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1.
太原地区植物区系的初步分析   总被引:1,自引:0,他引:1  
太原地区植物资源丰富,共有维管植物1000种,隶属543属,139科。初步分析结果表明,该区系的地理成分复杂多样,与世界和全国其它植物区系有着广泛的联系,是各种分布区类型交汇的地带,有较明显的交错渗透现象。其中以温带成分占绝对优势,具典型的温带性质。该区系主要起源于古北大陆,现存区系的主要成份是第三纪古热带的后裔和残遗,或更古老的成分。  相似文献   

2.
太行花(Taihangia rupestris)是我国植物分类学家俞德浚和李朝銮于1980年发表的新属、新种。自然生长在太行山阴湿崖壁上,分布区狭小,呈残遗状态。最近,我在整理河南省境内大别山区植物标本时,发现大别山海拔1000米以上山地也有太行花。从标本的根茎叶的形态看,与太行山山区的太行花和变种  相似文献   

3.
一、概况昆虫是生物群落的组成部分,任何一种昆虫在生物群落内都占有一定空间,成为它们的栖息地,如果把这些栖息地连结起来就构成该种昆虫的分布区。昆虫的栖息地或分布区具有一定的生态条件,反映出一定的自然地理景观。新疆地处中亚内陆,具大陆性气候,冬夏冷热悬殊,昼夜温差甚大,天气干燥少雨,因此大部分地区形成干旱草原荒漠,只在高海拔地区(如阿尔泰山地和天山山地)由于受到西来的潮湿气流影响,空气湿润,植被茂密,有原始针叶林分布,此外,河流两岸平原绿洲,也  相似文献   

4.
大鸨(Otis tarda)常栖居于草原和荒漠草原上,是典型的草原鸟类。近几十年来,由于农牧业活动加剧和偷猎狩猎,大鸨分布区日益缩小,部分前分布区已消失。IUCN将其列为易危(VU)级,我国将其列为国家Ⅰ级重点保护物种。为加强该物种的保护与管理,国内外学者开展了大量的研究工作。本文综述了大鸨分布与种群数量、食性、栖息地选择、繁殖生态、迁徙、行为生态等方面的研究进展,同时提出了需要进一步深入开展的研究方向。  相似文献   

5.
青海湖湖盆南部的植被与海拔梯度   总被引:3,自引:0,他引:3  
研究地区主要植被类型有三类,即温性草原、高寒灌丛和高寒草甸。温性草原主要分布于研究地区东段湖滨平原上;高寒灌丛分布于山地一定海拔范围内(3400-3800m):高寒草甸主要分布于海拔3800-4200m之间,群落中优势种的重要值沿海拔梯度呈“钟型”或近似“钟形”变化趋势,即优势 沿海拔梯度分布上有一最适区,但不同种群其最适区彼此分离;而优势种在其分布区边缘则常常相叠,表明群落之间并无明显界限,这与  相似文献   

6.
由于受到第四纪大陆冰川的影响较弱,这里保存第三纪古老的残遗种不少,尤其是裸子植物残遗种类,例如南方红豆杉、白豆杉、穗花杉、粗榧、三尖杉、竹柏、罗汉松、福建柏、南方铁杉等。资源冷杉也有零星的出现,有些还是小片的分布。  相似文献   

7.
《植物杂志》2011,(5):16-17
由于受到第四纪大陆冰川的影响较弱,这里保存第三纪古老的残遗种不少,尤其是裸子植物残遗种类,例如南方红豆杉、白豆杉、穗花杉、粗榧、三尖杉、竹柏、罗汉松、福建柏、南方铁杉等。资源冷杉也有零星的出现,有些还是小片的分布。  相似文献   

8.
金沙江河谷苏铁天然植物群落的研究   总被引:6,自引:1,他引:5  
近年在金沙江干热河谷及其邻近地区陆续发现的苏铁天然植物群落,为本属植物在欧亚大陆内陆分布的最北边缘。其中,面积最大和保存较好的是渡口市攀枝花苏铁(Cycas panzhihuaensis)植物群落。本文研究了这个群落的分布与生境、生长状况、外貌、种类组成以及群落的综合特征等。认为具有稀树草原的特点,而这里的稀树草原是次生性质的,苏铁群落是其中幸存的残遗植被类型。这对研究我国植物地理有着重要意义。  相似文献   

9.
西鄂尔多斯地区土壤与四合木微量元素含量特征分析   总被引:20,自引:3,他引:17  
从西鄂尔多斯地区生境适宜性特征的角度,研究四合木(Tetraena mongolia)的生态适应性,探讨迁地保护不易成活的原因,对不同生境条件下四合木分布区土壤和植株微量元素含量的测定结果表明,四合木分布区土壤中Cu、Fe、Mn、Zn、B、Mo、Se、Co、CI9种微量元素中,除B的含量明显高于国内土壤平均含量水平和荒漠区土壤平均含量水平;其它元素都低于国内土壤的平均含量;迁地实验区土壤中除Cu的有效量略低于荒漠区土壤和四合木分布区土壤的含量外,Fe、Mn、Zn、B、Mo的有效量均略高于荒漠区土壤和四合木分布区土壤,四合木植株中Fe、Cu、Zn、B、Se、Co的含量远高于各种类型草原植物,而Mo含量高于植物体含量均值,但低于荒漠草原植物,仅为荒漠草原植物的50%,四合木分布区土壤与四合木成株、幼苗9种微量元素相关性不显著,而且植物体中9种元素含量远远大于土壤中的有效量,从四合木植株中各元素含量与各类型草原植物(包括荒漠草原植物)和土壤中含量比较表明,四合木在生长过程中对各种元素呈富集特征,可见土壤微量元素的含量不是四合木迁地种植的制约因子。  相似文献   

10.
华西南干热河谷种子植物区系的特征,性质和起源   总被引:20,自引:5,他引:15  
华西南干热河谷种子植物的区系特征表现为其植物科、属、种各级分布区类型的多样性,明显的特有现象和丰富的标志种。根据本地区的区系成分分析,可以得出以下有关区系性质和起源的结论:(1)总体上看干热河谷种子植物区系属于亚热带性质;(2)本地区一些半稀树草原和马基状灌丛的区系成分类似于热带非洲、热带亚洲和地中海地区相同植被的成分;(3)许多植物料和属为古热带成分,起源于古南大陆;(4)少数残遗种或其后裔可追  相似文献   

11.
小叶、中间和柠条三种锦鸡儿的分布式样及其生态适应   总被引:8,自引:0,他引:8  
赵一之 《生态学报》2005,25(12):3411-3414
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。  相似文献   

12.
Clarifying spatial variations in aboveground net primary productivity (ANPP) and precipitation-use efficiency (PUE) of grasslands is critical for effective prediction of the response of terrestrial ecosystem carbon and water cycle to future climate change. Though the combination use of remote sensing products and in situ ANPP measurements, we quantified the effects of climatic [mean annual precipitation (MAP) and precipitation seasonal distribution (PSD)], biotic [leaf area index (LAI)] and abiotic [slope gradient, aspect, soil water storage (SWS) and other soil physical properties] factors on the spatial variations in ANPP and PUE across different grassland types (i.e., meadow steppe, typical steppe and desert steppe) in the Loess Plateau. Based on the study, ANPP increased exponentially with MAP for the entire temperate grassland; suggesting that PUE increased with increasing MAP. Also PSD had a significant effect on ANPP and PUE; where more even PSD favored higher ANPP and PUE. Then MAP, more than PSD, explained spatial variations in typical steppe and desert steppe. However, PSD was the dominant driving factor of spatial variations in ANPP of meadow steppe. This suggested that in terms of spatial variations in ANPP of meadow steppe, change in PSD due to climate change was more important than that in total annual precipitation. LAI explained 78% of spatial PUE in the entire Loess Plateau temperate grassland. As such, LAI was the primary driving factor of spatial variations in PUE. Although the effect of SWS on ANPP and PUE was significant, it was nonetheless less than that of precipitation and vegetation. We therefore concluded that changes in vegetation structure and consequently in LAI and/or altered pattern of seasonal distribution of rainfall due to global climate change could significantly influence ecosystem carbon and water cycle in temperate grasslands.  相似文献   

13.
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.  相似文献   

14.
许炯心 《生态学报》2005,25(6):1233-1239
以退耕还林还草为主要内容的大规模的生态环境建设正在我国兴起,如何进行科学的植被配置规划,是一个急待解决的理论和实践问题。以自然植被初级生产力(NPP)表征潜在的即最大可能的植被条件,并与现在的森林覆盖率分布以及植被构成特征进行了比较。通过大量实测资料的分析,查明了降水条件对森林覆盖率和NPP的影响及其临界条件。研究表明,以NPP表征的天然植被特征值在黄土高原地区的分布具有显著的地带性。NPP与年平均降水量的关系中存在着两个临界点,分别代表着植被类型的变化,Pm=250mm可视为荒漠与草原植被之间的临界点,而Pm=480mm则为草原(森林草原)与森林(落叶阔叶林)之间的临界点。尽管次生的人工植被受人为因素的控制,由于存在着自然稀疏化过程,将使人工林地最终达到某种与水分承载能力相一致的平衡状态,自然条件如年降水仍然是决定其覆盖度的重要因素。在森林覆盖率与年平均降水量的关系中表现出一个临界点。当Pm<480mm时,森林覆盖率很低,且随年降水的增大而增大的速率很慢;当Pm>480mm时,森林覆盖率随年降水量而急剧增大。人为建造的水土保持植被,是一个自然的人工生态系统,也是一个自组织系统,它通过自我调节而趋向于达到某种平衡,建立一定的群落结构甚至于趋向于某种顶极群落,从而实现乔木、灌木、草本植物组成的最优组合。从这一原理出发,提出了一个基于实测资料进行统计分析的方法,来确定使乔木面积在乔木、灌木、草本总面积中的最优或较优的比例,得出了具体的数据。  相似文献   

15.
In northern China, the Late Miocene-Pliocene red clay in the eastern Loess Plateau fills a gap of climate records between the well-known loess-soil sequences of the last 2.6 Ma and the Miocene loess-soil sequences from the western Loess Plateau. Previous studies indicate that the red clay is also of wind-blown origin, covering the period from ∼ 7-8 to ∼ 2.6 Ma. The red clay therefore provides a good archive to reconstruct paleoecological succession and paleoclimate change. In this study, a palynological investigation was conducted on the late Miocene-Pliocene red clay sequence at Xifeng, central Loess Plateau, which provides new insights into the nature of the evolution of vegetation and climate change from ∼ 6.2 to ∼ 2.4 Ma. Our results show that during this period the central Loess Plateau region was covered mainly by a steppe vegetation, indicating long lasting dry climatic condition. Three vegetational zones were recognized during this period. Zone A (∼ 6.2 to ∼ 5.8 Ma) is characterized by a steppe ecosystem; Zone B (∼ 5.8 to ∼ 4.2 Ma) is characterized by a significant increase of temperate forest plants, indicating a relatively humid regional climate; Zone C (∼ 4.2 to ∼ 2.4 Ma) indicates a typical steppe ecosystem. The vegetation shift at about 4.5-3.7 Ma, when the temperate forest plants decrease, the vegetation gradually changed to typical grassland and even to desert steppe. This is interpreted to represent a drying event. The uplift of the Tibetan Plateau at about 4.5 Ma that resulted in the intensification of the monsoon reversal is thought to have played an important role in this significant ecological change. High-latitude cooling may have partially contributed to the climate shift during ∼ 4.5 to ∼ 3.7 Ma in the Loess Plateau region, and most likely was the driving force for the ecological shift at about 3.7 Ma.  相似文献   

16.
植物多样性对维持生态功能的稳定发挥具有重要作用。以黄土高原不同植被带草地为研究对象,基于野外调查和实验分析,探究黄土高原不同植被带草地植物多样性与群落稳定性特征和二者之间的关系以及影响因素。结果表明:黄土高原草地群落结构特征(地上生物量、地下生物量)与植物多样性具有明显的纬度分布格局,草地植物多样性和生物量均表现出自东南向西北沿森林草原带—森林带—草原带—草原荒漠带逐渐递减趋势。森林草原带草地植物多样性和群落稳定性显著高于森林带、草原带和草原荒漠带;植物多样性与群落稳定性之间存在显著正相关关系,可以作为衡量群落稳定性的指标,其稳定性大小表现为森林草原带>森林带>草原带>草原荒漠带。降雨量是影响植物多样性和群落稳定性的主要因素,并通过改变土壤含水量影响群落稳定性。研究结果揭示了草地植物多样性与群落稳定性之间的关系及驱动机制,为维持黄土高原草地生态系统的群落稳定性提供了科学依据。  相似文献   

17.
黄土高原近10年植被覆盖的动态变化及驱动力   总被引:8,自引:0,他引:8  
肖强  陶建平  肖洋 《生态学报》2016,36(23):7594-7602
基于Timesat的非对称高斯函数(AG)拟合法重建MODIS-NDVI数据,利用像元二分模型估算了黄土高原近10年的植被覆盖度(VC),并分析了年植被覆盖度的变化趋势和其与降水温度的相关性。研究结果表明:黄土高原植被覆盖度总体上呈现东南高西北低、由东南向西北递减的特征。其中森林生态系统平均覆盖度最高,灌木、草地生态系统次之,荒漠生态系统最低,空间差异明显。2010年森林生态系统植被覆盖度达到81.6%,主要包括太行山、吕梁山和秦岭地区。暖温带森林区植被组成以落叶阔叶林为主,覆盖度常年较高,为80%以上。西北部温带草原区,植被覆盖度达到38.8%。温带草地主要依水分梯度,由东南到西北分布有以旱生性多年生草本植物为主的典型草原,植被覆盖度呈现相应的递减趋势。黄土高原总面积78.6%的地区年植被覆盖度呈增加趋势;而占总面积19.4%的地区年植被覆盖度呈下降趋势。在空间分布上,植被覆盖度显著增加的区域主要分布在榆林至延安周边地区和秦岭一带;植被覆盖度显著减少区域沿兰州至银川呈条带状分布。  相似文献   

18.
董雪蕊  张红  张明罡 《生物多样性》2019,27(12):1269-780
黄土高原地区植被类型多样, 森林、草原和荒漠在此交汇并逐渐过渡。由于水热条件限制和人类活动加剧, 该地区生态环境脆弱, 生物多样性保护面临的形势日益严峻, 因此获取该区域物种多样性的空间分布格局并阐明其影响因素成为该地区生物多样性保护的首要任务。本研究首先结合标本采集记录与环境因子, 利用物种分布模型获取了293种木本植物的潜在分布区, 分析了物种丰富度和物种加权特有性的空间格局。其次, 引入系统发育信息, 分析系统发育多样性和系统发育特有性的空间格局, 并进一步利用环境因子对上述格局分别进行解释。最后, 对黄土高原地区的特有中心性质和显著性进行分析。结果表明, 生物多样性热点地区均出现在黄土高原南部水热条件较好的地区, 即秦岭和中条山一带。本区域的生物多样性空间格局由年平均降水量和最冷月最低温主导, 符合植物区系交汇带的特点。特有中心集中在南部地区和青海省, 由南向北分别是古特有中心和混合特有中心, 不存在单独的新特有中心。黄土高原地区木本植物起源较为古老, 生物多样性格局的形成以来源于热带或亚热带的物种扩散为主, 物种的分化不占主导地位。上述结果表明了将植物的进化历史纳入生物多样性保护的重要性。  相似文献   

19.
Ecogeographical regionalization is the basis for spatial differentiation of biodiversity research. In view of the principle of international ecogeographical regionalization, this study has applied multivariate analysis and GIS method and based on some ecogeographical attributes limited to the distribution of plant and vegetation, including climatic factors, such as minimum temperature, mean temperature of the coldest month, mean temperature of the wannest month, annual average temperature, precipitation of the coldest month, precipitation of the wannest month, annual precipitation, CV of annual precipitation, biological factors such as vegetation types, vegetation division types, NPP, fiorisitic types, fauna types, abundance of plant species, genus and endemic genus; soil factors such as soil types, soil pH;topographical factors as longitude, latitude and altitude etc. The ecogeographical regionalization for biodiversity in China was made synthetically by using fuzzy cluster method. Four classes of division were used, viz., biodomain, subbiodomain, biome and bioregion. Five biodomains, seven subbiodomains and eighteen biomes were divided in China as follows: Ⅰ Boreal forest biodomain. Ⅰ A Eurasian boreal forest subbiodomain. Ⅰ A1 Southern Taiga mountain cold-temperate coniferous forest biome; Ⅰ A2 North Asian mixed coniferous-broad-leaved forest biome. Ⅱ Northern steppe and desert biodomain. Ⅱ B Eurasian steppe subbiodomain. Ⅱ BI Inner Asian temperate grass steppe biome; Ⅱ B2 Loess Plateau warm-temperate forest/shmb steppe biome. Ⅱ C Asia-Mrica desert subbiodomain. Ⅱ C1 Mid-Asian temperate desert biome; Ⅱ C2 Mongolian/Inner Asian temperate desert biome. Ⅲ East Asian biodomain. Ⅲ D East Asian deciduous broad-leaved forest subbiodomain. Ⅲ D1 East Asian deciduous broad-leaved forest biome, Ⅲ E East Asian evergreen broad-leaved forest subbiodomain. Ⅲ El East Asian mixed deciduous-evergreen broad-leaved forest biome; Ⅲ E2 East Asian evergreen broad-leaved forest biome; Ⅲ E3 East Asian monsoon evergreen broad-leaved forest biome; Ⅲ FA Western East Asian mountain evergreen broadleaved forest biome. Ⅳ Palaeotropical subdomain. IV F India-Malaysian tropical forest subbiodomain.Ⅳ Fl Northern tropical rain forest/seasonal rain forest biome; Ⅳ F2 Tropical island coral reef vegetation biome. Ⅴ Asian plateau biodomain. Ⅴ G Tibet Plateau subbiodomain. Ⅴ G1 Tibet alpine highcold shrub meadow biome;Ⅴ G2 Tibet alpine high-cold steppe biome; Ⅴ G3 Tibet alpine high-cold desert biome; Ⅴ G4 Tibet alpine temperate steppe biome; Ⅴ G5 Tibet alpine temperate desert biome.  相似文献   

20.
Understanding terrestrial vegetation dynamics is a crucial tool in global change research. The Loess Plateau, an important area for the study of Asian monsoons and early agriculture, poses a controversial question on the potential vegetation and its pattern. Fossil charcoal as direct evidence of wood provides precision in species identification and hence vegetation reconstruction. Charcoals from the Dadiwan and Xishanping sites suggest a great variety of plants between 5200 and 4300?cal. b.p. in the valley area of the western Loess Plateau. The deciduous broad-leaf wood from Quercus, Ulmus, Betula, Corylus and Acer is very frequent and makes up almost half the total abundance ratio of the represented taxa. Meanwhile, some typical subtropical taxa such as Liquidambar formosana, Eucommia ulmoides, Toxicodendron and Bambusoideae, are present at the two study sites. The high abundance of Picea appearing between 5200 and 4300?cal. b.p. suggests the development of Picea forests in the valley of the western Loess Plateau. The assemblages of charcoal indicate that the mixed forest of evergreen deciduous and conifer-deciduous broadleaved trees developed in the valley of the Loess Plateau during the Holocene optimum. Precipitation is the main controlling factor for forest development. The increasing precipitation is the probable reason for the appearance of north-subtropical forests between 5200 and 4300?cal. b.p.  相似文献   

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