基于遥感与GIS的黄河三角洲绿色空间生态服务价值评估

基于黄河三角洲1987、1997和2007年的TM遥感影像解译数据和野外调查结果,得到研究区三个年度的土地利用空间分布图。然后从土地利用的角度重新审视绿色空间的概念和内涵,建立基于土地利用类型的绿色空间生态评估体系,分析黄河三角洲地区的绿色空间生态服务价值及其变化情况。研究结果表明,1987—2007年间黄河三角洲地区绿色空间土地利用变化显著,其中,水体面积增加明显,农田、林地面积略有增加,湿地和草地面积显著减少,未利用地面积略有减少。土地利用面积的变化直接影响到其生态服务价值的变化,研究期间湿地生态服务价值减少了77.72亿元,草地减少9.00亿元,未利用地减少0.16亿元;水体的生态服务价值增加54.54亿元,农田和林地共增加3.41亿元。研究区绿色空间生态服务价值呈逐年减少的趋势,20年间研究区生态服务价值减少了28.94亿元。通过对绿色空间单项生态服务价值功能重要性进行评价,研究表明黄河三角洲地区单项生态服务价值以湿地、农田和水体占主要地位,这与各单项生态系统的面积及其单位生态服务价值量有关。     

黄河三角洲生物多样性分析

黄河三角洲是我国东部最年轻的陆地,保存着中国暖温带地区最广阔、最完整、最年轻的湿地生态系统。鉴于已有的研究工作对黄河三角洲地区生物多样性通过黄河与周边地区的联系方面的研究相对薄弱,以现有研究工作为基础,以黄河的廊道作用为主线,并结合2003年9月和2004年10月两次实地地面植被调查,主要对黄河三角洲自然保护区的植物区系组成状况进行统计分析,总结出黄河三角洲地区生物多样性状况、植物区系组成的特点及其与周边地区的相互关系。黄河三角洲地区生物多样性主要表现出如下特点:植被结构简单、覆盖度低、生态系统年轻性特点和湿地生态系统特点明显;植物种类少、常具有抗盐、抗旱特性;旱生、中旱生植物以及与内蒙古共有植物种类多,充分体现了黄河的生物廊道作用;主要保护动物种类多,生物多样性保护意义重大。这些特征既反映了黄河三角洲新生陆地的盐化生境特点,同时也深刻揭示了河流通道对区域生物多样性形成的重要作用。     

黄河三角洲湿地研究进展

从湿地研究内容和研究方法两方面,回顾了近10年来黄河三角洲湿地研究的成果。在这10年间,黄河三角洲湿地研究的内容和范围明显拓宽,主要研究内容包括湿地修复、湿地评价、湿地管理等。研究方法日趋先进成熟,模型模拟、遥感动态监测及3S等新技术和方法得到广泛应用。文章在分析黄河三角洲湿地的研究现状和特点的基础上,对未来研究趋势和热点进行了展望,认为未来黄河三角洲湿地的研究重点应在湿地演化机制与恢复、湿地对环境变化的响应与反馈、湿地动态监测、湿地保护技术等方面。     

黄河三角洲湿地土壤微生物群落结构分析

采用末端限制性片段长度多态性分析(T-RFLP)技术和16S rDNA克隆文库的方法,分析了黄河三角洲滨海湿地土壤不同深度细菌和古菌的群落结构.研究表明,随着深度的增加,细菌群落的多样性下降,而古菌群落多样性则有上升的趋势,且土壤的细菌和古菌群落结构都呈现出规律的层状分布.该土壤包括各种硫酸盐还原菌、产甲烷古菌、光合细菌等丰富的细菌和古菌资源.图5参27     

Vegetation competition model for water and light limitation. II: Spatial dynamics of groundwater and vegetation

In temperate climates groundwater can have a profound effect on vegetation, because it strongly influences the spatio-temporal distribution of soil moisture in the rootzone and therefore the occurrence of water and oxygen stress of vegetation. This article focuses on vegetation and groundwater dynamics along a hill slope by developing and evaluating a fully coupled hydrological-vegetation model for a temperate forest ecosystem. The vegetation model is described in part 1 of this series of two papers. To simulate the hydrology an extended version of the saturated-unsaturated hydrological model STARWARS has been used. The coupled model is used to investigate both the short and long-term dynamics for a system of two species. Both compete for light and water where one is adapted to wet conditions and the other to dry conditions. The daily dynamics show that the influence of groundwater is particularly strong in spring when waterlogging occurs due to decreased evapotranspiration in winter. Long simulation runs of 1000 years were performed to study the equilibrium state for the two species. Comparison of simulation results with observations of groundwater depth and vegetation types along a dry-wet gradient in a natural forest shows that a reductionist approach is able to capture these patterns well. Sensitivity analysis shows that the border between wet- and dry-adapted species moves upslope with increased rainfall, decreased slope angle and decreased aquifer thickness. These results are similar to previous findings which were based on global maximization of ecosystem evaporation or minimizing ecosystem stress. Comparison of runs with a fixed and a dynamic groundwater table shows that a dynamic groundwater table facilitates a wider transition zone between vegetation types along the hill slope. In this transition the biomass of vegetation is higher in the case of a dynamic groundwater than in case of a static groundwater table. This underlines the importance of incorporating spatial groundwater dynamics in models of groundwater influenced ecosystems.     

基于DNDC模型评估水位变化对滨海湿地净生态系统CO2交换的影响

水位是影响滨海湿地生态系统蓝碳功能的重要因素。气候变化引起的海平面上升以及极端气候事件的频发,可能加快水位的变化,从而改变生态系统碳交换的过程。然而,滨海湿地碳汇功能响应水位变化的机制尚不清楚。为了评估水位对滨海湿地净生态系统CO₂交换(NEE)特征的影响,以及验证DNDC(denitrification-decomposition)模型对模拟预测滨海湿地生态系统碳交换的适用性,该研究设计了野外水位控制试验(自然水位,地下20 cm水位、地表10 cm水位),并利用DNDC模型模拟和预测水位变化对滨海湿地NEE的影响。结果表明:(1)不同水位处理之间NEE差异显著,地表10 cm水位处理促进CO₂吸收,地下20 cm水位则抑制CO₂吸收;(2)经过校准和验证的DNDC模型可以准确模拟水位变化对黄河三角洲湿地NEE的影响,NEE模拟值的日动态与田间观测结果显著相关(R²>0.6);(3)通过改变气候、土壤和田间管理等输入参数对DNDC模型进行灵敏度检验,生态系统碳交换过程对日均温、降雨和水位改变的响应最为显著,其中,水位对NEE的影响主要作用于土壤呼吸(Rs)。未来气候情境下,不同水位变化下的生态系统碳交换过程随年份增长呈现不同的规律,因此未来的模拟研究应关注DNDC中水文模块和植被演替过程的完善。该研究可为预测水文变化情境下滨海湿地碳汇功能的未来发展以及政策制定提供参考。     

Modelling the impacts of land-use and drainage density on the water balance of a lowland–floodplain landscape in northeast Germany

This study presents the modelling approach and impact assessment of different strategies for managing wetland water resources and groundwater dynamics of landscapes which are characterised by the hydrological interactions of floodplains and the adjacent lowlands. The assessment of such impacts is based on the analysis of simulation results of complex scenarios of land-use changes and changes of the density of the drainage-network. The method has been applied to the 198 km² Lower Havel River catchment as a typical example of a lowland–floodplain landscape. The model used consists of a coupled soil water and groundwater model, where the latter one is additionally coupled to the surface channel network. Thus, the hydrological processes of the variable saturated soil zone as well as lateral groundwater flow and the interactions between surface water and groundwater are simulated in an integrated manner. The model was validated for several years of significantly different meteorological conditions. The comparison of lateral and vertical water balance components showed the dominance of lateral flow processes and the importance of the interactions between surface water and groundwater for the overall water balance and the hydrological state of that type of landscape.The simulation of land-use change scenarios showed only minor effects of land-use change on the water balance and groundwater recharge. Changes of groundwater recharge were particularly small within the wetland areas being part of the floodplain where interactions between surface water and groundwater are most pronounced. Alterations in vertical groundwater recharge were counter-balanced by the lateral interaction between groundwater and surface water. More significant deviations in groundwater recharge and storage were observed in the more peripheral areas towards the catchment boundaries which are characterised by greater groundwater distance from the surface and less intense of ground water–surface water interactions.However, the simulation results assuming a coarsening of the drainage network density showed the importance of drainage structure and geometry for the water balance: The removal of the artificial draining ditches in the floodplain would result in significant alterations of total groundwater recharge, i.e., less recharge from winter to early summer and an increase of groundwater recharge during summer and autumn. Furthermore the different effects of groundwater recharge alterations on the dynamics of groundwater stages within the wetland areas close to the floodplains compared to the more peripheral areas could be quantified. Finally, it will be discussed that a well-adjusted co-ordination of different management measures is required to reach a sustainable water resources management of such lowland–floodplain landscapes.     

黄河三角洲不同植被类型土壤酶活性的季节变化

黄河三角洲自然保护区的酶活性季节特征一定程度影响了该地植被分布类型,为研究黄河三角洲自然保护区不同植被土壤酶活性的季节特征,分别选取碱蓬(Suaeda salsa)、柽柳(Tamarix chinensis)、芦苇(Phragmites communis)、刺槐(Black Locust)和高粱(Sorghum)5种典...     

洞庭湖区湿地综合资源管理与复合生态系统建设

通过对洞庭湖区湿地衰退原因与特征的分析,提出合理开发湿地资源必须强化湿地整体管理,控制湿地开发规模,适度退田还湖还蓄（洪区）,调整农业布局与种植制度,走集约持续发展之路,建设复合高效湿地生态系统;进行适应洪涝灾害发生规律的避洪、耐渍型生态设计,建立适应浅水水体、湖洲和低湖渍害田的复合高效生态工程模式。     

Water shortages and countermeasures for sustainable utilisation in the context of climate change in the Yellow River Delta region,China

With an increasing population and rapid development of the economy and society of the Yellow River Basin region, the Yellow River is at crisis point. The discrepancy between supply and demand of water resources is a key issue. In 2000–2006, the mean annual discharge of the Yellow River entering the delta was 13.2 billion m³, a reduction of 18.6 billion m³ compared with the 1980s, and 9 billion m³ less than in the 1990s. The water requirements of various sectors are increasing. Large amounts of water essential to maintain the health of the delta ecosystem have been diverted for other users. The lower river channel is shrinking and the threat of flooding is becoming severe. Moreover, water pollution is increasing to a serious level; the river mouth ecosystem is subject to degradation. Due to overall decreased flow into the delta, and almost no flow into the delta for much of the year except in wet periods, biodiversity is threatened and there has been degradation of the ecological environment. In view of the water scarcity and variation in water supply, particularly in the context of climate change, measures need to be taken to realise sustainable water use in the Yellow River Delta region. In view of the lack of a complete index system for sustainable utilisation of regional water resources in China, this paper examines the major countermeasures for sustainable water use in the region. A rational adjustment mechanism for water prices is needed. Adjustment of agricultural infrastructure and water saving need to be directed by water prices, and thus the reasonable exploitation of groundwater must also be directed by water prices. Participation of the public is to be encouraged, with the development of a water user association that will become involved in formulating water rights, water allocation and water prices. Decision-making, management and supervision of this association will be done in a democratic way to promote the social management of water saving.     

盐渍土系统土壤水-地下水转化规律研究

通过野外定位观测和室内分析,探讨了苏打盐渍土微域特征(32m长的横截面)及其水分和地下水之间的转化规律。结果表明:土壤特征以及微地貌格局是制约土壤表层水分迁移的主要因素,并由此形成了大汽降水-土壤水-地下水转化的特殊模式。盐化草甸土分布在相对低洼的部位,苏打碱土分布在微坡地和高平地。苏打碱土质地为粉砂质亚粘土-粘土-粉砂-砂砾垂直结构,盐化草甸土以粉砂和砂砾结构为主。地表径流为水分迁移的关键环节,盐化草甸土成为地表水和地下水转化的通道。承接微坡地和高平地的径流,盐化草甸土在雨季含水率较多(甚至大到饱和)且迅速补给地下水,使地下水位逐渐上升。坡地土壤(苏打盐渍土)整个土层的含水率变化不显著。运用Vensim对盐渍土系统的土壤水-地下水的转化过程进行了模拟,结果与观测数据基本一致。在现代盐渍化过程研究中,以坡面系统为研究单元并考虑坡面径流,才能认识到盐渍化地区土壤水-地下水之间转化的实质。     

珠江入海口水体中多溴联苯醚及其来源分析

2005年3月至2006年2月,选取珠江8个入海口,进行每月1次为期1周年的水样采集。检测了96个水样的多溴联苯醚（PBDEs,包括BDE 28、47、66、85、99、100、138、153、154、183、196、197、203、206、207、208和209）的残留状况。水体中PBDEs的质量浓度为0.344～68.0 ng·L-1。PBDEs的组成分析结果表明：珠江水体PBDEs的来源以土壤和沉积物源为主,而目前珠三角陆地环境中PBDEs仍不断蓄积,其通过珠江地表径流迁移转换的PBDEs将逐年增多,给珠三角水生态环境带来的压力逐日增加,所造成的生态环境及公众健康影响将是深远的。     

海水混合和层化对叶绿素a垂直分布的影响

根据长江口海区、近岸浅水区、黄海冷水团海区和水深超过200m的陆架区等四个区域的定点调查获得的数据，分析了温度、盐度与叶绿素a垂直分布的相互关系。结果表明，长江口海区，陆源径流与海水混合不充分，表层营养盐含量较高，表层叶绿素a含量高于中下水层。近岸浅水区的苏北近岸海水垂向没有温跃层和盐跃层，叶绿素a的垂向分布也均匀，东海西部沿岸出现逆温跃层和逆盐跃层，海水垂直混合不充分，叶绿素a含量(6．72mg／m^3)在10m深水域最高。黄海冷水团海区海水的垂直混合不充分，叶绿素a的垂直变化显著，高值区出现在温跃层下方(4．37mg／m^3)。水深超过200m的陆架区，温度的阶梯状结构、营养盐跃层、光照等因素共同导致整个水层叶绿素a含量普遍较低。同时，结合历史资料分析认为，海水的混合、温度和盐度的层化将影响营养盐的浓度和分布，从而影响海水中叶绿素a的垂直分布。     

黄河三角洲潮沟湿地植被空间分布对土壤环境的响应

潮沟在黄河三角洲广泛存在,且分布有多种独特的湿地植被类型。通过设置有代表性的28个样地,获取了植被种类、多度和土壤环境因子数据;并运用双指示物种（TWINSPAN）,对黄河三角洲潮沟分布区植被进行了群落类型划分,得出研究区共有7种类型植物群落;同时利用典范对应分析（CCA）阐明了这些植被群落空间分布与土壤环境因子之间的关系,其分析结果显示构成黄河三角洲土壤盐分的主要是Cl-和Na＋,距离海洋的远近和土壤含水量共同影响土壤含盐量,盐地碱蓬和中华柽柳分布主要取决于土壤含盐量、Na＋含量及距离海洋距离,而各种植被类型的分布与土壤全磷（TP）、全氮（TN）、有机质、Ca2＋及Mg2＋含量存在一定的关系。     

A multi-objective optimization approach to allocate environmental flows to the artificially restored wetlands of China's Yellow River Delta

In this paper, a multi-objective optimization model has been developed for allocating freshwater to meet the environmental flow requirements of the restored wetlands in the Yellow River Delta, China. The model seeks a rational balance among appropriate water allocation for the wetlands, a healthy ecosystem, and optimum economic returns for the humans that use the wetlands to earn their livelihood, with the degree of ecosystem health represented by the difference between actual and ideal water levels. And then a holistic method has been used for satisfying multiple objectives to avoid the problem of decision-maker subjectivity, and then solved the resulting optimal allocation model for environmental flows of the wetlands using a genetic algorithm. With water from the Yellow River as the source, the model shows how the optimal monthly water release into the restored wetlands can be achieved in dry, average, and wet years. Using the model, 20-56% reductions in water use could be achieved compared with the current pattern of water release, and the optimal water level in each month would coincide better with the ideal value based on an indicator plant community (reeds). The results of the study demonstrate the capability of the multi-objective programming model to optimize ecological water allocation and management for the wetlands of the Yellow River Delta.     

黄河三角洲生态区土壤石油污染及其对碱蓬萌发的生态影响

基于黄河三角洲生态区内的油田生产区中石油污染土壤的调查取样,分析石油污染状况,并在实验室人工控制条件下,研究土壤中不同质量分数的石油污染对该区先锋植物——碱蓬（Salsola glauca Bung）的种子萌发影响。结果表明,油田区土壤受到了不同程度的石油污染;溢油处石油的质量分数最高达6.230 g·kg^-1。另外,萌发实验说明在土壤污染情况下种子萌发率具有不确定性,土壤石油污染质量分数为5～40 g·kg^-1时,对碱蓬种子的萌发无明显抑制作用。该研究对黄河三角洲生态区土壤石油类污染敏感指示指标的筛选和植物的生物修复具有重要意义。     

入田泥沙对黄河三角洲地区土壤物理性状的影响——以小开河引黄灌区为例

为研究人田泥沙对小开河灌区自然土壤的影响,用分析化验和工程测试等方法,分析了引黄泥沙和输沙人田后土壤颗粒组成、容重、孔隙状况等物理性状。结果表明：引黄泥沙中0．02～0．002mm的细粉粒比例最高,平均39-31％。小开河自然土壤中0．05-0．02mm的粗粉粒比例最高,为53．41％,泥沙中细粉粒和粘粒含量明显高于当地土壤。输沙人田使灌区土壤中0．02—0．002mm的细粉粒和〈0．002mm的粘粒比例明显增加,〉0．02mm的颗粒比例下降,虽有效避免了因渠首集中沉沙造成的土壤沙化和生态环境恶化,但增加了土壤的粘重程度。农田耕作在一定程度上增加土壤通气孔隙比例、降低土壤容重,但土壤毛管孔隙度依旧稳定在40％左右,毛管作用旺盛,使土壤通气状况不能满足作物需求。在黄河三角洲地区输沙入田的泥沙处理,应结合当地土壤的基本性质和水盐运动规律配置泥沙,以免增强当地土壤紧实、通透性差的性状。     

入田泥沙对黄河三角洲地区土壤物理性状的影响——以小开河引黄灌区为例

为研究入田泥沙对小开河灌区自然土壤的影响,用分析化验和工程测试等方法,分析了引黄泥沙和输沙入田后土壤颗粒组成、容重、孔隙状况等物理性状。结果表明:引黄泥沙中0.02～0.002mm的细粉粒比例最高,平均39.31%。小开河自然土壤中0.05～0.02mm的粗粉粒比例最高,为53.41%,泥沙中细粉粒和粘粒含量明显高于当地土壤。输沙入田使灌区土壤中0.02～0.002mm的细粉粒和﹤0.002mm的粘粒比例明显增加,0.02mm的颗粒比例下降,虽有效避免了因渠首集中沉沙造成的土壤沙化和生态环境恶化,但增加了土壤的粘重程度。农田耕作在一定程度上增加土壤通气孔隙比例、降低土壤容重,但土壤毛管孔隙度依旧稳定在40%左右,毛管作用旺盛,使土壤通气状况不能满足作物需求。在黄河三角洲地区输沙入田的泥沙处理,应结合当地土壤的基本性质和水盐运动规律配置泥沙,以免增强当地土壤紧实、通透性差的性状。     

黄河下游断流研究进展

介绍了黄河下游断流的发生特点、断流成因及断流对三角洲人民生产生活及对生态环境的影响三个方面的研究成果和进展。这些研究表明:黄河下游断流是自然与人为因素叠加所致,但主要影响因素为人类活动,而气候变化、源区生态环境恶化也是导致黄河径流减少的重要因子,但由气候变化引起的黄河径流量改变的百分比还未确定;黄河下游断流对河口海域生态系统、三角洲演变、工农业生产及城乡人民生活等方面都会产生影响,严重断流时会导致三角洲土地利用格局发生变化,并产生一系列生态问题。今后一段时间,要研究保障区域生态安全的生态用水量,合理利用黄河水量的丰枯周期,从根本上解决黄河下游的断流问题。     

花背蟾蜍性腺抗氧化酶对稀土尾矿库污染胁迫的响应

本研究以花背蟾蜍(Bufo Raddei)作为实验动物,以某稀土尾矿库周边受污染的水域湿地为研究样地,以相对无污染的小白河黄河湿地自然保护区为对照样地。通过检测两地花背蟾蜍精巢和卵巢的脏器系数、MDA和GSH含量、SOD、GSH-Px、GST、CAT和GR活性、T-AOC等相关指标。研究花背蟾蜍性腺抗氧化酶对该稀土尾矿库污染胁迫的响应效应。结果显示:与黄河湿地相比,稀土尾矿库湿地复合污染对花背蟾蜍精巢和卵巢脏器系数的影响差异不显著。稀土尾矿库花背蟾蜍精巢和卵巢中MDA含量、GPx、GST和CAT活性显著高于黄河湿地(P0.05),而GSH含量表现出相反的趋势。精巢中T-AOC显著高于卵巢(P0.01),但相同组织在两地间差异不显著。结果表明该稀土尾矿库复合污染对花背蟾蜍精巢和卵巢抗氧化能力有一定的毒害效应,且精巢和卵巢对污染胁迫的响应有明显的差异性。在应对稀土尾矿库湿地复合污染胁迫时,精巢更倾向于调用SOD-CAT系统的抗氧化机制,而在卵巢内GSH系统发挥作用更大。