景观规划中的生态廊道宽度

生态廊道具有保护生物多样性、过滤污染物、防止水土流失、防风固沙、调控洪水等多种功能。建立生态廊道是景观生态规划的重要方法,是解决当前人类剧烈活动造成的景观破碎化以及随之而来的众多环境问题的重要措施。按照生态廊道的主要结构与功能,可将其分为线状生态廊道、带状生态廊道和河流廊道3种类型。生态廊道设计包括的关键问题有廊道数目、本底、宽度、联接度、构成要素、关键点(区)等。由于生态廊道结构与功能的复杂性,使得廊道的宽度具有很大的不确定性。具体的讲,生态廊道的宽度由保护目标、植被情况、廊道功能、周围土地利用,廊道长度等多个因素决定。合适的廊道宽度应该根据对廊道主要生态过程的研究来确定。从景观的结构与功能分析出发,分别从生物保护廊道和河流廊道两方面对生态廊道的宽度及其影响因素进行分析,并对相关研究成果进行综述,总结得出两种类型生态廊道的适宜宽度值范围。最后提出确定宽度时应该注意的相关问题。     

Impact of a natural enemy overwintering refuge and its interaction with the surrounding landscape

1. Egg parasitoids in the genus Anagrus (Hymenoptera: Mymaridae) are important mortality factors for grape leafhoppers ( Erythroneura elegantula ; Homoptera: Cicadellidae) in California vineyards, yet must overwinter in habitats external to these vineyards. Existing evidence suggests that French prune trees, which harbour the overwintering host Edwardsiana prunicola , planted adjacent to vineyards may enhance early-season abundance of Anagrus.
2. Anagrus overwintering in French prune tree refuges were labelled with the trace element rubidium in four separate experiments. Rubidium-labelled Anagrus were captured in adjacent vineyards in two of the experiments, confirming that French prune trees contribute to early-season Anagrus populations. Anagrus from refuges were captured at the most distant sampling positions, 100 m from refuges.
3. Use of rare element labelling has, for the first time, enabled the relative contribution of different sources to early-season colonization by this parasitoid to be quantified. Refuges contributed 1% and 34% of Anagrus colonizing two of the experimental vineyards, respectively. The remainder originated from overwintering habitats external to the French prune/vineyard system.
4. The spatial patterns of Anagrus originating from external overwintering habitats suggest that the French prune trees are generating a 'windbreak effect'. Anagrus dispersing within the windstream colonized vineyards at a higher-than-average rate immediately downwind of refuges.
5. The amount of colonization by Anagrus from external overwintering habitats was apparently related to the distance to presumed overwintering habitats. These findings demonstrate that both the number of natural enemies emerging from a refuge and the composition of the surrounding landscape are important in determining the impact of local, small-scale habitat manipulations.     

周边区域湿地景观变化对洪河保护区涉禽栖息地的影响

以三江平原洪河国家级保护区及其周边3个农场为研究区域,利用GIS技术和栖息地评价模型方法,探讨了周边区域湿地景观变化对保护区内景观结构以及丹顶鹤、东方白鹳栖息地的影响。结果显示：（1）自1983年区域土地开发以来,周边区域湿地景观面积减少了63％,景观类型多样性趋于单一化;（2）保护区内湿地景观结构改变明显,类型多样性呈降低趋势,丹顶鹤和东方白鹳栖息地面积和空间分布均发生变化;（3）保护区与周边区域湿地景观连通度降低了70％,其结果严重改变了保护区与周边区域的景观生态联系,削弱了保护区原有湿地景观多样性和涉禽栖息地功能;（4）必须从景观尺度,恢复保护区周边一定面积的湿地景观结构,维持保护区与周边区域适当的景观生态联系,是有效管理和维护保护区可持续发展的最佳手段之一。     

Phylogeographical structure of the boreal‐montane orchid Malaxis monophyllos as a result of multi‐directional gene flow

We investigated the phylogeographical structure of the boreal‐montane orchid Malaxis monophyllos in its Eurasian geographical range. We analysed four sequences of plastid DNA (trnL, trnL–trnF, rps16 and accD‐psaI), resulting in 19 haplotypes and revealing a high level of intraspecific diversity (H_D = 0.702 and π = 0.196 × 10⁻²), but showing a lack of phylogeographical structure. This pattern might be caused by multiple phenomena and processes, e.g. broad‐fronted recolonization with accompanying multi‐directional gene flow between populations and expansion from at least two refugial areas. Despite the lack of phylogeographical structure, three centres of haplotype diversity were indicated in the European part of the range of M. monophyllos. According to these data, alpine and lowland glacial refugia located between the ice sheets in the European Alps and the Scandinavian glaciers seem most likely to be in Europe. Moreover, models of climatically suitable areas during the Last Glacial Maximum (LGM) confirmed the Alps as a possible refuge, and indicated an opportunity for the persistence of M. monophyllos populations in Beringia and parts of Siberia. Using two models [Model for Interdisciplinary Research on Climate (MIROC) and Community Climate System Model (CCSM)], we predicted a significant reduction in climatically suitable areas for M. monophyllos in the future (2080). Our study also demonstrated that the biological features of M. monophyllos, including breeding system and dispersal mode, seem to be crucial in understanding its phylogeographical pattern. Our results also highlighted the importance of anthropogenic habitats as reservoirs of genetic diversity and alternative habitats for this species in the context of declining natural populations. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 178 , 138–154.     

丽香铁路建设对沿线景观格局影响的尺度效应及其生态风险

高原铁路作为大型廊道工程,线长点多、途经环境敏感,其对沿线生态环境影响评价范围的界定在环评工作实践中易产生争议.本文以丽香铁路唐布至建塘段为研究对象,利用2012年1∶10000土地利用现状图和数字高程模型为数据源,采用缓冲区与景观指数方法,构建了廊道切割度指数和廊道干扰累积作用指数,改进了衡量铁路建设后的生态风险指数.通过定量分析不同空间尺度下铁路建设前后景观格局时空变化特征和演变规律,得到本段铁路最适宜评价尺度,并在该尺度内对铁路建设前后生态风险时空变化特征进行分析.结果表明：廊道切割度指数有效反映出铁路廊道对各种景观类型的切割方式和程度,廊道干扰累积作用指数可衡量铁路风险源与风险受体之间暴露与危害关系;铁路建设后,铁路廊道将对沿线景观产生较大的正中切割作用,边缘切割和内部切割作用较小,林地和草地所受影响最大;景观格局指数在600 m缓冲区内尺度效应最明显,因此设置600 m为本段铁路最适宜生态影响评价范围;铁路建设前,600 m评价区以低生态风险为主,铁路建设后,生态风险显著增加,以中等以上生态风险区域为主;研究区生态风险具有南低北高,多核环形的分布特征.     

武汉市绿色廊道景观格局

绿色廊道作为城市关键的景观结构要素,在维持城市生物多样性,改善城市生态环境,调节小气候等方面发挥着重要的作用.以武汉市建成区为例,探讨城市绿色廊道景观格局定量研究的方法,使其充分发挥生态功能,从而指导城市绿色廊道的规划与建设.利用GIS处理基础资料,对城市廊道系统进行提取与分类,生成拓扑关系图,并计算景观格局指标参数.从廊道景观的构成和绿色廊道的网络结构两方面详细分析了武汉市建成区各行政区内各类型绿色廊道的景观格局.结果表明：在武汉市建成区内,灰色廊道最长,占廊道总长的63.53﹪;绿色廊道极其缺乏,总密度仅为2.63 km/km^2;在绿色廊道中,绿色道路廊道最长,占绿色廊道总长的60.29﹪.绿色廊道普遍较窄,绿带的长度不到其它类型绿色廊道总长的1/3;绿色道路廊道最窄,少数达20 m.绿色铁路廊道面积较小,为1.68 km^2,其它类型的绿色廊道面积相当,各占总面积的30﹪左右;3个行政区中,武昌的绿色廊道长度最长,面积最大.绿色廊道网络线点率、环通度及连通度均不高,网络结构简单,不利于城市生物多样性的维持.绿色道路廊道网络结构相对最复杂;绿带的网络连通性最差,没有回路存在;武昌的绿色河流廊道、绿带以及绿色铁路廊道网络结构最复杂,绿色道路廊道网络最复杂的是汉口.武汉市绿色廊道的建设,应注重长度和宽度的增加,提高绿带的比例;重视各类型绿色廊道及其在各行政区间的均匀分布;减少绿色廊道的断开区,增加网络连通性;使其走向与城市主导风向一致,兼顾通风走廊的功能.     

面向连通性提升的旱区城市生态网络优化情景——以巴彦淖尔市及其周边地区为例

巴彦淖尔市作为典型的干旱区城市,经济发展与生态保护之间的矛盾突出,生态空间的破碎化日益严重。生态网络是景观连通性视角下耦合景观结构、生态过程和功能的有效途径。基于生态系统服务重要性、景观核心区与桥接区、自然保护区、重要湖泊湿地4个层面指标选取生态源地,使用最小耗费距离方法识别巴彦淖尔市及其周边区域的潜在生态网络,并设置了3种网络优化情景进行网络优化,包括情景一增加生态"踏脚石"、情景二清除生态障碍点、情景三保护生态夹点,结合"网络构建成本"及"生境连通效果"选取最佳优化方案。结果表明,研究区当前的生态网络由24处生态源地,44条生态廊道、39个生态障碍点和41个生态夹点组成。3种情景中生态夹点的保护对生态网络连通度的改善最明显,且相对保护成本较低。研究结果对干旱区城市生态网络构建提供了方法支撑。     

山地景观生态学研究进展

山地环境对全球变化的高度敏感性及其在陆地淡水资源与生物资源方面的巨大影响,推动山地景观生态学迅猛发展。在系统分析2000年以来山地景观生态学文献计量基础上,针对山地景观生态学主要学科方向与科学问题,以山地垂直带谱结构分布模式与形成机制,山地景观生态功能的分布格局与驱动因素,山地景观生态结构与格局对全球变化的响应等三大领域为重点,综述了自2000年以来的主要研究进展和取得的新认识,归纳了每个领域现阶段存在的主要前沿问题。围绕上述山地景观生态学重点领域,提出了山地景观生态学未来重点发展的6个研究方向:全球山地环境变化综合观测网络与方法、山地多维景观生态格局与时空变化规律及其驱动机制、整合景观生态学方法的林线动态与机制研究、山地生物生产力和物种多样性变化与模拟、景观生态水碳耦合循环变化与影响、山地垂直带谱结构理论与模式等,为进一步推动山地景观生态学发展、准确理解山地环境对全球变化的响应规律及其影响提供理论参考。     

Niche analysis of orchids of serpentine and non-serpentine areas: Implications for conservation

Orchids are known for their species richness, intriguing ecology, rarity and the fact that they grow in almost all terrestrial ecosystems. Although numerous studies about their ecology have been carried out concerning calcareous areas, little is known about orchids that occur in serpentine habitats. The aim of this study was to investigate the ecological preferences of orchids in serpentine and non-serpentine areas on the model of the Valjevo Mountain Range (W Serbia). Niche analysis of orchids was performed using outlying mean index analysis. Data concerning geographical coordinates, altitude, habitat type, inclination, bedrock type, light regime, soil moisture, acidity, nitrogen and temperature were used as explanatory variables. Data of 33 orchid taxa from 407 localities were analysed. The most important gradients that govern orchid distribution were geological bedrock, light regime and temperature. The results have shown that only Anacamptis morio and Gymnadenia conopsea have statistically significantly larger populations on serpentine compared with non-serpentine bedrocks. This study highlights the importance of serpentine habitats as orchid habitats, bearing in mind the occurrence of rare species and species which were found exclusively in serpentine habitats.     

May Rare Metallophytes Benefit from Disturbed Soils Following Mining Activity? The Case of the Crepidorhopalon tenuis in Katanga (D. R. Congo)

Cuprophytes are plants that mostly occur on Cu‐rich soil. In South Central Africa, these species are threatened by intensive mining exploitation destroying their habitats. Crepidorhopalon tenuis (Scrophulariaceae) is a tiny annual cuprophyte endemic to the Zambesian center of endemism and is particularly abundant in the Lubumbashi area. We investigate here the ecological niche of C. tenuis through the analyses of its abundance and distribution in relation to soil factors, plant community composition, and anthropogenic perturbations. Soil and vegetation data were collected in seven sites (five metalliferous and two nonmetalliferous). The current study shows that C. tenuis has its ecological optimum on copper‐rich soil and can be referred to as an elective pseudometallophyte. This species is rare in primary steppic savanna on natural metalliferous soil. Its frequency and abundance peak in pioneer communities on bare soil. In particular, the species showed a surprising ecological plasticity as it was able to benefit from anthropogenic disturbance and to colonize the large areas of bare, contaminated soil left over by mining activities. Our results strongly suggest that C. tenuis was a very rare species in natural metalliferous communities, restricted to patchy areas of open soil in steppic savanna. Recent anthropogenic habitats may have conservation value for some rare metallophytes with colonizing traits and low competitive ability.     

基于景观连接度的土地整理生态效应评价

近年来,土地整理区的生物多样性保护和景观功能的维持受到广泛关注。本文选取贵州省道真县洛龙镇国家重点土地整理项目区,运用基于结构与功能相结合景观连接度模型(综合连接度(IIC)和连接度概率(PC)),计算了500、1000、2000、3000和4000m种群迁移扩散距离阈值情景下,土地整理前后各生境斑块对景观连接度的重要程度,识别重要斑块变化范围,从功能角度评价整理后的生态效应。结果表明:连接度指数能较好地识别土地整理前后各生境斑块的重要类别及其改变;其中,巨型斑块所占面积最大,分别占总面积的57.0%和57.2%;小型斑块数目整理前后分别占斑块总数的48.0%和48.9%;空间上,斑块的重要性分布也产生一定的变化。整理后生境斑块的连通性较整理前也有所下降,IIC和PC平均值分别为0.434和0.680,且随着距离阈值的增大,连接度逐渐增大。巨型斑块对生境斑块景观连通性的相对重要值最大,中型斑块和大型斑块次之,小型斑块最低。研究表明,土地整理过程中,大面积生境斑块和"踏脚石"斑块对维持土地整理生态效益具有重要作用。     

京津冀城市群生态网络构建与优化

生态安全是人类生活的基本保障,快速城镇化致使大型生态源地破碎化、岛屿化,生态环境问题日益严重。构建生态网络不仅能加强生态源地间的连通性,完善生态功能,还能提高生态系统的综合能力,改善恶化的生态环境问题。以京津冀为研究区,基于地理空间分析技术确定京津冀生态源地,对研究区内的林地、湿地、草地,结合生态红线等进行区域叠加从而完成源地提取;基于最小成本路径方法,考虑土地利用及高程影响因子,提取京津冀城市群生态廊道,分析统计廊道分布情况;结合重力模型与重要生态源地连通性筛选出京津冀重要生态廊道,叠加现有国道、河流构建生态网络,对重要生态节点进行分析。研究结果表明,生态源地面积占研究区总面积比例为21.76%,林地、湿地、草地面积占总生态源地面积分别为82.78%,11.05%,6.17%;不同地貌区域生态源地类型不同,林地主要分布在山区,湿地主要分布在平原区域,草地主要分布在研究区西北部;景观成本值平原区域高于草原和山区,北京、天津、石家庄城区及周边景观成本值最高;采用最小成本路径模型提取廊道579条,其中张家口、承德区域生态网络较好,平原区域生态源地及生态节点缺失较为严重。最后,对北京、天津、白洋淀、衡水湖等重点生态区域提出修复和保护意见,为京津冀城市群发展提供参考。此外,本研究对其他地区生态网络的构建提供理论依据与技术支持。     

景观生态恢复与重建是区域生态安全格局构建的关键途径

生态恢复与重建是跨尺度、多等级的问题,其主要表现层次应是生态系统（生物群落）、景观,甚至区域,而不能仅仅局限于生态系统。景观的恢复与重建是针对景观退化而言,景观退化从表现形式上可分为景观结构退化与景观功能退化。景观结构退化即景观破碎化,是指景观中各生态系统之间的各种功能联系断裂或连接度(connectivity)减少的现象;而鲜受重视的景观聚集（aggregation）在很多情况下同样具有造成景观退化的负面效应。景观功能退化是指与前一状态相比,由于景观异质性的改变导致景观的稳定性与服务功能等的衰退现象。景观恢复是指恢复原生生态系统间被人类活动终止或破坏的相互联系;景观生态建设应以景观单元空间结构的调整和重新构建为基本手段,包括调整原有的景观格局,引进新的景观组分等,以改善受胁或受损生态系统的功能,提高其基本生产力和稳定性,将人类活动对于景观演化的影响导入良性循环。二者的综合,统称为景观生态恢复与重建,是构建安全的区域生态格局的关键途径。其目标是建立一种由结构合理、功能高效、关系协调的模式生态系统（model ecosystem）组成的模式景观（model landscape）,以实现生态系统健康、生态格局安全和景观服务功能持续,以3S(RS,GPS,GIS)技术为支撑的GAP(ageographic approach to protect biological diversity)分析将为大尺度景观恢复的诊断、评价、规划提供重要的手段。景观中某些关键性点、位置或关系的破坏对整个生态安全具有毁灭性的后果,研究景观层次上的生态恢复模式及恢复技术、选择恢复的关键位置、构筑生态安全格局已成为景观生态学家关注的焦点。     

Habitat suitability models for the sand lizard Liolaemus wiegmannii based on landscape characteristics in temperate coastal dunes in Argentina

The knowledge of environmental variables associated with the species occurrence allows the recognition of sites which fulfil ecological requirements eventually used for conservation of species. The coastal dunes of Argentina are inhabited by sand lizards. Anthropic activities have severely degraded this ecosystem, affecting the habitat structure at a large scale. In this context, the effects of landscape characteristics on the sand lizard's (Liolaemus wiegmannii, Liolaemidae) presence were analysed to build habitat suitability maps along the coastal dunes of Argentina. A thematic map of study area was obtained from supervised classification of satellite images to identify landscape characteristics. Surveys were conducted during the lizard activity season, and landscape variables were measured in two spatial units. All information collected was compiled into a Geographic Information System. The relationship between the presence of lizards and landscape variables was evaluated by Generalized Linear Models. The predictions of these models were transferred by using Geographic Information System to habitat suitability maps. Almost all individuals (80%) were observed in semi‐fixed dunes. The analysis of landscape metrics in the two spatial extents showed complementary results. The habitat suitability models suggest that: (i) heterogeneous landscapes composed by disaggregated patches of semi‐fixed dunes and low or null percentages of active dunes distant from the coastline are the preferred environments, and (ii) human modifications such as urbanizations and forestation of dunes, have a negative impact on species occurrence. Suitable habitats were almost absent in those sectors of coastal dunes with highest level of urbanization, whereas they were distributed almost continuously in those areas without human disturbances.     

Riverine landscapes: taking landscape ecology into the water

1. Landscape ecology deals with the influence of spatial pattern on ecological processes. It considers the ecological consequences of where things are located in space, where they are relative to other things, and how these relationships and their consequences are contingent on the characteristics of the surrounding landscape mosaic at multiple scales in time and space. Traditionally, landscape ecologists have focused their attention on terrestrial ecosystems, and rivers and streams have been considered either as elements of landscape mosaics or as units that are linked to the terrestrial landscape by flows across boundaries or ecotones. Less often, the heterogeneity that exists within a river or stream has been viewed as a `riverscape' in its own right.
2. Landscape ecology can be unified about six central themes: (1) patches differ in quality (2) patch boundaries affect flows, (3) patch context matters, (4) connectivity is critical, (5) organisms are important, and (6) the importance of scale. Although riverine systems differ from terrestrial systems by virtue of the strong physical force of hydrology and the inherent connectivity provided by water flow, all of these themes apply equally to aquatic and terrestrial ecosystems, and to the linkages between the two.
3. Landscape ecology therefore has important insights to offer to the study of riverine ecosystems, but these systems may also provide excellent opportunities for developing and testing landscape ecological theory. The principles and approaches of landscape ecology should be extended to include freshwater systems; it is time to take the `land' out of landscape ecology.     

基于二维小波分析的景观特征尺度识别

采用3种常用小波基（Haar、Daubechies和Symlet）,探讨了二维小波分析在沈阳地区城市、城乡交错区和农村3种景观类型特征尺度识别中的有效性.由于二维小波分析的变换尺度必须为2的整数次幂,这会导致景观中一些特征尺度无法精确识别,故本文将各景观类型影像像元大小分别重采样为3、3.5、4和4.5 m,以增加分析时的尺度密度.结果表明：应用二维小波分析可清晰地识别景观特征尺度;Haar、Daubechies、Symle可分别作为城乡交错区景观、城市景观和农村景观特征尺度识别的最优小波基;Haar和Symlet均可应用于农村景观精细特征尺度的识别和城乡交错区景观边界的检测;Daubechies和Symlet可分别用于城市景观和农村景观的边界检测.     

景观生态学在土地整治中的应用研究进展

在土地整治中融入景观生态学理念是推动土地整治生态建设的必然要求。阐述了土地整治中的景观生态学原理,分析了相关文献变化和研究重点,总结了中国土地整治中的景观生态学研究现状,提出了土地整治中的景观生态学研究展望:(1)重视土地整治中景观生态学的基础理论研究,构建土地整治的景观生态学理论与技术体系;(2)加强土地整治的景观动态与生态效应机制研究,建立适用土地整治景观生态影响的方法和模型;(3)强化土地整治的多尺度和长序列景观生态研究,揭示土地整治过程中的尺度效应和多尺度耦合机制;(4)加强土地整治中多种生态系统服务的集成与优化,强化用于指导土地整治生态规划设计与管理工作,以期为深化土地整治中的景观生态学研究提供借鉴和启示。     

甘肃临泽绿洲景观的空间结构与生产特性

绿洲景观生态系统包括居民点,耕地,林地,草地,水域,岩漠,砾漠,沙漠,道路,水系10种景观组分;基质为耕地,成因类型为引入型;斑块包括居民点,林地,草地,水域,岩漠,砾漠,沙漠7种类型,成因类型可以分为3类;居民点,林地,耕地为引入型,岩漠,砾漠,沙漠为残留型,草地为环境淘汰型及残留型;廓道包括水系和道路2种类型,道路的廓道密度为水系的1.03倍,耕地以植物生产为主,在利用上应增加生产层次,发展动物生产,避免扩大面积,以维持景观生态系统的景观异质性和景观多样性,对于具有环境资源型和残留型成因特征的景观要素,适当减少生产层次,开发前植物生产,发挥水土涵养,旅游休闲,防风固沙的生态功能,有利于景观异质性与多样性的维持与稳定,对于以残留型为主的成因类型,利用上应发掘前植物生产的潜力,适当发展植物生产,可以避免景观结构的恶化。