内蒙古中部表土花粉研究

采用花粉百分含量分析和主成分分析方法对内蒙古中部表土花粉与植被的关系进行了对比研究 ,探讨了草原花粉组合的特点及其形成原因。研究发现 ,草原区表土花粉以藜科和蒿属 ( Artemisia)为主 ,并以前者占优势地位 ,麻黄属 ( Ephedra)亦较常见。草原区植被的 A/C(蒿属 /藜科 )值较干旱区草原植被为低 ,分布规律也较干旱区复杂 ,但仍能反应干旱程度的差别 ,而且还反映了草原植被的退化程度。松属 ( Pinus)和桦属 ( Betula)的花粉在个别样品中占有较大比例 ,是环境噪音 (指外源性的、超代表性的花粉 )的主要来源。不同植被类型在花粉组合上各有特点 ,可以从花粉百分含量的数量特征上进行区分。在研究中还发现草原区的严重退化在花粉组合上具有明显表现     

内蒙古锡林郭勒草原大针茅-克氏针茅群落的种间关联特征分析

内蒙古锡林郭勒草原处于我国典型草原分布区, 但部分地区有戈壁针茅(Stipa gobica)等荒漠成分侵入, 并与大针茅(S. grandis)和克氏针茅(S. krylovii)共同形成斑块状格局分布, 目前尚不清楚群落中优势种之间的相互作用关系。采用2 × 2列联表, 通过方差分析、Pearson相关分析和Spearman秩相关分析等研究方法, 对大针茅+克氏针茅群落的大针茅斑块、克氏针茅斑块和戈壁针茅斑块中的24种主要植物的种间联结动态进行了定量分析。结果表明: 1)群落主要成分总体上种间联结呈无关联, 种间关联松散; 2) 3种针茅斑块的种间关联分析, 验证了由于干扰、竞争、土壤环境与植物相互作用形成的斑块分布格局, 此结果为种对正、负关联理论提供了有力证据; 3) 同一种对的联结性质(正关联或负关联)或关联程度因斑块不同而发生改变, 根据24个优势种群对环境的适应方式和主导生态因素, 可将它们划分为3大生态种组。     

Numerical Characteristics of Pollen Assemblages of Surface Samples from the West Kunlun Mountains

A total of 31 suface sediment samples were collected from West Kunlun Mountain in south Xinjiang Autonomous Region in northwest China. These samples are from seven types of vegetation: Picea schrenkiana Fisch. et Mey. forest, Sabina Spach. woodland, sub-alpine steppe, alpine meadow, desert vegetion, cushion-vegetation and vegetation adjancent to glaciers. Pollen percentages and pollen concentrations were calculated in all samples. The dominant pollen types in the region are Chenopodiaceae, Artemisia, Picea, Ephedra, Gramineae, Cyperaceae, Rosaceae, Leguminosae, Compositae etc. In order to reveal the relationship between pollen composition and the vegetation type from which the soil sample was collected, principal component analysis and group average cluster analysis were employed on the pollen data. The results revealed that the major vegetation types in this region could be distinguished by pollen composition: a. Samples from desert vegetation were dominated by pollen of Chenopodiaceae (about 60195%). The percentages of all other pollen types were low. b. Picea forest samples were rich in Picea pollen (about 20%) Sabina forest had more Sabina pollen grains than other vegetation types (about 5%, others <1%). Pollen percentages of Artemisia, Chenopodiaceae and Ephedra were comparatively higher (each about 20%) in these samples from the two types of vegetations. C. Pollen percentages of Artemisia, Cyperaceae, Gramineae and Chenopodiaceae were high in both sub-alpine steppe and alpine meadow. But steppe containal more Artemisia and Chenopodiaceae (steppe 33.75% and 32.30%, meadow 15.57% and 19.48% in average), less Cyperaceae and Gramineae (steppe 2.58% and 7.60%, meadow 22.35% and 12.93% in average) than meadow. d. Samples from cushion-vegetation and vegetation adjacent to glaciers were mainly composed of pollen grains transported from other sites. It was not easy to distinguish them from other vegetation types. Principal component analysis and cluster analysis distinguish samples from Picea forest, Sabina woodland, sub-alpine steppe, alpine meadow and desert vegetation. Therefore we think it will be possible to apply the module to reconstruct past vegetation in this region and other similar regions. Regression analysis was also applied to reveal the relationships between pollen and plant percentages of Artemisia, Chenopodiaceae, Cyperaceae and Gramineae. The results indicated that a linear relationship existed between pollen and plant percentages for Artemisia, Chenopodiaceae and Cyperaeeae.     

内蒙古草原草场放牧退化模式研究及退化监测专家系统雏议

本文将定位研究与路线考察相结合,将放牧影响下草原的动态演替及其在牧压梯度上的空间变化相对比,研究了内蒙古主要草原草场的放牧退化模式,并在此基础上初步探讨了判别草场退化的数量指标和退化监测专家系统。1)植物种与牧压关系的分析,区别出放牧的定性和定量指示植物及宜中牧植物,并划分植物为不同的放牧生态种组。2)退化草原恢复过程的研究表明,根茎禾草的恢复快于丛生禾草;群落恢复过程是单稳态的,且恢复演替动态与其牧压梯度上的空间变化相对应。3)内蒙古高原主要草原草场在持续放牧影响下均趋同于冷蒿(Artemisia frigida)草原。冷蒿是最可靠的正定量放牧指示植物,但同时又是优良牧草和草原退化的阻击者。4)讨论了草原草场退化的概念,论述了草原逆向演替与草场退化的区别和联系,提出了区分草原的逆向演替为草场熟化和退化两个过程,并依草场群落与牧压的关系建立了判定草场是否退化及退化程度的数量指标。5)初步设计了草原草场退化监测—决策专家系统,包括监测、判别和决策三个步骤。     

内蒙古中部四子王旗荒漠草原过渡带表土花粉分析

通过研究内蒙古中部四子王旗地区的表土花粉,试图揭示荒漠草原地区小尺度范围中表土花粉的植被和气侯指示意义.源自4个不同植物群落的19块表土花粉显示:研究区表土花粉组合主要以草本植物蒿属(Artemisia)、藜科(Chenopodiaceae)花粉占优势,两者百分含量一般在60%以上;禾本科(Poaceae)花粉具低代表性,平均含量在5%左右;另含有一定数量的白刺属(Nitraria)、麻黄属(Ephedra)、菊科(Asteraceae)和葱属(Allium)等花粉为特征.笔者首次提出的(蒿属+禾本科+菊科)/(白刺属+麻黄属+藜科)百分比值,有效地揭示了研究区北部较南部要干旱,与A/C比值及当地现生植被生境和气候因子相吻合.研究结果对我国内陆干旱、半干旱荒漠草原区第四纪古植被的恢复,以及古气候的重建提供了参照依据.     

西藏扎布耶盐湖地区现代花粉雨的初步研究

从扎布耶盐湖和藏南地区采集的２１块表土花粉分析结果,提供了花粉与植被,花粉与亚环境之间的定性关系,在扎耶盐湖,ａ泉水沼泽,以莎草科花粉占优势。ｂ．盐盘,藜科和麻黄属花粉含量高。ｃ．山坡,分布变色锦鸡儿灌丛,表土花粉以蒿属和藜科为优势。ｄ．河流沙滩,以蒿属和禾本科花粉为主,ｅ．常年盐湖,以蒿属占优势,松属、云杉属、冷杉属、铁杉属、桦属和桤木属等乔木植物花表土中普遍存在。以松粉百分含量最高（平均２６．     

A survey of modern pollen and vegetation along a south–north transect in Mongolia

Aim This modern pollen‐rain study documents the spatial and quantitative relationships between modern pollen and vegetation in Mongolia, and explores the potential for using this relationship in palaeoclimatic reconstructions. Location East‐central Mongolia. Methods We collected 104 pollen surface samples along a south–north transect across five vegetation zones in Mongolia. Discriminant analysis was used to classify the modern pollen spectra into five pollen assemblages corresponding to the five vegetation zones. Hierarchical cluster analysis was used to divide the main pollen taxa into two major groups and seven subgroups representing the dry and moist vegetation types and the main vegetation communities within them. Results Each vegetation zone along the transect can be characterized by a distinctive modern pollen assemblage as follows: (1) desert zone: Chenopodiaceae–Zygophyllaceae–Nitraria–Poaceae pollen assemblage; (2) desert‐steppe zone: Poaceae–Chenopodiaceae pollen assemblage; (3) steppe zone: Artemisia–Aster‐type–Poaceae–Pinus Haploxylon‐type pollen assemblage; (4) forest‐steppe zone: Pinus Haploxylon‐type–Picea–Artemisia–Betula, montane forb/shrub and pteridophyte pollen assemblage; and (5) mountain taiga zone: Pinus Haploxylon‐type–Picea–Poaceae–Cyperaceae, montane forb/shrub and Pteridophyte pollen assemblage. Main conclusions Based on the ratio between the major pollen taxon groups and subgroups, we propose two pollen–climate indices that represent the precipitation and temperature conditions in the study region. When plotted along our south–north transect, the moisture indices (M) and temperature indices (T) mimic the regional gradients of precipitation and temperature across Mongolia very closely. These pollen–climate indices can be used for palaeoclimatic reconstruction based on fossil pollen data.     

末次盛冰期以来沙漠-黄土过渡带植被演替及其对气候变化的响应

末次盛冰期(LGM)以来的增温期和全新世高温期是人类古文化进步的重要时期。黄土高原北部沙漠-黄土过渡带两个自然剖面高分辨率花粉分析结果显示,该区LGM以来为草原植被景观,但优势群落和伴生植物随气候变化而有所不同,温度和降水变化对植被演替有着重要的控制作用。气候干冷时,以耐干旱的草本植物种属为主,群落成分单一,植被盖度低;增温期和高温期,出现少量暖温带乔木植物如胡桃科、栎属等,植被盖度高,群落发育良好。全新世暖期是植被发育良好、植被盖度高的适宜期。本研究为黄土高原地区未来增温下植被响应的分析提供了历史相似型。     

内蒙古克氏针茅草原植物物候及其与气候因子关系

 植物物候作为气候变化敏感的生物圈指示计, 已经成为全球变化研究的热点。利用1985~2002年地面物候观测数据, 构建了内蒙古克氏针茅(Stipa krylovii)草原植物物候的时间序列谱, 并分析了植物物候的时间变异与气候因子之间的相关关系。结果表明: 1) 从1985~2002年内蒙古克氏针茅草原的气候朝着暖干趋势发展, 主要表现在春、夏气温的显著性增加与秋季(9月)降水的显著性减少; 2) 主要植物物候的变化整体呈返青期推后其它物候期提前趋势; 3) 植物生长盛期(7、8月)对气候变化最敏感; 4) 光照和温度是影响内蒙古克氏针茅草原植物物候格局的主要因素, 年内最寒冷的1月月均温和2、3月的光照对春季返青期具有负效应, 而其它物候期与7、8月的光照则呈显著的负相关关系, 6、7月的降水对发育盛期的花序形成、抽穗与开花具有显著的负效应, 8、9月的降水量能显著推后枯黄期的结束, 从而有利于生长季的延长。     

锡林郭勒草原1983～1999年NDVI逐旬变化量与气象因子的相关分析

 陆地生态系统对气候变化的响应关系一直是全球变化研究的热点。大量研究表明表征植被生长状况的遥感植被指数——NDVI与温度、降水的相关性非常高。但这些研究都忽略了NDVI 数据本身的累积性,而这一点对研究较短时间尺度上植被生长与气候因子间的关系尤为重要。因此,本文提出应以NDVI的变化量序列取代一般研究中使用的NDVI时间序列数据。基于该论点,该文采用1983～1999年NOAA/AVHRR的NDVI逐旬变化量数据序列对锡林郭勒盟草原的草原植被生长与气象因子的相互关系进行了研究。研究结果表明：1）NDVI变化量与气象因子之间的相关性最高的时间段为植被生长过程中NDVI增长阶段部分,这一时期草原植被的生长对气候反映最为敏感,在衰败阶段,其相关性比较弱;2）在典型草原,温度和降水与NDVI变化量的相关性随其主要植被类型的不同而不同,在以羊草（Leymus chinensis ）为主的典型草原,温度比降水的影响作用高;而在以克氏针茅（Stipa krylovii）为主的典型草原,降水的影响高于温度;在大针茅（Stipa grandis）为主的草原,两者与NDVI变化量的相关性相差不大。而在荒漠草原,降水是最主要的影响因子,同期的温度作用并不显著; 3）无论是典型草原还是荒漠草原,该地区草原植被的生长对同期的降水反应最为敏感,而非前期。而在荒漠草原以及以旱生性较强的克氏针茅为主的典型草原,温度对NDVI变化量会有较明显的时滞效应;4）在温度升高、降水基本不变的情况下,典型草原和荒漠草原 N DVI变化量对温度的响应能力都有所提高,降水的响应能力则变化不大。     

刈割对克氏针茅草原群落优势与亚优势植物的影响

基于内蒙古中部克氏针茅草原长期刈割试验,分析了不同留茬高度下克氏针茅草原植物群落中5个优势及亚优势种地上生物量和群落稳定性的变化.结果表明：留茬高度在10 cm以上时对5种植物地上生物量的影响较小.留茬高度为10 cm适于冷蒿生长,而不利于克氏针茅的生长.糙隐子草在留茬高度为2 cm时表现最佳.黄囊苔草对群落的贡献在留茬高度为5 cm时最大,此时其生物量与刈割年限呈正相关.留茬高度为2和15 cm不利于星毛委陵菜生长.植株较高、竞争力强的多年生植物对干扰的耐受能力较强,刈割的留茬高度不低于10 cm时,有益于维持草原生态系统的稳定性.     

Correlation analysis of Normalized Different Vegetation Index (NDVI)difference series and climate variables in the Xilingole steppe,China from 1983 to 1999

There is a crucial need in the study of global change to understand how terrestrial ecosystems respond to the climate system.It has been demonstrated by many researches that Normalized Different Vegetation Index (NDVI)time series from remotely sensed data,which provide effective information of vegetation conditions on a large scale with highly temporal resolution,have a good relation with meteorological factors.However,few of these studies have taken the cumulative property of NDVI time series into account.In this study,NDVI difference series were proposed to replace the original NDVI time series with NDVI difference series to reappraise the relationship between NDVI and meteorological factors.As a proxy of the vegetation growing process,NDVI difference represents net primary productivity of vegetation at a certain time interval under an environment controlled by certain climatic conditions and other factors.This data replacement is helpful to eliminate the cumulative effect that exist in original NDVI time series,and thus is more appropriate to understand how climate system affects vegetation growth in a short time scale.By using the correlation analysis method,we studied the relationship between NOAA/AVHRR ten-day NDVI difference series and corresponding meteorological data from 1983 to 1999 from 11 meteorological stations located in the Xilingole steppe in Inner Mongolia.The results show that:(1)meteorological factors are found to be more significantly correlation with NDVI difference at the biomass-rising phase than that at the falling phase;(2)the relationship between NDVI difference and climate variables varies with vegetation types and vegetation communities.In a typical steppe dominated by Leymus chinensis,temperature has higher correlation with NDVI difference than precipitation does,and in a typical steppe dominated by Stipa krylovii,the correlation between temperature and NDVI difference is lower than that between precipitation and NDVI difference.In a typical steppe dominated by Stipa grandis,there is no significant difference between the two correlations.Precipitation is the key factor influencing vegetation growth in a desert steppe,and temperature has poor correlation with NDVI difference;(3)the response of NDVI difference to precipitation is fast and almost simultaneous both in a typical steppe and desert steppe,however,mean temperature exhibits a time-lag effect especially in the desert steppe and some typical steppe dominated by Stipa krylovii;(4)the relationship between NDVI difference and temperature is becoming stronger with global warming.     

RAPD analysis of genetic diversity and population genetic structure of Stipa krylovii Reshov. in Inner Mongolia steppe

Random amplified polymorphic DNA (RAPD) analysis was used to characterize the genetic diversity and population genetic structure of Stipa krylovii populations in Inner Mongolia steppe of North China. Thirteen 10 bp oligonucleotide primers, which generated 237 RAPD bands, were used to analyze 90 plants of five populations from three regions, meadow steppe, typical steppe and desert steppe, from the east to the west. The genetic diversity of Stipa krylovii that was revealed by observed number of alleles (na), expected number of alleles (ne), Nei's diversity index (h), Shannon's diversity index (H), amplificated loci, polymorphic loci and the percentage of polymorphic loci (PPB) increased from the east to the west. The Pearson's correlation analysis between genetic diversity parameters and ecological parameters indicated that the genetic diversity of Stipa krylovii was associated with precipitation and cumulative temperature variations along the longitude (humidity were calculated by precipitation and cumulative temperature). Dendrogram based on Jaccard's genetic distance showed that the individuals from the same population formed a single sub-group. Although most variation (56.85%) was within populations, there was high genetic differentiation among populations of Stipa krylovii, high differentiation within and between regions by AMOVA analysis. Either Nei's unbiased genetic distance (G(ST)) or gene flow (Nm) among pairwise populations was not correlated with geographical distance by Mantel's test (P > 0.05), suggesting that there was no consistency with the isolation by distance model in these populations. Natural selection may have played a role in affecting the genetic diversity and population structure, but habitat destruction and degradation in northern grassland in China may be the main factor responsible for high genetic differentiation among populations, within and among regions.     

新疆艾比湖小叶桦湿地3900年以来的植被及环境演变

在新疆艾比湖小叶桦湿地取得深度190 cm的地层剖面,结合具有较高时间分辨率的孢粉数据和AMS 14C测年揭示出该研究区3900年以来植被和环境演变的动态.在3420-3940 cal.aBP期间,该区为以藜科和蒿属植物为主的荒漠景观;2830-3420 cal.aBP时段,局域的优势种变为沼泽蕨,周围仍是以藜科和蒿属...     

内蒙古中东部草原区克氏针茅种群遗传分化的RAPD研究

采用 RAPD-PCR技术对内蒙古中东部草原分布的 7个克氏针茅 (Stip a krylovii Roshev.)种群进行了分析。从 10 0个 10碱基随机引物中筛选出 2 1个有效引物 ,共扩增出 2 2 9条稳定的 DNA带 ,其中 171条带具有多态性 ,多态性百分比 (PPB)为74.67%。将每个扩增产物看作一个独立的性状 ,按其有无列出二元数据矩阵 ,计算 Jaccard、简单匹配系数 (SM)和 Dice遗传相似性系数 ,通过 UPGMA法构建分子标记聚类图 ;并通过主成分分析 (PCA)和主轴法分析 (PAF) ,将 7个种群分类 ;统计各个种群特异性 DNA带 ,计算占总扩增条带的百分数。结果表明 :(1)不同地理种群之间扩增结果差异明显 ,具有丰富的遗传多样性 ;(2 )不同地理种群间存在一定程度的分化 ,这种分化是与种群之间的实际距离相联系的 ,相距越远 ,种群相似程度越低 ,进一步分析表明种群的分化是与所处生境逐渐旱化相一致的 ;(3 )聚类图上将 7个种群分为 3类 ,PCA和 PAF分析通过 3个成分或因子也将 7个种群分为 3类 ,支持了聚类图的分类结果 ;(4)特异性位点所占百分比与种群所处生境也有一定的联系 ,它与环境干燥度的相关系数为 0 .76(P<0 .0 5)。     

Anthropogenic and climatic impacts on surface pollen assemblages along a precipitation gradient in north‐eastern China

Aim To understand the scenarios of ‘anthropogenic biomes’ that integrate human and ecological systems, we need to explore the impacts of climate and human disturbance on vegetation in the past and present. Interactions among surface pollen, modern vegetation and human activities along climate and land‐use gradients are tested to evaluate the natural and anthropogenic forces shaping the modern vegetation, and hence to aid the reconstruction of vegetation and climate in the past. This in turn will help with future predictions. Location The North‐east China Transect (NECT) in north‐eastern China. Methods We analysed 33 surface pollen samples and 213 quadrats across four vegetation zones along the moisture/land‐use gradients of the NECT. Detrended correspondence analysis (DCA) and redundancy analysis (RDA) of 52 pollen taxa and three environmental variables were used to distinguish anthropogenic and climatic factors that affect surface pollen assemblages along the NECT. Results The 33 surface samples are divided into four pollen zones (forest, meadow steppe, typical steppe and desert steppe) corresponding to major vegetation types in the NECT. Variations in pollen ratios of fern/herb (F/H), Artemisia/Chenopodiaceae (A/C) and arboreal pollen/non‐arboreal pollen (AP/NAP) represent the vegetation and precipitation gradient along the NECT. DCA and RDA analyses suggest that surface pollen assemblages are significantly influenced by the precipitation gradient. Changes in the abundance of Chenopodiaceae pollen are related to both human activities and precipitation. Main conclusions Surface pollen assemblages, fossil pollen records, archaeological evidence and historical documents in northern China show that a large increase of Chenopodiaceae pollen indicates human‐caused vegetation degradation in sandy habitats. The A/C ratio is a good indicator of climatic aridity, but should be used in conjunction with multiple proxies of human activities and climate change in the pollen‐based reconstruction of anthropogenic biomes.     

内蒙古典型草原克氏针茅与冰草的生存策略

在内蒙古自治区多伦县中科院植物所生态恢复试验站,选择优势种克氏针茅(Stipa krylovii) 和冰草（Agropyron cristatum）,使用Li-6400便携式光合测定系统观测光合生理生态特征的生长季变化(DOY155-265)。结果表明：水分是本区域植物生长的最重要的限制因子。冰草与针茅受5cm和20cm表层土壤含水率的影响较大。水分是本区域植物生长的最重要的限制因子。冰草与针茅受5cm和20cm表层土壤含水率的影响较大。植物的光合速率和蒸腾速率受自身的气孔导度限制,光合速率和蒸腾速率随气孔导度的增大而增大,冰草这一特征较为明显,即冰草对环境响应更为敏感。作为优势种冰草和针茅的生态适应策略并不相同,针对当地现有环境条件,针茅更具生存优势。随着全球环境变化,干旱胁迫对草原生态系统产生了重大影响,使得这些地区成为响应环境变化的敏感区域,通过对半干旱温带草原优势种克氏针茅和冰草对光、水等环境资源的利用及之间的关系研究,有助于我们对全球环境变化提出本区域合适的应对策略。     

阴山山脉东段花粉通量及其与表土花粉比较研究

阴山山脉东段蛮汉山和大青山山顶草甸、桦木林、虎榛子灌丛、人工油松林及杂草草原5个植被类型花粉通量与表土花粉对比研究发现,不同植被类型及同一植被类型不同样点花粉通量和花粉浓度差异明显,捕捉器样品花粉源区面积小于表土样品,能较好地反映样品点周围植被组成,但受虫媒植物和局地植物花粉影响,与表土样品花粉组合差异明显;表土样品中松属、桦属、蒿属及藜科花粉含量多高于捕捉器样品,表明这些花粉不仅易于传播,而且在表土中具有较强的保存能力;禾本科花粉具低代表性,花粉保存能力较低.地层花粉分析中应引起注意.     

新疆巴里坤湖8.8cal.kaBP以来植被演替的花粉记录

本文利用新疆东部巴里坤盆地内巴里坤湖的地层孢粉记录,结合14C定年,重建了该地区8.8cal.kaBP以来植被的演化历史.结果表明在8.8-8.0cal.kaBP、8.0-4.3cal.kaBP、4.3-3.8cal.kaBP、3.8-0.6cal.kaBP以及0.6cal kaBP至今,植被分别经历了荒漠、荒漠草原/草原、荒漠、荒漠草原/草原再到荒漠的演化过程.研究区中全新世以来的这种植被变化模式与亚洲中部干旱区的其它研究记录具有很好的一致性.     

西藏羊湖地区近1.4万年以来孢粉植物群及古气候研究

通过对西藏羊湖地区ZK1和卡拉苏代牙剖面（IP16）的孢粉分析和总有机碳（TOC）、元素含量分析等,建立了羊湖地区近1.4万年以来的孢粉组合带、重建当时的植被类型及古气候演变序列。结果显示：该时期经历了5次植被类型的更替,即草原型→疏林草原型→草原型→疏林草原型→草原型,与之相对应的气候经历了5次波动（2个半旋回）, 即11 220 a.B.P.左右的第一气候旋回：由干旱→半干旱半湿润转化;8 970a.B.P.左右的第二气候旋回,同样由干旱→半干旱半湿润转化,然后进入半个气候旋回,即干旱气候期,推测今后有可能进入半干旱半湿润气候期。