Improving the Accuracy of Vegetation Index Retrieval for Biomass by Combining Ground-UAV Hyperspectral Data-A New Method for Inner Mongolia Typical Grasslands

Grassland biomass is an important parameter of grassland ecosystems.The complexity of the grassland canopy vegetation spectrum makes the long-term assessment of grassland growth a challenge.Few studies have explored the original spectral information of typical grasslands in Inner Mongolia and examined the influence of spectral information on aboveground biomass(AGB)estimation.In order to improve the accuracy of vegetation index inversion of grassland AGB,this study combined ground and Unmanned Aerial Vehicle(UAV)remote sensing technology and screened sensitive bands through ground hyperspectral data transformation and correlation analysis.The narrow band vegetation indices were calculated,and ground and airborne hyperspectral inversion models were established.Finally,the accuracy of the model was verified.The results showed that:(1)The vegetation indices constructed based on the ASD FieldSpec 4 and the UAV were significantly correlated with the dry and fresh weight of AGB.(2)The comparison between measured R^(2) with the prediction R^(2) indicated that the accuracy of the model was the best when using the Soil-Adjusted Vegetation Index(SAVI)as the independent variable in the analysis of AGB(fresh weight/dry weight)and four narrow-band vegetation indices.The SAVI vegetation index showed better applicability for biomass monitoring in typical grassland areas of Inner Mongolia.(3)The obtained ground and airborne hyperspectral data with the optimal vegetation index suggested that the dry weight of AGB has the best fitting effect with airborne hyperspectral data,where y=17.962e^(4.672x),the fitting R^(2) was 0.542,the prediction R^(2)was 0.424,and RMSE and REE were 57.03 and 0.65,respectively.Therefore,established vegetation indices by screening sensitive bands through hyperspectral feature analysis can significantly improve the inversion accuracy of typical grassland biomass in Inner Mongolia.Compared with ground monitoring,airborne hyperspectral monitoring better reflects the inversion of actual surface biomass.It provides a reliable modeling framework for grassland AGB monitoring and scientific and technological support for grazing management.

Analysis of a Typical Case of Meteorological Service in Tangpu Reservoir

The continuous rainy precipitation process from February to March in 2019 was selected to analyze the effect of meteorological service in Tangpu Reservoir basin,so as to sum up service experience and then lay a better foundation for subsequent services.In response to the rainy weather from December 2018 to early 2019,three rounds of flood discharge were carried out in Tangpu Reservoir.During February-March in 2019,the hit rate of short-term area rainfall forecast for Tangpu Reservoir was 80.0%.Compared with the median of forecast interval,the average absolute error was 7.6 mm,and the relative error was 32.7%.The large deviation in the forecast from March 27 to 28 was deeply analyzed,and it is found that the main reasons were excessive reliance on and trust in a single model,insufficient correction of the actual situation,and insufficient judgment of the nature of precipitation.For the future reservoir meteorological service,three aspects of thinking were put forward,such as further strengthening the sharing of hydrological and meteorological information,improving the forecasting ability,and deepening the research of runoff forecast models.

Analysis on Typical Spatio-temporal Characteristics of Open-cast Mining and Its Countermeasures

In order to deal with the special spatio-temporal environmental changes encountered in the process of open-cast mining,taking Huolinhe No.1 Open-cast Mine as the research object,this paper studied its typical problems in river reconstruction and cultural relics protection.The study focused on eight key core aspects,including the design optimization of the spatial layout of the mining area,the accurate estimation of the mineral resources reserves,the scientific theoretical demonstration of the mining scale,the fine analysis and calculation of the stripping ratio,the comprehensive consideration of the transport distance and efficiency,the accurate judgment of the best time for the implementation of the transformation,the analysis and evaluation of the slope stability,and the overall planning of the production system.The results show that the extracted problem-solving strategies and scheme system for special mining conditions can not only provide specific and practical guidance for Huolinhe No.1 Open-cast Mine,but also serve as a valuable reference and practical reference for other open-cast mine enterprises facing similar challenges.

Trade-off and Synergy of Rural Functions Under County Depopulation in the Typical Black Soil Region of Northeast China

As the population continues to shrink in the black soil region of Northeast China since 2000,it is critical to master the impact of population shrinkage on rural functions to realize rural revitalization and sustainable development.In this study,we focused on the impacts of depopulation on the evolution and interrelationship of rural subfunctions.Based on the rural function indexes system,the TOPSIS(Technique for Order Preference by Similarity to an Ideal Solution)method,spatial analysis method,and mathematical statistics analysis method were used to summarize the spatial and temporal characteristics of rural function development,as well as the effect of population shrinkage in the typical black soil region of Northeast China.The results showed that depopulation varied in the extent and duration between the forested region and plain areas,which both impacted the trajectories of rural subfunctions evolution.For the economic development function and ecological conservation function,the effect of continuous slight depopulation was beneficial,while the effect of rapid depopulation was adverse,which was exactly opposite to the agricultural production function.All forms of population shrinkage were conducive to the development of the social security function.With the deepening population shrinkage,depopulation mainly promoted the collaborative development between subfunctions in this study,except the relationship between agricultural production and social security function.But effects of depopulation on the interrelationship of rural subfunctions varied between the forested region and plain areas in some cases.The results provided evidence for the cognition that population shrinkage had complicated effects on rural subfunctions.

A case of atypical neurological symptoms and high cerebro-spinal fluid acetone level due to transdermal exposure to isopropanol

Dear editor, Isopropanol, also named 2-propanol or isopropyl alcohol(IPA), is a colorless, volatile liquid found in numerous household chemicals, such as cleaners and disinfectants, which typically contain a 70% solution of IPA in water. IPA is also extensively used in industry and laboratories as a solvent.

数字经济赋能乡村生态农产品价值实现的典型模式与形成机制分析

【目的】生态农产品价值实现是多元化推进乡村振兴的关键举措,探索数字经济赋能乡村生态农产品价值实现的典型模式和形成机制有利于培育壮大乡村绿色发展新动能,促进和美乡村建设和农民增收。【方法】通过对全国数字化先进县的典型案例进行梳理,从其关键做法,主要成效和价值体现,以及何以实现等方面系统分析数字经济赋能乡村生态农产品价值实现的典型模式和形成机制。【结果】“互联网+现代农业”融合发展、产学研合作,以及物联网与大数据技术应用是案例中数字经济赋能乡村生态农产品价值实现的3种典型模式。在此基础上,得出数字经济赋能乡村生态农产品价值实现的3条形成路径,即数字经济通过推动产业升级,为乡村生态农产品价值实现提供驱动力;数字经济通过提高乡村农产品流通效率,为乡村生态农产品价值实现创造良好的条件;数字经济通过创新商业模式,为乡村生态农产品价值实现建立有效路径。【结论】目前乡村数字经济发展仍处于较低水平,相应的政策措施和管理机制应该联合政府、企业和社会多方力量,聚焦在数字基础设施建设和人才培养等方面,推动乡村数字技术渗透的广度和深度,促进乡村生态农产品价值实现。

Automatic Extraction of Typical River Vegetation Elements Based on Low-altitude Remote Sensing Images

Based on low-altitude remote sensing images,this paper established sample set of typical river vegetation elements and proposed river vegetation extraction technical solution to adaptively extract typical vegetation elements of river basins.The main research of this paper were as follows:(1)a typical vegetation extraction sample set based on low-altitude remote sensing images was established.(2)A low-altitude remote sensing image vegetation extraction model based on the focus perception module was designed to realize the end-to-end automatic extraction of different types of vegetation areas of low-altitude remote sensing images to fully learn the spectral spatial texture information and deep semantic information of the images.(3)By comparison with the baseline method,baseline method with embedded focus perception module showed an improvement in the precision by 7.37%and mIoU by 49.49%.Through visual interpretation and quantitative calculation analysis,the typical river vegetation adaptive extraction network has effectiveness and generalization ability,consistent with the needs of practical applications of vegetation extraction.

海温异常对长江流域夏季典型旱涝的影响研究

为研究长江流域夏季旱涝特征及其与海温异常之间的关联性,基于中国326个气象站降水量、NCEP/NCAR再分析资料等,采用合成分析、EOF分解等方法,分析了长江流域夏季典型旱涝年的降水分布、同期大气环流及前期海温特征,并以2018年为例,初步揭示了2018年前期海温异常对大气环流的可能影响。结果表明:①长江流域夏季典型旱年,仅嘉陵江和岷沱江会表现出局部偏涝,全国为典型的Ⅰ类雨型,多雨区位于黄河流域及以北地区。前期冬季赤道太平洋表现出类拉尼娜的东冷西暖分布,同时黑潮区海温偏低,西风漂流区海温偏暖。受多海域协同作用,同期欧亚环流场上自西北向东南呈现出“+-+”三极型分布,东亚地区为自北向南“-+-”的EAP负位相。长江流域典型涝年,全国多为典型的Ⅱ类和Ⅲ类雨型,环流及海温呈现出相反特征。②2018年为典型的长江中下游偏旱年,仅在岷沱江降水偏多近3成,为历史第4多,与长江流域夏季降水的主模态正位相类似,解释方差达24%。③2018年前冬出现弱拉尼娜、春末夏初西风漂流区异常偏暖、NAT异常正位相,三者共同作用,使得东亚副热带西风急流偏北,东亚沿岸出现EAP负位相,大陆热低压明显偏强,东亚夏季风为1961年以来最强,同时副高脊线最北,造成夏季降水主雨带北推至华北、西北地区,岷沱江、嘉陵江异常多,而长江中下游异常少,为典型的Ⅰ类雨型。研究成果可为长江流域旱涝预测、水资源调度提供参考。

创新企业的中微观集聚特征及邻近性机制研究——基于长三角地区4座典型城市的实证

在创新型经济重构空间使用逻辑的背景下,以解析城市内部创新要素的集聚和选址为出发点,构建创新企业集聚的邻近性框架,运用中小型创新企数据以及问卷调查数据,对长三角上海、南京、杭州、苏州4座典型的创新型城市进行研究,透视创新在空间利用上的新变化和新需求。研究得出以下结论:(1)集聚趋势。在我国内城更新与新城开发同步推进的城镇化语境下,创新企业的集聚兼具回归城区和近郊生长的双重动力,而且低密度、品质高的新兴园区与创新人才的需求形成了较好契合。(2)结构演化。创新企业的集聚结构与城市的空间转型、功能演化形成紧密互动。城市的区域职能分工、空间结构对企业的集聚有深刻影响。创新企业的集聚强度由中心向外围衰减,形成半径为1~3 km的核心-边缘结构。(3)区位逻辑。除政策、产业等传统因素外,创新企业不仅侧重于向“年轻集群”和应用导向的科研集群集聚,而且呈现出明确的生活指向,品质、氛围等软性因素成为不可忽视的高阶需求。

语义通信的数学理论

自从1948年经典信息论诞生以来,在其指导下,现代通信技术已经逼近了理论性能极限,例如信息熵H(U)、信道容量C=max_(p(x))I(X;Y)以及率失真函数R(D)=min_(p(x|x):Ed(x,x)≤D)I(X;X)。长期以来,由于经典信息论只研究语法信息,限制了通信科学的进一步发展。近年来,研究语义信息处理与传输的通信技术获得了学术界的普遍关注,语义通信开辟了未来通信技术发展的新方向,但还缺乏一般性的数学指导理论。为了解决这一难题,构建了语义信息论的理论框架,对语义信息的度量体系与语义通信的理论极限进行了系统性阐述。首先,通过深入分析各类信源的数据特征,以及各种下游任务的需求,总结归纳出语义信息的普遍属性——同义性。由此指出语义信息是语法信息的上级概念,是许多等效或相似语法信息的抽象特征,表征隐藏在数据或消息背后的含义或内容。将语义信息与语法信息之间的关系命名为同义映射,这是一种“一对多”映射,即一个语义符号可以由许多不同的语法符号表示。基于同义映射f这一核心概念,引入语义熵H_(s)(U)作为语义信息的基本度量指标,表示为信源概率分布与同义映射的泛函。在此基础上,引入上/下语义互信息I^(s)(X;Y)(I_(s)(X;Y)),语义信道容量C_(s)=max_(f_(xy))max_(p_((x)))I^(s)(X;Y)以及语义率失真函数R_(s)(D)=min_({f_(x),f_(x)})min_(p(x|x):Ed_(s)(x,x)≤D)I_(s)(X;X),从而构建了完整的语义信息度量体系。这些语义信息度量是经典信息度量的自然延伸,都由同义映射约束,如果采用“一对一”映射,则可以退化为传统的信息度量。由此可见,语义信息度量体系包含语法信息度量,前者与后者具有兼容性。其次,证明了3个重要的语义编码定理,以揭示语义通信的性能优势。基于同义映射,引入新的数学工具——语义渐近均分(AEP),详细探讨了同义典型序列的数学性质,并应用随机编码和同义典型序列译码/编码,证明了语义无失真信源编码定理、语义信道编码定理和语义限失真信源编码定理。类似于经典信息论,这些基本编码定理也都是存在性定理,但它们指出了语义通信系统的性能极限,在语义信息论中起着关键作用。由同义映射和这些基本编码定理可以推断,语义通信系统的性能优于经典通信系统,即语义熵小于信息熵H_(s)(U)≤H(U),语义信道容量大于经典信道容量C_(s)≥C,以及语义率失真函数小于经典率失真函数R_(s)(D)≤R(D)。最后,讨论了连续条件下的语义信息度量。此时,同义映射转换为连续随机变量分布区间的划分方式。相应地,划分后的子区间被命名为同义区间,其平均长度定义为同义长度S。特别是对于限带高斯信道,得到了一个新的信道容量公式C_(s)=B log[S^(4)(1+P/N_(0)B)],其中,平均同义长度S表征了信息的辨识能力。这一容量公式是经典信道容量的重要扩展,当S=1时,该公式退化为著名的香农信道容量公式。综上所述,语义信息论依据同义映射这一语义信息的本质特征,构建了语义信息的度量体系,引入新的数学工具,证明了语义编码的基本定理,论证了语义通信系统的性能极限,揭示了未来语义通信的巨大性能潜力。

基于风险评估模型的传染病预警体系的建立

目的建立一套基于风险评估模型的传染病预警体系,推动传染病管理水平的提升。方法通过搜集、整理最新的研究成果,参考相关的传染病预警评价指标体系的理论框架,构建基于风险评估模型的传染病预警体系。结果本次研究共纳入了12名专家,筛选出了三个一级指标,涉及流行前期指标、典型症状期指标、非典型症状期指标等,同时涉及7个二级指标。体系的必要性平均得分为8.27±0.24分,可获得性平均得分为7.74±0.34分。结论基于风险评估模型的传染病预警体系的建立有利于当地及时掌握传染病流行趋势,并进行调查指标分布趋势分析,然后提出相应的预警方案,可为有效预防传染病提供相关的依据。

先进典型在高校思想政治教育中示范引领作用的调查与研究

结合十余所高校先进典型示范引领问卷调查结果,对当前先进典型示范引领的现状及产生问题的原因进行分析,为增强高校先进典型选树宣传工作的有效性提供依据。

中国典型涉外经营企业竞争情报工作调查研究

[目的/意义]针对中国科学技术情报学会竞争情报分会会员企业之外的中国典型涉外经营企业开展竞争情报工作实态调查,更好展示中国企业竞争情报实际工作全貌,为新时期竞争情报研究与服务工作创新发展提供新的视野、素材和参考。[方法/过程]按照透过“名”与“实”分离表象了解新时期中国企业竞争情报工作真实情况的逻辑思路,以企业合规管理为竞争情报“名”与“实”分离的典型场景,基于2018—2023年合规管理主题公开会议,采取对派出报告人的企业统计分析、专家咨询访谈、合规管理标杆企业案例研究、承接企业合规管理体系建设项目的咨询服务机构企业客户名单调查研究、公开资料收集分析相结合的研究方法,对中国典型涉外经营企业进行竞争情报工作实态调查。[结果/结论]调查得到以下主要发现:(1)所有涉外经营企业的合规管理都是无“名”有“实”的竞争情报工作;(2)新时期中国典型涉外经营企业对事实上的竞争情报普遍具有强烈而持久的需求;(3)中国典型涉外经营企业的竞争情报工作专业水平呈现显著的差异性;(4)中国典型涉外经营企业对名为合规管理实为竞争情报的工作有很高的要求;(5)中国典型涉外经营企业对符合企业需要的竞争情报专业人才需求迫切且需求数量巨大;(6)有“实”而无“名”是中国典型涉外经营企业竞争情报工作存在的最大问题。

祁连山南坡微地形下典型生态系统土壤蓄水能力差异

[目的]探讨祁连山地区微地形形态下典型生态系统土壤蓄水能力差异性,为该区进一步提高水源涵养能力提供参考。[方法]以微地形不同坡向青海云杉和高山草地为研究对象,采取野外采样和室内试验分析相结合的方法,研究不同坡向对典型生态系统土壤蓄水能力的影响。[结果](1)微地形高山草地所在阳坡区域,土壤水分贮存量随坡位上升逐渐呈减少趋势,坡中上(PZS)为土壤水分贮存量最低的坡位;坡位对土壤饱和蓄水量影响较小。(2)坡位显著影响着阴坡青海云杉土壤水分贮存量,土壤贮水量沿坡位上升呈增加趋势,坡顶处(PSD)土壤水分贮存量最高;坡位对青海云杉土壤潜在蓄水能力影响显著,坡中和坡中上土壤潜在蓄水能力最强。(3)两类典型生态系统土壤蓄水能力存在显著差异,高山草地(阳坡)土壤实际蓄水能力在不同坡位均高于青海云杉,青海云杉(阴坡)土壤潜在蓄水能力在坡位和土层尺度均显著大于高山草地(阳坡)。[结论]研究区微地形坡中上至坡顶段是该区保水增蓄的重点区域,坡中上以下区域是两类生态系统土壤蓄水能力核心区域,应继续保护。

5A发射电流空心阴极热特性模拟分析

采用有限元分析方法,建立了国产5 A空心阴极的热仿真模型,并进行了模型校验和典型工况下的温度场分析。结果显示:模型能够较好地反映空心阴极内部的能量传动过程,温度的仿真结果与试验比对误差小于5%;加热电流是造成空心阴极温度差异的主要原因;环境温度主要影响着空心阴极的外部部件温度,并且在太阳辐照影响时的高温环境更有利于推力器的启动;空心阴极加热且处于自持放电状态时,发射体温度在环境温度0℃和94℃下分别达到2 122℃和2 126℃,已接近发射体材料的耐温极限,因此空心阴极必须避免此极端使用工况。

典型大洪水下珠江磨刀门河口拦门沙演变模式研究

磨刀门是珠江八大口门中输水、输沙量最大的口门,也是珠江最重要的泄洪通道,在珠江三角洲水系中占有极其重要的地位,研究其拦门沙冲淤演变模式对磨刀门河口地貌演变趋势分析及未来治理开发工程规划具有指导意义。以2005年6月典型大洪水过程为例,建立二维波流耦合的泥沙数学模型,分析磨刀门河口拦门沙冲淤演变特征。结果显示,典型大洪水条件下,上游来水来沙丰富,波浪对泥沙的转运作用相对被弱化,能够在较短时间内促进浅滩等沙体发育,形成新的地貌单元,并促进两侧沙体以沙嘴的形态快速向前淤进,伴随发育河口次级分汊地貌单元。研究表明,影响河口冲淤演变特征的因素包括河道地形、流场、余流余沙场及水流挟沙力等,上游来水来沙量、潮汐、波浪等因素则主导河口拦门沙演变模式。

我国区域典型城市国际化水平的定量分析及对策思考

采用层次分析法,从经济开放、科技创新、国际影响和城市宜居四个层面构建准则层,选取18个指标评价14个区域典型城市的国际化水平,结果表明:(1)区域典型城市的国际化水平总体评分及经济开放指标评价呈现东部最优、西部次优,而中部最靠后;(2)科技创新上,东部科技创新实力强劲,中部城市的武汉处于第二位次城市组别,西部城市成都处于第一层次城市群里;(3)国际影响上,第一层次东部占据前三城市,中部4个城市均居于第三层次,西部城市成都处于第一层次里第四位次;(4)城市宜居上,东中西部典型城市分值差别不大。

基于CBL的中医耳鼻咽喉科典型临床病例库实践教学平台的建设

中医药教育网络化建设是中国医学教学改革的重要部分,对目前的高校医学教育具有推动作用。现行的临床教学网络化建设具有易取得、易整理、易更新及可多次重复、满足学生个性化需求的优势,但无法突出自主学习的全过程,难以调动学生的学习积极性。中医耳鼻咽喉科教学内容繁多、抽象,相关机制及解剖复杂,存在一定的学习困难;且当前存在教学任务重、患者自我保护意识强、临床典型示教案例较少等问题。因此基于以病例为基础的教学法(CBL)建设中医耳鼻咽喉科典型病例库教研室平台,并将其应用到临床见习和实习教学中,为学生提供临证实感和氛围,不仅能提高带教效率、锻炼学生临床思维,还能弥补耳鼻咽喉科疾病季节性发病及教学资源不足的缺点,使学生在短时间内对疾病的特征有感性、立体的理解,从而更充分地掌握耳鼻咽喉常见病的辨病辨证思路;有助于医学生临床思维的培养,同时还能优化教学方法和资源,对于系统化教学信息建设也具有重要意义。

新生大鼠缺氧缺血性脑损伤模型中TRPC3通路介导的神经自噬研究

目的:探讨新生大鼠缺氧缺血性脑损伤模型中TRPC3通路介导的神经自噬作用。方法:7日龄Sprague-Dawley(SD)雄性幼鼠随机分为4组,每组20只,分别为Sham组、HIBD组、HIBD+Vector组和HIBD+TRPC3组。HIBD+Vector组和HIBD+TRPC3组在诱导HIBD模型前24 h,分别将Vector或TRPC3注射到左侧脑室中。评估各组幼鼠脑梗死面积、神经系统评分、脑水肿体积、神经元凋亡和线粒体自噬。体外将小鼠海马神经元细胞系(HT22)分为以下6组:Control组、OGD/R组、OGD/R+TRPC3组、OGD/R+NC组、OGD/R+si-Pink1组和OGD/R+TRPC3+si-Pink1组。除Control组外,其他组使用氧气-葡萄糖剥夺/再灌注(Oxygen-glucose deprivation/reperfusion,OGD/R)方法建立体外脑缺血再灌注模型。通过线粒体膜电位的检测线粒体损伤情况。结果:与Sham组相比,HIBD组和HIBD+Vector组显示出较大的梗死面积、脑含水量、神经学评分和神经元凋亡(P<0.05)。HIBD+TRPC3组的梗死面积、脑含水量、神经学评分和神经元凋亡较HIBD+Vector组明显降低(P<0.05)。与Sham组相比,HIBD组和HIBD+Vector组线粒体自噬相关蛋白PTEN诱导假定激酶1(PTEN induced putative kinase 1,Pink1)、E3泛素连接酶(Parkin RBR E3 ubiquitin protein ligase,Parkin)和微管相关蛋白轻链3(light chain 3,LC3)Ⅱ的表达水平增加(P<0.05)。与HIBD+Vector组相比,HIBD+TRPC3组Pink1、Parkin和Lc3Ⅱ的表达水平进一步增加(P<0.05)。体外实验显示,TRPC3上调可以强烈增加Pink1、Parkin的表达和Lc3Ⅱ/Lc3Ⅰ比值,以及减少选择性自噬接头蛋白(sequestosome-1,p62)的表达。Pink1沉默可以部分阻止TRPC3对线粒体自噬的影响。TRPC3上调增加了健康线粒体的数量,减少了受损线粒体的数量,提高了HT-22细胞的生存率。然而,Pink1沉默阻止了TRPC3对线粒体功能和增殖能力的恢复。结论:TRPC3通过激活Pink1/Parkin通路介导的线粒体自噬,在HIBD早期阶段中发挥了重要的保护作用。

祁连山典型植被土壤有机碳分布特征及其影响因素

探讨祁连山典型植被土壤有机碳空间分布特征及其影响因素,可为评估该地区森林土壤固碳效应提供科学依据。以退耕地为对照,以草地、天然乔木(青海云杉、祁连圆柏)、人工乔木(落叶松)和灌木5种典型植被为研究对象,测定0~100 cm深度土壤有机碳含量、有机碳密度、土壤粒度、pH、电导率、全氮、全钾和全磷含量,比较分析不同植被土壤有机碳组分的分布差异及其主要影响因素。结果表明:1)不同植被类型平均土壤有机碳含量排序为青海云杉(5.99 g/kg)>祁连圆柏(5.59 g/kg)>落叶松(2.91 g/kg)>灌木(1.83 g/kg)>草地(1.66 g/kg)>退耕地(1.16 g/kg);平均土壤有机碳密度排序为青海云杉(3.43 kg/m^(2))>祁连圆柏(2.76 kg/m^(2))>落叶松(2.16 kg/m^(2))>灌木(2.08 kg/m^(2))>草地(2.00 kg/m^(2))>退耕地(1.33 kg/m^(2))。2)随着土层的加深,不同植被土壤有机碳含量整体上呈减小的趋势,土壤有机碳密度呈先增后减的趋势。3)不同植被类型土壤C/N为9.30~15.73,均值表现为青海云杉(14.96)>草地(11.66)>退耕地(11.54)>灌木(10.83)>落叶松(10.69)>祁连圆柏(10.63)。4)不同植被类型土壤有机碳和全氮含量均呈极显著正相关(P<0.01),有机碳与全磷、黏粒、粉粒呈极显著或显著正相关(P<0.01,P<0.05),有机碳与砂粒含量呈极显著或显著负相关(P<0.01,P<0.05),有机碳与pH均呈显著负相关(P<0.05)。祁连山自然生长的乔木土壤有机碳固持能力较好,在建设碳汇林时应充分考虑土壤有机碳的影响,优先选择乔木植被。