南矶山湿地典型植被群落表层土壤养分含量特征分析

以鄱阳湖区的南矶山国家级湿地自然保护区为研究区域,采用多种分析方法对研究区域内3种典型湿地植被群落表层土壤有机质、有效磷和有效氮的含量进行特征分析。结果表明同种植被群落下各采样点土壤养分含量基本一致,而不同植被群落下相应土壤养分含量差异较明显。其中有机质变化趋势:苔草群落南荻群落芦苇群落;有效氮含量变化趋势:芦苇群落南荻群落苔草群落;有效磷含量变化趋势:苔草群落南荻群落芦苇群落。典型植被下3种土壤养分之间存在着显著的相关性,其中有机质与有效磷呈显著正相关,有机质与有效氮呈显著负相关,有效氮与有效磷呈显著负相关。相较于其他湿地类型,南矶山湿地的表层土壤中3种养分的含量总体不高。     

黄河口湿地柽柳灌丛对土壤养分分布的影响

运用单因素方差分析(ANOVA)和克里金空间插值法,对黄河三角洲河口湿地群落演替方向上碱蓬群落、碱蓬-柽柳群落和柽柳群落中柽柳灌丛对土壤养分分布的影响进行了研究,结果表明:①土壤有机质(SOM)和水解氮(AN)含量沿群落演替方向呈递增趋势;速效磷(AP)在碱蓬-柽柳群落含量最大、柽柳群落含量最小;速效钾(AK)在碱蓬-...     

黄河三角洲湿地土壤养分空间分布特征

为研究滨海湿地不同植物群落下土壤养分的空间分布特征,在黄河三角洲国家级自然保护区湿地内,分层采集了柽柳、柽柳-碱蓬、芦苇-柽柳、碱蓬-芦苇和芦苇等5种植物群落下的土壤样品,并对样品中各养分以及含盐量和pH值进行了测定。结果表明:黄河三角洲湿地0～30 cm土层中TOC、SOM和TN、TP、AN、AP平均含量分别为0.19%、0.33%和202.27、539.80、4.47、2.64 mg/kg。随着离海岸线距离的增加,土壤中TOC、SOM、TN、AN和AP含量呈现出相同的波动趋势,其中芦苇-柽柳群落与柽柳群落下土壤中养分含量较高,而所有群落TP变化不大;5种群落的土壤养分含量垂直差异均不显著。相关性分析表明,土壤中TN、AN、AP含量与TOC含量之间存在显著的正相关关系,而土壤含盐量和pH值对各养分含量并无显著影响。     

黄土高原吕二沟流域土地利用对土壤养分的影响

文章在甘肃天水吕二沟流域,选择5种不同的土地利用类型地块进行试验,分析和探讨不同土地利用类型下(刺槐林地、草地、梯田耕地、梯田果园和坡耕地)土壤有机质和氮磷钾含量情况,为提高土地生产力,实现土地可持续利用提供指导。     

土壤养分对神东矿区造林成活率的影响

用现场调查和实验分析的方法,分析不同土壤养分条件对文冠果和樟子松造林成活率的影响,经实验分析得出结论：随着速效K含量的增加,文冠果和樟子松成活率均有明显升高的趋势。     

滨海湿地原生灌草群落土壤养分与盐分关系

通过灌草群丛划分、土壤采样以及室内测定、数理统计等方法,分析了黄河三角洲原生湿地灌草群落土壤的养分、盐分分布特征及相互关系,发现原生灌草群落土壤可溶性盐的垂直分布变异性较大,其中,碱蓬群丛与柽柳群丛土壤可溶性盐分布具有较强的表聚性,而土壤有机质含量表现为芦苇群丛>柽柳群丛>碱蓬群丛,且灌草群落中土壤C/N值都大于5,表明其有机质腐殖化程度较高。另一方面,土壤全氮与有机质存在明显的线性正相关;而土壤全盐与有机质、全氮之间存在明显的倒数关系,表明全盐对二者的制约作用,其中15~20g/kg的土壤盐分范围对应的是土壤全氮、有机质由迅速减少向缓慢减少的变化趋势。研究结果可以为盐碱土改良提供重要参考。     

会仙湿地小流域土壤养分时空分布特征

为揭示漓江流域会仙湿地小流域土壤养分的时空分布规律及其变异特征,同步连续监测了河道沉积物、消落带、耕地等区域中土壤的pH、有机质、全氮、全磷、硝态氮、铵态氮等指标,应用单因素方差分析、曼-惠特尼U检验、Pearson相关性分析和反距离插值法,研究土壤养分的时空分布特征,探究河道沉积物、消落带和耕地土壤养分之间的相互关系。结果表明：河道沉积物、消落带、耕地土壤的全氮、有机质和硝态氮含量受季节影响较大,在不同季节间存在显著差异,而受年份的影响较小;河道沉积物土壤养分受河道河床变化、人类活动等影响,沿程变化呈现复杂性;河道沉积物、消落带、耕地土壤三者间的养分含量有着密切的联系,且受降雨的影响较大。     

降雨坡面土壤养分流失影响因素研究综述

降雨产生的地表径流在造成水土流失的同时也会造成表层土壤养分随水分流失。系统介绍了降雨、地形条件、植被、土壤特性对坡面土壤养分流失的影响规律,旨在为控制坡面养分流失和揭示坡面养分流失机理提供参考。     

固沙植物对沙丘土壤剖面组成与养分含量的影响

流动沙丘通过围封治理和栽植固沙植物.促进自然植被恢复,沙丘迅速稳定,流动风沙土部面出现明显层次,有机质与其他养分含量显著提高.人工固定沙丘,土壤腐殖质层厚度达0.3-4.5cm.固定5-6年的沙丘,0-30cm土层有机质含量提高0.221%,全P提高0.004%.全K提高0.255%,全N变化不明显.固定10年以上的沙丘有机质提高0.397%,全N提高0.029%,全P提高0.004%,全K提高0.270%.     

鄱阳湖南矶湿地典型植被对水深和淹没频率的响应分析

水文要素是控制湿地生态过程发展与演替的主要驱动因子,在湿地形成、发育、演替直至消亡全过程中起重要作用。湿地植被群落是湿地生态系统重要组成成分和主要初级生产者,其结构、功能和生态特征综合反映着湿地生态环境的基本特点和功能特性。本文以鄱阳湖南矶湿地国家级自然保护区为例,运用植被群落—水文要素丰度直方图和敏感性指数,分析探讨了保护区内5种典型湿地植被群落对水深和淹没频率两种水文要素的耐受性和敏感性。结果表明:不同植被群落对水深、淹没频率的耐受性和敏感性不同。其中:(1)虉草和蓼子草2种群落对水深的耐受性最强,南荻群落最弱;苔草群落对淹没频率的耐受性最强,蓼子草群落最弱。(2)相较于淹没频率,5种典型植被群落对水深的敏感性更强;(3)南荻群落对水深和淹没频率变化的敏感性最强,而蓼子草群落对水文要素变化的响应最不敏感。     

鄱阳湖南矶山湿地土壤磷释放研究

研究鄱阳湖南矶山湿地土壤的磷释放,探讨土壤中磷的形态与磷释放的关系以及土壤吸附大量磷后的再释放情况。结果表明:土壤磷的释放有限,土壤吸附大量磷后的再释放是缓慢的;pH值、温度、NO3-浓度、扰动和溶解氧对土壤磷的释放均有影响;土壤中磷释放取决于磷的形态,可溶性磷和铁磷在土壤磷的释放中所起作用较大,其余形态的磷所起作用较小。     

若尔盖湿地土壤特性空间变化研究

若尔盖湿地是青藏高原高寒湿地生态系统的典型代表,近年来湿地急剧萎缩和退化。根据若尔盖湿地分布特点,采用野外调查和室内试验分析相结合的方式,对在6个样区采取的349个土壤样品进行测试分析,研究若尔盖湿地土壤质地、土壤水分、养分空间特性变化,探讨湿地生态系统演化对土壤状况的影响。研究结果表明:若尔盖湿地土壤质地变化在空间和垂向上差异较小,花湖地区主要为壤土,纳若桥、达水曲、排水沟、哈丘湖为砂壤土,喜马拉也地区则为壤砂土。土壤pH值的变异系数最小,空间变异性相对较弱,有机质的变异系数相对较大,其次为速效磷和速效钾;有机质从表层到80 cm处呈降低趋势,有机质含量花湖纳若桥排水沟哈丘湖达水曲喜马拉也。不同区域的土壤水分特征曲线Van Genuchten模型参数差异显著,喜马拉也和达水曲区域的A和n值明显高于其余区域,土壤水分持水性能较弱。研究结合不同区域的土壤性质、水分及养分特性变化,对若尔盖未来湿地保护和管理的重点方向和区域进行指导和建议。     

The impact of agricultural management practices on nutrient losses to water: data on the effects of soil drainage characteristics.

Against the background of increasing nutrient concentrations in Irish water bodies, this study set out to gain information on the potential of agricultural grassland to lose nutrients to water. Overland flow, flow from artificial subsurface drains and stream flow were gauged and sampled during heavy rainfall events. Dissolved reactive phosphorus (DRP), potassium (K), total ammonia (TA), and total oxidised nitrogen (TON) were measured in water samples. When the nutrient concentrations in water were examined in relation to the grassland management practices of the study catchments it emerged that soil P levels, the application of organic and inorganic fertilisers before heavy rainfall and the presence of grazing animals could all influence nutrient concentrations in surface and subsurface drainage water. Overall, the drainage characteristics of soil were found to have a considerable influence on the potential of land to lose nutrients to water.     

The effects of deep zones on wetland nitrogen processing.

Twelve research wetlands were operated under varying conditions at a site west of the city of Phoenix. These were constructed as a triplicated design, with zero, one, two and three internal deep zones, all containing an inlet distribution and an outlet collection deep zone, together comprising 12.5-35% of the wetland areas. The water supply was partially nitrified effluent from a city wastewater treatment plant. Total nitrogen was reduced by about 50%, from inflow concentrations between 6 and 8 mg/L. Speciation of the inflow was approximately 25% organic nitrogen, 25% ammonium nitrogen and 50% nitrate nitrogen. Typical outflow concentrations were about 1.2 mg/L organic, 0.5 mg/L ammonium and 0.0-2.5 mg/L nitrate. Rate constants for total nitrogen were 15-20 m/year at 20 degrees C, and 20-30 m/year for nitrate, which agree well with other project reports. Temperature factors averaged 1.100 for total nitrogen, and 1.184 for nitrate. There were no differences in the internal hydraulics with deep zone numbers. Deep zone numbers in the wetlands did not affect nitrogen treatment performance. No differences with deep zone numbers were found for temperature, dissolved oxygen, pH, or nitrogen removals or rate constants. In conjunction with other reported results, there appears to be no large treatment benefit or detriment of incorporating internal deep zones in free water surface wetlands.     

洪河国家级自然保护区水资源需求研究

基于洪河国家级自然保护区水资源退化现状及湿地生态规律,认为洪河保护区水资源需求应从动态需求和静态需求两个方面来综合分析与计算。计算静态需求量时,视洪河保护区为一个平原水库,通过做出水位库容曲线,查出相对于原始状态保护区的静态需水量;计算动态需求量时,主要以湿地生态活跃期对水资源的动态需求过程为计算依据。通过分析计算,提出保护区维持现状和相对原始状态两种情况下的每年水资源动态需求量。     

The influence of soil desiccation on plant production,nutrient uptake and plant nutrient availability in two French floodplain grasslands

The effects of summer soil desiccation on plant production and plant nutrient availability (determined by wet chemical extraction) in floodplain grasslands along the rivers Allier and Loire in France were investigated. Soil desiccation in these river floodplains is the result of human interference with the natural flooding regime of rivers, such as dam construction and gravel mining. Flooding periods along the Allier have a longer duration (maximum of 202 days as opposed to 38 days for the Loire). The main comparison was between floodplain grasslands along the two rivers. Additional comparisons were made between relatively high lying, wetter areas (‘ridges’) and low lying, drier areas (‘swales’) within both floodplains. Thus, areas with different soil moisture content were examined, independent of river influences. The availability of P was higher in the Allier floodplain than in the Loire floodplain, but it was similar between ridges and swales. It was concluded that P-availability was not related to soil wetness, but to river sedimentation. Plant production, plant nutrient uptake, and biologically mediated soil processes, such as N-mineralization and nitrification, were all higher on the wetter Allier floodplain and in the wetter swales. These higher process rates were noted where higher amounts of soil bound carbon and nutrients were found as well. Plant production, N-mineralization and nitrification were moisture limited at the dry ridge on the Loire floodplain, as moisture levels were below the wilting point here (pF>4.2). On the wetter parts of the floodplain, plant production was N-limited. This was concluded from low tissue N/P ratios (about 10) and a positive relation between plant production and N-mineralization. On the wetter parts, the rate of N-mineralization depended on the size of soil organic-N pools. The size of these pools was positively related to soil wetness, which can be interpreted as a positive effect of river flooding. Reduced flooding lowers the nutrient input to floodplains and contributes to the occurrence of soil desiccation in summer, which results in lower nutrient cycling and reduced accumulation of soil organic matter. These effects have negative consequences for important floodplain functions, such as nutrient retention and biomass production. © 1998 John Wiley & Sons, Ltd.     

围封治理对风沙土养分含量的影响

为了改善沙地干旱不良特性,保障栽培植物的成活生长,在沙丘地区,采取围封治理。经过栽培固沙植物,对围封禁牧与实施人工栽培固沙植物等措施,促进了沙地植被恢复,增加了风沙土养分含量,通过治理沙地,防止风沙,改善了生态环境,取得了经济效益。     

水电开发条件下自然保护区管理的实践创新——以长江上游珍稀特有鱼类国家级自然保护区为例

为协调金沙江下游的水电开发与鱼类生态保护,国家设立了长江上游珍稀特有鱼类国家级自然保护区。系统介绍了自2005年以来,各级政府主管部门、相关科研设计机构和中国长江三峡集团有限公司在金沙江下游共同开展的保护区管理工作,工作内容包括保护区机构与基础设施建设、渔民安置、鱼类增殖放流、水生态监测与生态保护相关科研等多个方面。在保护区建设与管理中,参与各方首次构建了规划策划-实施运行-监测评估-管理改进(Plan-Do-Check-Act,PDCA)的适应性管理机制,开创了“企-政-地-研”多方共同参与的保护区工作格局。该管理机制的实践创新有效协调了水电开发与鱼类生态保护,秉持“生态优先”原则,贯彻“自然恢复”理念,为自然保护区管理中各方良好协作、高效实时调整提供了新的思路。     

基于RIA的武夷山保护区生态水文信息系统

传统的信息管理方式很难有效对大量复杂密集的水文信息进行整合、查询、综合分析及可视化。利用GIS技术并结合近年兴起的RIA技术,使水文信息系统在界面表现力和交互力、网络传输等方面具有明显的优势。提出具有代表性的Flex技术和ArcGIS API for Flex,结合动态图表展示插件FusionCharts,通过ArcGIS Server10平台,构建基于RIA的武夷山保护区生态水文信息系统。该系统充分利用RIA技术的优点,实现集生态水文数据的查询、分析统计与输出和动态实时展示为一体的功能,为用户提供更友好的交互界面和数据可视化能力。