芨芨草群落土壤盐分特征

通过对内蒙古及青海9个样点芨芨草群落及其相邻地带性群落土壤电导率的研究,从区域大尺度及生境小尺度揭示了土壤盐分对芨芨草群落分布的影响,并基于土壤的盐分特征分析了芨芨草群落的植被属性。结果表明:在区域大尺度,芨芨草群落的分布与土壤盐分不存在直接的相关性,芨芨草既可以在低盐环境下形成群落,也可在盐分较高的环境下形成群落,是一个生态幅较宽的耐盐物种;而在相同地点的小尺度上,芨芨草群落的土壤含盐量总是比相邻地带性针茅群落的土壤含盐量高,地带性针茅群落的耐盐性不及芨芨草群落;青海地区大面积的芨芨草草原发育在含盐量较高的土壤环境,远高于相邻地带性针茅群落。土壤盐分特征分析结果表明,芨芨草群落表现出明显的非地带性植被特征,其分布与区域降水不存在直接的相关性。     

青藏铁路沿线温性草原区芨芨草（Achnatherum splendens）群落特征

芨芨草群落是青藏铁路沿线一类重要的温性草原植被类型,对青藏铁路两侧及其四周的水土保持起着非常重要的作用。对青藏铁路西格段海晏县附近的芨芨草草原的空间分布特征、物种丰富度和生物量等特征进行了分析。结果显示,研究地区芨芨草群落由芨芨草斑块和针茅斑块镶嵌而成,两类斑块的数量、大小和斑块间大小变化幅度等特征在空间上表现出一定的规律;芨芨草斑块大小在样线上所占的比例比针茅斑块为小,且有随远离铁路而减小的趋势,而物种丰富度则出现相反的变化趋势;芨芨草斑块的盖度和单位面积上地上生物量显著高于针茅斑块。斑块的大小和数量在一定程度上反应了芨芨草群落的退化状况。人为活动往往会加剧芨芨草群落的斑块片段化。针对芨芨草群落的特征和现状,建议加强对这些区域内人为活动的限制力度以减少对芨芨草群落的干扰。     

青藏铁路沿线温性草原区芨芨草(Achnatherum splendens)群落特征

芨芨草群落是青藏铁路沿线一类重要的温性草原植被类型,对青藏铁路两侧及其四周的水土保持起着非常重要的作用。对青藏铁路西格段海晏县附近的芨芨草草原的空间分布特征、物种丰富度和生物量等特征进行了分析。结果显示,研究地区芨芨草群落由芨芨草斑块和针茅斑块镶嵌而成,两类斑块的数量、大小和斑块间大小变化幅度等特征在空间上表现出一定的规律;芨芨草斑块大小在样线上所占的比例比针茅斑块为小,且有随远离铁路而减小的趋势,而物种丰富度则出现相反的变化趋势;芨芨草斑块的盖度和单位面积上地上生物量显著高于针茅斑块。斑块的大小和数量在一定程度上反应了芨芨草群落的退化状况。人为活动往往会加剧芨芨草群落的斑块片段化。针对芨芨草群落的特征和现状,建议加强对这些区域内人为活动的限制力度以减少对芨芨草群落的干扰。     

呼伦贝尔草原南缘植被类型分异及生物多样性特征

以呼伦贝尔草原为对象,对其南缘从东到西200 km范围内的植物群落进行了系统调查,并采用数量生态学方法对研究区内植被类型及生物多样性进行分析。调查共发现98种植物,其中以菊科(Compositae)、豆科(Leguminosae)、禾本科(Gramineae)和百合科(Liliaceae)为主,其植物种数占全部物种数的52.58%。植物水分生态类型主要以旱生植物为主;植物生活型则以多年生草本植物为主。对呼伦贝尔草原南缘94个样地进行NMDS排序的结果表明,水热因子影响植被分布格局,其中降水是最主要因素;相似性分析和相似性百分比分析结果显示,荒漠草原群落与草甸草原群落物种组成相异性最大,群落分离明显,与典型草原群落间也形成了显著差异。典型草原与草甸草原镶嵌分布,且草甸草原呈向典型草原转变的趋势,这表明日趋加剧的干旱气候和不合理的人为活动导致所有植被类型向旱生化方向演变。3种草原类型的Rényi多样性排序结果显示,物种丰富度、Shannon多样性指数、Simpson多样性指数均为草甸草原最高,典型草原次之,荒漠草原最低,而优势度呈现与多样性相反的结果,整个研究区的生物多样性总体上呈现下降的趋势。这种从个体到群落向单一化和旱生化演变的趋势将严重影响呼伦贝尔草原的保护及开发利用。     

鄂尔多斯高原植物群落多样性时空变化特点

作者利用1999年和2000年野外植物群落调查资料,结合李博(1990)的植物群落调查结果,分析了鄂尔多斯高原植物群落多样性的时空变化特点。鄂尔多斯高原主要植物群落类型有23类,不同植被类型的群落多样性表现出一定的差异性,其中丰富度指数的差异不显著,而Simpson指数和Shannon-Wiener指数及群落盖度的差异明显。中东部典型草原表现为高多样性高盖度;西鄂尔多斯荒漠草原和草原化荒漠物种多样性较高,但盖度较低;毛乌素沙地植物群落物种多样性低,但盖度较高。从1986年到2000年,该地区典型草原群落、荒漠草原和沙地植被的群落多样性指数都有下降趋势;典型草原和草原化荒漠的群落盖度有所增加,荒漠草原有所下降。以上结果表明,沙地植被和草原化荒漠生物多样性已经得到了一定的保护,但还有待加强,而荒漠草原的保护亟待引起重视。     

内蒙古高原温带稀树草原生态系统特征与成因

内蒙古高原分布的温带榆树稀树草原生态系统在中国乃至世界上都是一种特殊的生态系统,对于它的研究可加深对植被分布规律的理解,且有利于该系统的保护。本文分析了该生态系统的地理分布、气候特点、土壤状况、物种组成、群落结构及天然更新状况等,比较了草原、森林和稀树草原3个生态系统的特征,提出了在内蒙古高原分布的温带榆树稀树草原生态系统是在独特的气候、土壤和地形条件下形成的经度(水分梯度)地带性顶极植被,决定其存在的最关键因素首先是降水量和土壤的水分条件,其次才是沙质土壤。这种生态系统既不是草原,又不是森林,而是介于落叶阔叶林和草原之间的一种生态系统类型。在此纬度带上,从东到西分布的经度地带性植被谱应为:温带森林、温带稀树草原、典型草原、荒漠草原等。在同一纬度带上,沙质土壤的基质并不完全被稀树草原生态系统所覆盖,还有沙漠等生态系统类型。建议《中国植被》增加一个新的植被类型,温带稀树草原。     

中国草原/荒漠植物多样性监测网 模式植物群落监测方案

“模式群落”是指能够反映某种植被分类单元基本特征, 并可作为准确描述该植被类型“标准”的典型植物群落。中国生物多样性监测网络——草原/荒漠植物多样性监测网旨在统一监测方法和技术规范的基础上, 在草原/荒漠植被主要群系分布的典型地段建立模式植物群落监测固定样方, 定期复查, 长期监测草原和荒漠的植物多样性变化。文章强调了典型植物群落监测是生物多样性监测的重要组成部分, 阐述了模式群落的概念, 介绍了草原/荒漠植物多样性监测网的总体思路和布局, 以及主要监测内容、方法、指标和预期产出。     

从阿尔金山的植被特点论柴达木盆地在植被区划上的位置

通过对阿尔金山和柴达木盆地西段植被的研究,我们认为在中国植被区划问题上把柴达木盆地放在荒漠区是不正确的。因为阿尔金山和祁连山西段北坡均发育有完整的高寒草原带,它和青藏高原的高寒草原同属一个整体类型,完全隔断了柴达木盆地和塔里木盆——河西走廊荒漠地区之间的连系。柴达木盆地在第三纪时曾和塔里木地块连在一起,故两地分布有几种相同的植物群落。但自青藏高原隆升以后,柴达木盆地的荒漠群落即成了“飞地”类型,且只龟缩于柴达木盆地东部条件较好,实际上是非地带性生境的干河床中,生长得稀疏、憔悴,显然处于衰亡之中,完全失去了地带性意义。所以柴达木盆地在植被区划上应当是欧亚草原区青藏高原高寒草原亚区的一个下属分区单位。     

地带性植被

又称“显域植被”。地球上各种植被类型的分布,基本上取决于热量和水分等相应的气候条件。太阳辐射供给地球的热量,从赤道向南、北两极形成了不同的气候带,而在分布上与气候带界线大体相符的大面积的植被类型就称为地带性植被。所以地带性植被就住往被用来指水平地带上的各类典型植被,如热带雨林和季雨林、亚热带常绿阔叶林、温带草原、温带落叶阔叶林、温带荒漠、寒温带针叶林等。大多数生物圈保护区中的核心区,都包含了该保护区所在地的地带性植被的各种群落类型。     

祁连山西段与酒泉盆地草地资源可持续利用分析

调查和分析甘肃省祁连山西段及酒泉盆地草地和植被资源及其分布规律,发现该区草地类型主要为沼泽草地、低湿地草甸草地、荒漠草地、山地荒漠草地、荒漠化草原、山地草原、高寒草原、山地草甸、高寒草甸以及高寒荒漠。分析了草地资源现状和合理利用问题,并提出了可持续利用该区草地资源的对策。     

Characteristics of the Achnatherum splendens community along the Qinghai-Tibet Railway, China

The Achnatherum splendens community is an important type of warm steppe vegetation which plays a very important role in environmental protection in the area along the Qinghai-Tibet Railway. In order to under-stand its dynamic features, the characteristics of the A. splendens community, such as spatial distribution pattern, species richness and biomass, were examined near Haiyan County, Qinghai Province. Results showed that the A. splendens community consisted of two types of mosaic patches, the microaggregation dominated by A. splendens and the microaggregation dominated by Stipa sp. The number and size of the two patches showed an interesting distribution pattern. The A. splendens patch decreased with increasing distance away from the railway, while species diversity increased. The total coverage of A. splen-dens was significantly higher than that of Stipa sp. The number and size of patches may indicate the degradation of the A. splendens community, which could be acceler-ated by human activities. Based on the characteristics and status quo of the A. splendens community, we suggest that some measures be taken to control human activities and rodents to conserve the A. splendens community.     

小叶、中间和柠条三种锦鸡儿的分布式样及其生态适应

确定了小叶锦鸡儿、中间锦鸡儿和柠条锦鸡儿3种植物的分布式样:小叶锦鸡儿为蒙古高原东部-F松辽平原西部-华北山地分布种,中间锦鸡儿为东戈壁-鄂尔多斯高原-黄土高原北部分布种,柠条锦鸡儿为南阿拉善-西鄂尔多斯分布种。小叶锦鸡儿适应分布于蒙古高原典型草原带和森林草原带以及华北山地落叶阔叶林带,在草原带高平原上可形成灌丛化草原的景观,在草原带的沙地上可形成以小叶锦鸡儿为建群种的沙地灌丛植被;中间锦鸡儿适应分布于蒙古高原的荒漠化草原及草原化荒漠带、鄂尔多斯高原的典型草原和荒漠化草原带的沙地及梁地上、黄土高原北部的黄土丘坡上,常形成以中间锦鸡儿为建群种的沙地灌丛植被;柠条锦鸡儿则适应分布于草原化荒漠和典型荒漠带的固定和半固定沙地上。近缘的3种锦鸡儿的地带性分布从东至西或从北向南形成明显的有规律的地理替代分布格局。     

Characteristics of desert flora and vegetation in lower reach of Shiyang River论Basin

石羊河下游位于干草原向荒漠过渡区域,有天然种子植物23个科,73个属,123个种,不仅有典型的戈壁荒漠成分,也渗入一些草原化荒漠植物种类.其荒漠植被特征更明显,群落层片结构简单,群丛建群种的74.4%是灌木和半灌木,构成了灌木、半灌木旱生群落;1年生草本植物随季节性降雨可形成＂灌草丛＂,成为荒漠植被的重要组成部分.在植物地理区系成分上,温带成分属占优势,其中地中海至中亚分布型及其变型最多,其次为北温带分布及其变型.整个区域内植物的分布集中在生境较适宜的区域,空间结构的成群性高,但在小区域内植物种的分布则较单一.植被可划分为4个植被型,5个植被亚型,13个群系组,23个群系,38个群丛.地域性植被以绿洲为中心,成环状分布,可分为3个带.     

青海湖地区芨芨草群落主要种群分布格局研究

以青海省三角城种羊场地区典型的芨芨草草原为研究对象,采用相邻格子样方法取样,应用方差/均值比率法、负二项参数(K);扩散系数(C);C ass ie指标(CA);丛生指标(I)和聚块性指标(m*/m)等指标,比较了青海湖地区围栏内、外芨芨草群落主要种群的空间分布格局。结果表明,围栏内芨芨草群落优势种群的空间格局除多裂蒲公英为随机分布外,其余均为聚集分布;围栏外除西伯利亚蓼外,其余种群也全部为聚集分布,而且围栏外种群的聚集强度大于围栏内。物种的这种分布格局主要与物种本身的生态和生物学特性有关。     

中国针茅属植物的地理分布

本文论述了中国针茅属植物的地理分布、生态特点及其与植被分布的关系。中国针茅属有32种1亚种及4变种,据该属各个种所处环境中的气候和土壤等因素的变化,不同种的分布也各异。属的分布区的类型属于吴征镒(1979)的中国植物区系分区的泛北极植物区中的6个植物亚区,即亚洲荒漠植物亚区,欧、亚森林植物亚区,青藏高原植物亚区,中国-喜马拉雅植物亚区,欧、亚草原植物亚区及中国-日本森林植物亚区。     

青海湖地区植被及其分布规律

青海湖地区位于青藏高原东北部。境内复杂的地貌类型及青海湖的存在对植被有重要影响。本区植物种类贫乏,现有种子植物52科、174属、445种。主要植被类型有寒温性针叶林、高原河谷灌丛、高寒灌丛、沙生灌丛、温性草原、高寒草原、高寒草甸、沼泽草甸、高寒流石坡植被等。植被分布表现出明显的规律性变化。草原分布于湖盆及河谷地带,由东而西植被类型有更加适应寒旱趋势。温性草原以青海湖为中心;呈环带状分布,而高寒草原的分布则与生境寒冷干旱相一致。山地垂直带谱表现为草原带、高寒灌丛与高寒草甸带以及高寒流石坡植被带。本区植被水平地带性分异受到青海湖的影响,其植被组合及特征表现出与青藏高原植被的明显相似性。作为祁连山南麓中部地区的一个大型山间盆地,其东西方向界于青海省东部地区和柴达木盆地之间,植被东西方向的水平地带性并未表现出明显的过渡特征。根据植被特点及分布规律分析,本区植被有其自身的特殊性,并与青藏高原隆升之后气候寒冷干旱相一致。因此,青海湖地区就整体而言应属祁连山地区植被一个相对独立的组成部分。     

Patterns of zonal changes in the spatial structure of Orthopteran communities in the European steppe

Patterns of zonal changes in the species composition, diversity, and community structure of Orthoptera were studied along the latitudinal series of steppe types from meadow to desert steppe in European Russia. The maximum abundance of Orthoptera was recorded in the typical steppe, while the maximum species richness shifted to the southern dry steppe. Changes in the ecological preferences of orthopterans due to aridization are shown by the example of zonal communities. A gradual decline of the forest-steppe orthopteran complex and an increase in the number of semidesert and desert species are demonstrated. The changes in the species composition are accompanied by the intra-landscape shifts of areas with high species diversity. Most species in the meadow steppe occupy mesophytic habitats in depressions. In the typical and dry steppe, the species richness and abundance are restricted to habitats with zonal and xerophytic vegetation. In the desert steppe, the species diversity is the highest in dry habitats, including halophytic ones, where xerophilic and desert species predominate. The diversity and evenness indices increase in the northern and southern ecotones of the steppe zone.     

The Fundamental Characteristics of the Steppe Vegetation in Xizang Plateau

The steppe vegetation of the Xizang (Tibet) Plateau is somewhat similar to the temperate steppe of our country, but it possesses its own characteristics: 1. The elements of the Qinghai-Xizang floral region or plant species taking the Qinghai-Xizang Plateau as their chief distribution center play a dominant part in tile constitution of the steppe communities. In these communities, the plants are usually sparse and dwarf, their growth period is shorter and the biological productivity is lower than the steppe in the temperate zone. They possess synusia consisting of herbaceous plants fit for cold climate, synusia consisting of kobresia and synusia consisting of cushion plants. 2. There are 4 types of steppe vegetation in the Xizang Plateau. And the tussock-grass steppe is the most typical. According to their different ecological characteristics, they may be divided into 3 types. Of these, the most widely distributed type is the cold temperate-weak semiarid steppe. And there are many characteristical steppe communities. 3. Distributionally, the steppe in the Xizang Plateau belongs to a special type of vertical distribution in the subtropical latitude zone, it is different from the gene- rally known montane vertical belt, and possesses a vertical-horizontal distributive nature, i.e. "zonation of plateau". Within the Plateau steppe region, steppe eommunities with different ecological characteristics have clearly marked areal differentiaton, and which has determined the nature of the vertical belts in these areas. According to different basal belts of the vertical belt spectrum, such belts may be divided into 3 types. There are no forests in the montane vertical belt spectra in the Plateau steppe region, and the upper distributional limit of the steppe vegetation reaches an altitude of about 5200 (5400) m., which is the highest distributional limit of steppe on the earth.     

Characteristics of the Vegetational Zones in the Nei Monggol Autonomous Region

Vegetation of the Nei Monggol (Inner Mongolia) Autonomous Region can be classified into the following four major natural vegetational regions: Eurasia Coniferous Forest Region, East Asia Broad-Leaf Forest Region, Eurasia Steppe Region and Asia-Africa Desert Region. As a result of the differences in the temperature caused by the latitudes and in the precipitation by the southeast monsoon, five zones of vegetation may be distinguished in this region: the bright coniferous forest zone of cold-temperate type, the deciduous broad-leaf forest zone of mid-temperate type, the steppe zone of mid-temperate type, the steppe zone of warm-temperate type and the desert zone of warm- temperate type. Each of them has its own representative of vegetation formation and soil type, with corresponding climatic index. These characteristics have important bearing on the development of agriculture and animal-husbandry in this region. The vegetation of steppe and desert in this region is more arid than the Kazakstan steppe and Middle Asia desert. It is shown by the higher xerophilizaticn of edifieators and the lower productivity of communities. Difference of the characteristics of soil caused by different characteristics of vegetation may also be noticed.     

A study on the vegetation in the east side of Helan Mountain

This paper analyzed the vegetation data obtained from a field survey conducted in the East Side of Helan Mountain, China, to reveal the features of mountainous vegetation growing in a transitional zone between the steppe and desert regions. Detrended correspondence analysis (DCA) was applied to the process of analysis, to clarify the spatial variation of floristic composition of the vegetation in the lower mountain range.The preliminary results obtained from the analysis are: (1) There are 53 vegetation formations existing in the area, following the China's criteria of vegetation classification system. (2) Those vegetation types compose a vertical vegetation spectrum in the East Side of Helan Mountain due to the climatic gradient caused by elevation variation. The spectrum consists of 4 zones. They are, from the foot up to the peak in turn, mountain steppe zone, mountain open forest and steppe zone, mountain coniferous forest zone, and alpine bush and meadow zone. The mountain coniferous forest zone can be further divided into two subzones: Pine forest subzone and Spruce forest subzone. (3) Most of the vegetation types show clear xeromorphic features due to the base zone of the vertical vegetation spectrum lying in the arid region of China. (4) The distribution of vegetation types and flora is sensitive and susceptible to the moisture condition that the vertical vegetation spectrum has quite different expressions between northern and southern exposures. (5) Floristic composition of the vegetation shows a northern temperate feature. The families that are rich in species in the area include Gramineae, Compositae, Leguminosae, Chenopodiaceae, Rosaceae and others, most of which are abundant in herbaceous species. (6) The variation of the ecological conditions from the north to the south also leads to the differentiation of vegetation and its floristic composition in the area. (7) The broad-leaved forest can not form a forest zone in the vertical vegetation spectrum. This may be a special characteristic of the spectrum sitting on a transitional zone between the steppe and desert regions.