沙湖湿地的生态环境健康评价的研究

通过对生态系统健康评价体系的研究,以沙湖为例进行论证,最终得出沙湖生态系统健康度为0.32,属于不健康,制约沙湖不健康的疾病因子在于：湿地的补水水质差,导致湿地水质污染加重,富营养化现象严重,并且由于人为因素,导致物种多样性逐年下降,以上因素最终导致了沙湖湿地生态系统抗干扰能力下降,湖区湿地健康水平较低,根据对沙湖湿地功能的分析,最终设计出了沙湖湿地生态系统健康恢复技术方案。     

缙云山3种典型森林降雨过程及其氮素输入

选取重庆缙云山的常绿阔叶林、毛竹林和针阔混交林为研究对象,于2012年5~10月对大气降水、穿透雨和树干径流等降水过程及其氮素输入进行研究.结果表明:①研究期间总降雨量564.88 mm,常绿阔叶林、毛竹林和针阔混交林的穿透雨量占总降雨量的比例分别为74.0%、85.0%和71.6%,且树干径流量所占比例分别为1.9%、10.3%和1.6%;3种林分的穿透雨量、树干径流量与林外降雨量之间均呈显著的线性关系(P<0.05),且穿透雨率、树干径流率与林外降雨量之间都呈对数关系(P<0.05).②与大气降水相比,穿透雨和树干径流的NO-3和NH+4浓度要高,且3种林分的大小关系为针阔混交林>常绿阔叶林>毛竹林;穿透雨和树干径流的总无机氮输入量(以N计)分别为针阔混交林(18.93 kg·hm-2)、常绿阔叶林(14.93 kg·hm-2)和毛竹林(15.31 kg·hm-2).③3种林分的无机氮输入量与穿透雨量、树干径流量之间均呈显著的线性关系(P<0.05).     

模拟氮沉降对太岳山油松林土壤呼吸的影响及其持续效应

以太岳山油松林为研究对象,对林地分别作3种凋落物处理:对照(C)、去凋(B)、去凋+切根(A),并设计了4个氮水平:对照(CK,0 kg·hm-2·a-1,以N计,下同)、低氮(LN,50 kg·hm-2·a-1)、中氮(MN,100 kg·hm-2·a-1)和高氮(HN,150 kg·hm-2·a-1),研究了土壤呼吸速率在施氮后的连续变化,以及与温度、湿度、微生物生物量C、N、土壤酶活性的关系.结果表明:去凋+切根、去凋、对照样方不同施氮水平下土壤呼吸速率基本都在施N后的第1 d处在最高峰,随即下降,切根+去凋、去凋处理样方的土壤呼吸速率在施氮后第3 d趋于稳定,而对照处理样方的土壤呼吸速率一直处于下降状态.施氮在一定程度上抑制了切根+去凋处理的土壤呼吸速率,而促进了去凋处理、对照处理的土壤呼吸速率,并且土壤微生物生物量C、N的变化与土壤呼吸速率变化一致,土壤呼吸速率与土壤酶活性、土壤湿度的拟合关系不显著(p0.05),而与土壤温度的拟合关系显著(p0.05).以土壤温度、土壤湿度构建的复合模型R s=aebTWc预测土壤呼吸的准确性高于单因子模型,施氮降低了每种凋落物处理指数关系模型(R s=aebT)的决定系数R2,并且施氮降低了切根+去凋、去凋处理的温度敏感性指数Q10,而对对照处理的Q10无明显影响.     

江汉湖群典型湖泊生态系统健康评价——以梁子湖、洪湖、长湖、斧头湖、武湖为例

湖泊生态系统健康评价对湖泊生态健康状况评定、环境问题诊断和湖泊生态系统管理具有重要意义.根据江汉湖群实际情况和生态特点,选取江汉湖群五大湖泊—梁子湖、长湖、洪湖、斧头湖和武湖为研究对象,采用野外调查、资料收集并结合GIS技术的研究方法,从生物、水质、生境特征及生态压力4个方面选择15个代表性评价指标,构建江汉湖群典型湖泊生态系统健康评价指标体系,并利用基于模糊综合评价模型的评价方法,对江汉湖群五大湖泊生态系统健康进行评价.结果表明,江汉湖群五大湖泊生态健康综合评价得分值为5.47~7.46,梁子湖得分最高,其余依次为斧头湖、洪湖、长湖和武湖.从湖泊生态系统健康等级看,五大湖泊中梁子湖和斧头湖处于比较健康状态,而洪湖、长湖和武湖处于亚健康状态.通过实例分析表明,本研究建立的湖泊生态系统健康评价方法能够较客观系统地评价江汉湖群生态系统健康状况,具有较高的可行性和可靠性,可作为江汉湖群健康诊断的评价方法.本文研究结果可为江汉湖群的分类管理提供较为重要的参考依据.     

基于分形理论的矿区生态系统稳定性评价

引入非线性理论对矿区生态系统的稳定性进行研究.通过相空间重构的方法确定各混沌吸引子的关联维数,对矿区生态系统的稳定性进行评价.研究表明:焦作矿区矿产资源保有指数、矿产资源回收指数和矿产资源综合利用指数3个指标的分维值都较小,说明自然资源支持度的脆弱性是造成矿区生态系统不稳定性的主要原因.     

基于无人机多传感吊舱系统的火点实时定位方法

林火定位是林火智能监测设备的核心技术。提出了一种基于激光雷达、红外热像仪及组合惯导多数据融合的火点定位方法。首先设计了一个通用的无人机吊舱系统,并基于ROS框架实现数据采集、数据处理和数据传输等功能;其次提出了一个基于无人机吊舱系统的火点全局定位方案,根据红外热像仪成像特性识别火点,同时将密集点云与红外图像进行数据融合,估计出火点的三维空间位置;然后根据无人机位姿提出了一种基于墨卡托投影的火点全局定位方案,得到了火点的GPS位置。最后通过试验得到了该方案的全局定位精度：在实验中经度最大误差为2.36×10^-5°,纬度最大误差为1.84×10^-5°,高程最大误差为0.926 1 m,为其他林火定位方案提供了技术支持。     

Effect of vegetation type on throughfall deposition and seepage flux

This paper compares different vegetation types (coniferous and deciduous forest, grassed and pure heathland) in terms of input (throughfall deposition) and output (seepage flux) in a region with intermediate nitrogen load (+/-20kg Nha(-1)y(-1) via bulk precipitation) in comparable conditions in north Belgium. Coniferous forest (two plots Pinus sylvestris and two plots Pinus nigra) received significantly higher nitrogen and sulphur throughfall deposition than deciduous forest and heathland. Grassed and pure heathland had significantly highest throughfall quantities of Ca(2+) and Mg(2+), respectively. The observed differences in throughfall deposition between the different vegetation types were not univocally reflected in the ion seepage flux. Considerable seepage fluxes of NO(3)(-), SO(4)(2-), Ca(2+) and Al(III) were only found under the P. nigra plots. We discuss our hypothesis that the P. nigra forests already evolved to a situation of N saturation, while the other vegetation types did not.     

Sensitivity analysis of a parameterization of the stomatal component of the DO3SE model for Quercus ilex to estimate ozone fluxes

A sensitivity analysis of a proposed parameterization of the stomatal conductance (g(s)) module of the European ozone deposition model (DO(3)SE) for Quercus ilex was performed. The performance of the model was tested against measured g(s) in the field at three sites in Spain. The best fit of the model was found for those sites, or during those periods, facing no or mild stress conditions, but a worse performance was found under severe drought or temperature stress, mostly occurring at continental sites. The best performance was obtained when both f(phen) and f(SWP) were included. A local parameterization accounting for the lower temperatures recorded in winter and the higher water shortage at the continental sites resulted in a better performance of the model. The overall results indicate that two different parameterizations of the model are needed, one for marine-influenced sites and another one for continental sites.     

Images of war: using satellite images for human rights monitoring in Turkish Kurdistan

In areas of war and armed conflict it is difficult to get trustworthy and coherent information. Civil society and human rights groups often face problems of dealing with fragmented witness reports, disinformation of war propaganda, and difficult direct access to these areas. Turkish Kurdistan was used as a case study of armed conflict to evaluate the potential use of satellite images for verification of witness reports collected by human rights groups. The Turkish army was reported to be burning forests, fields and villages as a strategy in the conflict against guerrilla uprising. This paper concludes that satellite images are useful to validate witness reports of forest fires. Even though the use of this technology for human rights groups will depend on some feasibility factors such as prices, access and expertise, the images proved to be key for analysis of spatial aspects of conflict and valuable for reconstructing a more trustworthy picture.     

Types of Ectomycorrhiza of Mature Beech and Spruce at Ozone-Fumigated and Control Forest Plots

In the Kranzberg forest near Freising (Germany) a novel “Free-Air Canopy O₃ Exposure” system has been employed for analysing O₃-induced responses from sub-cellular to ecosystem levels that are relevant for carbon balance and CO₂ demand of 60-year-old beech trees. The below-ground ectomycorrhizal community was studied in two-fold ambient O₃ concentrations (five cores per sampling) and in a control plot with an ambient O₃ concentration (four cores per sampling). Five samplings were taken throughout two vegetation seasons (2003 and 2004). Types of ectomycorrhiza were determined by their morphological, anatomical and molecular characteristics and quantified by counting. The total number of mycorrhizal fine roots was higher at the fumigated plot as compared with the control site. The numbers of ectomycorrhizal types at the fumigated and control plots were 28 and 26, respectively. Cenococcum geophilum was present in all soil cores at all sampling times with a significant increase in abundance under ozone-fumigated trees. Other mycorrhizal types present at higher abundance at the fumigated than at the control plot were identified as Russula densiflora, R. fellea, R. illota, Tuber puberulum, Lactarius sp. 2 and Russula sp. 2. Some mycorrhizal types were present exclusively at the fumigated plot (Fagirhiza fusca, F. setifera, Lactarius acris, Piceirhiza nigra and Russula sp. 1). A possible ecological role for the abundant types of ectomycorrhiza and their putative application in bio-indication is discussed.