基于生态网络的生态安全格局评价

生态网络可用于描述、评价生境破碎条件下景观空间组织方式与物种存续的关系.本文以青岛市为研究区域,基于最小成本路径方法模拟得到2005年林地、湿地生态网络,并基于廊道累计成本值对得到的生态网络进行分级.利用介数指数、相关长度-逐块筛选指数对生态网络中斑块与廊道等结构要素进行重要性区分,形成生态网络结构体系.并在评价2005—2013年新增建设用地对生态网络影响的基础上,提出应对建设用地变化的生态安全格局.结果表明: 在生态网络框架基础上,图形理论的相关评价方法能够量化评价识别生态用地的具体属性(如生态网络斑块的面积)和生态用地之间的功能联系;2005—2013年间,青岛市新增建设用地对湿地侵占面积较大,且没有考虑具体林地、湿地在整个地区生态系统连通性维护中的作用;基于生态网络的生态安全格局的划定可以优化地区生态基底,为生态保护与恢复提供更加精确的空间决策依据,同时为城市空间扩张提供科学合理的空间指引.     

生态网络视角下武汉市湿地生态格局分析

城市湿地是城市发展的重要生态保障。快速城市化进程导致湿地景观破碎化,威胁湿地生态系统安全。生态网络通过廊道连接重要生境斑块,基于生态网络分析城市湿地生态格局,不仅可了解湿地的空间分布情况,还可反映湿地系统的结构与连通性特征。以武汉市为研究区,利用形态学空间格局分析(Morphological Spatial Pattern Analysis, MSPA)方法识别湿地源地,结合地表景观类型、地形坡度及人类活动强度因素构建综合阻力面,采用最小累积阻力模型(Minimum Cumulative Resistance, MCR)提取生态廊道构建湿地生态网络,最后对网络进行重要性分级。分析网络的结构及区域特征,结果表明:武汉市湿地规模较大,但破碎化严重且空间分布不均;网络空间结构不完备但景观结构良好,重要廊道多位于城市边缘斑块间且集中分布在南部地区;各区域湿地格局特征不同,江夏区及汉南区湿地资源丰富且斑块质量高,廊道分布多且景观结构较好但重要性不高,黄陂区及东西湖区湿地总量少且形态破碎,区内廊道少、重要性低且景观结构有待改善,新洲区湿地规模小,廊道分布较少且景观结构不完善,但湿地及廊道重要性均较高。研究结果将为武汉市湿地保护与建设工作提供科学依据。     

疏勒河流域景观生态风险评价与生态安全格局优化构建

以疏勒河流域为研究区域,利用RS和GIS技术,建立基于景观格局的景观生态风险指数,分析研究区域内景观生态风险的时空变化特征和聚集模式。利用最小累积阻力模型,以自然保护区、水域、林地等作为生态"源地",以生态安全水平、海拔和坡度作为阻力因子生成阻力面,构建流域生态安全格局,识别潜在廊道和节点,建立优化后的生态安全网络。结果表明:疏勒河流域北部的生态风险高于南部,生态风险水平在30年间有所改善,1980—1995年生态风险等级退化的区域主要位于流域西南部和东部;1995—2010年等级退化的区域面积小于1980—1995年。景观生态风险指数在空间上呈正的自相关性,30年间空间自相关程度有所减弱,空间趋同性逐渐降低。优化后的生态网络将生态源地、潜在廊道和节点等景观组分结合,充分利用已有的河流水系,打通廊道,避开城镇工矿用地和交通干线,并在生态脆弱区设置关键点作为物种扩散的"踏板"。     

黄淮海地区湿地系统生物多样性保护格局构建

以黄淮海地区为研究对象,首先分析了区域现有湿地保护状况,再基于湿地类型、保护状况和目标保护物种分布,综合考虑GDP、人口密度等社会经济因素,以湿地生物多样性保护为目标,运用系统保护规划的理论和方法,以Marxan作为空间优化模型,进行多目标的湿地系统保护预案设计,构建区域湿地不同保护水平的保护空缺和不可替代性格局,确定合理的湿地系统保护格局。研究结果表明:现有的湿地保护体系仅覆盖了区域17%左右的湿地,尚有许多重要生境游离于现有保护区系统外。为完善黄淮海地区湿地保护体系,需要对黄海海区域内28个保护区进行功能区划调整或者保护等级提升,并在山东(5个县)和河北(4个县),河南、江苏和安徽(各3个县),北京和天津(各1个县)等20个县市内建立新的保护区,与现有湿地保护系统有机整合,最终形成一个黄淮海地区湿地生物保护网络合理格局。结果表明:同其他相关研究方法对比,系统保护规划方法在区域大尺度生物多样性保护方面更具有意义;同时也表明该方法在中国的应用前景广阔。     

长江中游生态区湿地保护空缺分析及其保护网络构建

构建了综合反映长江中游生态区地形、植被与地表覆盖特征的GIS综合空间数据库,在对长江中游生态区核心湿地保护物种,即白鹤（Grusleucogeranus）、东方白鹳（Ciconiaboyciana）、小白额雁（Anser erythropus）、中华秋沙鸭（Mergus squamatus）分布范围和生境需求分析基础上,建立了反映物种分布与GIS数据库中生态地理因子关联的生境适宜性单元,从而确定了核心物种分布的潜在生境,对照现有保护区分布格局,找到了区域湿地生境保护的薄弱和空缺区域（Gaps）,评价了现有保护区系统对潜在生境保护的有效性。基于Gap分析结果和现有保护区分布格局,进一步考虑保护网络的整体性和连通性以及保护成本,构建了长江中游湿地保护区生物保护网络的合理格局。研究结果表明：长江中游生态区核心物种潜在生境涉及134个县（市）级单元,而目前长江中游湿地保护网络仅覆盖了23．49％的潜在生境,仍有大量潜在生境游离于现有保护区系统外。为完善长江中游生态区湿地保护网络,应在湖北（13县）、安徽（8县）和江西（1县）所属22个县域内建立新的湿地保护区或保护小区,并与现有湿地保护系统有机整合,最终才能形成较为完善的由45个县级单元构成的的长江中游生态区湿地生物保护网络合理格局,并保护80％以上核心物种的潜在生境。本研究同时也表明基于GIS生态地理空间数据库和生境适宜性单元概念进行大尺度生境分析具有一定可行性和应用价值。     

不同等级道路对生态网络的影响——以福州市为例

道路的扩张导致生态网络破碎化加剧及其景观连接度受阻,科学分析不同等级道路对景观连接度及生态网络的影响对指导道路规划和生态保护具有重要意义。本研究以福州市为研究区域,基于2020年道路网络、土地覆盖类型、数字高程模型等数据,运用形态学空间格局分析和电路理论在不同物种扩散距离(1、3、5、10 km)范围内进行生态网络构建,并在景观-斑块-廊道尺度分析不同等级道路(高速公路、城市快速路、一级公路、二级公路)对景观连接度的影响。结果表明：在景观尺度,整体景观连接度与物种扩散距离呈显著正相关,其中,高速公路、城市快速路、一级公路、二级公路均在10 km物种扩散距离范围内导致整体景观连接度的下降率最低,分别为15.6%、5.3%、1.5%、5.2%;在斑块尺度,在不同等级道路的比较中,高速公路在1、5 km物种扩散距离范围内导致斑块连接度的下降率最大,一级公路在3、10 km物种扩散距离范围内导致斑块连接度的下降率最大;在廊道尺度,城市快速路在5 km物种扩散距离范围导致整体最低成本路径的成本加权距离、整体最低成本路径的成本加权距离与其长度之比、整体有效阻力和廊道总长度的上升率最高,分别为43....     

基于系统保护规划的黄河流域湿地优先保护格局

黄河流域湿地为我国生物多样性维持提供了重要生境.本研究基于黄河流域气候分区、地貌单元及湿地遥感数据,构建黄河流域生态地理综合湿地分类系统.在系统保护规划理论框架下,将湿地气候-地貌分类单元作为生态系统层次保护对象,结合黄河流域鸟类分布范围作为物种层次的保护对象,设定30%湿地优化目标,将公路、铁路、城镇、农村居民点、水坝等作为度量因子创建黄河流域保护代价图层,并利用系统保护规划工具--Marxan软件构建黄河流域湿地保护优化格局,识别湿地保护空缺.结果表明: 黄河流域大部分沼泽湿地集中在黄河上游区域,目前源区保护区覆盖面积大,在内蒙古、甘肃及四川部分区域一些稀有湿地类型游离在保护体系外;黄河中游湿地类型以河道和河滩湿地类型为主,保护覆盖率极低,保护空缺严重,经优化保护网络体系后,保护成效可分别得到29.1%、37.6%的提升.黄河下游湿地主要集中在黄河三角洲区域,目前保护体系完整,保护空缺面积极小.总体上,黄河流域中游河流湿地的保护空缺比例最高,亟需重视.本研究基于湿地保护格局优化结果分区分析黄河流域湿地保护模式,为黄河流域湿地的保护规划管理提供了科学性建议,从宏观层面上为黄河流域水生态保护奠定了基石.     

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。     

基于鸟类功能性连接度的林地网络评价——以长沙市宁乡县中心城区为例

基于功能性连接度的相关理论,以长沙市宁乡县中心城区为研究区域,以灰椋鸟Sturnus cineraceus为城区鸟类的指示物种,采用连接度指数IIC、PC对研究区域现有林地网络的功能性连接度进行分析,并选取11个核心林地斑块和15个重要林地斑块,11条核心飞行廊道和16条重要飞行廊道;再利用最小累积阻力模型对林地斑块及斑块间的连线进行分析,识别出不利于灰椋鸟进行生态扩散过程的林地斑块及飞行廊道:核心林地斑块中斑块31、斑块43受中度干扰,核心飞行廊道中廊道50-42、廊道28-3处于中度阻碍状态,在今后进行城市生态格局规划时需对其进行优化。     

海岸带区域陆海统筹生态安全研究

海岸带既是区域经济发展的黄金地带，亦是陆海系统交互胁迫的敏感区域，快速城镇化与工业化导致海岸带关键生态系统服务受损、生态网络格局紊乱、珍稀物种安全保障空间萎缩等重大生态安全问题。以闽三角海岸带珍稀物种-栖息地系统为研究对象，从“多物种-多生境-多尺度”视角出发，基于陆海统筹理念系统评估了闽三角海岸带珍稀物种-栖息地系统的脆弱性，建立了基于物种水平的海岸带生态保护与修复网络，构建了海岸带陆海统筹生态安全“一张图”。研究结果表明：(1)高强度围填海驱动下，闽三角红树林与水鸟栖息地脆弱性显著增加，高脆弱区域主要集中于九龙江河口、厦门同安湾和泉州湾；(2)闽三角生态安全网络由12条水鸟迁徙廊道和11个生态节点组成，其中影响陆海统筹生态安全的生态节点4个，预警生态节点3个；(3)闽三角海岸带未来安全韧性生境(水鸟栖息地与文昌鱼、中国鲎低脆弱生境较密集的区域)分布于云霄红树林保护区、东山岛近岸、九龙江河口、厦门大嶝海域、围头湾、深沪湾。本研究能够为设计规划未来韧性海岸带“受损海水-滨海湿地-珍稀物种”一体化修复与保护的生态安全格局，保障陆海统筹生态安全提供理论支撑和一体化解决方案。     

青岛市湿地生态网络评价与构建

在快速城市化背景下,城市社会经济发展与空间扩张不可避免,往往造成栖息地数量、面积、质量锐减、栖息地之间联系破碎等后果。此外,全球气候变化也加剧了栖息地恶化过程。生态网络通过保护恢复重点栖息地及构建栖息地之间物质、信息及能量传播的连接廊道,在整体上维持生态系统的动态平衡。青岛市位于东部沿海经济发达地区,地处海洋与陆地生态系统的交汇处,生态环境极为脆弱,易遭受外力破坏,且难以恢复。选取青岛地区湿地作为研究对象,在RS,GIS技术支持下,基于最小成本路径法构建青岛市湿地生态网络,并利用关联长度指数、介数指数对网络的整体结构及斑块重要程度进行评价。结果表明,不同路径成本阈值水平下,网络的连通性有很大差别;核心斑块中,胶州湾湿地、大沽河等具有较高重要程度;歇脚石斑块中,重要程度较高的斑块位于以胶州湾湿地为中心,以胶莱河、潍河河口,白马河、潮河河口及丁字湾为端点的连线上。在青岛市及周边地区划定"一心、二轴、一环"的湿地生态网络控制框架的策略,为青岛市湿地生态系统保护与城市发展空间选择提供科学方法与量化依据。     

Habitat connectivity for conserving cervids in a multifunctional landscape

Habitat fragmentation is a considerable threat to biodiversity worldwide. To minimize the effects of fragmentation, it is important to identify and conserve the existing habitat connections that facilitate dispersal and gene flow among populations. Connected populations are more resilient to the changing environment that affects local populations due to greater demographic stability and higher genetic diversity. Our study is the first attempt to identify the crucial habitats facilitating the dispersal of two key sympatric cervids - spotted deer Axis axis and sambar Rusa unicolor in central India. We use species distribution models followed by landscape pattern analyses and connectivity analyses to delineate the essential habitats. Thereafter, we estimated the relative contribution of habitats outside protected areas in maintaining the ecological network, using graph-based metrics. We then locate and predict the areas that have a high risk of human-influenced cervid mortality using a Bayesian regression model that accounts for spatial structure in the data. The results show that about 55% of the core habitats, integrated across both species, lie outside the protected areas and are important in maintaining the ecological network for these cervids. Some peripheral habitats have an increased risk of anthropogenic cervid mortality, which poses high demographic risk. There is an urgent need to regulate the nature and intensity of human activities in areas of human-wildlife coexistence to maintain habitat connectivity and ensure the survival of wildlife populations. Our results on cervids complement analyses on connectivity for large carnivores and thus enables one to account for important trophic interactions among wildlife species in land use planning.     

Complementary strengths of spatially-explicit and multi-species distribution models

Species distribution models (SDMs) project the outcome of community assembly processes – dispersal, the abiotic environment and biotic interactions – onto geographic space. Recent advances in SDMs account for these processes by simultaneously modeling the species that comprise a community in a multivariate statistical framework or by incorporating residual spatial autocorrelation in SDMs. However, the effects of combining both multivariate and spatially-explicit model structures on the ecological inferences and the predictive abilities of a model are largely unknown. We used data on eastern hemlock Tsuga canadensis and five additional co-occurring overstory tree species in 35 569 forest stands across Michigan, USA to evaluate how the choice of model structure, including spatial and non-spatial forms of univariate and multivariate models, affects ecological inference about the processes that shape community composition as well as model predictive ability. Incorporating residual spatial autocorrelation via spatial random effects did not improve out-of-sample prediction for the six tree species, although in-sample model fit was higher in the spatial models. Spatial models attributed less variation in occurrence probability to environmental covariates than the non-spatial models for all six tree species, and estimated higher (more positive) residual co-occurrence values for most species pairs. The non-spatial multivariate model was better suited for evaluating habitat suitability and hypotheses about the processes that shape community composition. Environmental correlations and residual correlations among species pairs were positively related, perhaps indicating that residual correlations were due to shared responses to unmeasured environmental covariates. This work highlights the importance of choosing a non-spatial model formulation to address research questions about the species–environment relationship or residual co-occurrence patterns, and a spatial model formulation when within-sample prediction accuracy is the main goal.     

Effects of branching spatial structure and life history on the asymptotic growth rate of a population

The dendritic structure of a river network creates directional dispersal and a hierarchical arrangement of habitats. These two features have important consequences for the ecological dynamics of species living within the network. We apply matrix population models to a stage-structured population in a network of habitat patches connected in a dendritic arrangement. By considering a range of life histories and dispersal patterns, both constant in time and seasonal, we illustrate how spatial structure, directional dispersal, survival, and reproduction interact to determine population growth rate and distribution. We investigate the sensitivity of the asymptotic growth rate to the demographic parameters of the model, the system size, and the connections between the patches. Although some general patterns emerge, we find that a species’ modes of reproduction and dispersal are quite important in its response to changes in its life history parameters or in the spatial structure. The framework we use here can be customized to incorporate a wide range of demographic and dispersal scenarios.     

Accounting for dispersal and biotic interactions to disentangle the drivers of species distributions and their abundances

Although abiotic factors, together with dispersal and biotic interactions, are often suggested to explain the distribution of species and their abundances, species distribution models usually focus on abiotic factors only. We propose an integrative framework linking ecological theory, empirical data and statistical models to understand the distribution of species and their abundances together with the underlying community assembly dynamics. We illustrate our approach with 21 plant species in the French Alps. We show that a spatially nested modelling framework significantly improves the model's performance and that the spatial variations of species presence-absence and abundances are predominantly explained by different factors. We also show that incorporating abiotic, dispersal and biotic factors into the same model bring new insights to our understanding of community assembly. This approach, at the crossroads between community ecology and biogeography, is a promising avenue for a better understanding of species co-existence and biodiversity distribution.     

应用Maxent生态位模型预测淡水钩虾(甲壳纲,端足目)的分布(英文)

预测物种的适生区对于物种资源的评估、保护以及生物多样性的管理非常重要。由于全球气候变化和人类的过度开发,冷水性无脊椎动物的衰减速度比在陆地和海洋生活的无脊椎动物都要高。目前关于中国淡水钩虾分布方面的研究很少,本研究基于103个地表淡水钩虾的不同分布位点和广布种湖泊钩虾Gammarus lacustris 23个不同分布位点以及32个环境因子数据,使用生态位模型(Maxent)预测了淡水钩虾和湖泊钩虾在我国的适生分布区域。结果显示淡水钩虾非常适合分布在我国的一些偏远山区,如长白山、太行山、横断山、天山、昆仑山和祁连山,而青藏高原的东部、西部边缘地区和南部分布地区、尼泊尔、不丹和朝鲜半岛也是淡水钩虾的潜在适生区域,但淡水钩虾在我国华南、华中和华北的平原地区分布却很少,其在我国的潜在分布区与-10℃和5℃1月平均气温线间的区域相似。淡水钩虾是典型的狭温性物种,在不适宜温度条件下很难存活,这可能也是限制其扩散和存活的关键性因素。     

The role of wildlife science in wetland ecosystem restoration: Lessons from the Everglades

There has been little discussion of how and when to integrate wildlife science into ecological restoration projects. The recent emergence of wetland ecosystem restoration offers an opportunity to use wildlife science to increase the probability of a project being successful. This paper traces the evolution of wetland ecosystem restoration in North America and proposes three roles for wildlife science in wetland ecosystem restoration: (1) contribute to conceptual ecosystem models, (2) develop quantitative performance measures and restoration targets that track the progress of restoration, and (3) achieve social feasibility by sustaining long-term public support for a project. The extensive knowledge base for many species of wildlife makes them especially useful for contributing to conceptual ecosystem models. Wildlife species are often the subject of long-term monitoring and research because they have commercial value, are conspicuous, or have aesthetic appeal. Wildlife parameters can be good performance measures for large-scale restoration projects because some species integrate information over large spatial scales and are long-lived. Parameters associated with threatened or endangered wildlife species should get special consideration as performance measures because the information will meet multiple needs rather than just those of the conceptual ecosystem model. Finally, wetland ecosystem restoration projects need to sustain funding over decades to ensure the restored system is self-sustaining. Wildlife are a valued resource that can help achieve the social feasibility of a project by providing a way to communicate complex science in terms that society understands and values.     

基于智能体模型的土地利用动态模拟研究进展

土地利用动态变化是全球变化和可持续发展研究的基础,对区域水循环、大气循环、环境质量、气候变化及陆地生态系统生产力等具有重要影响,也是造成生物多样性衰减的最主要原因.目前,建立于复杂性科学基础上的的智能体模型(ABM)成为土地利用动态模拟的重要方法.智能体模型能模拟个体或群体的行为及决策模式,从而能将政府、城市规划、房地产开发商、住户等社会群体及个人对土地利用产生的影响进行模拟,同时能对不同社会经济政策对土地动态影响进行模拟.智能体模型在元胞自动机基础上,加入了人为因素的智能体概念,从而能更好地模拟土地动态.在分析总结了智能体模型的相关概念和组织结构,并分析了其在土地利用动态、城市动态模拟及生态过程模拟等方面的应用与元胞自动机的关系,比较了常用的智能体模型的主要软件,最后概括了智能体模型优点、发展趋势及存在的主要问题.     

Dispersal corridors for plant species in the Poyang Lake Basin of southeast China identified by integration of phylogeographic and geospatial data

Measuring the dispersal of wildlife through landscapes is notoriously difficult. Recently, the categorical least cost path algorithm that integrates population genetic data with species distribution models has been applied to reveal population connectivity. In this study, we use this method to identify the possible dispersal corridors of five plant species (Castanopsis tibetana, Schima superba, Cyclocarya paliurus, Sargentodoxa cuneata, Eomecon chionantha) in the Poyang Lake Basin (PLB, largely coinciding with Jiangxi Province), China, in the late Quaternary. The results showed that the strongest population connectivity for the five species occurred in the Wuyi Mountains and the Yu Mountains of the eastern PLB (East Corridor) during the late Quaternary. In the western PLB, populations of the five species were connected by the Luoxiao Mountains and the Jiuling Mountains (West Corridor) but with a lower degree of connectivity. There were some minor connections between the eastern and the western populations across the Gannan Hills. When the corridors of five species were overlaid, the East Corridor and the West Corridor were mostly shared by multiple species. These results indicate that plant species in the PLB could have responded to the Quaternary climate changes by moving along the East Corridor and the West Corridor. Given that dispersal corridors have seldom been considered in the governmental strategies of biodiversity conservation in the PLB, preserving and restoring natural vegetation along these corridors should be prioritized to mitigate the effects of anthropogenic climate change by facilitating migration of plant species and other biota.