青藏高原高山植被的初步研究

青藏高原是我国高山植被类型最丰富、独特和分布最广泛的区域,发育有大面积的高山灌丛、高寒草甸、高寒草原,高寒荒漠、高山流石坡稀疏植被及零散分布的高山垫状植被。它们占据着森林上线至永久雪线之间的高山带和广阔的高原面,从高原东南部至西北部有水平方向的地域分异。联系高山带以下各垂直带的植被特征及各地的气候条件分析,初步认为高原东南部的山地植被垂直带谱属于湿润型山地垂直带结构类型,高原腹地及西北部的山地植被垂直带谱属于干旱型山地垂直带结构类型。此外,还对青藏高原高山植被类型的丰富性及高山垫状植被的生态地理分布特点进行了初步探讨。     

青海省东部地区的自然植被

青海省东部地区地处青藏高原和黄土高原的交汇地带。该地区受青藏高原和黄土高原的影响,自然植被与青藏高原上的高寒植被和黄土高原上的植被类型均有一定联系,从而形成该区较为复杂的植被类型。据考察,该地区的主要植被类型包括荒漠草原、草原、森林、灌丛、高寒灌丛和高寒草甸,并在该地区形成明显的垂直分布。在海拔较低的河谷低山分布着与黄土高原相连的植被类型;而海拔较高的山地则分布与青藏高原相连的高寒植被,形成有一定过渡性而又独具特色的植被景观。我们认为,该地区是青藏高原和黄土高原的过渡地带。     

青海省柴达木盆地及其周围山地植被

 柴达木盆地位于青藏高原东北部,其植被分布规律较复杂。东部为半干旱荒漠草原地带,地带性植被为荒漠化草原;中部为干旱荒漠地带,地带性植被为灌木和矮半灌木砾漠;西部为极端干旱裸露荒漠地带,在砾石戈壁和低山基本上无植被。本区盆地底部随着地貌、土壤和地下水的变化,出现了植被环带状分布规律。从盆地边缘向中心依次发育着洪积平原灌木、矮半灌木砾漠带,冲积平原灌木沙漠带,冲积—湖积平原灌木盐漠带,湖积平原盐生草甸带,最后为裸露盐壳和盐湖。本区山地的植被垂直带自东而西明显不同。荒漠草原地带的带谱为：山地草原—山地常绿针叶林—亚高山灌丛—高寒草甸—高山稀疏植被;荒漠地带为：矮半灌木山地石漠—高寒草原—高寒草甸—高山稀疏植被;极端荒漠地带为：裸露低山石漠—矮半灌木山地石漠,高寒草原—高山稀疏植被.     

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。     

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顾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,由东而西植被兴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示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。     

祁连山地区植被特征及其分布规律

分析和讨论了祁连山地区主要植被类型及其分布特征。祁连山地区随着青藏高原的强烈隆升表现为整体抬升,植被具有明显的生态地理边缘效应特征和高原地带性规律。该区植被虽然受到四周的较大影响,但各类高寒植被占有绝对优势,表现出与青藏高原植被整体明显的相似性和广泛的一致性。另一方面,本区植被也有其特殊性及与高原面存在一些差异。因此,建议把祁连山地区做为青藏高原植被区的次一级独立单元     

青海省癿扎林区森林植被调查初报

位于青藏高原东南部的癿扎林区,是高山暗针叶林分布的边缘。其植物种类单纯,结构简单。本林区是森林植被向高寒灌丛、草甸的过渡地带,在一定意义上反映出青藏高原植被从森林一草甸中间过渡的一些特点。本文采取典型调查和路线踏查相结合的方法,在7300余公顷林地中共选出20×20m2典型样地8块。在8块样地的野外调查基础上,参考有关资料,首次对癿扎林区高寒常绿针叶林的生态环境、主要类型及其分布规律等问题作初步论述。     

青藏高原高寒地区种子植物区系的研究

研究了青藏高原海拔４２００ｍ以上大体是林线以上的高寒地区的种子植物区系。这一地区自然条件恶劣,地带性植被为高山灌丛、高寒草甸、高寒草原、荒漠化草原和冰缘植被,然而植物区系仍比较丰富,共有种子植物６７科,３３９属,１８１６种及２０４个种下等级（变种、亚种、变型）。对这些属种的地理分布、系统演化关系以及这一地区的古植物学资料进行了分析研究;对５７种进行了细胞染色体的观察。认为本区系是一个温带性质的植物区系,与中国─喜马拉雅区系关系密切,在喜马拉雅和青藏高原隆起的过程中逐渐形成,是一个年青的区系,但有着久远的历史渊源。     

青海湖地区植被演变趋势的研究

青海湖地区作为祁连山系中段南麓的一个大型山间盆地,是一个独具特色的地区。这里的以草原为基带及其周围山地的高寒灌丛和高寒草甸垂直系列,有其自身的特点和发展趋势。随着整个青藏高原的强烈隆升,本区植被也具有一系列的明显变化。大片森林趋于消退,仅残存有少数适应高寒生境的树种;温性植被类型局限于海拔较低处,而高寒植被类型相对分布较广。分析表明,青海湖地区的整体植被景观有向寒旱生境方向发展的演变趋势。本区植被出现上述演变趋势的主要原因在于该地区生境因抬升而趋于寒旱的过程中,植物种对其生境变化表现出不同的忍耐性和适应性所致。     

青藏高原中东部表土轻组碳氮含量分布及其影响因素

土壤轻组(LF)能够反映因人为活动或环境变化引起的土壤微弱改变。为探究青藏高原土壤LF含量分布及其影响因素,分析了青藏高原中东部不同植被类型下表土LF、重组(HF)及其碳氮含量和碳氮比(C/N),讨论了LF碳氮含量及C/N与环境因子的相互关系。结果表明:青藏高原中东部表土LF占土壤总有机质的比例很小(2.11%),不同植被类型表土LF含量排序为:林地高寒草甸高山草原荒漠。表土轻组有机碳(LFOC)、重组有机碳(HFOC)平均含量分别为27.23%和2.39%,以林地最高(31.73%,2.64%),荒漠LFOC和高寒草甸HFOC含量最低,分别为24.63%和2.30%。轻组总氮(LFTN)、重组总氮(HFTN)平均含量分别为1.22%和0.12%,以高寒草甸最高(1.28%,0.12%),林地最低(1.14%,0.10%)。轻重组C/N均值分别为27.67和11.59,以林地最高(36.95,15.15),高寒草甸轻组C/N和高山草原重组C/N最低,分别为25.45和10.03,表明林地腐殖化程度较高,有效氮含量较低,而高寒草甸和高山草地与之相反。青藏高原中东部表土LF含量及分布受植被类型影响明显,土壤pH值是影响LF碳氮含量最重要的环境因子。     

贡嘎山地区主要植被类型的分布

贡嘎山位于青藏高原东南缘横断山系大雪山脉中段,主峰海拔高7556m。该地区有维管束植物185科,869属,约2500种。其植物区系特点为：区系成分起源古老;物种分化显著,特有种丰富;成分复杂,地理替代明显。贡嘎山主要植被类型有：冷杉、云杉组成的亚高山针叶林;松、铁杉组成的中山针叶林;松、杉、柏、油杉组成的低山针叶林;铁杉、桦木、槭树组成的针叶,阔叶混交林;樟、楠、阔楠、石栎,青冈等组成的常绿阔叶林;栎、桦、槭、杨、桤等组成的落叶阔叶林;高山栎类组成的硬叶常绿阔叶林;杜鹃、柳、圆柏等组成的高山灌丛;仙人掌(Opuntia monacantha)、金合欢、羊蹄甲等组成的河谷灌丛;嵩草(Kobresia)、羊茅(Festuca ovina), 韭和风毛菊、绢毛菊、绵参(Eriophyton wallichii)等组成的高山草甸与高山流石滩稀疏植被。贡嘎山地区水平地带性植被为常绿阔叶林,它兼有我国亚热带东部和西部常绿阔叶林的特点。 贡嘎山东坡植被垂直带谱是：1．常绿阔叶林带,海拔1100—2200m。2．山地针叶、阔叶混交林带,2200—2500m。3．亚高山针叶林带,2500—3600m。4．高山灌丛草甸带,2600—4600m。5．高山流石滩稀疏植被带,4600—4900m。6．永久冰雪带,海拔4900m以上。贡嘎山西坡植被垂直带谱是：1．亚高山针叶林带,海拔2800一4000m。2．高山灌丛草甸带,4000—4800m。3．高山流右滩稀疏植被带,4800—5100m。4．永久冰雪带,海拔5100m以上。     

中昆仑山北坡及内部山原的植被类型

 中昆仑山西始乌鲁乌斯河,东迄安迪河,东西迤逦600余公里,平均海拔高度6000m。该区有野生种子植物52科,211属,398种。植物区系以种类成份单纯、地理成份复杂为特征。北坡中山带和高山带下部年降水量300—500mm,草原带发育完整,尤以中段的策勒山地草原发育最好。草原带以上高寒荒漠不存在,高寒草甸则有一定发育。中昆仑山北坡植被类型的垂直带谱是：1)山地荒漠,自山麓线多在2200—2500m,个别在3000m;2)山地荒漠草原在3000—3200m;3)山地真草原在3200—3600m;4)高寒草原在3600—3800m(阳坡上升到4200m以上);5)高寒草甸在3800—4200m;6)高山垫状植被仅见于东段山地和高寒草甸复合分布;7)高山流石坡稀疏植被在4200—5000m。中昆仑山内部山原极端寒冷干旱,多为砾漠所占据,高寒荒漠和高寒荒漠草原呈片状星散分布。     

藏北高原典型植被样区物候变化及其对气候变化的响应

植被物候作为陆地生态系统对气候变化的响应和反馈的重要指示,已成为区域或全球生态环境领域研究的热点。基于非对称高斯拟合方法重建了2001—2010年MODIS EVI时间序列影像,利用动态阈值法提取藏北高原植被覆盖2001—2010年每年关键物候参数。选取研究区内东部高寒灌丛草甸、中部高寒草甸及西部高寒草原和高寒荒漠4种典型植被类型,并结合附近的4个气象台站气候资料,分析典型植被物候在近10a对关键气候因子的响应特征。研究结果表明:(1)4种不同典型植被的物候特征(EVImax降低、返青期延后和生长季长度缩短)均表现出高寒灌丛草甸→高寒草甸→高寒草原→高寒荒漠草原的过渡;(2)藏北高原近10a的年平均气温及春、夏、冬三个季度的平均气温均呈显著升高的趋势,升温幅度在0.8—3.9℃/10a,降水减少趋势不显著,在这种水热条件下典型植被均表现出返青提前(7.2—15.5d/10a)、生长季延长(8.4—19.2d/10a)的趋势,而枯黄出现时间为年际间自然波动;(3)高寒灌丛草甸EVImax主要受春季降水量和气温影响,且降水的影响程度大于气温;对高寒草甸植被而言,春、夏季的气温和降水均有较大的影响;而高寒草原和高寒荒漠草原主要受夏季平均气温和降水量影响;(4)高寒灌丛草甸的返青时间主要受前一年秋季降水量的影响,相关系数达-0.579;而高寒草甸、高寒草原和高寒荒漠草原主要受春季平均气温影响,高寒荒漠草原的特征最为明显(r=-0.559)。     

圣海伦斯火山和高山植被

 Mt. St. Helens is an active volcano on the western flank of the Cascade: range in the southwestern Washington State, USA. It is located at lat. 46˚00′—46˚30′N, long 121˚52′—122˚40′W.We had investigated the alpine vegetation at Pine Creek, Butte Camp on Mt. St. Helens for three times, totaling ten days during August and eptember of 1983.The volcano had erupted sending out much pyroclastic, pumice and lava, which devdstated the vegetation around the crater. They not only mechanically destroyed plants tissue, but also buried entirely or partly of the plants.The radiant heat from the volcanic eruption caused the melting of ice and snow, creating huge mudflows, which estroyed and buried vegetation. The high temperture from direct radiant heat incinerated and scorched all the plants. On the other hand, the higher the elevation is, the stronger the wind and the lower the temperture; also snow was present on the alpine range, and this provided a lee for plants, and consequently some plants survived, and new ones row out of the ground. The alpine vegetation on Mt. St. Helens bears both the characteristic of alpine plants and the brand of volcanic activities: vegetation is sparse, species composition of plants limited, structure of community simple, production low and vegetation propagation being the main type of vegetative reproduction.The different types of lpine vegetation grow in different habitats: The community of Luekea pectinata grow in places covered by ice and snow; the community of Polygonum newberryi, Eriogonum pyroleafolium in localities covered by mudflow; the community of Phyllodace empetriformis on slopes of steep rocks and the community of grasses and sedges on low hills and plains. Hese are the four main communities on Mt. St. Helens. The recovery and succession of the alpine vegetation has been discussed. There are two types of succession, the primary and the secodary, with the secondary being the main one.Finally, the paper has analysed the reason why no forest occurs, on Mt. St. Helens. We think that it is a result of the ctive period of the volcano and that the climate conditions are favouable for forest. Also, we have suggested that some herbaceous plants be sown as soon as possible for they can accelerate the recovery of vegetation, and prevent the runoff of soil and water.     

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。     

从生态学论“三北”防护林在宁夏的规划原则

Ningxia Hui Autonomous Region is situated in 30;14′–30;14′ and 30;33′–30;39′.Though its area. Is only 67000km2, it has many various ecosystem categories. The vegetation is the core of the ecosystem, so it is very important to research. The vegetation in Ningxia is the combination of many various vegetation types which have certain egularity of ecogeographical distribution. The zonal vegetation types in Ningxia arc the semi-desert, the steppe and the meadow-steppe from north to south. And there are the spectrums of the vertical belts of the vegetation in Helan mountain and Lupan mountain. There are also many intrazonal vegetation types—the saline-meadow, the grass-swamp, the salt vegetation, etc. Every vegetation type exists many various plant communities. And each vegetation type or plant community can reflect the comprehensive ecological factors. According to the regularity, we may put forward a principle of plan of the "Sanbei’(northeast, north and northwest China)shelter-forest in Ningxia:l. It is suitable to establish the scrub belts in Ningxia. In the semi-desert, the steppe, the meadow-steppe and the grass-tuft, the soil erosion on the slopes may be controled by the scrub belts following contour-line and the wind-sand-harm on the plateau plain may be prevented by the scrub networks; 2. To plant the shrubs, the semi-shrubs and the therophytes is suitable for fixing the sanddrift; 3. It isn’t difficult to plant the shelter-forest in the irrigation farmland. But it is very important to choose the tree species adapting various soil; 4. All of the forest and the scrub in the mountains must be closed and tended. The mixed-forest may be expanded on the meadow slope.     

Field evidence for earlier leaf-out dates in alpine grassland on the eastern Tibetan Plateau from 1990 to 2006

Worldwide, many plant species are experiencing an earlier onset of spring phenophases due to climate warming. Rapid recent temperature increases on the Tibetan Plateau (TP) have triggered changes in the spring phenology of the local vegetation. However, remote sensing studies of the land surface phenology have reached conflicting interpretations about green-up patterns observed on the TP since the mid-1990s. We investigated this issue using field phenological observations from 1990 to 2006, for 11 dominant plants on the TP at the levels of species, families (Gramineae—grasses and Cyperaceae—sedges) and vegetation communities (alpine meadow and alpine steppe). We found a significant trend of earlier leaf-out dates for one species (Koeleria cristata). The leaf-out dates of both Gramineae and Cyperaceae had advanced (the latter significantly, starting an average of 9 days later per year than the former), but the correlation between them was significant. The leaf-out dates of both vegetation communities also advanced, but the pattern was only significant in the alpine meadow. This study provides the first field evidence of advancement in spring leaf phenology on the TP and suggests that the phenology of the alpine steppe can differ from that of the alpine meadow. These findings will be useful for understanding ecosystem responses to climate change and for grassland management on the TP.     

Grassland composition,structure, and diversity patterns along major environmental gradients in the Central Tien Shan

What species and traits signal vegetation types along prominent environmental gradients in the Central Tien Shan and what are the corresponding diversity patterns? Vegetation was sampled at 41 sites throughout the Kyrgyz Republic using quadrats stratified throughout a 1,000-m² sample area. Relationships among major environmental gradients, vegetation structure, and species composition were explored with nonmetric multidimensional scaling. Species distributions were examined to characterize phytogeographic patterns. Seven vegetation types ranging from desert grassland to meadow steppe were identified with cluster analysis, ordered primarily along elevation/mean annual temperature gradients. Four arid grassland types were distinguished, ranging mainly from 900 to 1,700 m elevation, and characterized by co-dominance of grasses and forbs with secondary dominance by shrubs. Annual and biennial forbs equaled perennial forbs in total importance. Grasses include C3 and C4 species. Three montane grassland types were recognized and characterized by co-dominance of perennial C3 grasses and forbs. Transition to montane steppe occurred from 1,500 to 1,900 m and is correlated with absence of C4 grasses and dominance of Festuca valesiaca. Highest diversity was found at intermediate elevations, from 1,800 to 2,600 m, in meadow steppe habitats. Forty-six percent of 580 identified species are Middle Asian endemics and remaining species primarily have distributions including Eastern Europe, the Caucasus, and western Siberia. Although grassland degradation from overgrazing has been chronic throughout the region, grasslands are widespread throughout the Kyrgyz Republic and many, particularly mid-elevation meadow steppes, retain high levels of native species diversity.