北京山区河岸植被恢复立地类型划分

[目的]对北京山区不同立地条件下的河岸带进行立地类型分类,为山区河岸带的植被恢复工作提供理论依据。[方法]以北京市怀柔区怀九河河岸60个80m长的样地为基础,进行野外实地观测调查,并确定了土壤层厚度、坡面组成物质、坡度、硬化面积、坡长5个因子为河岸立地类型划分的主导因子。[结果](1)怀九河河岸带的立地类型可划分为3个立地类型区,9个立地类型组,15个立地类型。(2)加杨、旱柳、荆条、胡枝子等作为适宜当地生长的优势植物种,在进行植被恢复时可结合其它适生物种进行合理的配置。[结论]北京山区河岸带多以短坡薄土层为主,边坡坡面砾石裸露严重,表现为严重的人为干扰,应加快河岸边坡生态环境安全建设。     

太行山北段东麓采石废弃地立地类型划分及评价

为了加快太行山北段东麓采石废弃地的植被恢复,选取地形、植被、土壤等14个指标,采用相关性分析、主成分分析、聚类分析等方法,探讨影响采石废弃地植被恢复的主要影响因子,明确划分太行山北段东麓采石废弃地的立地类型并进行立地评价。结果表明:1)土壤养分质量分数、土壤层厚度和地形特征等因子是研究区植被恢复的主要限制性因子,同时也是研究区采石废弃地上判断某一立地条件优劣的重要因子;2)依据主成分分析、聚类分析结果以及调查结果,可将研究区采石废弃地分成8类立地类型;3)根据立地质量评价结果,可将立地类型划分为立地条件较好的立地(综合得分≥24)、立地条件稍差的立地(综合得分20~24)、立地条件较差的立地(综合得分18~20)和立地条件较为恶劣的立地(综合得分<18)4类,并按照立地情况提出相应的植被恢复建议。     

微立地因子植被恢复法在汶川地震植被重建中的应用

“5·12”汶川大地震造成的滑坡、泥石流、崩塌等地质次生灾害使当地的植被毁坏严重,微立地因子植被恢复法适用于地震灾区复杂的立地条件植被重建。在研究灾区植被破坏类型的基础上,将损毁植被的坡面划分为岩质边坡、土质边坡、土石边坡3种类型,并对不同坡面进行微立地因子类型划分,针对不同立地条件选择适宜植被恢复技术,促使灾区尽快植被重建,并为微立地因子植被恢复法的完善提供重要依据。     

黄土区大型露天煤矿复垦排土场植被恢复立地类型划分——以安太堡露天煤矿为例

露天开采对土地破坏严重,立地条件复杂。只有综合环境因素与植被生态习性,针对不同的立地类型进行植被配置与管护才能达到对矿区生态修复的目的。为此以安太堡露天煤矿西排土场为研究对象,选定58个样点,在样点10 m×10 m范围内对海拔、坡向、坡位、坡度、坡型、覆土基质、覆土厚度、土壤容重、土壤含水量、有机质含量、全氮含量、植被类型组合、归一化植被指数（NDVI）、地面非均匀沉降、河流动能指数、地形起伏度,共18个立地因子进行调查。分析排土场立地条件及特征,运用SPSS聚类分析法对样点进行立地类型划分。最终划分为平台、边坡2个立地小区;平台小区化分为9个立地类型组、13个立地类型,边坡小区化分为9个立地类型组、20个立地类型。研究结果可以为排土场立地改良、植被恢复与维护及生态系统恢复提供依据。     

中捷农场滨海盐碱地立地类型划分及其植被恢复技术

 为了指导滨海盐碱地因地制宜地进行植被恢复,通过野外调查、室内分析测试与因子分析等方法,对中捷农场45块样地的土壤类型、土壤含盐量、地下水位、距海距离、盐分类型、土壤质地、pH值、海拔等因子进行测定与分析。结果表明:影响盐碱地立地类型划分的主导因子为盐渍化土壤形成因子、土壤因子和碱化度因子;对立地类型划分贡献大小的变量依次为距海距离>地下水位>土壤类型>土壤质地>海拔>盐分类型>土壤含盐量>pH值;中捷农场的滨海盐碱地可划分出滨海盐化潮土、滨海盐化草甸土和滨海盐土3类立地类型和11类立地亚型,不同立地类型可以采取不同的植被恢复措施。研究结果可为中捷农场盐碱地造林与植被恢复提供理论依据。     

贵州省强度石漠化区立地分类系统研究

根据贵州省地质地貌条件的特殊性,通过立地因子筛选,研究建立了贵州省强度石漠化区立地分类系统。结果表明:立地类型组划分的主导因子为岩性,立地类型划分的主导因子为坡性。全省可分为5个立地类型区,2个立地类型组及2个立地类型,共形成20个立地类型组合。在立地评价的基础上,分类系统将为该类地区植被恢复提供自然本底依据。     

城市周边破坏山体的立地条件类型划分及其植被恢复措施——以山东淄博市为例

以淄博市城市周围破坏山体为研究对象,根据野外调查结合植被恢复的影响程度分析,选定破坏山体外貌形态、坡度、边坡高度、土层厚度和砾石含量5个立地因子,并对之进行分级量化;利用聚类分析法将破坏山体划分为7个立地条件类型和16个亚型;不同立地条件类型植被恢复难易程度不同,在分析各立地条件类型特征的基础上,因地制宜地提出不同的植被恢复措施。研究成果可为破坏山体的植被恢复提供科学依据。     

基于RS的北京门头沟植被覆盖时空演变研究

应用RS技术,以1979年和2005年的Landsat TM影像为数据源,并对其进行边界修补、去云处理、地形校正、大气辐射订正和反射率计算,然后运用归一化植被指数和改进的像元二分模型,分别计算其归一化植被指数ND-VI及植被覆盖度,对北京市门头沟区的植被覆盖进行动态遥感监测。结果表明:(1)门头沟区植被覆盖整体呈下降趋势,覆盖度从1979年的76.4%减少为2005年的72.7%;(2)覆盖度在60%以上的区域比较稳定,是植被覆盖的主体;(3)覆盖度在80%以上的大面积减少,说明该区植被破坏严重,这与城市化进程的加快、对土地大规模利用、经济增长有很大关系;(4)由于居民点建设中采沙、采石和采煤占用绿地,永定、龙泉、谭柘寺植被退化最严重;军庄退耕还林和果林绿化是唯一植被覆盖增加的乡镇。其它乡镇植被退化平均在5%以内,妙峰山、王平、大台、斋堂四个中部乡镇由于采矿、采石等人为活动,特别是京西矿业集团的煤矿多基本集中在此,使这4个乡镇植被退化明显,并已形成采空区和塌陷区;雁翅、清水乡植被退化主要以自然退化为主,退化幅度相对较小。     

基于植被恢复潜力的强度石漠化地区立地因子研究

 石漠化地区立地分类及其植被恢复潜力评价是石漠化地区生态修复的重要基础,立地因子研究是立地分类与评价的前提。通过对典型强度石漠化地区毕节石桥小流域和花江峡谷立地条件调查,利用成因分析与统计分析方法,研究强度石漠化地区影响植被恢复潜力的主要立地因子。结果表明：岩性和坡性是强度石漠化地区基于植被恢复潜力的主导立地因子。研究结果可为强度石漠化地区立地分类的建立与植被恢复潜力评价提供依据。     

基于自然植被的延河流域生物量空间分布格局评估

研究植被的生物量分布及环境对生物量的承载状况,对于区域植被恢复规划、布局等具有重要意义.以黄土丘陵区延河流域为研究区,以自然植被为参照,利用广义相加模型(GAM,generalized additive model)及GIS空间分析技术预测了流域潜在生物量的分布格局;同时,利用遥感资料,预测出流域现有的植被生物量及其空间格局.以潜在生物量为参照,现实生物量为基础,通过空间分析,对流域环境的生物量承载状况进行评估.结果表明:在流域东南部地区,潜在生物量高于现实生物量;而在中北部,有较多的立地环境的现实生物量大于潜在生物量,超过了环境生物量的最大现实承载能力,导致人工植被在这些立地环境条件下的退化.识别这些植被,对于流域植被的改造和利用、流域植被恢复规划与布局等具有重要的应用价值.     

Physical Properties of the Soils of Sibay City of the Republic of Bashkortostan

Eurasian Soil Science - The results of the study of the properties of urban soils of the city of Sibay located in the mining region of the Republic of Bashkortostan are presented. A specific...     

食用仙人掌萎蔫气象条件分析

塑料大棚内种植的食用仙人掌在土壤墒情较好时也有萎蔫现象发生，通过试验观测和对仙人掌生理习性的分析，发现阴雨过后天气突然放晴温度急剧上升易使仙人掌发生萎蔫现象，并提出了田间管理的应对措施。     

Heterogeneity of Organic Matter of Aggregates of Protocalcic Chernozems

Eurasian Soil Science - Layers were step-by-step removed from macroaggregates (2–1 mm in diameter) of Protocalcic Chernozems via successive abrasion in a revolving rotator during 5, 10, 15,...     

青海省耕地资源开发利用分析及对策研究

分析论述了青海省耕地资源开发利用的现状、特点和问题。在此基础上,提出了对青海省耕地资源进行研究的框架体系和思路,同时基于GIS/RS技术设计了相关的技术路线。最后依据所做设计对青海省耕地资源开发利用做了初步分析,并进行了相关的对策研究分析。     

Characterization of physical and chemical properties of Varzea soils of Goias State of Brazil

Abstract

Brazil has approximately 30 million hectares of lowland areas, known locally as “Varzea,”; distributed throughout the country. Soils in these areas have the potential to support agricultural production, but very little is known about their fertility. The current experiment was undertaken to characterize the chemical and physical properties of representative “Varzea”; soils collected at 0–20, 20–40, 40–60, and 60–80 cm depth intervals from 23 sites in Goias State of Brazil. Organic matter contents averaged 42 g/kg in the surface 20 cm of soil and should make a significant contribution to overall nutrient availability. Soil pH increased slightly with depth from a mean value of 5.2 in the surface 20 cm of soil to a mean value of 5.4 in the 60–80 cm depth interval. Several soils had exchangeable Al values ≥ 1.0 cmol Al/kg, but soil Al saturation was generally less than the 60% level frequently associated with Al toxicity. However, cereal and legume production could benefit from lime addition in many of these soils. Although base saturation was fairly low in some soils, exchangeable Ca and Mg levels were, in general, adequate throughout the profile. Extractable P levels were adequate in most surface soil samples. Extractable K levels in these soils were generally low, and the application of K fertilizers should be beneficial, especially in conjunction with lime addition. The high clay content “Varzea”; soils of the Brazilian lowlands have some drainage problems but generally exhibit favorable chemical properties for crop production when compared to soils of the well‐drained Cerrados.     

Estimation of potential nitrogen-fixing activity of agrophytocenoses soils of the subtropical zone of Russia

An estimation of potential nitrogen-fixing activity of various soil types under agrophytocenoses of tea, filbert, peach, and pawpaw which grow in the area of Greater Sochi is given. High indicators of nitrogen fixation activity in the soil in the course of vegetation were characteristic of agrocenoses of pawpaw, peach, and filbert. The lowest level of nitrogen fixation was noted in the soil of a tea plantation. A negative correlation dependence of potential nitrogen-fixing activity on the acidity of the soil solution was established. A study of the seasonal dynamics of the activity of nitrogen fixation of soils of agrocenoses of the subtropical zone of Russia made it possible to distinguish a less active winter and more active spring-summer-autumn periods.     

Kinetics of Popping of Popcorn

The rate of popping of popcorn was measured in oil and in air. Kinetic data for lifetimes of individual kernels from a large population were obtained in oil at six constant temperatures (180–250°C) and also in an air‐popper at 202°C. The data are characterized by an induction period, which is, significantly, followed by a first‐order decrease in the number of unpopped kernels versus time. The activation energy for the first order process is 166.7 kJ/mol between 180 and 210°C, and 53.8 kJ/mol between 210 and 250°C. These data are consistent with a model that assumes 1) that the rate of heat transfer into a kernel follows Newton's law of cooling; 2) that in a sample of kernels there exists a distribution of critical pressures; 3) that for an individual kernel, the probability of popping is directly proportional to the difference between the internal aqueous vapor pressure and the kernel's critical pressure; and 4) that the measured rate constant at any temperature is an average overall of the kernels in the sample with critical pressures equal to or less than the internal aqueous vapor pressure. Minimum popping temperatures predicted by the model are 181 ± 2°C (oil) and 187 ± 2°C (air), in good agreement with previously reported direct measurements.     

物联网安全及解决措施

物联网是一个集信息通信、数据交换、传感器技术与软件工程于一体的综合性产业,探讨和分析了物联网的结构体系与发展中遇到的安全问题。     

荔枝种子结构的扫描电镜观察

荔枝种子从果实中剥离出来后, 即使在室内条件下, 也极易失水干缩, 潮湿环境中又易发霉而腐烂。扫描电镜观察表明: 种皮上布满纹孔, 水分散失面积很大; 种脐部为疏松的海绵组织, 且营养丰富。据此, 生产上应对种子彻底清洗, 并保存于适当湿度的环境中, 以提高其发芽率。