三峡库区面源污染研究进展

为掌握三峡库区面源污染研究动态并明确研究中存在的问题, 基于1990-2018年三峡库区面源污染的相关研究成果, 检索、分类并统计分析了已发表论文数量变化趋势和高频被引论文内容, 从机理、影响因素、负荷与模型模拟、防治四个方面论述了库区面源污染的研究进展, 以便更好地进行区域生态系统管理。面源污染机理研究主要集中在降雨径流、土壤侵蚀、不同土地利用类型、不同管理措施下泥沙、N、P等污染物流失特征, 多关注单一过程及单一尺度, 严重破碎化土地利用格局背景下的面源污染发生过程、扩散格局及其转化机制有待进一步研究。影响因素多讨论土地利用, 景观格局变化对面源污染的影响机制仍不明晰。负荷模拟研究主要是建立经验模型和探讨国外模型在库区的适用性, 原始开发少。面源污染防治措施多集中于工程及单一技术措施, 最佳管理措施(BMPs)的研究较少, 缺乏生态系统、景观及流域尺度面源污染综合防控技术。提出三峡库区面源污染研究需在以下方面有所加强: (1)不同尺度和格局下N、P、泥沙等耦合作用下的运移、转化机理及其不同污染物在不同陆面斑块界面之间转化机制; (2)景观过程与面源污染动态关系; (3)借鉴国外模型理念, 研发适合我国区域地理特征的面源污染机理预测模型; (4)建设标准化面源污染监测系统; (5)统筹“山水林田湖草”系统治理, 研发面源污染综合防控技术体系。     

河流景观生态服务供给与需求/消费的互馈机制

河流景观系统孕育了人类文明,为人类社会提供类型多样的生态系统服务。其本身是一个自然景观过程和社会经济过程高度耦合的社会-生态系统,具有极高的空间异质性、时间动态和鲜明的组织尺度等级结构。当前,对河流景观系统这种特点所决定的生态系统服务供给与需求/消费互馈的机制研究不够深入,普遍缺乏从过程角度刻画生态服务供给与需求/消费互馈关系及其时空异质性和尺度特征。生态服务供给、需求和消费产生于社会-生态系统,是社会-生态耦合的纽带。阐述了河流景观生态服务供给和需求/消费的时空异质性,阐释了它们时空耦合机制和尺度特征,梳理了当前对生态服务供给、需求/消费互馈机理研究的不足。认为未来需要在社会-生态系统的框架下,从景观结构和生态过程出发,融合景观生态过程和社会过程来深入认识河流景观系统的生态服务供给与区内人类对生态服务的需求/消费之间的互馈机制。未来应重点关注：（1）河流景观结构和过程决定的生态服务供给和消费的空间分异及驱动机制;（2）河流生态服务传输的自然和人文载体及其耦合格局;（3）将生态服务需求/消费通过景观结构和生态过程对生态服务供给的反馈融入生态服务评估的方法框架,研发基于生态服务供给和需求/消费的社会-生态互馈过程模型。     

“山水林田湖草沙生命共同体”耦合框架、模型与展望

“山水林田湖草沙生命共同体”系统保护与修复是我国生态文明建设的重要内容。明确生命共同体的耦合机制，是科学地进行生态保护和修复工作的关键。针对当前生命共同体耦合机制不清、理论和方法不健全的问题，从耦合的视角出发，在小流域尺度上单一生态系统内部生态要素的耦合、流域尺度上不同生态系统之间的耦合、区域尺度上人与自然的耦合三个方面进行整合，在此基础上探讨了多尺度山水林田湖草沙耦合理论，提出了一般性的山水林田湖草沙耦合理论框架。梳理并比较了当前主要的生态系统模型、景观模型、统计学模型以及复合生态系统的多模型耦合方法，综合提出了一个适用于"山水林田湖草沙生命共同体"耦合研究方法。对进一步完善山水林田湖草沙一体化保护修复提出了建议，包括：一是构建多源信息数据库，推进定量化耦合机制研究；二是开展全生命周期监测与评估，探索适应性治理路径；三是强化多元主体参与，完善协同保护机制。     

区域景观格局与地表水环境质量关系研究进展

摘要：区域景观格局对地表水环境具有重要影响,1970s以来国外学者对区域景观格局与地表水水质之间的关系开展了大量研究。在系统梳理景观格局与水质关系的研究思路和技术方法的基础上,综合国内外文献探讨了水化学离子、常规污染物、营养物、重金属、有机物、水生生物,直至当前的河流健康等各类水环境指标对景观格局的响应程度,以及景观格局影响水环境的尺度效应问题。认为当前研究存在划定流域边界未能严格避免流域嵌套及土地利用空间自相关、选择景观格局变量尚未充分重视空间结构和水文地貌因素、数据分析技术多限于半定量分析等问题,并尝试提出相应的解决方案。试探性地提出国内研究的未来方向,指出在关注研究区域的流域边界是否明确和点源污染是否控制两个理论前提基础上,进一步根据非点源污染物在景观格局中的累积和迁移转化行为特征,进行相应的土地利用景观分类将是十分重要和迫切的基础性工作,提出了将景观格局与过程关系理论应用于城市面源污染调控的关键科学问题,包括非点源与目标水体的空间位置关系、不透水面和透水面的空间格局关系、区域不透垫面比例是否存在阈值,以及设置透水面的最佳空间尺度等。     

生态系统模拟模型的研究进展

从四个方面概述了生态系统模拟模型的发展现状：1)个体及种群,种群动态模型主要模拟在一个生境中单个种的动、植物个体出生或发芽、成长及其死亡过程,还有种内竞争和种间相互作用,主要分析生境中生物之间的相互作用。主要概述了林窗模型和土壤一植物一大气系统模型。2)群落与生态系统,概述了生态系统生产力模型、生物地球化学循环模型及演替模型。主要模拟植物种类在整个生态系统发展过程中的变化,以及植被类型的转变和相关的生物地球化学循环过程的改变,从而反映生物群落对气候变化的响应。3)景观生态系统,景观动态研究包含了时空两个方面的动态变化,一般可分为随机景观模型和基于过程的景观模型。随机模型用于模拟群落格局在演替过程中的动态变化等,基于过程的景观模型深入研究组成景观的各生态系统的空间结构。4)生物圈与地球生态系统,基于过程的陆地生物地球化学模式被用来研究自然生态系统中碳和其它矿物营养物质的潜在通量和蓄积量,较为流行的模式有陆地生态系统模式TEM、CENTURY、法兰克福生物圈模式FBM、Biome-BGC、卡内基-埃姆斯-斯坦福方法CASA等。这些模式己被用于估算自然生态系统对大气CO2加倍及相关气候变化在区域和全球尺度的平衡响应。最后,结合实际工作展望了生态系统模拟模型在各方面的发展方向。     

异质景观中水土流失的空间变异与尺度变异

综述了景观格局与水土流失过程的空间变异与尺度变异的理论和方法研究进展,提出了水土流失空间变异与尺度变异的研究方向。景观格局与生态过程的尺度变异一般处于单一尺度变异和多重尺度变异的连续体之中。尺度转换即尺度外推包括尺度上推和尺度下推,其可行性决定于尺度变异特征。水土流失不仅是多因子综合影响的一个复杂的时空变异过程,而且也是一个典型的多重尺度变异过程。传统的水土流失研究一般集中在坡面径流小区和小流域两个单一尺度上,这在很大程度上限制了水土流失的空间尺度外推和过程分析。近年来,尽管国内外很多学者开始关注水土流失的尺度变异及其影响因子．但只是对水土流失在不同大小的样地尺度以及小集水区尺度上的差异及其影响因子进行了初步的比较研究,尤其缺乏水土流失及其相关环境因子的连续尺度变异特征的机制分析。空间变异和尺度变异研究方法包括统计模型模拟法、物理模型与物理过程模拟法以及综合分析与综合预报法三大类。每种方法都有其优缺点和其特定的适宜性,最佳方法组合的选取因研究对象、研究地区和研究时间的不同而异。土壤侵蚀预报模型包括经验统计模型和物理过程模型,就解决水土流失的跨尺度关系而言,基于物理过程的空间分布式的土壤侵蚀预报模型显著优于经验模型。这些模型在关键参数的空间变异性描述和水土流失的尺度变异性分析方面非常薄弱,尤其缺乏模型分辨率和研究范围对输出结果的影响研究。完善水土流失的“尺度一格局一过程”理论,加强多重尺度上水土流失及其相关环境因子的空间变异格局和尺度变异性的实地观测与数学分析,改进土壤侵蚀预报模型这3个方面是将来的研究重点。     

2010年来黄土高原景观生态研究进展

严重的水土流失以及不合理的土地利用加剧了黄土高原土地资源的退化,导致该地区生态环境脆弱、生态系统服务不断下降。针对黄土高原地区存在的问题,我国学者基于景观生态学原理和方法,围绕"景观格局演变-驱动机制-水土流失过程-生态系统服务"的框架开展了大量研究,取得了一系列研究成果。通过梳理和总结2010年以来黄土高原地区景观生态学研究的现状和特点,指出了目前研究中存在的问题和不足,突出表现在区域比较研究、景观格局与生态过程耦合研究、生态服务权衡方法和模型构建等方面比较缺乏。建议未来黄土高原的景观生态学研究应加强区域尺度上的综合研究和不同地区之间的比较研究,深化景观格局演变的形成机理;进一步开展景观格局与过程的定量识别方法学研究,开发格局-过程耦合模型;加强生态系统过程与服务研究,同时开展相应的实证性研究,研发适宜的生态服务权衡模型,进而深入探讨区域生态系统服务的权衡机制。     

景观对河流生态系统的影响

从景观的视角研究河流生态系统,是目前河流生态学中受到广泛关注且发展迅速的内容之一。流域内多尺度景观强烈影响河流的理化及生物特征,已成为共识,但有关量度、整合景观与河流生态系统二者之间联系的理论体系与方法的建立尚处于起步阶段。对景观组成与空间格局影响河流生态系统的机制与途径进行了系统总结,提出了该领域研究中的主要难题,即如何识别景观中人为因素和自然因素的协变现象,如何衡量多空间尺度景观对河流生态系统的交互影响,如何理解景观阈值的不确定性。为克服当前研究面临的困难与挑战,填补已有知识的不足,提出今后研究的重点方向:河流景观分类系统的改进;更具代表性时空数据的采集;新型景观指标的开发与应用;微观尺度数据与宏观尺度数据的整合等。     

陆地生态系统物质交换模型

陆地生态系统物质交换模型是生态系统水、碳、养分循环研究的重要方向和极具发展前景的不可替代的手段.本文对近年来发展的众多陆地生态系统物质交换模型进行了归类:1)根据建模思路不同分为经验模型、过程模型和混合模型;2)根据物质传输机制的不同分为生物物理模型和生物地球化学模型;3)根据对植被结构处理方式的不同分为单层模型、双层模型和多层模型;4)根据模型应用性不同分为诊断性模型和预测性模型;5)根据构建模型的逻辑结构不同分为自下而上模型和由上而下模型;6)根据研究尺度的不同分为生态系统尺度模型、景观尺度模型和区域尺度模型;7)根据植物生理过程的不同分为光合作用模型和蒸腾作用模型.最后对不同类型模型的优缺点进行综合分析,探讨了新的发展方向.     

景观服务研究进展

生态系统服务强调了生态组成要素对人类福祉贡献的服务功能特性,近年来逐渐成为生态学研究的热点。然而,如何从生态组成要素的综合格局——景观的服务角度阐述生态系统服务,仍然是当前研究的巨大挑战。本文详细介绍了景观服务的概念、分类和应用尺度,并从制图方法和评价指标两方面阐述了景观服务的定量化方法,在此基础上探讨了景观服务在规划设计中的应用问题。最后,提出了新的研究展望,即要继续完善景观服务概念及分类体系,探讨景观服务的多尺度相互影响机理,寻求有效的景观服务空间定量化制图方法,评价景观服务未来发展变化,探索多项景观服务间的相互影响机理以及系统的景观服务规划方法,以期为今后景观服务的应用研究提供方向性参考意见。     

Landscape controls on seston stoichiometry in urban stormwater management ponds

1. Stormwater management ponds (SWMPs) are taking the place of natural ponds and wetlands in urban areas. SWMPs have the potential to serve as hotspots for nutrient cycling, yet little is known about how urban catchments affect nutrient chemistry and stoichiometry within these ponds. 2. We sampled 50 SWMPs in Southern Ontario, Canada, to characterise their seston stoichiometry and make comparisons with published lake and pond data and models of seston stoichiometry. We tested (i) whether C : N : P ratios were similar to natural ponds and small lakes, (ii) whether seston stoichiometry was scale dependent and (iii) whether variability in seston chemistry could be explained by landscape and pond characteristics, such as catchment imperviousness and hydrological condition (based on recently received rainfall). 3. Seston C : N and C : P ratios were significantly lower in SWMPs than published ratios for small lakes, likely because of high nitrogen and phosphorus concentrations in SWMPs. Our results also showed no dependency of stoichiometric ratios on pond size. Analyses of ratios versus landscape and pond characteristics revealed significant relationships only when ponds were grouped based on the hydrological condition of the catchments. 4. It is likely that SWMPs function very differently during wet and dry periods. When SWMPs are disconnected from the landscape after a lengthy dry period, internal processes become increasingly important for seston stoichiometry.     

Incorporating landscape connectivity into household pond configuration in a hilly agricultural landscape

Manmade ponds are common landscape features in rural areas and also important habitats for maintaining biodiversity. However, they are vulnerable to anthropogenic activities, land-use changes, and habitat degradation; many ponds being filled or (re)created arbitrarily. Little attention has been paid to quantifying the spatial structure of these manmade ponds at a landscape scale, nor to their potential functional benefits in promoting ecological flows and interactions between habitats for whole-ecosystem integrity. In this study, we investigated the patch-based landscape connectivity of household ponds, a particular type of domestic pond prevalent in hilly rural areas of China, by using least-cost path modelling and graph theory based network analysis. A hierarchical network was modelled consisting of 4606 individual ponds, 373 pond patches and 772 potential links within a 1.5-km threshold distance. Network importance analysis revealed that the largest pond patch contributes 24.5 % to network building and that patches with larger areas are generally more important. In contrast, the importance of the simulated links is only 2.3 % at most, indicating that the network has spatial redundancy which can strengthen resilience to uncertain disturbances. Our study moves beyond network simulation and importance assessment by directly relating the connectivity analysis to a real construction context through the incorporation of a spatially explicit land suitability analysis. This approach systematises the analysis of pond landscapes and guides integration with the wider landscape matrix. It provides operational spatial suggestions for holistic landscape planning across local to regional scales.     

Landscape connectivity affects individual survival in unstable patch networks: The case of a freshwater turtle inhabiting temporary ponds

1. The loss of connectivity is among the main threats for species occupying freshwater pond networks. Landscape connectivity can impact the persistence of patchy populations by reducing movement rates among ponds, thereby increasing the likelihood of local extinctions in source–sink systems, and reducing the probability of colonisation following extinctions. In addition, loss of connectivity may also reduce survival rates if individuals have to cross a hostile matrix, though this hypothesis has been rarely tested. Here, we address these issues by evaluating how individual survival and inter-patch movement probabilities of the European pond turtle (Emys orbicularis) are influenced by patch connectivity.
2. The study was carried out in a network of temporary ponds embedded in a heterogeneous agricultural matrix in southwestern Portugal, encompassing a period associated with a severe drought (2003–2005) and another with wetter climatic conditions (2010–2014). We mapped the location of ponds and land uses around each pond, and quantified connectivity among ponds using least-cost distances based on patch location and resistance to movement of different land uses. We then used multistate capture-recapture modelling to quantify how survival and movement of this freshwater turtle were related to different metrics of landscape connectivity, in the wet and dry periods.
3. We captured 221 pond turtles, including 89 juveniles, 58 females, and 74 males. Survival was higher in ponds more connected with other ponds, especially for juvenile turtles. The probability of movement between ponds decreased with increasing least-cost distances. Movement probabilities tended to be higher in the dry than in the wet period.
4. Our results support the idea that landscape connectivity affects both movement and survival rates in a patchy population inhabiting a temporary pond network. These effects are likely to be particularly marked in unstable freshwater systems like ours, where individuals may have to move widely to escape drying ponds during particularly dry years.
5. Overall, our findings suggest that focusing conservation efforts solely on protecting discrete freshwater habitats such as temporary ponds may be insufficient, requiring also due consideration of landscape connectivity offered by the surrounding agricultural matrix to assure long-term persistence of patchy populations inhabiting such habitats.

     

An expert-based landscape permeability model for assessing the impact of agricultural management on amphibian migration

The persistence of pond-breeding amphibian populations is influenced on different spatial scales ranging from the individual breeding pond to surrounding habitat patches to landscape clusters of breeding pond populations. The connectivity among breeding ponds as well as the availability of suitable terrestrial habitats surrounding the ponds plays a major role in long-term viability of amphibian species. Besides road traffic and urban structures agricultural land activity can disrupt landscape connectivity through the use of pesticides, fertilizers and physical activity such as tillage. We developed an expert-based model to assess the impact of agricultural management measures on the migration area and terrestrial habitat availability for seven amphibian species. The model is based on a Habitat Suitability Index to identify suitable terrestrial habitats and includes a landscape permeability approach. Size of migration areas, connectivity of breeding ponds and number of reachable terrestrial habitats were modeled considering species-specific migration ranges and habitat preferences. We consider how pesticides application might lead to fragmentation and isolation of amphibian breeding pond populations. Therefore the potential disrupting impact of pesticides was simulated by inflating landscape resistance to medium and high migration cost. One amphibian species showed a decrease of migration area by 48.3% and a decrease of reachable terrestrial habitats by 41.5% at high migration costs. Three additional species showed a decrease of their migration areas between 31.5 and 35.7%. At increased migration cost, some of the investigated populations were isolated at breeding pond level or restricted to pond clusters. Our model could be used to prioritize conservation efforts for pond-breeding amphibians with adequate consideration of agricultural land use and its impact on amphibian migration.     

Limited influence of local and landscape factors on finescale gene flow in two pond‐breeding amphibians

Dispersal and gene flow within animal populations are influenced by the composition and configuration of the landscape. In this study, we evaluated hypotheses about the impact of natural and anthropogenic factors on genetic differentiation in two amphibian species, the spotted salamander (Ambystoma maculatum) and the wood frog (Lithobates sylvaticus) in a commercial forest in central Maine. We conducted this analysis at two scales: a local level, focused on factors measured at each breeding pond, and a landscape level, focused on factors measured between ponds. We investigated the effects of a number of environmental factors in six categories including Productivity, Physical, Land Composition, Land Configuration, Isolation and Location. Embryos were sampled from 56 spotted salamander breeding ponds and 39 wood frog breeding ponds. We used a hierarchical Bayesian approach in the program GESTE at each breeding pond and a random forest algorithm in conjunction with a network analysis between the ponds. We found overall high genetic connectivity across distances up to 17 km for both species and a limited effect of natural and anthropogenic factors on gene flow. We found the null models best explained patterns of genetic differentiation at a local level and found several factors at the landscape level that weakly influenced gene flow. This research indicates multiscale investigations that incorporate local and landscape factors are valuable for understanding patterns of gene flow. Our findings suggest that dispersal rates in this system are high enough to minimize genetic structuring and that current forestry practices do not significantly impede dispersal.     

环巢湖地区多水塘景观时空格局演变特征及其驱动因素

快速城市化背景下,小型水体(人工、自然、半自然)景观正在大量消失,以环巢湖地区多水塘景观(水塘面积小于10 hm2)为例,基于遥感影像数据,综合运用RS/GIS技术和Fragstats 3.3软件对1989年、2000年和2016年3个年份环巢湖地区多水塘景观格局时空动态进行分析,运用地理探测器深入探讨多水塘景观面积变化驱动要素,对帮助理解多水塘景观演变带来的景观格局——过程关系及多水塘景观保护、利用和恢复等具有重要的现实意义。研究结果表明:(1) 1989—2016年间,农田景观面积比例呈下降趋势,表现的更加破碎,建设用地景观面积比例大幅度增加,森林绿地景观持续破碎化,水体景观面积比例下降,多水塘景观斑块数量、面积、斑块形状指数、最大斑块指数均呈下降趋势;(2)基于3 km×3 km网格单元多水塘景观时空演变特征分析表明,巢湖北岸多水塘景观集中在烔炀镇、黄麓镇,巢湖南岸多集中在白山镇、盛桥镇和槐林镇,这些地区也是多水塘景观格局变化最剧烈的地方;(3)基于地理探测器,揭示环巢湖地区多水塘景观用地变化的主要影响因子。因子探测结果表明,自然环境条件中的坡度因子q值最大,为0.545,其次为建设用地变化量、农田变化量、人口密度变化量和林地变化量等,交互探测结果表明,多水塘景观面积变化各因子交互作用后,对多水塘景观面积变化的影响显著增强,由此表现出多水塘景观变化影响要素的多样性和复杂性。     

Source–sink dynamics explain the distribution and persistence of an invasive population of common carp across a model Midwestern watershed

Source–sink theory is an ecological framework that describes how site and habitat-specific demographic rates and patch connectivity can explain population structure and persistence across heterogeneous landscapes. Although commonly used in conservation planning, source–sink theory has rarely been applied to the management of invasive species. This study tested whether the common carp, one of the world’s most invasive species, exhibits source–sink dynamics in a representative watershed in the Upper Mississippi River Basin comprised of a dozen interconnected ponds and lakes. To test for source–sink population structure, we used standard fish sampling techniques, tagging, and genetic assignment methods to describe habitat-specific recruitment rates and dispersal. Five years of sampling revealed that while adult carp were found across the entire watershed, reproductive success (the presence of young carp) was restricted to shallow ponds. Additionally, nearly a third of the carp tagged in a representative pond dispersed into the connected deeper lakes, suggesting that ponds in this system serve as sources and lakes as sinks. This possibility was confirmed by microsatellite analysis of carp tissue samples (n = 1041) which revealed the presence of two distinct strains of carp cohabitating in the lakes, whose natal origins could be traced back to one of two pond systems, with many adult carp attempting to migrate back into these natal ponds to spawn. We conclude that the distribution and persistence of invasive carp in complex interconnected systems may often be driven by source–sink dynamics and that their populations could be controlled by suppressing reproduction in source habitats or by disrupting dispersal pathways, instead of culling individuals from sink habitats.     

基于低影响开发的滨海工业园区景观生态规划——以营口市沿海产业基地二期为例

工业园区的低影响开发(LID)是我国海绵城市建设的重要内容.本研究根据景观生态学原理,通过分析景观格局对水文过程的影响,探讨工业园区雨洪管控的生态空间结构优化方法.首先,根据滨海地区水文和地质条件对工业园区进行景观格局优化,梳理水系廊道,整合绿地斑块;然后,根据下垫面特征进行雨洪管控区域划分,确定不同管控分区的径流控制指标,并选择不同景观节点的LID技术措施,实现工业园区生态基础设施合理的空间配置.结果表明: 通过景观格局优化,工业园区内构建的生态网络加强了景观的连通性,多种LID技术的组合使园区径流控制率由45%提升至70%,其中,透水铺装、下沉式绿地、雨水花园、湿塘、植草沟面积占总面积的比例分别为1.3%、1.9%、0.2%、0.2%、0.1%.本研究能够为滨海工业园区的低影响开发建设提供新的思路和方法.     

宜昌运河公园多塘型城市绿地水质水量调控效果及运行研究

对建成运行多年的宜昌运河公园中的多塘进行了监测,分析了它的水量水质的调控效果并结合现场观察和访谈总结了公园管理运行中的经验。主要结论有:1)多塘通过蓄滞和释放达到削减洪峰和延迟洪峰的效果,串联形式的多塘形成了多级的调蓄作用。2)多塘对高浓度污染物有较好的削减作用,污染物浓度较低时削减作用不明显;从沿程去除效果来看,多塘前半部分污染物去除率高,后半部分去除率低或为负;在停止运行状态下,蓄积在塘中的水体24 h后污染物含量会增加。3)公园经过长时间的运行和使用,最初的设计目标出现了简化、丢失和改变的情况,但这也使景观变得丰富和多样。     

Unravelling the correlates of species richness and ecological uniqueness in a metacommunity of urban pond insects

City ponds have the potential to harbour a rich biodiversity of aquatic insects despite being located in an urban landscape. However, our current knowledge on the correlates of pond biodiversity is limited and even less is known about the factors that influence the ecological uniqueness of urban ponds. The multiple environmental gradients, at different spatial scales, that may affect biodiversity and ecological uniqueness of urban ponds can thus be seen both as an opportunity and as a challenge for a study. In this study, we aimed to fill this gap by focusing on aquatic insect assemblages in 51 ponds in the Swedish city of Stockholm, using a metacommunity perspective. We found that species richness was primarily determined by the density of aquatic insects, water depth and proportion of buildings around the pond. The uniqueness of ponds was estimated as local contributions to beta diversity (LCBD), and it was primarily related to the proportion of arable land and industry around the ponds. With regard to the metacommunity we found two interesting patterns. First, there was a negative relationship between richness and LCBD. Second, biodiversity was spatially independent, suggesting that spatially-patterned dispersal did not structure species richness or LCBD. These last two patterns are important when considering conservation efforts of biodiversity in city ponds. We hence suggest that the conservation of insect biodiversity in urban pond should consider the surroundings of the ponds, and that high-richness ponds are not necessarily those that require most attention because they are not ecologically the most unique.