首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
贵州黔灵山土壤系统分类   总被引:12,自引:1,他引:11  
贵州省是我国喀斯特分布的集中区域 ,因其环境脆弱形成了独特的喀斯特环境。选取了贵州省中部具有典型代表性的黔灵山进行土壤系统分类研究 ,论述了黔灵山成土环境 ,将《中国土壤系统分类 (修订方案 )》应用到喀斯特环境中 ,划分了 3个诊断层和 5个诊断特性 ,并在此基础上分出了 7个亚类 ,归纳总结了土壤类型空间分布规律与发生条件的关系 ,为应用遥感和地理信息系统技术在喀斯特地区制作土壤系统分类图和进行土壤资源研究奠定了基础。  相似文献   

2.
2007年1~4月,对韶关市郊不同类型坡地的土壤动物进行采集调查,共获得动物标本663只,隶属3门10纲19目,其中蜱螨目和弹尾目是优势类群,盲蛛目、鞘翅目、膜翅目、颤蚓目为常见种类;稀有种类因植被的不同各有差异,竹林动物种类与数量比较多.土壤动物垂直分层分布现象比较明显,随土层的加深而减少;植被类型是影响土壤动物群落结构和多样性的主要生态因子.  相似文献   

3.
Rising atmospheric CO2 and temperature are altering ecosystem carbon cycling. Grasslands play an important role in regional climate change and global carbon cycle. Below-ground processes play a key role in the grassland carbon cycle because they regulate …  相似文献   

4.
Three suborder soils in southwest China were adopted, namely Ustic Vertisol, Stagnic Anthrosol and Ustic Ferrosol, so as to carry out the basic physical and chemical analysis respectively, to design a dynamic measuring method for water stability of soil structure and conduct the comparative study on the quality of the soil structure. The results indicated that (1) The water stability dynamic characteristic of the soil structure could well reflect the maintaining capability of the soil structure as time goes on. (2) The quality of several soil structures in southwest China was sequenced as follows: Stagnic Anthrosols 〉 Ustic Vertisols 〉 Ustic Ferrosols. (3) The water stability of soil structure is very positively correlated with the capillary porosity and the clay particle (D 〈 0.002 mm) content (Co), but is very negatively correlated with the silt (D is 0.05-0.002 ram) content (Csc), and (4) The dynamic functional equation of the water stability of soil structure in southwest China was established, so that the water stability characteristics of various soil structures could be quantitatively expressed and the quality of different soil structures can be quantitatively compared from each other.  相似文献   

5.
为了掌握成都市郊区土壤动物群落特征及不同土地利用方式对土壤动物群落的影响,2008年10月对成都市郊区的绿化林、农田和莱地内的土壤动物进行了调查.共捕获大型土壤动物213只,隶属于2门6纲10类(目),优势类群为大蚓类(Macrodrilc oligochaetes)和小蚓类(Microdrilc oligochaetes);中小型土壤动物1118只,隶属4门7纲10类(目),优势类群为弹尾目(Diplura)、线虫类(Nematode)和线蚓类(Enchytraeidae);大型和中小型土壤动物类群和个体数的大小顺序均为菜地〉林地〉农田,但仅有中小型土壤动物的个体数有显著差异(P〈0.05);大型土壤动物群落间的多样性差异不显著(P〉0.05),中小型的差异显著(P〈0.05);大型土壤动物群落间相似性低于中小型;林地和菜地土壤动物垂直分布的表聚性高于农田,大型土壤动物的表聚性高于中小型.研究结果表明,不同土地利用方式对大型和中小土壤动物群落的影响不同.  相似文献   

6.
The response of soil temperature and moisture to vegetative cover in the active layer of permafrost and seasonally frozen soil were assessed and compared. Soil temperature and moisture, under a range of vegetation covers (92%, 65% and 30%) in the permafrost and vegetation covers (95%, 70%―80%, 40%―50% and 10%) in the seasonally frozen soil, were measured on a daily basis. A decline in vege-tation cover led to a decrease in the integral of freezing depth of active permafrost layer, but an in-crease in seasonally frozen soil. The maximum invasion depth and duration of the negative isotherm during the frozen period and of the positive isotherm during the non-frozen period clearly increased when vegetation cover declined. With a reduction of vegetation cover, the soil moisture in the active layer of the permafrost decreased for depths of 0.20―0.60 m, but increased for depths of 0.60―0.80 m, while for seasonally frozen soil, soil moisture of the entire profile (0.10―1.20 m) increased. Variation in vegetation cover alters soil heat-water processes, but the response to it is different between permafrost and seasonally frozen soil.  相似文献   

7.
焦化废水污染土壤中原生动物的群落特征   总被引:1,自引:0,他引:1  
对陕西省耀县受焦化废水污染的土壤及对照土壤中的原生动物群落特征进行了研究,共鉴定到原生动物43种,隶属于2门、6纲、10目、25科、32属,其中对照土壤中有28种,污染土壤中有25种,对照土样和污染土样共有种是10种;q=0.23;物种多样性指数在对照土壤中为3.3,在污染土壤中为2.4.结果表明,焦化废水污染对土壤原生动物群落有很大影响,主要体现在群落结构发生很大变化,群落物种多样性明显下降.  相似文献   

8.
Experimental study on soil respiration of temperate grassland in China   总被引:6,自引:0,他引:6  
Understanding of CO2 source and sink characteristics of terrestrial ecosystem is one of the most critical prob-lems at present, but till now, most studies concerning the natural terrestrial ecosystem carbon cycle are concentrated on the forest ecosystem. Not enough attention is paid to the natural grassland, especially to the temperate natural grassland, whose area is almost equal to that of tropical forest in the world. Little is known about the role of the grassland, which takes about 25% of…  相似文献   

9.
 水土资源是人类赖以生存的重要物质基础。水土保持作为人类对生态系统干预的有效手段,其生态服务功能价值也受到越来越多的重视。本文介绍了中国水土流失状况、动态变化,水土流失治理概况与成效,分析了水土保持效益及中国水土保持生态服务功能现状,提出未来水土保持需以控制水土流失为基础,提高生态系统服务功能为终极目标,实现人与自然和谐。  相似文献   

10.
基于气候和土壤要素的中国耕地适宜性指数构建   总被引:1,自引:0,他引:1  
中国历史土地利用的重建工作主要分为数据重建和空间重建,而建立具有空间指示作用的参数对于历史土地利用的空间重建具有举足轻重的指示意义.本文基于此想法,参考前人经验,构建了一套耕地适宜性指数,作为历史土地利用空间重建的基础.首先通过分析影响耕地时空分布的多种自然要素和人文因素,从中厘定土壤和气候这2个关键要素,然后基于此构建了一套计算耕地适宜性指数的方法.通过获取的气候适宜性与土壤适宜性的空间分布图与实际土地利用的相关性分析验证了这2个要素的一定代表性.本文最终的结果代表自然状态下耕地分布的最初可能性,具体特征有:1)对耕地分布起影响的气候适宜性分为4个等级的块状分布;2)对耕地分布有影响的土壤适宜性比较零散,但是大体还是以秦岭-淮河一线为分界线,呈现北高南低的分布;3)对于不同地区耕地分布,影响的主导因素有区别,西北为土壤要素,东南为气候要素;4)耕地适宜性最高的地区基本集中在华北平原、长江中下游平原区域,而青藏高原地区的适宜性最低.结合人口、经济等因素,这样一套耕地适宜性分布图对历史土地利用空间分布有重要的空间指示作用.  相似文献   

11.
铁矿尾砂掺土对土壤几种物理性质的影响   总被引:2,自引:0,他引:2  
利用铁矿尾砂掺土培养实验,测定金山店铁矿尾砂掺土对其尾矿库边坡覆土即红色石灰土几种物理性质的影响,结果表明,铁矿尾砂掺土使土壤自然容重和压实容重分别增加了4.0%~26.8%和2.6%~24.8%,但与掺砂比例并不呈线性关系.随掺砂比例增加,土壤密度增加了1.7%~20.2%,与掺砂比例呈显著的线性相关.适当的掺砂比例可以显著增加土壤孔隙度.土壤吸湿系数随掺砂比例增加下降了10%~87%,与掺砂比例呈显著的线性负相关.随掺砂比例增加,土壤最大吸水量的变化可分为稳定、急降和缓降3个阶段.综合吸湿水和最大吸水量,适当的掺砂比例可以降低土壤凋萎系数,增加有效水的含量范围,从而能提高土壤抗旱能力.总之,适当比例的铁矿尾砂掺土可以改善土壤的物理性质,调节所用土壤的水、气状况,因此铁矿尾砂的土壤利用可以作为一种铁矿尾砂资源化利用的新技术,最佳掺砂范围应在30%~40%.  相似文献   

12.
吉林省黑土资源生态分类   总被引:2,自引:0,他引:2  
为了可持续利用黑土资源,以吉林省为例,尝试对黑土进行生态分类.综合运用主成分分析、聚类分析、模糊综合评判方法,研究了黑土生态适宜性,探讨自然、经济、社会因素影响下,不同种类黑土的生态土地类型.黑土生态分类是黑土生态区划的基础,可为黑土生态环境建设和环境管理政策的制定提供科学依据.  相似文献   

13.
Water vapor, energy exchange, and CO2 flux were measured continuously from 2003 to 2005 using the eddy covariance technique in a paddy ecosystem in the subtropical region of China. The CO2 fluxes at nighttime during fallow periods (from middle October to late April) were used to analyze the dynamics of soil respiration and its relationship with soil temperature, and to simulate the annual dynamics of soil respiration in paddy ecosystems. The variation of soil respiration showed a clear seasonal pattern. The soil respiration rates at night during the fallow periods were 52--398 mg· m^-2· h^-1, and exponentially correlated (P〈0.001) with soil temperatures at different depths of soil (5, 10, and 20 cm), particularly the temperature measured at a depth of 5 cm. Based on the simulated exponential equations developed, annual average soil respiration rates and total soil respiration of paddy soil in the subtropical region of China were estimated to be 178.5--259.9 mg· m^-2· h^-1 and 1.56--2.28 kg· m^-2· a^-1, respectively. The simulation equations can be applied to evaluating soil respiration in paddy ecosystems during the rice-growing season.  相似文献   

14.
复合土钉支护中土钉内力实验   总被引:1,自引:0,他引:1  
为了解土钉-预应力锚杆-微型桩复合土钉支护体系中土钉的受力情况,对北京市某复合土钉支护的深基坑工程中的土钉轴力进行现场原位实验,分析土钉轴力变化规律。结果表明:土钉受力具有时间效应与瞬时开挖效应,锚杆的张拉锁定可有效减缓上层土钉轴力的增长速度;土钉轴力的分布表现为两头小、中间大的特点,其峰值沿深度呈上下小、中间大的分布形式,最大峰值点位于基坑边坡中部;在坡脚附近,土钉最大轴力峰值点未出现在坡脚,而与坡脚有一定距离;喷射混凝土面层承受的侧向土压力较小,并随深度呈上下小、中间大的分布规律。  相似文献   

15.
The basic characteristics, X-ray analysis and micromorphology of soil developed from the parent ruified soil had been probed, results showed that there were similarities among different types of the rubified soils. The soil clay (D<0.002 mm) contents (C c ) were relative higher as between 29.16% and 80.03%. In addition, organic matter contents were lower as between 2.2–6.6 g/kg. The clay minerals in the rubified soils had high content of 2:1 type swelling minerals, e.g., smectite and vermiculite, which were the basic causes of formation of soil cracks and crevices. Soil micromorphology characteristics showed that microcosmic crevices universally distributed within the tight and compact soil microstructure were the microcosmic characteristics of crevices formation. The soil cracks and crevices changed the erosion process. Obviously, well developed soil crevice carries a significant connection with strong soil erosion in Yuanmou, Yunnan province, China. The term “soil crevice erosion” was coincided with the viewpoint put forward that soil crevice erosion played a dominant role in regional and violent soil erosion in this area. Foundation item: Supported by the Knowledge Innovation Program of the Chinese Academy of Sciences(KZCX2-YW-409) and the National Key Technology R&D Program of China (2006BAC01A11)  相似文献   

16.
基于模糊信息优化处理法的膨胀土分类   总被引:2,自引:0,他引:2  
针对膨胀土胀缩性“高低”划分属于模糊概念,应用模糊信息优化处理方法对国道G316公路沿线某段膨胀土滑坡区域膨胀土进行分类。首先将22组土样的试验资料,按照二维正态信息扩散公式分别建立液限、塑性指数、含水量和胀缩等级之间的模糊关系矩阵R,然后将10组验证土样的液限、塑性指数和含水量按一维信息分配公式进行信息分配,求得原因集Xo;最后通过两级模糊近似推论得出了该10组土样的分类结果,并将其与灰色系统理论方法的分类结果进行比较,其中7组的分类完全相同,而其余3组土样的分类精度则更高。结果表明该方法是一种有效的膨胀土分类方法,可以为膨胀土的工程治理设计提供参考。  相似文献   

17.
中国典型地带土壤原生动物群落结构及其特征   总被引:12,自引:0,他引:12  
在中国典型地带土壤中鉴定到290种原生动物,分别隶属于2门2亚门9纲28目77科138属.主要的优势类群有动基体目、金滴目、表壳目、变形目、下毛目和肾形目.稀有类群有团虫目、腰鞭目、双滴目、领鞭目、细胶丝目、合膜目和寡毛目.暖温带、温带、北热带、高寒带、中热带和亚热带各样点的原生动物群落多样性指数依次为847、787、777、638、629和431.群落结构特征研究结果表明,土壤原生动物群落与淡水原生动物群落在结构上既有密切联系,又有较大差异.  相似文献   

18.
土壤抗剪强度测定与影响因素研究进展?   总被引:2,自引:0,他引:2  
本文系统梳理了目前土壤抗剪强度的几种主要测定方法,相关影响因素及其与土壤侵蚀之间的关系研究现状,分析了现有研究中存在的问题,提出今后研究应在确定统一抗剪强度影响因素评价指标基础上,加强土壤抗剪强度与土壤水蚀、风蚀之间的相关关系的定量研究.  相似文献   

19.
【目的】探讨不同空间抽样方法和插值方法对土壤侵蚀预测精度的影响,为县域土壤侵蚀快速评价提供技术支撑。【方法】以沂蒙山区蒙阴县为研究区,GF-1号和GF-6号卫星影像、1∶1万地形图等数据为基础数据源,基于空间自相关理论,采用不同的空间抽样方法和空间插值方法,对研究区土壤侵蚀状况进行快速抽样预测研究。【结果】①根据全局Moran’s I指数、Z score和平均图斑类型,选取400 m×400 m方格为抽样单元最优尺寸。②与空间随机抽样、空间系统抽样方法相比,空间分层抽样样本容量最少(150个,其他样本容量最均超过250个),抽样精度最高(96.69%),抽样效率最高。③空间分层抽样下,普通克里金法和协同克里金法的计算结果与栅格计算法差异较小,相对差异分别为8.25%和9.85%(另两种方法的相对误差大于25%),但在空间分布上,受坡度影响的协同克里金法土壤侵蚀强度分布更为详细。【结论】综合考虑抽样调查的精度和工作量,在沂蒙山区县域尺度开展土壤侵蚀调查工作时,可采用空间分层抽样和协同克里金法或普通克里金法的方法进行土壤侵蚀快速预测,从而为区域生态环境保护提供重要数据支撑。  相似文献   

20.
本文对黄河三角洲土壤动物群落多样性和相似性进行系统分析,探讨成土年限、植被类型对土壤动物群落演替的影响.研究结果表明,黄河三角洲土壤环境条件恶劣,土壤动物种类贫乏,且优势类群明显,群落异质性差,土壤动物群落的多样性较低,多样性指数不及最大多样性指数的二分之一.农田生态系统则因为人类的活动而改善了土壤环境,土壤动物的种类和数量均有所增加,多样性较高.11个样点、3个年代三角洲或6种植被类型之间土壤动物群落相似性较高,土壤含盐量是影响土壤动物最为重要的环境因子.随成土年限或植物群落演替,土壤动物群落在较高分类阶元上未能表现出明显的演替过程,有必要对土壤动物的分类进一步细化.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号