福田红树林湿地生态系统EWE模型构建

以福田红树林湿地生态系统为研究对象,将其生物组成分为红树植物、底栖动物、浮游植物、浮游动物、鸟类和碎屑等15个功能组,运用Ecopath with Ecosim(EWE)软件,构建了福田红树林湿地生态系统的EWE模型,探讨了红树林湿地生态系统的状态、特征及不同物种之间的营养关系,并评价红树林湿地生态系统当前的健康状况。分析表明,福田红树林湿地生态系统能流的最主要来源是碎屑,能流主要在营养级Ⅰ到Ⅳ之间流动,转化效率最高发生在第Ⅰ和第Ⅱ营养级之间(28.8%),总体转化效率为11.2%,且系统对营养级Ⅱ的利用最为充分。处于低营养级的功能组在系统能量传递的过程中起着非常关键的作用,并且对整个系统的影响强烈。生态系统总体特征参数生物量/总流量(TB/TT)、连接指数(CI)和系统杂食性指数(SOI)分别为0.163、0.123和0.018,综合分析表明,福田红树林湿地生态系统目前有退化的趋势。     

湖泊生态缓冲带识别与生态系统服务价值评估——以滇池为例

湖滨带及环湖区域是发挥湖泊生态功能的关键区域,湖泊生态缓冲带建设是生态系统服务功能提升和湖泊生态保育的重要手段。基于原地产污贡献、单位面积价值当量因子和GIS分析等方法,以滇池为例识别湖泊生态缓冲带并评估生态系统服务价值。结果表明：(1)滇池生态缓冲带识别划定出山体型缓冲带、农田型缓冲带、村落型缓冲带、城镇型缓冲带和湿地型缓冲带等5种类型,上边界和下边界长度为171.50km和127.55km,平均宽度为349.49m,总面积为38.12km²;其中湿地型占主,缓冲带宽度处于20—825m之间,面积为10.31km²、占比27.05%;(2)2000—2020年环滇池区域生态系统服务价值整体呈下降趋势,价值总量由12.40亿元降低至7.78亿元;价值等级以低等级和中等级别为主,多期评估显示二者占比处于70.21%—77.66%之间;外海北岸和草海区域生态系统服务价值降低最为明显,反映出城镇建设等人类活动的影响;(3)环滇池区域湿地型、林地型和草地型三种情景模拟对生态系统服务价值分别提升58.87%、21.08%和17.48%,湿地型情景下水文...     

湿地生态系统生态特征变化及其可持续性问题

湿地是具有多种功能和价值的生态系统,是人类最重要的环境资源之一,被称为“景观之肾”［１］。湿地在蓄洪防旱、调节气候、控制土壤侵蚀、促淤造陆、降解环境污染等方面起着极其重要的作用［２］。随着人口的增长,人类对其影响的规模和速度在不断扩大,这其中有直接的...     

湿地生态系统网络模型鲁棒性分析

近年来随着人类活动的加剧,湿地生态系统的结构和功能都受到强烈干扰和破坏,研究遭受干扰后的湿地生态系统结构的演化过程,对湿地生态系统的保护、管理、恢复都有重要意义。本文根据复杂网络相关理论和生态系统特征构建湿地生态系统的网络模型,同时基于生物的谢尔福德耐受性和生态系统的自我调节能力,提出了一种考虑过载和欠载状态的湿地生态网络结构的演化模型。从初始负载、负载容量、负载冗余范围和负载重分配四个方面对遭受攻击的生态网络结构的演化过程进行刻画,同时利用鲁棒性指标揭示物种遭受干扰消亡后对湿地生态系统鲁棒性的影响。针对Teacapan湿地生态系统数值仿真,发现不同营养级的关键物种消亡对生态系统结构和鲁棒性的影响程度不同。初级生产者中的关键物种(红树林的碎屑和水中物质)消亡会导致Teacapan湿地生态网络结构迅速崩溃,生态系统鲁棒性指标迅速下降为0;而消费者中的关键物种消亡对生态网络结构波动和系统鲁棒性的影响较小,生态系统能够在一定时间内达到二次平衡,此时湿地生态系统仍具有一定的抵抗外界干扰的能力。这一结果体现了红树林中的碎屑作为支撑食物链的主要食物来源对湿地生态系统的重要性,为湿地生态系统的动植物...     

基于Ecopath模型的三门湾生态系统结构与功能

生态系统的结构决定生态系统的物质循环、能量流动和系统功能.本研究采用Ecopath模型,根据2017-2018年中国东海三门湾海洋生态实地调查数据,构建了三门湾生态系统的生态通道模型,描述了三门湾生态系统的能流结构,分析了其功能特征.结果显示:三门湾生态系统营养级范围在1～3.80,能流渠道主要表现为牧食食物链,系统能...     

利用Ecopath模型评价鲢鳙放养对千岛湖生态系统的影响

“保水渔业”是中国控制“水华”暴发等生态灾变的措施之一,其结果存在较大的不确定性。在浙江省的新安江水库(千岛湖),“保水渔业”的实施带来了水质改善和渔业增产的双重效果。但在生态系统自组织层面,这种人工干预手段引起的生态系统结构化效应的研究,尚未真正展开。基于2008—2010年千岛湖的生态和渔业资源调查数据,应用EwE(V6.6)构建了2010年千岛湖生态系统的Ecopath模型,并将其与2004和2016年的模型进行对照,分析了千岛湖生态系统在鲢、鳙鱼放养下的变化。千岛湖生态系统在3个年份均为4个整合营养级,营养能流分布成典型的金字塔型,且营养流总量中流向碎屑的占比很大,营养级Ⅰ、Ⅱ的能量被利用得不够充分;除鲢、鳙鱼外大部分鱼类的生物量逐渐下降,浮游植物和碎屑的生物量增多;系统的初级生产力和规模得到了一定提升,但总体的能量转换效率有所降低。在一些和系统成熟度、复原力和稳定性密切相关的参数方面,总初级生产量/总呼吸量增加,Finn氏循环指数和Finn氏平均路径长度逐渐降低,3个年份的连接指数(CI)分别为0.223、0.219、0.263,系统杂食指数(SOI)分别为0.087、0.1...     

基于Ecopath模型分析分水江水库生态系统结构和功能

根据2008-2009年浙江分水江水库渔业资源和生态环境调查数据,采用Ecopath with Ecosim软件构建了分水江水库的物质平衡Ecopath模型.模型构成包括鲢、鳙、鳊、花〖HT5,7〗鱼〖KG-*3〗〖HT5,6〗骨〖HT5F〗、翘嘴鲌、鲴类、其他鱼类、寡毛类、水生昆虫、浮游动物、浮游植物、有机碎屑等14个功能组,较好地模拟了分水江的水库生态系统.结果表明： 分水江水库生态系统包含5个营养级,且营养物质流动主要发生在前3个营养级.牧食食物链和碎屑食物链是系统中的主要能流,但是食物网结构较简单,容易受到外界干扰的影响.转移效率在低营养级较低,表明系统的能量利用较低,过多的营养物质储存在系统中可能导致富营养化的发生.较低的联结指数、系统杂食性系数、Finn氏循环指数以及Finn氏平均路径长度值都表明该生态系统处于不稳定状态,而生产量/总呼吸和生产量/生物量的值较高,说明此生态系统的初级生产力远高于其呼吸量,系统处于生态发育前期.分水江水库由于发育历史较短,仍处于由不成熟向成熟发育的过程中.     

基于Ecopath模型的千岛湖生态系统结构和功能分析

为探索千岛湖生态系统现状及其历史变化, 根据2016年千岛湖的渔业资源与生态环境调查数据, 构建了千岛湖生态系统的 Ecopath 模型, 综合分析系统的能量流动过程、营养级结构和生态系统总体特征。2016年千岛湖 Ecopath 模型由18个功能组组成, 有效营养级范围为1—3.41, 牧食食物链的能量流动占系统总能量的56%。系统杂食指数(SOI)、联结指数(CI)、Finn循环指数分别为0.13, 0.26和5.15%。千岛湖与其他湖泊和水库比较, 其生态系统的各功能组的聚合度较高, 联结程度较为紧密, 物质再循环比例较高, 系统较为成熟。但千岛湖的系统总流量较低为24698.27 t/(km2·a), 总初级生产量与总呼吸量的比值为6.51, 表明系统总体规模较小且仍处于发展阶段。根据千岛湖生态系统历年变化趋势分析: 千岛湖生态系统的总体规模有变大趋势, 稳定性和复杂性有所增强, 但营养交互关系变弱, 系统抵抗外界干扰的能力仍较低。同时, 千岛湖生态系统的初级生产者转化效率较低, 食物网趋于简单, 应采取适当的管理措施, 以保障千岛湖生态系统的健康发展。     

基于SD模型的上海市湿地生态系统服务变化过程与情景研究

湿地是上海市城市生态系统的重要组成部分,但其面积在过去几十年间显著减少,影响了城市生态系统服务的供给。通过构建系统动力学模型模拟上海市湿地生态系统服务变化的过程与未来情景。研究表明:(1)该模型有效且具有实际仿真的可操作性,并可根据政策要求设定参数,对上海市湿地生态系统服务价值的变化进行模拟与预测,结果可为上海市制定湿地保护或生态规划政策提供可行性分析。(2)对4种不同"湿地面积增长率"的情景进行模拟,结果显示了未来经济以不同增速条件发展时湿地生态系统服务价值的变化:无论哪种情景,文化服务价值最高,占总价值的64%以上,且在研究时段内呈增长趋势;调节服务价值次之,呈增长趋势;供给服务价值最低,呈下降趋势。(3)到2025年,按照现行的政策,上海市湿地面积将减少至37.92×10⁴hm²,届时湿地生态系统服务价值为4711.56×10⁸元,占上海市国内生产总值的20%,人均1.95×10⁴元。     

基于Ecopath模型的温州湾海域生态系统结构和功能分析

为探究温州湾生态系统整体结构,根据2019-2020年温州湾渔业资源调查结果,利用Ecopath with Ecosim 6.5软件构建了由21个功能组组成的生态系统能流通道模型,分析了该海域生态系统总体特征、营养结构和能量流动过程。结果表明：生态系统各功能组的营养级范围为1.000～4.372,带鱼(Trichiurus lepturus)营养级最高;系统总流量为10 874.67 t/(km²·a),系统净生产量为3 392.965 t/(km²·a);系统能量流动呈金字塔状分布,能量流量随着营养级的升高而降低,来源于初级生产者转化效率为15.20%,来源于有机碎屑的转化效率为16.03%,系统总能量转化效率为15.49%;系统总初级生产量/总呼吸量为3.636,系统连接指数为0.298,Finn’s循环指数为2.22%,Finn’s平均路径长度为2.324,杂食指数为0.167。温州湾生态系统处于不成熟状态,系统稳定性相对较低,建议加强对关键物种的保护,以期提高能量利用效率和保障生态系统结构完整性。     

Biogeochemical cycle of Sulfer in the Calamagrostis angustifolia wetland ecosystem in the Sanjiang Plain, China

To better understand the Sulfur (S) cycle in the wetland ecosystem, the S cycle and its compartmental distribution within an atmosphere-plant-soil system were studied using a compartment model in the Calamagrostis angustifolia wetland in the Sanjiang Plain, Northeast China. The results showed that the soil was the main S storage and flux hinge in which 97.78% S was accumulated. In the plant subsystem, the root was the main S storage, and it remained at 79.60% of the total S contents, which in the Calamagrostis angustifolia wetland ecosystem showed that the parts above the ground took up 0.75 g S/m², the S re-transferring biomass to the root was 0.24 g S/m², and to the litter was 0.51 g S/m²; the root took up 3.76 g S/m² and the S transferring biomass to the soil took up 3.07 g S/m²; the litter S biomass was 0.75 g S/(m²·a) and the S transferring biomass to the soil was more than 0.52 g S/(m²·a). The emission amount of H2S from the Calamagrostis angustifolia wetland ecosystem to the atmosphere was 1.42 mg S/m², whereas carbonyl sulfide (COS) was absorbed by the Calamagrostis angustifolia wetland from the atmosphere and the absorption amount was 1.83 mg S/m². The S input biomass from the rain to the ecosystem was 4.85mg S/m² during the growing season. The difference between input and output amounts was 5.26 mg S/m², which indicated that S was accumulated in the ecosystem and would lead to wetland acidification in the future.     

Using an Ecosystem Modeling Approach to Explore Possible Ecosystem Impacts of Fishing in the Beibu Gulf,Northern South China Sea

Using the Ecopath with Ecosim software, a trophic structure model of the Beibu Gulf was constructed to explore the energy flows and provide a snapshot of the ecosystem operations. Input data were mainly from the trawl survey data collected from October 1998 to September 1999 and related literatures. The impacts of various fishing pressure on the biomass were examined by simulation at different fishing mortality rates. The model consists of 20 functional groups (boxes), each representing organisms with a similar role in the food web, and only covers the major trophic flows in the Beibu Gulf ecosystem. It was found that the food web of the Beibu Gulf was dominated by the primary producers path, and phytoplankton was the primary producer mostly used as a food source. The fractional trophic levels ranged from 1.0 to 4.02, and the marine mammals occupied the highest trophic level. Using network analysis, the ecosystem network was mapped into a linear food chain, and six discrete trophic levels were found with a mean transfer efficiency of 11.2%. The Finn cycling index was 9.73%. The path length was 1.821. The omnivory index was 0.197. The ecosystem had some degree of instability due to exploitation and other human activities, according to Odum’s theory of ecosystem development. A 10-year simulation was performed for each fishery scenario. The fishing mortality rate was found to have a strong impact on the biomass. By keeping the fishing mortality rate at the current level for all fishing sectors, scenario 1 had a drastic decrease in the large fish groups. The biomass of the small and medium pelagic fish would increase to some extent. The biomass of the small and low trophic level species, jellyfish, prawns and benthic crustaceans would be stable. The total biomass of the fishery resources would have a 10% decrease from the current biomass after 10 years. In contrast, the reduced fishing mortality rate induced the recovery of biomass (scenarios 2–4). In scenario 2, the biomass of the large demersal fish and the large pelagic fish would increase to over 16 times and 10 times, respectively, of their current level. In scenario 4, the biomass of the large pelagic fish would increase to over 3 times of its current level. The total biomass of the fish groups, especially the high trophic level groups, would become significantly higher after 10 years, which illustrates the contribution on biomass recovery by relaxing the fishing pressure. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Author contributions: Xiaoping Jia designed research; Zuozhi Chen and Yongsong Qiu performed research; Zuozhi Chen, Yongsong Qiu, and Shannan Xu analyzed data; and Zuozhi Chen and Shannan Xu wrote the article.     

开垦对黄河三角洲湿地净生态系统CO2交换的影响

近年来, 由于对湿地的不合理利用, 自然湿地被大面积地垦殖为农田, 导致湿地生态系统碳循环的模式发生改变, 从而影响了湿地生态系统碳汇功能。该研究通过涡度相关法, 对山东省东营市黄河三角洲芦苇(Phragmites australis)湿地和开垦多年的棉花(Gossypium spp.)农田的净生态系统CO₂交换(NEE)进行了对比观测, 以探讨该地区典型生态系统NEE的变化规律及其影响因子, 揭示开垦对芦苇湿地NEE和碳汇功能的影响。结果表明: 在生长季, 湿地和农田生态系统NEE的日平均值各月均呈明显的“U”型变化曲线, 非生长季NEE的变幅很小。生长季湿地生态系统日最大净吸收值和释放值分别为16.04 g CO₂·m^-2·d^-1(8月17日)和14.95 g CO₂·m^-2·d^-1(8月9日); 农田生态系统日最大净吸收值和释放值分别为18.99 g CO₂·m^-2·d^-1 (8月22日)和12.23 g CO₂·m^-2·d^-1 (7月29日)。生长季白天两个生态系统NEE与光合有效辐射(PAR)之间呈直角双曲线关系; 非生长季NEE主要受土壤温度(T_s)的影响; 生态系统生长季夜间NEE受T_s和土壤含水量(SWC)的共同影响; 湿地和农田的生态系统呼吸熵(Q₁₀)分别为2.30和3.78。2011年生长季, 黄河三角洲湿地和农田生态系统均表现为CO₂的汇, 总净固碳量分别为780.95和647.35 g CO₂·m^-2, 开垦降低了湿地的碳吸收能力; 而在2011年非生长季, 黄河三角洲湿地和农田生态系统均表现为CO₂的源, CO₂总释放量分别为181.90和111.55 g CO₂·m^-2。全年湿地和农田生态系统总净固碳量分别为599.05和535.80 g CO₂·m^-2。     

基于PSR模型的陕西省土地生态系统健康评价

基于"压力-状态-响应"(PSR)模型和熵值法对陕西省十市一区的土地生态系统健康状况进行诊断,分析了 2009-2017年间土地生态系统健康等级时空变化趋势,以及影响土地生态系统健康变化的驱动因素.结果表明:2009-2017年间,陕西省土地生态系统健康水平整体提升,其中,2009-2014年间土地生态系统健康程度较低...     

南海北部生态系统食物网结构、能量流动及系统特征

根据20072008年在南海北部(107°00'120°00'E、17°00'23°30'N)进行的海洋生态综合调查数据,应用Ecopath with Ecosim软件构建了南海北部生态系统的生态通道模型,并通过模型分析了南海北部海洋生态系统的食物网结构、能量流动和系统的总体特征,并简要总结过度捕捞生态系统的基本特征。结果表明,南海北部海洋生态系统以捕食食物链为主要能流通道,初级生产者是系统能量的主要来源。各功能群的营养级范围为13.99,哺乳动物占据了最高的营养层,平均渔获物营养级为2.93。利用生态网络分析,系统的能量流动主要有6级,来自初级生产者的能流效率为12.6%,来自碎屑的转换效率为10.4%,平均能量转换效率为11.5%。系统连接指数(Connectance Index,CI)和系统杂食指数(System Omnivory Index,SOI)分别为0.290和0.239;Finn’s循环指数(Finn’scy cling index,FCI)和系统平均路径长度(Finn’s mean path length,MPL)分别为4.380和2.476;总初级生产力/总呼吸为2.596,综合研究表明当前南海北部海洋生态系统处于不成熟阶段。     

Differences of ecological functions inside and outside the wetland nature reserves in Sanjiang Plain, China

Conservation effectiveness of wetland nature reserves is determined by both the management intensity inside the reserves and the hydrological status outside the reserves. Therefore, differences of ecological functions inside and outside the reserves are an integrated indictor for assessing conservation effectiveness. Based on the land use map created from Landsat-TM satellite image and 1:50000 Digital Elevation Model (DEM) data in the study area, the catchments that belong to the wetland reserves were determined as their hydrological sensitive zones by SWAT (Soil and Water Assessment Tool) hydrological model. The ecological function indices of wetland reserves and their corresponding hydrological sensitive zones were calculated through expert consultation and value assessment on wetland ecosystem service functions. The results showed that the ecological functions of national wetland reserves were better than those of local reserves in general. However, the wetland ecological functions of hydrological sensitive zones of the former were not always better than those of the latter. Meanwhile, clustering analysis showed that the wetland ecological functions of several adjacent reserves in Nongjiang-Bielahonghe watershed were similar. But correlation analysis found that there existed a remarkable positive correlation between the wetland ecological function indices of local reserves and their hydrological sensitive zones.