Service accessibility of ecological nodes: An exploratory way to enhance network connectivity in a study case of Wu'an,China

With a background of globalization and urbanization, the population agglomeration puts tremendous pressure on the ecosystem inside and around the city. Compared with ordinary cities, ecological protection for resource-based cities is more urgent. The construction of green infrastructure can alleviate the environmental constraints of urban development to a certain extent., and it contains a vital landscape element, ecological node, which is of great significance. Therefore, the purpose of this paper is to discuss ecological nodes based on different threshold selections of shape and distance to changes landscape network connectivity. Regarding the service accessibility of the green infrastructure network, a new cognition is to break the traditional land-use map and patches, while providing a new reference to enhance network connectivity by ecological nodes depicted as circles as the core, 400 m as the optimal threshold as transmission distance for ecosystem service evaluation and optimization. This new optimization method of ecological nodes strengthens the connectivity of green infrastructure networks through small changes within ecological nodes, reduces the ecological resistance of key positions of green infrastructure networks through land-use change of ecological nodes, in order to improve the ecosystem service connectivity for Wu'an or other resource-based cities.     

Functional connectivity as an indicator for patch occupancy in grassland specialists

Habitat specialists living in metapopulations are sensitive to habitat fragmentation. In most studies, the effects of fragmentation on such species are analyzed based on Euclidean inter-patch distances. This approach, however, ignores the role of the landscape matrix. Recently, therefore, functional distances that account for the composition of the landscape surrounding the habitat patches have been used more frequently as indicators for patch occupancy. However, the performance of functional and non-functional connectivity measures in predicting patch occupancy of such species has never been compared in a multi-species approach.Here we evaluate the effect of habitat connectivity on the patch occupancy of 13 habitat specialists from three different insect orders (Auchenorrhyncha, Lepidoptera, Orthoptera) in fragmented calcareous grasslands. In order to calculate functional distances we used four different sets of resistance values and rankings. We then modelled species’ occurrence using both Euclidean and functional (based on least-cost modelling) inter-patch distances as predictors.We found that functional connectivity measures provided better results than the non-functional approach. However, a functional connectivity measure that was based on very coarse land-cover data performed even better than connectivity measures that were based on much more detailed land-use data.In order to take into account possible effects of the landscape matrix on patch occupancy by habitat specialists, future metapopulation studies should use functional rather than Euclidean distances whenever possible. For practical applications, we recommend a ‘simple approach’ which requires only coarse land-cover data and in our study performed better than all other functional connectivity measures, even more complex ones.     

Incorporating ecological connectivity into ecological functional zoning: A case study in the middle reaches of Yangtze River urban agglomeration

Ecological functional zoning is critical for multiobjective sustainable management of social-ecological systems. However, the framework of ecological functional zoning needs to be further improved. In terms of the index system, the existing “element-structure–function” index system mainly considers the structural characteristics that have a negative impact on ecological processes, e.g., disturbances, while ignoring positive impacts, e.g., connectivity, which may weaken the role of key nodes in the ecosystem and is not conducive to regional ecological protection. In terms of research methodology, the widely used self-organizing feature mapping neural network (SOFM) produces a number of clusters that easily exceed expectations, thus increasing management difficulties. Therefore, there is an urgent need to explore new combining methods. Here, an improved index system combining ecological connectivity and ecological functions and a traditional index system including only ecological functions were constructed, and a zoning method combining a self-organizing feature mapping neural network and fuzzy mean clustering (SOFM-FCM) was used for functional zoning of the middle reaches of the Yangtze River urban agglomeration. The advantages of functional zoning incorporating ecological connectivity were verified by comparing the results of both zoning procedures before and after improvement. The results indicate that the study area could be divided into ecological conservation areas, biodiversity conservation areas, urban development areas, and grain production areas. The zoning schemes before and after the improved framework were reliable compared with the national planning scheme, but there was 20.6% inconsistency in the results after the improved framework. This was mainly manifested by the shift from biodiversity conservation areas to ecological conservation areas and from urban development areas to food production areas. This shift was more conducive to improving spatial continuity and landscape multifunctionality, thus maximizing ecological conservation, pushing back smart urban growth, and achieving food security. This study expands the research perspective concerned with ecological functional zoning, and these results can provide an important reference for regional ecological protection and related research.     

生态斑块重要性综合评价方法研究——以四川省为例

生态斑块为生物提供生存和发展的场所,城市化的推进引发生态斑块面积锐减且趋于破碎化,严重威胁生态系统服务。通过对生态斑块重要性的分析,可识别对保持景观连接度有关键作用的区域,是优化有限资金配置、实现高效生态保护和分级管理的有效途径。以2015年的四川省为例,从景观连接度出发,基于网络建模和拓扑指标计算,结合逼近理想点排序法(TOPSIS)和有序样品聚类进行了斑块重要性的综合评估和排序。研究结果表明,四川省内生态斑块呈现西北部相对连续,南部和东部零散而稀疏的分布特点,在此基础上构建的生态基础设施网络具有无标度性;所选拓扑指标结合综合评价方法后可有效评估斑块重要性,所有斑块可分为5个重要性层级,高层级斑块主要位于相对核心的位置,低层级斑块分布于全省边缘。针对不同层级斑块的特点提出了相应规划建议,从整体角度出发引导局部生态规划,以期为有限资源下省域尺度复合种群保护工作提供参考与借鉴。     

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。     

不同生态恢复措施对草地样带食物消费的影响——以锡林郭勒盟为例

生态工程的实施对区域居民生产生活产生了重要影响。以锡林郭勒草地样带为例,利用2017年8月—2018年7月农牧户食物跟踪调查数据、农牧户问卷调查数据、生态恢复措施数据,结合土地利用数据和社会经济数据等,重点分析了不同生态恢复措施对锡林郭勒草地样带农牧户食物消费的影响。研究结果显示:(1)锡林郭勒草地样带生态恢复措施沿样带自北向南实施力度逐渐变弱,草地恢复措施由以草畜平衡、休牧和禁牧为主向休牧和围栏封育为主转变,草地恢复措施中对人类活动的限制也随之由弱变强;(2)沿草地样带自北向南居民食物消费形成了三种模式,在食物消费数量和消费结构上呈显出由牧区特征向农区特征的转变,即人均食物消费量沿样带递减,食物消费由肉蛋奶和蔬菜水果为主向粮食和蔬菜水果为主转变;(3)食物消费模式受到草地供给、收入及其结构、文化习俗和职业分布等生态、经济和社会多方面因素的影响。研究为实现区域生态、经济和社会的协调发展相关政策的制定提供参考。     

羌塘地区草食性野生动物的生态服务价值评估——以藏羚羊为例

随着羌塘草原野生动物种群规模的扩大,草食性野生动物与家畜争夺草场的矛盾愈来愈突出.生态补偿无疑是解决这一矛盾的重要途径之一,而进行野生动物的生态服务价值评估是建立生态补偿标准的基础.通过羌塘地区社会经济资源环境现状调查和人群支付意愿调查,并采用直接市场法和虚拟市场法,对西藏自治区羌塘地区草食性野生动物藏羚羊的生态经济价值进行了评估.把藏羚羊的生态经济价值分为利用价值包括商业价值、游憩娱乐价值、维持生物多样性的价值、教育美学价值和科学研究价值,以及非利用价值包括存在价值、遗产价值、选择价值两大类.对野生动物生态价值的评估结果表明,羌塘地区藏羚羊的生态服务价值高达7.51亿元/a.其中,藏羚羊的利用价值为6.35亿元/a,非利用价值为1.16亿元/a.也就是说,羌塘地区15万只藏羚羊每年产生的生态服务价值远高于羌塘自然保护区涉及的6个县域2007年的总产值4.79亿元.     

“吉三角”区域生态规划与生态网架建设

利用实际调研走访与区域生态规划相结合的研究方法,对“吉三角”区域生态环境现状、生态系统脆弱性、生态环境敏感性等进行了分析,并构建了研究区生态网架.结果表明：依据生态资源丰富度、生态恢复性、农田防护林体系、环境承载力、林业基础、生态系统完整性等因素,可将研究区划分为东部低山丘陵生态区、中部平原生态区和西部平原湿地生态区3种区域生态功能区;在对研究区生态节点进行标识的基础上,构建了区域生态廊道（哈大线区域轴带、长春-吉林、长春-松原、吉林-松原、吉林-四平、松原-四平交通廊道）及区域生态网架（一环、三核、三带）;基于区域生态安全的要求,建构了包括区域生态保育区、区域生态恢复区和区域生态治理区在内的“吉三角”区域生态安全格局框架.     

基于斑块复合属性特征的城市生态安全格局构建——以杭州市为例

城市生态安全格局构建是保障国家与区域生态安全的基础与核心,是实现城市可持续发展的重要途径。生态源地识别与空间阻力面判断一直是生态安全格局构建中的技术难点。以杭州市为例,从城市生态斑块的复合属性特征出发,提取生态源地并判别空间阻力关系,运用最小累积阻力模型构建综合生态安全格局,明确城市关键性生态廊道的空间分布。结果表明：杭州城市生态安全格局围绕生态源地向周围辐射递减,整体呈东部低、西部高态势。源间连接通道对城市生态斑块维护具有较大影响。根据生态安全格局的不同等级划分了城市生态保障空间、城市生态缓冲空间以及城市生态过滤空间,并提出相应的格局优化策略,为城市生态网络建设提供参考,从而有效引导城市空间发展与规划。     

面向居民生态福祉的国土空间生态网络构建——以临沂市为例

构建面向居民福祉的生态安全体系,统筹考虑生态安全格局中的生态系统要素连通关系和生态系统服务供需关系,是强化国土空间生态修复规划成果,提升居民生态福祉的重要途径。研究基于"源-汇"理论,构建景观生态安全维育网络与生态系统服务亲近网络。结果显示：（1）45%的生态系统服务保护目标是实现高生态系统服务供给和低机会成本的合理阈值,基于此识别的生态供给源地面积为1230.89km²,中心城区及部分主要街道的生态系统服务供需关系呈现高需求-低供给现象;（2）共识别景观生态安全维育廊道75条,其中重要廊道1054km,次重要廊道1154km,一般廊道1366km;（3）生态系统服务亲近廊道分为10个组团,网络化程度低,西北部主要由森林构成,中东部主要由沿河湿地提供服务;（4）构建临沂市"三区两带五廊多组团"的国土空间生态安全格局,在保障景观生态安全的同时有效协调区域生态系统服务供求关系,促进生态-社会协同可持续发展。     

Tree loss impacts on ecological connectivity: Developing models for assessment

Trees along linear features are important landscape features, and their loss threatens ecological connectivity. Until recently, trees outside of woodlands (TOWs) were largely unmapped however; the development of innovation mapping techniques provides opportunities to understand the distribution of such trees and to apply spatially explicit models to explore the importance of trees for connectivity. In this study, we demonstrate the utility of models when investigating tree loss and impacts on connectivity. Specifically, we investigated the consequences of tree loss due to the removal of roadside trees, a common management response for diseased or damaged trees, on wider landscape functional connectivity. We simulated the loss of roadside trees within six focal areas of the south east of the UK. We used a spatially explicit individual-based modelling platform, RangeShifter, to model the movement of 81 hypothetical actively dispersing woodland breeding species across these agriculturally fragmented landscapes. We investigated the extent to which removal of trees, from roadsides within the wider landscape, affected the total number of successful dispersers in any given year and the number of breeding woodlands that became isolated through time. On average roadside trees accounted for < 2% of land cover, but removing 60% of them (~ 1.2% of land cover) nevertheless decreased the number of successful dispersers by up to 17%. The impact was greatest when roadside trees represented a greater proportion of canopy cover. The study therefore demonstrates that models such as RangeShifter can provide valuable tools for assessing the consequences of losing trees outside of woodlands.     

Auditory resting-state network connectivity in tinnitus: a functional MRI study

The underlying functional neuroanatomy of tinnitus remains poorly understood. Few studies have focused on functional cerebral connectivity changes in tinnitus patients. The aim of this study was to test if functional MRI "resting-state" connectivity patterns in auditory network differ between tinnitus patients and normal controls. Thirteen chronic tinnitus subjects and fifteen age-matched healthy controls were studied on a 3 tesla MRI. Connectivity was investigated using independent component analysis and an automated component selection approach taking into account the spatial and temporal properties of each component. Connectivity in extra-auditory regions such as brainstem, basal ganglia/NAc, cerebellum, parahippocampal, right prefrontal, parietal, and sensorimotor areas was found to be increased in tinnitus subjects. The right primary auditory cortex, left prefrontal, left fusiform gyrus, and bilateral occipital regions showed a decreased connectivity in tinnitus. These results show that there is a modification of cortical and subcortical functional connectivity in tinnitus encompassing attentional, mnemonic, and emotional networks. Our data corroborate the hypothesized implication of non-auditory regions in tinnitus physiopathology and suggest that various regions of the brain seem involved in the persistent awareness of the phenomenon as well as in the development of the associated distress leading to disabling chronic tinnitus.     

城市产业生态网络特征与演进规律——以北京市为例

产业生态系统发展规律对于产业转型升级至关重要,对其进行研究也是当前产业生态学的新方向。产业生态系统是指在一定区域内,产业组分以及环境组分之间通过物质交换及能量流动等形成的有机统一整体。产业生态网络则是其各组分之间通过物质流等相互作用构成的生态关系的一种拓扑结构。基于货币型投入产出模型通过物质型转化构建城市尺度产业生态网络,借鉴生态网络分析方法,提出通过循环性、生态效率、上升性3类特征指标判定产业生态网络的演进规律。实证研究了2005—2014年北京市产业生态系统的特征及其演进规律,阐明了其发展的趋势。主要结论是:从趋势分析,北京市产业生态系统循环性、生态效率和上升性有随时间而提升的趋势。其中,循环性和上升性变化趋势一致:总体呈现上升趋势,且2007年数值明显高于其他年份;生态效率总体随年份呈现波浪式增速的趋势;从指数分析:各年份循环指数(FCI)介于0—1之间,表明产业系统的物质循环流量均小于直接流量;A/C指数介于0.187—0.256之间,表明离理论可持续发展状态(0.401)还有相当的距离;生态效率10年提高2.4倍,在2013年已经接近1,到2014年实现大于1的水平,其生态效率已达到这10a间的最优的状态。总体上,北京市产业系统正在向物质循环性、生态效率以及系统上升性逐步提高的方向转型。     

基于生态网络的江苏省生态空间连通性变化研究

经济社会高速发展背景下,人类土地利用强度加大,部分地区生境斑块趋于破碎,生物交流通道趋于阻断,研究生态空间连通性变化,有针对性的进行保护和修复,对区域可持续发展意义重大。研究以江苏省为例,采用形态学空间格局分析（Morphological Spatial Pattern Analysis,MSPA）方法分析景观格局变化并识别重要生态源地破碎与新增情况,利用最小累积阻力（Minimum Cumulative Resistance,MCR）模型构建生态网络并分析生态空间连通性。研究选取整体连通性指数量化斑块/廊道的相对重要性;结合生态网络结构,具体分析廊道连通性的变化、原因及其影响;并运用电路理论、障碍改善方法识别廊道维护与疏通关键点,提出生态网络保护和修复建议。研究结果表明：（1）2000-2015年,江苏省生态网络呈现西密东疏的格局,局部地区生态节点破碎12处,新增5处,源地斑块整体趋于破碎;（2）新沂市马陵山风景区等6处节点的破碎使北部生态网络多条廊道结构功能下降,亟须修复;（3）因沿河防护林及道路林网建设,中部网络与北部网络间廊道连通性有所改善,但缺乏中间节点;（4）丹阳市打雁山丘陵节点的破碎使南部网络与长江湿地间联系削弱,宁镇山脉的结构重要性相对凸显;（5）东部沿海滩涂节点与其他节点间的联系尚处于薄弱状态,有待改善;（6）建议修复生态节点7处,新增生态节点7处,建设踏脚石44处,维护廊道关键点18处,疏通其中5处。     

道路网络对景观生态风险的影响——以云南省红河流域为例

道路网络扩展既影响周围的景观格局,也对生态过程造成直接或间接的影响。以云南省红河流域为研究区域,利用GIS和RS技术,进行格网划分,从空间上分析道路对景观格局和土壤侵蚀的影响,并通过基于景观格局和过程的景观生态风险指数计算,分析道路网络扩展影响下的景观生态风险规律。结果表明:红河流域道路周围景观类型以耕地、林地和草地为主,其中林地和草地的格局风险指数随着距离道路的增加而减少,受道路影响显著;一级路、三级路和四级路缓冲区内土壤侵蚀量随着距离道路的增加而减少,三四级路分布广泛,更容易发生土壤侵蚀;道路密度和基于景观格局和过程的景观生态风险指数在空间分布上具有一定的相关性。     

深圳市生态用地景观连通性动态评价

生态用地是快速城市化地区敏感的土地利用类型,景观连通性是研究景观结构和景观功能互馈关系的重要途径.利用1996-2008年深圳市土地利用数据和基于图论的整体连通性指数、可能连通性指数和斑块重要值,对深圳市生态用地的景观连通性进行动态评价,试图从空间上识别出维持整体景观连通性的重要斑块,并结合深圳市基本生态控制线,评价生态控制线内外生态用地景观连通性的变化.结果表明:1996-2008年,深圳市生态用地全局连通性基本呈下降趋势,维持连通性的重要斑块的重要程度及其分布均发生变化;基本生态控制线对维持线内生态用地的景观连通性发挥了一定作用.     

草原矿区土壤环境损害基线评估判定的应用研究——以内蒙古草原矿区为例

草原生态环境损害评估鉴定中,土壤基线是重要的评价标准。如何确定土壤基线,寻找适宜的基线判定方法,进而判定草原土壤的受损害程度,已成为草原生态系统损害评估鉴定、生态系统保护及修复工作中的关键。基于科学、务实、准确的原则,对内蒙古2个草原矿区土壤的总有机质（TOM）、N、P、K含量进行采样分析,采用历史数据法、参考点位法和统计点位法来判定土壤基线。结果表明,胜利矿区土壤养分均值与参考点位法基线值差异较小,采矿对胜利矿区土壤养分含量未见直接的影响。宝日希勒矿区土壤中TOM含量均值明显低于3种方法得出的基线值,N、K均值与参考点位法基线值相似,P均值位于3种基线值之间。可见采矿对宝日希勒矿区土壤中TOM的含量造成了直接影响,对N、P、K含量未见直接的影响。最适宜该地区的方法取决于样本质量和评估尺度,建议以参考点位法为主,历史数据法和统计点位法作为验证工具,3种方法共同使用。     

基于生态系统服务的城市生态管理分区——以深圳市为例

生态系统服务是人类赖以生存和发展的基础,开展城市生态系统服务评估并对生态管理单元实行分区管控有助于人居环境的改善。针对高度城市化地区生态系统服务的功能特征,采用生态系统服务价值当量测算不同用地类型的生态系统服务价值。研究从生态功能和经济功能2个方面构建生态系统服务指标体系,对2017年深圳市666个社区单元的生态系统服务价值进行评估;运用空间自相关分析方法,依据局部空间自相关的集聚特征叠加产生的组合类型,划分不同社区生态管理单元,并提出生态分区管控策略。研究结果表明:(1)生态系统服务价值评估便于高度城市化地区城市生态系统服务功能的整体评价。(2)2017年深圳市生态系统服务价值空间差异明显,呈现东部高、中西部低的空间格局。深圳市生态系统服务总价值约583.96亿元,最高值为大鹏新区的160.25亿元,最低值为福田区的13.24亿元。(3)将深圳市666个社区单元划分为4类城市生态管理分区,并采用差异化的分区管控措施,表明有效的城市生态管理分区能够兼顾各项生态系统服务功能并实现功能效益的最优化。该研究结果可为区域生态系统服务精细化管理和生态治理差异化管控提供借鉴。     

基于生态网络效用的城市碳代谢空间分析——以杭州为例

城市碳排放占全球碳排放总量的78%,通过模拟生物代谢来剖析城市碳代谢机理从而控制城市碳排放是缓解全球气候变暖危机的关键。为研究杭州城市化过程中土地利用变化对城市碳代谢的综合作用,以4个时间段(1995—2000,2000—2005,2005—2010,2010—2015)为例,建立了一个"碳流"模型来分析城市生态系统中自然和人工分室在城市碳代谢正负"碳流"产生中的作用,之后利用生态网络效用方法分析"碳流"产生的生态关系及其空间分布,同时利用互惠指数M综合评价土地利用变化对城市碳代谢的综合作用。结果显示(1)净"碳流"在研究期间持续呈现负值且在2000—2005年间达到峰值,负"碳流"主要源自耕地与工业用地之间的转换,正"碳流"主要源自工业用地与城市用地之间的转换。(2)1995—2000年互惠指数(M)呈现先增加后减少再增加的变化趋势,M平均值小于1,说明土地利用变化对城市碳代谢的综合作用是消极的。(3)竞争关系集聚在高负碳代谢密度分室,互惠共生关系主要集聚在高正碳代谢密度分室。(4)从1995—2000至2010—2015,以每5年为时间间隔,生态关系分布空间变化如下:掠夺限制生态关系呈现向西北、西南和南部方向蔓延—西北方向移动—东南方向移动的变化趋势,竞争生态关系呈现东南方向移动—南部和西北部方向蔓延—零星分布的变化趋势,互惠共生生态关系呈现向东南方向移动—暂时不存在—零星分布的变化趋势。研究结果为低碳城市发展提供了理论依据。     

城市群生态网络协同构建场景要素与路径分析——以粤港澳大湾区为例

城市群生态网络构建是城市与区域协同发展面临的重要场景之一,合理的生态网络能加强生态源地间的连通性,提高生态系统的生态功能,有效缓解生态环境问题,对保障城市与区域生态安全,提升人类福祉具有重要意义。以粤港澳大湾区城市群为例,以场景为依托开展生态网络协同构建场景要素与协同路径分析,结合景观连通性和形态学空间格局分析方法（MSPA）获得生态源地,并基于最小累积阻力模型识别生态廊道与生态节点,构建大湾区生态网络总体格局,最后从跨区域协作角度探讨城市群生态网络协同构建的潜在路径。研究结果表明：（1）研究区生态网络由40个生态源地、780条潜在生态廊道与892个生态节点构成,生态源地面积1.88万km²,占湾区总面积比例为33%,所识别的生态源地及生态廊道与自然保护区、广东省万里碧道、珠江三角洲绿道网重合程度较高;（2）识别跨区域生态廊道552条,其中,跨越佛山与广州市的生态廊道较多,一半以上的廊道跨越三个及以上城市,跨陆海区域的生态廊道连接了湾区南部主要沿海城市,构成陆海生态网络的关键组成部分;（3）提出城市群生态网络协同构建的潜在模式,应结合生态源地、生态廊道、生态节点等构建主体,分析城市内、城市间生态网络构建过程涉及的协同需求、协同对象,探索差异化的协同路径;（4）以场景为依托识别城市群生态网络构建场景的主题、时空特征、对象、路径和价值,可为进一步开展生态网络协同构建与应用示范过程提供指导。本研究是对城市群生态网络协同建设的有益探索,基于跨区域生态廊道协同构建场景模式的探讨能够为今后进一步探索区域统筹协同机制、实现景观格局协同构建和优化、促进区域生态共建共享提供理论依据。