Ca-H-Al exchanges and aluminium mobility in two Chinese acidic forest soils: a batch experiment     

J.?GuoEmail author  R.?D.?Vogt  X.?Zhang  Y.?Zhang  H.?M.?Seip  H.?Tang 《Environmental Geology》2004,45(8):1148-1153

Exchange reactions between Ca²⁺, H⁺ and Al species and their effects on the aluminium mobility in two Chinese acidic forest soils were studied. The study was based on a batch experiment using extractant solutions with different base cation (calcium) concentrations and pH. The experimental data showed that increased Ca²⁺ concentrations increased the release of soil hydrogen—and aluminium ions, especially from the more acid soil. In agreement with a cation exchange process, the treatment with Ca²⁺ extracts gave significantly decreased soil aluminium saturation (AlS) and increased calcium saturation (CaS) on the ion exchanger. Geochemical calculation using AlCHEMI program showed that activities of Al³⁺ in the extracts were all strongly under-saturated with respect to any gibbsite mineral in the studied pH region (i.e. below 4.1). There were instead apparently two different mechanisms controlling the activities of Al³⁺ in extracts. At pH between about 4.1 and 3.7, the Al³⁺ activity did not change significantly with pH. This is especially the case in the more acid soil. Apparently there are no sizeable pools available to release Al in this pH region. At pH below 3.7 (induced by higher Ca²⁺concentration) the activity of Al³⁺ increased with H⁺ though not in a pattern that complies with a gibbsite solubility control. An increase of base cation deposition would therefore mainly enhance the release of hydrogen ions between pH 4.1 and 3.7 and aluminium ions below pH 3.7 from Chinese mature acidic soils. This will cause an increased acidity of soil water in the short term and a decrease in the soil acidity in the long term. More attention should be paid to this fact in Chinese acid rain studies and control options.  相似文献   

基于广义3S技术的森林资源经营管理系统建设   总被引：8，自引：0，他引：8  

冯仲科  臧淑英  姚山 《测绘工程》2006,15(2):1-6

针对我国森林资源经营管理处于比较粗放的水平,将现代测绘科学与林业相结合,构建基于广义3S技术的森林资源经营管理系统。  相似文献   

多种定位终端与通信相结合的森林防火应急指挥调度系统的设计与实现     

李雁楠  林富明  张庆全  周源 《测绘与空间地理信息》2012,35(11):136-137,140

结合位置服务技术与通信技术,针对林区移动信号覆盖不全的特点,以GPS车载定位终端、GPS手机、GPS无线对讲机、北斗定位终端为定位与通信介质,建立基于多终端定位与通信的森林防火应急调度系统,解决林区因信号覆盖不全而引起通信与信息传输受阻的问题,为森林防火应急指挥调度提供解决方案。  相似文献   

系统抽样方法在典型天然阔叶林调查中的应用     

黄如楚 《山地学报》2012,30(4):450-453

以福建省永安市麻岭村9 hm2的典型天然阔叶林为试验研究对象,应用系统抽样方法,分别200 m×100m、100 m×100 m、100 m×50 m和100 m×25 m四种抽样密度,探讨林分主要测树因子的抽样估计精度.结果表明:试验的天然阔叶林分平均树高、平均胸径、平均密度与平均单位面积蓄积量等主要测树因子的估计精度都分别要求达到70％以上、75％以上、80％以上和85％以上的最小抽样密度分别是100 m×100 m、100 m × 50 m、100m×50 m和10 0m×25 m.试验的天然阔叶林分胸径Ⅲ组林木蓄积量的估计精度分别要求达到70％以上、75％以上和80％以上的最小抽样密度分别是100 m×50 m、100 m×25 m和100 m×25 m.  相似文献   

利用遥感技术建立墨西哥热带地上生物量模型(英文)     

AGUIRRE-SALADO Carlos Arturo  TREVIO-GARZA Eduardo Javier  AGUIRRE-CALDERóN Oscar Alberto  JIMéNEZ-PéREZ Javier  GONZáLEZ-TAGLE Marco Aurelio  VALDEZ-LAZALDE José René  MIRANDA-ARAGóN Liliana  AGUIRRE-SALADO Alejandro Iván 《地理学报(英文版)》2012,22(4):669-680

Spatially-explicit estimation of aboveground biomass(AGB) plays an important role to generate action policies focused in climate change mitigation,since carbon(C) retained in the biomass is vital for regulating Earth’s temperature.This work estimates AGB using both chlorophyll(red,near infrared) and moisture(middle infrared) based normalized vegetation indices constructed with MCD43A4 MODerate-resolution Imaging Spectroradiometer(MODIS) and MOD44B vegetation continuous fields(VCF) data.The study area is located in San Luis Potosí,Mexico,a region that comprises a part of the upper limit of the intertropical zone.AGB estimations were made using both individual tree data from the National Forest Inventory of Mexico and allometric equations reported in scientific literature.Linear and nonlinear(expo-nential) models were fitted to find their predictive potential when using satellite spectral data as explanatory variables.Highly-significant correlations(p = 0.01) were found between all the explaining variables tested.NDVI62,linked to chlorophyll content and moisture stress,showed the highest correlation.The best model(nonlinear) showed an index of fit(Pseudo-r2) equal to 0.77 and a root mean square error equal to 26.00 Mg/ha using NDVI62 and VCF as explanatory variables.Validation correlation coefficients were similar for both models:lin-ear(r = 0.87**) and nonlinear(r = 0.86**).  相似文献   

京、津、冀地区的碳排放趋势估计   总被引：2，自引：0，他引：2  

王铮  刘晓  朱永彬  黄蕊 《地理与地理信息科学》2012,28(1):84-89

通过多种方法相结合,估计了京、津、冀地区2009-2050年的能源碳排放量、水泥工艺碳排放量和森林碳汇量,计算了区域总的碳排放量和净碳排放量。结果表明:1)京、津、冀地区碳排放量都呈现先升后降的Kuznets趋势,森林年碳汇量对碳排放降低影响不明显;2)在自由排放条件下,北京、天津均在2030年前达到碳排放高峰期,河北省及整个京津冀地区的碳排放高峰将延迟到2039年;3)在2050年前,北京、天津年碳汇量将有所降低,河北年碳汇量则上升。  相似文献   

黄河三角洲湿地柽柳林生长动态密度结构的响应特征     

夏江宝  陆兆华  孔雪华  刘京涛  韩瑞东  朱金方 《湿地科学》2012,10(3):332-338

为了阐明滨海湿地不同密度柽柳(Tamarix chinensis)林的生长动态,探索滨海湿地柽柳林的密度合理性,在黄河三角洲莱州湾南岸的山东昌邑海洋生态特别保护区内,利用标准木树干解析法,对10a生的3种密度(2400株/hm2、3 600株/hm2和4400株/hm2)的柽柳林地上生物量、林木生长动态和基径分布特征进行研究.结果表明,3种密度林分的地上生物量、树高生长量和林木基径生长过程差别较大.随着林分密度增大,林木单株生物量和基径减小,但单位面积林分生物量增加;树高、基径的速生期都出现滞后现象.3种密度林分基径分布的偏度系数(SK)差别较大;密度为3 600株/hm2林分的SK值为0.085,接近正态分布,林分密度结构和基径分布较为合理;密度为2 400株/hm2和4 400株/hm2林分的SK值分别为-0.842和0.303,偏离正态分布,林分密度结构不合理.密度为2 400株/hm2林分的峰度系数(K)为0.017,林木生长相对整齐;密度为3 600株/hm2和4 400株/hm2林分的K值相差不大;密度因素对林木分化作用较小.若不考虑10a间的林木间伐利用,该区柽柳人工造林合理的初植密度建议为3 600株/hm2(株行距约2.0 m×2.0 m).  相似文献   

水源林区人工湿地污水处理技术的应用示范     

陆豫  李云涛  陆王烨 《湿地科学与管理》2012,8(3):40-42

针对水源林区的污水处理和循环利用等问题,设计了水平潜流人工湿地+垂直流人工湿地污水处理工艺,该工艺依靠重力作为动力,无需能耗,管理简单,污水处理效果较好,抗冲力负荷能力较强。运行结果表明,工艺出水主要指标达到了《地表水环境质量标准》(GB3838-2002)规定的I类水质标准。  相似文献   

Past,present and future vegetation-cloud feedbacks in the Amazon Basin     

E. Pinto  Y. Shin  S. A. Cowling  C. D. Jones 《Climate Dynamics》2009,32(6):741-751

To begin exploring the underlying mechanisms that couple vegetation to cloud formation processes, we derive the lifting condensation level (LCL) to estimate cumulus cloud base height. Using a fully coupled land–ocean–atmosphere general circulation model (HadCM3LC), we investigate Amazonian forest feedbacks on cloud formation over three geological periods; modern-day (a.d. 1970–1990), the last glacial maximum (LGM; 21 kya), and under a future climate scenario (IS92a; a.d. 2070–2090). Results indicate that for both past and future climate scenarios, LCL is higher relative to modern-day. Statistical analyses indicate that the 800 m increase in LCL during the LGM is related primarily to the drier atmosphere promoted by lower tropical sea surface temperatures. In contrast, the predicted 1,000 m increase in LCL in the future scenario is the result of a large increase in surface temperature and reduced vegetation cover.  相似文献   

河南省近年来遥感监测的森林火灾时空分布规律分析   总被引：2，自引：0，他引：2  

郭其乐  陈怀亮  邹春辉  薛龙琴  赵学斌  刘忠阳   《气象与环境科学》2009,32(4):29-32

森林火灾作为一种自然灾害,其发生原因不仅来自于自然因素,从众多的火灾调查中发现,更多地来自于人类活动因素,其发生的时空分布特点和规律,受自然和人类活动共同影响.对2003-2008年春、冬季(11月-次年4月)河南省森林防火期内遥感监测并已查明的森林火灾进行统计分析,结果发现:河南省森林火灾近年来有逐年增多的趋势;冬、春之交的3月为森林火灾的高发月份;从火灾的日变化规律来看,12-15时为一天中森林火灾的高发时段;从火灾发生的空间分布来看,伏牛山南麓发生森林火灾的频率较高.  相似文献