutch coast, restoration projects have been carried out since 1952. Restoration measures consisted of re-introducing traditional management techniques in dune slacks, such as mowing, grazing and sod removal, or constructing artificial dune slacks to compensate for lost biodiversity elsewhere. An analysis of successful and unsuccessful projects showed that constructing new dune slacks was not very successful for maintaining new populations of endangered dune slack species, since such projects were often carried out in areas where seed banks were depleted, while hydrological conditions and seed dispersal mechanisms were sub-optimal. The construction of sand dikes to prevent sea intrusion in large beach plains was, unintentionally, a temporary success for the establishment of many Red List species, although such measures often disrupted natural dune slack formation. Successful sites were all characterised by a regular discharge of calcareous groundwater provided by local or regional hydrological systems, where not very long ago populations of typical dune slack plants were present. Under such conditions, sod removal was a successful measure to create pioneer stages which were relatively stable, due to a very slow accumulation of organic matter in the topsoil. It is argued that new and more flexible coastal defence strategies can provide new opportunities for natural and relatively stable pioneer stages of dune slack formation, suitable for the long term preservation of endangered dune slack species.     

景观生态学在海岸带地区的研究进展

海岸带是景观生态学研究的重要领域,并且取得了长足的发展。系统剖析景观生态学在海岸带陆地土地利用变化的景观格局分析与优化、滨海湿地景观格局破碎化及其生态效应、海岛开发和保护的景观规划与设计、近岸海域空间开发的景观格局分析与评价、海洋环境过程与空间格局的相互作用关系等领域研究取得的成绩及其存在的主要问题。在此基础上,结合我国生态文明建设要求,探讨了景观生态学在海洋生态文明建设中的研究尺度匹配、格局-过程耦合理论引导、景观格局指数量化考核方面的学科优势。景观生态学可以在围填海平面设计与规划研究、海岸带生态修复与景观建设、海洋保护区选划与管理、海岛开发与保护、海陆统筹下的海岸带综合管理等方面开拓应用发展领域,助力海洋生态文明建设,承担建设海洋强国、美丽海洋的新使命。同时也为景观生态学在近岸海洋资源环境中的应用、近岸海洋景观生态学的发展梳理框架与思路。     

Plant responses to rising water tables and nutrient management in calcareous dune slacks

Plant species of oligotrophic wet dune slacks have dramatically decreased as a result of desiccation and eutrophication. The aim of this study was to test in a field experiment the effects of restoration management in oligotrophic, wet dune slacks (groundwater level rise in combination with topsoil removal or mowing) on abiotic variables and on survival and biomass of four plant species. The effect of groundwater level rise on abiotic variables strongly differed between mown sampling locations and those with topsoil removal. At locations with a mowing treatment, a large rise in water tables led to increased N availability and higher reduced iron concentrations than at other locations. Such effects were absent at locations with recent topsoil removal. No effect of groundwater level rise on P-availability was found. Topsoil removal on average lowered N availability by 13%, P availability by 65% and Fe²⁺ by 56%. All phytometer species survived better in mown dune slacks than in dune slacks that had received topsoil removal. Survival of all species was negatively related to groundwater level rise. On the short term local extinction risks of small populations may be enhanced by rewetting and topsoil removal. On the long-term, however, such measures are crucial to maintain vegetation of oligotrophic wet dune slacks in a degraded dune landscape.     

Can soil seed banks contribute to the restoration of dune slacks under conservation management?

Questions: Does the soil seed bank resemble the former early successional stages of a dune slack system more than the established later successional vegetation? Does it have the potential to contribute to the conservation of a highly endangered habitat? Location: Dune slacks at Newborough Warren, UK. Methods: The composition of the soil seed bank in two depth layers was determined using the seedling emergence method between March 2004 and April 2005. Long-term monitoring data on the floristic composition of the established vegetation were obtained from the national conservation agency, and additional monitoring was undertaken in 2003. Floristic composition, seed weights, seed longevity of component species and Ellenberg indicator values were used to compare the seed bank and established vegetation. Results: The soil seed bank was diverse and contained typical dune slack species, species of early successional stages and species of conservation interest. A comparison between the composition of the seed bank and historical data on the composition of the established vegetation showed that the seed bank reflects earlier successional stages more closely than the current aboveground vegetation. This study increases the scarce information currently available on the seed bank ecology of several species, including two orchid species. Conclusions: The soil seed bank can be expected to contribute to vegetation change after disturbance. Stimulation of germination from the seed bank through management may contribute to the conservation of both characteristic and threatened species typical of dune slacks.     

国际景观生态学研究新进展

20世纪90年代中期以来,国际景观生态学发展迅速.景观生态学研究最为活跃的地区集中在北美、欧洲、大洋洲(澳大利亚)、东亚(中国),表明景观生态学理论、方法和应用的广泛性和越来越高的认知度.从研究内容上看,景观生态评价、规划和模拟一直占居主导地位,其次是景观生态保护与生态恢复、景观生态学的理论探讨.随着景观生态学研究的深入,以科学和实践问题为导向的学科交叉与融合不断加强,促进了景观生态学新的学科生长点的形成和发展,主要包括水域景观生态学、景观遗传学、多功能景观研究、景观综合模拟、景观生态与可持续性科学.在全球化背景下,中国的景观生态学研究也已经取得了长足进展,国际同行开始关注并在重要学术刊物上评介中国的景观生态学研究,标志着中国景观生态学已逐步走上国际舞台.然而,中国景观生态学进一步发展的挑战和机遇并存.中国科学家需要抓住人类对可持续发展和可持续性科学的共同夙求,放眼国际前沿、服务本土需求,从中国自身的特色出发,关注受人类干扰的和以人为主导的景观,以景观格局与生态过程的多尺度、多维度耦合研究为核心,区域综合与区内分异并重,推动综合整体性景观生态学的建立和完善.     

Genetic diversity and ecological differentiation in the endangered fen orchid (<Emphasis Type="Italic">Liparis loeselii</Emphasis>)

Liparis loeselii is a rare and endangered orchid occurring in Europe and north-east America. Genetic diversity and structure of this species in north-west France and the United Kingdom were investigated using amplified fragment length polymorphisms (AFLPs). Although clonality and autogamy are common in L. loeselii, we found moderate to important variability within populations. We observed a significant genetic differentiation between populations occurring in dune slacks and fens. This may be correlated with leaf shape as dune slack individuals are sometimes treated as the distinct variety L. loeselii var. ovata. Genetic differentiation between populations was generally low suggesting that gene flow can occur over long distances and possibly across the English Channel. These results show that populations from dune slacks and fens should be managed separately and that geographically distant populations may be equivalent.     

Dune Slack Vegetation in Southern New Zealand

A range of slack vegetation in southern New Zealand was described by detailed sampling of four dune slacks, contrasting in topographic situation and in vegetation. Comparison is made with a slack previously sampled on Stewart Island. The five slacks differed markedly in the plant communities present. One slack, where there was considerable peat accumulation, was dominated by the megaherb Phormium tenax and the restiad Leptocarpus similis. In another, the peat was deep and had apparently accumulated over a long period; the vegetation contained the trunked sedge Carex secta and was similar in species composition to carr vegetation described from the region. These two slacks were predominantly native in species composition, though the European Erica lusitanica was a component at the second. The other two slack sites were on substrate largely comprising sand; the vegetation was shorter, and included a mixture of native and exotic species. Many of the exotic species found in these sites have been recorded in European slacks. Communities were defined by Cluster analysis. With rare exceptions, each plant community was specific to one or another of the five sites. Even the few community/site overlaps were in the vegetation of the surrounding dune areas, not of the slack itself. The communities within a site generally formed discrete zones, related to small differences in elevation. The environment was characterised in terms of elevation, water table level, and soil salinity (chloridity), organic content, pH, physical texture and fertility (assessed by bioassay). There were varying amounts of organic matter accumulation, but the mineral part of the substrate was almost pure sand throughout, except that at one site a stream had brought in silt. In three of the sites, the mineral base was below high tide level. The water table fluctuated through the year, with the same pattern as described for Northern Hemisphere slacks. Chloridity was low, but varied through the year. Some features of the yearly variation could be related to weather events. It is concluded that slacks in the area show considerable variation in vegetation, much of which can be correlated with peat accumulation.     

Restoration of Wet Dune Slacks on the Dutch Wadden Sea Islands: Recolonization After Large-Scale Sod Cutting

The effects of sod cutting were studied in a dune area on the Dutch Wadden Sea Island of Texel. Sod cutting was carried out in a range of different dune slacks in order to restore dune slack vegetation with many endangered Red List species. Sod cutting removed approximately 96% of the soil seed bank. Species abundant in the seed bank, notably Juncacea, also had a high frequency in the vegetation that established during the first year after the restoration measures. Many other species not registered in the seed bank or in the former vegetation also appeared. Species richness in the monitored plots exceeded that of uncut reference plots after a few years. Colonization rates were higher than extinction rates in most plots, indicating that a stable state has not been reached after 5 years. Differences in species richness between slacks appeared to be related to the occurrence of source areas nearby and availability of dispersal agents, such as flooding and animals.