中国沙棘(Hippophae rhamnoides subsp. sinensis)天然群体的遗传变异分析

近十年，植物群体遗传学的研究飞速发展，然而与海拔相关的植物群体遗传结构和遗传变异研究却相对较少。到目前为止，还不清楚遗传变异与海拔之间是否有一个通用的格局。在山区，各种生态因子，如温度、降水、降雪、紫外线辐射强度以及土壤成分都随海拔梯度急剧变化，造成了即使在一个小的空间区域，植被类型变化显著，这种高山环境的异质性和复杂性为我们研究植物群体遗传结构和分化提供了方便。沙棘(Hippophea)属于胡颓子科(Elaeagnaceae)为多年生落叶灌木或乔木，雌雄异株，天然种群分布极为广泛。中国沙棘(H. rhamnoides subsp. sinensis)是沙棘属植物中分布较广的一个亚种，种内形态变异非常丰富，加之其具有独特的繁育系统和广泛的生态地理分布，是研究沙棘属植物遗传变异和系统分化的理想材料。本文从1,800 m 到3,400 m 分5 个海拔梯度进行取样，用RAPD 和cpSSR 分子标记研究了卧龙自然保护区中国沙棘天然群体的遗传结构和遗传变异。5 个取样群体依次标记为A、B、C、D 和E，它们分别代表分布在海拔1,800，2,200，2,600，3,000 和3,400 m 的5 个天然群体。RAPD实验用11 条寡核苷酸引物，扩增得到151 个重复性好的位点，其中143 个多态位点，多态率达94.7%。在5 个沙棘群体中，总遗传多样性值(HT)为0.289，B群体内的遗传多样性值为0.315，这完全符合沙棘这种多年生、远交的木本植物具有高遗传变异的特性。5 个群体内遗传多样性随海拔升高呈低－高－低变异趋势，在2,200 m海拔处的B群体遗传多样性达最大值0.315，3,400 m海拔处的E群体则表现最小仅0.098。5 个群体间的遗传分化值GST＝0.406，也即是说有40.6%的遗传变异存在于群体间，1,800 m海拔处的A群体与其它群体的明显分离是造成群体间遗传分化大的原因。UPGMA聚类图和PCoA散点图进一步确证了5 个群体间的关系和所有个体间的关系。最后，经过Mantel检测，遗传距离与海拔表现了明显的相关性(r = 0.646, P = 0.011)。cpSSR 实验中，经过对24 对cpSSR 通用引物筛选，11 对引物能扩增出特异性条带，只有2 对引物(ccmp2 和ARCP4)呈现多态性。4 个等位基因共组合出4 种单倍型，单倍型Ⅰ出现在A 群体的所有个体和B 群体的8 个个体中，C、D、E 三个群体均不含有，而单倍型Ⅱ出现在C、D、E 三个群体的所有个体及B 群体的18 个个体中，A 群体不含有。另外两种单倍型Ⅲ和Ⅳ为稀有类型，仅B 群体中的4 个个体拥有。这种单倍型分布模式和TFPGA 群体聚类图揭示了，C、D、E 群体可能来源于同一祖先种，而A 群体却是由另一祖先种发展起来的，B 群体则兼具了这两种起源种的信息，这可能是因为在历史上的某一时期，在中国沙棘群体高山分化的过程中，B 群体处某个或者某些个体发生了基因突变，具备了适应高海拔环境的能力，产生了高海拔沙棘群体的祖先种。 In recent ten years, studies about population genetics of plants developed rapidly,whereas their genetic structure and genetic variation along altitudinal gradients have beenstudied relatively little. So far, it is uncleared whether there is a common pattern betweengenetic variation and altitudinal gradients. In the mountain environments, importantecological factors, e.g., temperature, rainfall, snowfall, ultraviolet radiation and soil substratesetc., change rapidly with altitudes, which cause the vegetation distribution varying typically,even on a small spatial scale. The mountain environments, which are heterogeneous andcomplex, facilitate and offer a good opportunity to characterize population genetic structureand population differentiation.The species of the genus Hippophae L. (Elaeagnaceae) are perennial deciduous shrubs ortrees, which are dioecious, wind-pollinated pioneer plants. The natural genus has a widedistribution extending from Northern Europe through Central Europe and Central Asia toChina. According to the latest taxonomy, the genus Hippophae is divided into six species and12 subspecies. The subspecies H. rhamnoides ssp. sinensis shows significant morphologicalvariations, large geographic range and dominantly outcrossing mating system. Thesecharacteristics of the subspecies are favourable to elucidate genetic variation and systemevolution. To estimate genetic variation and genetic structure of H. rhamnoides ssp. sinensisat different altitudes, we surveyed five natural populations in the Wolong Natural Reserve at altitudes ranging from 1,800 to 3,400 m above sea level (a.s.l.) using random amplifiedpolymorphic DNA markers (RAPDs) and cpSSR molecular methods. The five populations A,B, C, D, and E correspond to the altitudes 1,800, 2,200, 2,600, 3,000 and 3,400 m,respectively.Based on 11 decamer primers, a total of 151 reproducible DNA loci were yielded, ofwhich 143 were polymorphic and the percentage of polymorphic loci equaled 94.7%. Amongthe five populations investigated, the total gene diversity (HT) and gene diversity within population B equaled 0.289 and 0.315, respectively, which are modest for a subspecies of H.rhamnoides, which is an outcrossing, long-lived, woody plant. The amount of geneticvariation within populations varied from 0.098 within population E (3,400 m a.s.l.) to 0.315within population B (2,200 m a.s.l.). The coefficient of gene differentiation (GST) amongpopulations equaled 0.406 and revealed that 40.6% of the genetic variance existed amongpopulations and 59.4% within populations. The population A (1,800 m a.s.l.) differed greatlyfrom the other four populations, which contributes to high genetic differentiation. A UPGMAcluster analysis and principal coordinate analyses based on Nei's genetic distances furthercorroborated the relationships among the five populations and all the sampling individuals,respectively. Mantel tests detected a significant correlation between genetic distances andaltitudinal gradients (r = 0.646, P = 0.011).Eleven of the original 24 cpSSR primer pairs tested produced good PCR products, onlytwo (ccmp2 and ARCP4) of which were polymorphic. Four total length variants (alleles) werecombined resulting in 4 haplotypes. The haplotype was present in all individuals of Ⅰpopulation A and 8 individuals of populations B, the other three populations (C, D and Epopulations) did not share. The haplotype was present in all individuals of populations C, D Ⅱand E and 18 individuals of populations B, population A did not share. The other twohaplotypes and were rare haplotypes, which were only shared in 4 individuals of Ⅲ Ⅳpopulation B. The distribution of haplotypes and TFPGA population clustering map showedthat the populations C, D and E might be origined from one ancestor seed and population Amight be from another, whereas population B owned information of the two ancestor seeds. Itwas because that gene mutation within some individual or seed in the location of population Bwas likely to happen in the history of H. rhamnoides, which was the original ancestor of thehigh-altitude populations.

彭州市白水河自然保护区生物多样性及种子植物区系研究

对白水河自然保护区进行了生物多样性和植物区系调查，根据获得的生物多样性数据和标本的鉴定结果分析，得到结果和推论如下：1．白水河自然保护区生物多样性的垂直分布格局1.1 植物群落α 多样性随海拔梯度的变化乔木种的丰富度及多样性随海拔上升表现出明显的线性下降趋势。而灌木和草本物种丰富度及多样性随海拔上升表现出抛物线式的下降趋势。乔木种从海拔1400m 的15 种至林线时下降为2 种；灌木和草本植物分别从35 和38 种至山顶时下降为5 种和20 种。乔木物种随海拔升高出现明显的物种替代现象，表明海拔梯度包含了多种环境因子的梯度效应，影响着植物群落的分布与结构及物种多样性。1.2 植物群落β 多样性随海拔梯度的变化海拔2200 m 左右是一个明显的生境转折点。海拔2200 米以下相邻群落的相似性( CJ ) 明显大于海拔2200 m 以上的群落，说明海拔2200 m 以下的群落间共有种多，生境差异较小；而海拔2200 以上的群落则相反，相似性较低。低海拔区由于人为干扰较大，所以群落具有较高的物种丰富度，相邻群落之间的物种替换总量(Cody 指数) 较大。海拔2800 米到海拔3200 米之间因杜鹃群落的影响，物种替换总量(Cody 指数) 略有升高。研究β 多样性沿海拔梯度的变化必须考虑到物种丰富度和群落类型的影响，用不同指数从不同角度能更好地理解β 多样性沿环境梯度的变化。2．白水河自然保护区植物区系性质及起源白水河自然保护区自产种子植物计138 科421 属990 种。本文在科、属的水平上对该保护区植物区系特性进行了较深入的统计和分析。统计表明，温带和热带分布型均占有相当比重，但温带分布型稍占优势；热带、亚热带和温带的科、属多，中国特有属也有相当比例，它们是保护区具有特征意义的类群，其中许多属为古老和残遗成分。结论认为白水河保护区植物区系起源古老，较完好的保存了北极－第三纪古植物群。We have collected the specimens and gotten the biodiversity datas of BaiShuihe Nature Reserve in Peng Zhou，analysed the datas，the results as follows：1. Diversity of the plant community along altitudinal gradient1.1 α diversity of the plant communities along altitudinal gradientFrom 1400m to 3900m at Baishuihe Nature Reserve, 52 plots were investigatedwith an interval 100m in altitude； α diversity and β diversity of plant communitiesand their variety along altitudinal gradient were studied. The results showed that indifferent successional layers of trees, richness and diversity decreased linearly withthe increase of altitude. But shrub and herb layers don’t decrease linearly with theincrease of altitude. Tree species decreased from 15 species at 1400m so only 2species at timberline. Shrub and herb species decreased from 35 and 38 species at2000m to 5 and 20 species at 3800m respectively. Tree species are replacedobviously with the increase of altitude； It shows that altitude includes manyenvironmental facts, which infect the distribution, structure and diversity of plant population.1.2 The variety of βdiversity along altitudinal gradient.The entironment changed obviously near 2200m according to our research. Forsimilarity(CJ) between neighboring plots above 2200m is larger than wich below it.It shows that below 2200m，the neighboring plots has more same species，and thehabitats of neighboring plots has more similarity. Above 2200 is the other way round.The plant communites have higher species richness and species turnoverlargestly between neighboring plots because of the disturbance from humanity at lowaltitude. Between 2800m and 3200m species turnover not so obviously because ofmore Rhododendron live there.We should think over species and the types of plant communities effect thevariety of β diversity along altitude gradient. Use more biodiversity indexs and fromseveral aspects to understand the variety of β diversity along altitudinal gradient.2.Origin and characteristic features of Bai Shuihe Nature Reserve990 species of wild seed plants (belonging to 421 generas in 138 families) inthe floristic region of Bai Shuihe Nature Reserve were reported here. The statisticsand comparatively intensive analysis at generic and familiar levelss. Based on thestatistics，the results show that both temperate and tropical distribution types areacounted for considerable proportion of the total，but formal is a little moreimportant than the later. The North Temperate and E.Asia-N.America disjunctedpatterns are more concentrated in this area. These may be considered as thecharacteristic features of Bai Shuihe Nature Reserve flora, while many of them arearchaic and relic elements. According to above data，the floristic region of BaiShuihe Nature Reserve may be considered as a typical region in Chinese flora. Also，the flora of Bai Shuihe Nature Reserve are originated since ancient time as a wellconserved Arctic-Tertiar flora.

四川九顶山西坡及龙肘山维管植物区系和植物多样性研究

横断山地区是一个十分自然的植物区系地区，在中国植物区系分区中是作为泛北极植物区中国-喜马拉雅亚区中的一个地区，其种子植物区系具有丰富的科、属、种，地理成分复杂，特有现象和替代现象明显。该地区作为植物区系和生物多样性的研究热点地区，长期以来极受中外植物学家关注。横断山脉东缘是中国-喜马拉雅和中国-日本植物区系的交汇过渡区域，北部的岷江流域以及南部的金沙江流域，孕育了该区丰富的物种资源和植被资源。而岷江干热河谷和金沙江干热河谷的相似性和相关性，更为该区的植物区系和生物多样性南北的对比研究提供了有利的条件。 本研究选择的九顶山西坡和龙肘山分别位于横断山区北部和南部，九顶山属岷江流域而龙肘山属金沙江流域。本研究结合植物区系研究和生物多样性研究，对该区的植物资源进行调查。通过样带调查和样线踏查结合，大量详实的野外样方调查和标本采集，进行传统的区系研究和生物多样性研究。研究该区物种多样性的海拔梯度格局及其潜在的影响影子，并利用新的区系评估质量方法对九顶山西坡的植物区系质量进行定量的研究，以期能更为深刻的理解该区的植物资源，为该区的资源保护和利用提供合理可行的建议。主要研究结论如下： 1）九顶山西坡植物区系的性质和特点 经鉴定和统计，九顶山西坡共有1707 种维管植物，分属617 属和140 科,其中种子植物1616 种，分属572 属117 科。就科的分布区成分构成而言，该区系的热带成分与温带成分相当，热带成分略占优势，表明九顶山西坡的植物区系与热带植物区系有较强的联系。但是，在九顶山西坡属的分布区类型所占的比例上，温带成分远远超过了热带成分，本区的种子植物分布表现出明显的温带性质。且温带分布类型的许多物种组成了九顶山西坡植被的建群种和优势种，是本区系最重要的成分，充分体现了本区系的温带性质。 2）九顶山西坡不同植被带的生物多样性海拔梯度格局 基于对土门-断头崖、茶山-九顶山、雁门沟-光光山三条垂直植被样带的调查，我们发现九顶山西坡的生物多样性沿海拔梯度的变化呈现出一定的规律性，不同样带之间有一定差异。就三条样带的物种组成相似性来看，虽然土门－断头崖样带属于涪江水系，而茶山－九顶山样带和雁门沟－光光山样带属于岷江水系，但不同水系对该区物种组成的影响并不明显。三条样带中，草本层物种丰富度均远远大于灌木层和乔木层，而以乔木层物种丰富度最低；α－多样性指数随着海拔梯度的变化在土门-断头崖样带中呈现单一下降趋势，在茶山-九顶山样带表现为双峰模型，而在雁门沟-光光山样带则表现为不显著波动变化；均匀度指数在土门-断头崖样带呈现出单一下降的趋势，在雁门沟-光光山样带表现为凹形曲线，而在茶山-九顶山样带却无明显的变化规律。β－多样性指数在土门-断头崖样带和茶山-九顶山样带呈现出明显的波动状态，植被类型替代现象明显；而在雁门沟-光光山样带却并未有十分显著的转折点，因其水平植被带受到干扰，同海拔替代现象不显著。 3）九顶山西坡维管植物丰富度的海拔梯度格局 我们考察了九顶山西坡和两条垂直样带（土门－断头崖和雁门沟－光光山样带）的不同分类等级（包括科、属、种）和不同生活型物种（乔木、灌木、禾草、蕨类和其它草本）的丰富度沿着海拔梯度的分布。结果发现，物种的丰富度海拔梯度格局具有不同的模式，单一下降和中间膨胀格局依然是其主流。不同生活型的物种具有不同的丰富度格局，但是对于环境需求相似的类型具有较相似的丰富度格局。不同的丰富度格局可能由多因素导致，包括：气候，海拔跨度，面积，人为干扰等等。 4）九顶山西坡区系质量评估 我们尝试使用传统的区系质量评估方法对九顶山西坡的区系质量进行评估，并尝试使用一种新的区系质量评估体系对该区的区系进行评价。在九顶山西坡随着海拔梯度的上升，平均保守性系数在各条植被带中均呈现出逐渐上升的趋势。区系质量指数随着海拔的升高都表现为双峰模型，在植被交错区区系质量指数相对较高，而在海拔的两极，区系质量指数都很低。大部分地区使用新方法计算所得的加权平均保守性系数和区系质量指数都比传统方法计算的平均保收性系数和区系质量指数要高，说明在九顶山西坡的三条样带中，大部分地区都是那些保守性系数较高的物种占据优势，同时也表明九顶山西坡具有很高质量的区系和自然植被。 5）龙肘山种子植物区系的性质和特点 龙肘山种子植物区系的物种较为丰富，共有154 科，544 属，1156 种。科的优势十分明显，单种属和寡种属数量众多，说明本区系植物成分较为复杂、起源古老、物种多样性指数较高。地理成分复杂，分布类型多样，其中热带成分在总数量上高于温带成分，但是许多温带成分的属是该区植被的重要建群类群和优势类群，表现出明显的亚热带性质。 6）龙肘山生物多样性的现状和特点 在海拔梯度上，龙肘山地区无论是科、属、种的数量，还是不同等级分类单元之间的数量比，均呈现先升后降的趋势，并在中海拔地区达到峰值。物种多样性指数从总体上来说变化幅度不大，略有先升后降的趋势，在中海拔梯度物种多样性最高。乔、灌、草三层的多样性指数表现出乔木层<灌木层<草本层的特征；乔木层均匀度的变化很大，而灌木层和草本层均匀度的变化较小；灌木层均匀度的波动又强于草本层。β－多样性指数呈现单峰模式，中海拔地区最高。就龙肘山东、西坡物种多样性相比较而言，两者虽然在数值上交替上升，但是却体现出了较为一致的趋势，但西坡因受到干热河谷气候的影响，其平均气温要高于东坡，导致了东坡植物群落和物种的分布比西坡要低。在区系成分构成上，低山区的相同海拔段，西坡的热带亚热带成分所占的比例要比东坡高，这是因为西坡的平均气温比东坡稍高，导致了热带、亚热带物种分布更多。而随着海拔的上升，东、西两坡的气候、土壤等条件趋于一致，其植物区系成分的构成格局也趋于一致。 The Hengduan Mountain region is a very natural floristic region; it belongs toChina-Himalaya sub-region of Holarctic region in floristic subarea of China. The flora in this areais rich in family, genus and species; has a very complex composition of geographical elements;especially with high richness of endemic species and obvious substitution phenomenon. Thisregion as a hot-spot area of floristic and biodiversity, has fascinated biologists in the world for along time. The eastern range of Hengduan Mountain is the transition zone of China – Himalayaforest sub-region and China-Japan forest sub-region in floristic. The water systems are quitedifferent, Minjiang River in the north and Jishajiang River in the south grow quit different but alsoabundant plant species and vegetation resources. The similarity and correlativity of Minjiang River dry valleys and Jinshajiang River dry valleys have provided advantageous condition tocontrast flora and biodiversity between north and south. In the present study, the Jiuding Mountainlies in the north of Hengduan Mountain and belongs to Minjiang River, and the LongzhouMountain lies in the south of Hengduan Mountain and belongs to Jinshajiang River. In our study, we combined the methods of floristic research and biodiversity investigation toexplore the resources of plant species and vegetations; sampled with transects along the altitudinalgradients and also with transverse straps with similar elevation; collected the vascular plant specimen with sampling plots of ecology. We explored the plant species richness patterns alongaltitudinal gradients and discussed the underlying factors aroused these patterns; and used a novelmethod to assess the quality of Jiuding Mountain’s flora. All for a deeper comprehension of the plant recourses of this region; and provided feasible and reasonable suggestion for the protectionof resources. The results were as follows: 1 The characteristic of the flora of the west slope of Jiuding Mountain We had collected 1707 species of vascular plants belonging to 617 genera in 140 families inthe west slope of Jiuding Mountain，in which included 1616 seed plant species belonging to 572genera and 117 families. As for the composition of the areal types of the Families of seed plants,tropic components and temperate components are well-balanced, and percentage of tropicscomponents is higher than that of temperate ones for a litter bit. This shows the flora in the westslope of Jiuding Mountain has strong relationship with the tropic flora. But for the composition ofthe areal types of genera, temperate components have far exceeded the tropics ones, indicated thewhole flora with a conspicuous temperate character. Temperate components possess maximumproportion in the west slope of Jiuding Mountain, and many of them belong to constructivespecies and dominant species in the vegetation, are most important components in JiudingMountain’s Flora, also have embodied the temperate character of this area sufficiently. 2 Biodiversity patterns along altitudinal gradients in different vegetation transects in the westslope of Jiuding Mountain Based on the investigation of three vegetation transects (including Tumen-Duantouya transect,Chashan-Jiudingshan transect and Yanmengou-Guangguangshan Transect) in the west slope ofJiuding Mountain, we found the change of biodiversity along the altitude gradients displayedcertain regularity, but have differences among different transects. The three transects belong todifferent water systems; the Tumen-Duantouya transect belongs to Fujiang River, and the othertwo belong to Minjiang River. From the similarity of species compositions of different transects,we found different water system didn’t show obvious impact on the species composition. In all thethree transects, the species richness of herb layer was remarkably higher than shrub and tree layer,and the species richness of tree layer was the lowest one. With the increasing of the altitude, theline of α-diversity was monotonically decreasing curve in Tumen-Duantouya transect, andbimodal curve in Chashan-Jiudingshan transect, but in Yanmengou-Guangguangshan transectshowed a wave-like curve although not very obvious. Species evenness showed monotonicallydecreasing trends in Tumen-Duantouya transect, and very low at mid-altitude in Yanmengou-Guangguangshan transect, but in Chashan-Jiudingshan transect changed irregularly. Changes inβ-diversity corresponded with the transition of vegetation in the Tumen-Duantouya transect andChashan-Jiudingshan transect, and the curve of β-diversity along altitude had obvious turningpoint; but in Yanmengou-Guangguangshan transect had no obvious turning point, and thesubstitution phenomenon was not obvious, transverse vegetation straps distributed interlaced. 3 Richness patterns of vascular plant species along altitude in the west slope of Jiuding Mountain Direct gradient analysis and regression methods were used to describe the species richnesspatterns along the altitudinal for Mt. Jiuding, as well as separately for Tumen-Duantouya Transectand Yanmengou-Guangguangshan Transect. Altitudinal gradient of diversity of units at differenttaxonomic level (including Family, Genus and Species) and at different life form (including tree,shrub, pteridophyte, grass and other herb) were tested to find differences among the richnesspattern. We found altitudinal richness also shows different patterns, and both monotonicallydecreasing pattern and hump-shaped pattern can be founded in vascular species richness. Speciesin different life forms show different altitudinal patterns, but those species with similarrequirements to environmental conditions show similar richness patterns along altitudinalgradients. Different richness patterns can be aroused by different climate, different altitudinal span,area factor, anthropogenic factor and so on. 4 Floristic quality assessments in the west slope of Jiuding Mountain We used both the conventional method broadly adopted in the USA and the new one toassess the floristic quality in the west slope of Jiuding Mountain. The Mean Coefficient ofConservatism (MC) had the trend of increment along the altitudinal gradients. The FloristicQuality Index (FQI) was a bimodal curve with increasing of elevation; FQI got maximum valuesin the transition zones of different vegetations in the middle altitude, and had very low values atthe two end of elevation. In most areas of the west slope of the Jiuding Mountain, the resultscalculated using the new methods were higher than those using the conventional method. Thisindicated the dominant species of the communities had very high coefficients of conservatism inmost areas of Jiuding Mountain, and the communities are relatively kept pristine and the habitats very integrative. 5 The characteristic of the flora of Longzhou Mountain The flora of Longzhou Mountain has very abundant in species composition; there are about1156 species of seed plants belonging to 544 genera in 154 families. In which, twelve families with more than 20 species include totally 232 genera and 532 species, and form the majority of itsflora. The origin of its flora is old, monospecific genera and oligotypic genera amounts to 510 innumber, which constitute 93.75% of total number of genera. The geographical components arevarious in Longzhou Mountain, the majority of flora are temperate and pantropic ones. The tropiccomponents overtopped temperate components on genera quantity, but many temperatecomponents belong to constructive species and dominant species in the vegetation, and the wholeflora shows an obvious subtropical character. 6 Current situation and characteristic of biodiversity in Longzhou Mountain With the increasing of altitude, the number of species, genus, family and the ratios ofdifferent taxonomic levels all displayed a trend of descending after rising first, and peaked atmiddle height area. The change of α-diversity was not very acutely, with the trend of descendingafter rising first in some degree, the middle height area had highest α-diversity. As studying thetree layer, shrub layer and herb layer respectively, the Shannon-Wiener index was in followingorder: tree layer < shrub layer < herb layer; the change of evenness was more complicatedly thanthat of diversity, the tree layer changed acutely, but the shrub layer and herb layer fluctuatedsmoothly. Changes in β-diversity also showed the trend of descending after rising first. TheJaccard index and Cody index all peaked at the middle height forest area. As for the comparison ofplant diversity and evenness between the west and east slope, the numerical values ascendedalternatively, but the trend of changing was similar. The distribution of similar plant communitiesand species in east slope were lower than the west slope for the influence of Jinsha River DryValley. As for the composition of different floristic components, in lower altitude area of westslope, the tropic and sub-tropic plants had higher ratio than east slope’s and even could be equal tothe temperate plants. With the increasing of elevation, the floristic composition become morelikely between the east and west slope and temperate plants dominated the flora.

中国西部亚热带常绿阔叶林木本植物小枝功能生态学初步研究

常绿阔叶林以其富饶的生物资源、丰富的生物多样性和巨大的生态与环境效益引起了人们越来越大的重视，它的研究已成为国际植被科学界关注的主题之一。我国分布着世界上面积最大的亚热带常绿阔叶林，在世界植被中具有重要地位，它的分布表现出明显的地带性差异，存在着多样的植物群系及其对应的气候特征。但是在植物功能性状领域，与全球范围其它生物群系相比，常绿阔叶林物种的研究较少，其功能性状间、功能性状与环境间的关系尚不清晰。 本研究以常绿阔叶林木本植物的当年生小枝为对象，试图从小枝水平上的生物量分配格局、叶片大小与数量的权衡关系、小枝茎的构型效应、叶片元素化学计量学，以及小枝大小的成本与效益分析等方面，较为系统地揭示小枝水平上的植物功能性状间及其与气候间的关系。因此，在华西雨屏带内部的不同纬度设置峨眉－青城－雷波－平武的温度梯度进行比较，并对有降水差异的川西南偏湿性（雷波）与偏干性常绿阔叶林（西昌）进行对比研究，同时在不同山体进行不同海拔梯度的比较研究。 本文主要研究结果如下： （1）小枝生物量分配格局叶水平上，叶片重－叶柄重（Y轴vs.X轴,下同）呈斜率小于1的异速生长关系，表明叶柄对叶内部的生物量分配影响显著。小枝水平上，叶和茎的生物量以及它们与小枝总生物量间基本呈等速生长关系，表明大的小枝或大叶物种不一定在叶生物量的分配上占优势。不同生活型间，在小枝或者茎的生物量一定时，常绿物种叶片的生物量比例较落叶物种稍高。与温度和水分较优越（峨眉及其低海拔）的生境相比，在相对低湿（螺髻）与低温（平武）的生境中的植物会减少对叶的投入而增加对支撑部分的投资比例。 （2）小枝叶片大小与数量的权衡无论是不同气候带还是不同生活型以及不同海拔梯度，叶片大小与出叶强度基本都是呈负的等速生长关系，表明了叶片大小－数量在小枝水平上的权衡。在不同气候梯度的对比中，叶片数量（出叶强度）一定时，高温和高水分生境（峨眉）比低温（平武）和低湿（螺髻山）生境中的物种的叶片大小（质量和面积）更大，表明不同生境的比较中，小的叶片可能具有较高的出叶强度和更高的适合度收益。“出叶强度优势”（Leafingintensitypremium）假说可能不适宜解释不同生境物种叶片大小差异。 （3）小枝茎的构型效应虽然茎长和茎径与叶片大小都呈正相关关系，与出叶强度都呈负相关关系，但茎长/茎径比与叶/茎生物量之比呈负相关关系；与叶片的大小呈负相关关系，与出叶强度呈正相关关系。这说明小枝构型能影响小枝叶/茎生物量分配和叶大小－数量的权衡关系。其影响机制可能是小枝内部的顶端优势。另外，茎长/茎径比在低湿和低温等不利生境中的植物中较高，而在降水和温度较适宜环境中较低。 （4）叶片C、N、P化学计量学N含量和P含量，C/N比和比叶重（LMA,leafmassperarea）呈正的等速生长关系，而N和LMA，P和LMA呈负的等速生长关系。在LMA一定时，C/N比随着生境胁迫压力的增加而降低，N、P含量随着生境压力的增加而增加。在P含量一定时，N含量随着生境压力的增加而降低，即N/P比在生境条件较优（峨眉及其低海拔）时较高。常绿和落叶植物叶片的N/P比没有差异，在LMA一定时，常绿植物的N、P含量较高、C/N比较低。总之，植物的C、N、P化学计量学特征受叶片属性如LMA与气候，及其相互作用的影响。 （5）小枝大小的代价与效益分析、TLA与小枝总重总叶面积（TLA,totalleafarea，Y轴，下同）与总叶重（X轴）均呈斜率小于1的异速生长关系，TLA与小枝横切面积呈斜率为1的等速生长关系。表明叶片面积的增加总是小于叶重和小枝总重的增加，随着小枝的增大，它的叶面积支撑效率下降。在热量和降水优越的生境（峨眉及其低海拔）中，相同小枝重或者相同茎横切面积的小枝，其叶面积支撑效率较低湿与低温环境下（螺髻山、平武及高海拔）的高。 总体上，本文初步研究了小枝水平上可能存在的以下三种权衡关系：叶－茎生物量分配权衡；叶片大小－数量的权衡；小枝茎长－茎径的权衡关系，以及气候要素等对这三种权衡关系的影响。在此基础上，我们还讨论了这些权衡关系的可能形成机制，及其与物种生态适应的联系。本研究丰富了生活史对策中关于权衡关系的研究内容，为我国常绿阔叶林功能生态学研究积累了材料。 Evergreen broad-leaved forests are attracting much more attention from vegetation ecologists than ever before because of their abundant nature resource and biological diversity, and also great ecological benefits. China has the largest distribution of subtropical evergreen broad-leaved forests (temperate rainforests) that are typical and representative in the world. The forests span over more than ten degrees in latitude and more than 30 degrees in longitude, providing an ideal place to study plant functional ecology, i.e., the climatic effect on plant functional traits and the relationship between the traits. However, relative to the other biomes, there are few studies addressing functional ecology of the plant species from subtropical evergreen broad-leaved forests. In this study, I focused on the leaf size-twig size spectrum of the woody species of subtropical evergreen broad-leaved forests in southwestern china. I collected data on leaf size and number, twig size in terms of both mass and volume, and stem architecture from five temperate mountains, and then I analyzed the relationships between leaf and stem biomass and between leaf size and number, the effect of stem length/diameter ratio on biomass allocation and on the relationship between leaf size and number, leaf C:N:P stoichiometry, and the twig efficiency of supporting leaf area in relation to twig size. I also addressed the climate effect on the spectrum. The temperature gradient from warm to cool sites was represented by Emei Mountain, Qingchengshan, Leibo, and Pingwu, and the rainfall gradient was assumed to emerge from the comparison between Leibo (High) and Luojishan (Low). In addition, altitudinal effects were analyzed with comparisons between low and high altitudes for each mountains. My main results are as follows. Isometric relationships were found between leaf mass and twig mass and between lamina mass and twig mass, suggesting that the biomass allocation to leaves or laminas was independent of twig mass. Petiole mass disproportionably increase with respect to lamina mass and twig mass, indicating the importance of leaf petioles to the within-twig biomass allocation. In addition, the investigated species tended to have a larger leaf and lamina mass, but a smaller stem mass at a given twig mass at favorable environments including warm and humid sites or at low altitude than unfavorable habitats, which might be due to the large requirements in physical support and transporting safety for the species living at unfavorable conditions. Moreover, the evergreen species invested more in leaves and laminas than the deciduous at given stem or twig biomass within any specified habitats. Negative, isometric scaling relationships between leaf number and size broadly existed in the species regardless of climate, altitude, and life forms, suggesting a leaf size/number trade-off within twigs. Along the climatic gradients, at given leaf number or leafing intensity, the leaves were larger in the favorable environments than the poor habitats. This suggested that the fitness benefit gained by small leaves could be larger than that with high leafing intensity in the stressful sites. I concluded that the “leafing intensity premium” hypothesis was not appropriate to interpreting between-habitat variation in leaf size. Both stem length and diameter were positively correlated to leaf size but negatively correlated to leafing intensity. The ratio of stem length to diameter was negatively correlated to leaf mass fraction, and it was negatively correlated to leaf size but positively correlated to leafing intensity. This suggested that the stem architecture influenced twig biomass allocation and the relationship between leaf size and number. The mechanism underlying the architectural effect might lie in the apical dominance within twig. Moreover, the ratio was greater in unfavorable habitats but smaller in favorable environments. Positive, isometric relationships were found between N and P contents per leaf mass, and between C/N ratio and leaf mass per area (LMA), but N and P contents scaled negatively to LMA. C/N ratio decreased but N and P increased with increasing habitat stress at a given LMA. N content declined with increasing habitat stress at given P content. These indicated that N/P and C/N were higher but LMA was lower in favorable habitats than in the other circumstances. The evergreen and deciduous species were non-heterogeneous in N/P, but the evergreen species have higher N and P contents and lower C/N than the deciduous ones. In general, C:N:P stoichiometry were related to both climatic conditions and other important functional traits like LMA. Total leaf area (TLA) allometricly scaled to leaf mass with a slope shallower than 1, similar to the relationship between TLA and total twig mass (leaf mass plus stem mass), suggesting that TLA failed to keep pace with the increase of leaf mass and twig size. However, TLA scaled isometricly to twig cross-sectional area. Thus, it could be inferred that the twig efficiency of displaying leaf area decreased with increasing twig size. In addition, the efficiency at a given twig size was large in favorable than unfavorable habitats. In general, in this preliminary study, I studied three tradeoff relationships within twigs, i.e., between leaf and stem biomass, between leaf number and size, and between stem length and diameter, as well as the climatic effect on the relationships. I discussed the mechanisms underlying the tradeoff relationships in view of biophysics and eco-physiology of plants. I believe that this study can serve as important materials advancing plant functional ecology of subtropical forest and that it will improve the understanding of life history strategies of plants from this particular biome.

青杨组(Populus Section Tacamahaca Spach)不同种对非生物胁迫的响应差异

土壤是人类赖以生存的自然环境和农业生产的重要资源，目前土壤受到干旱和盐胁迫的危害越来越严重。杨树具有适应性强、生长快和丰产等特性，本论文以青杨组杨树为模式植物，研究杨树对土壤干旱和盐胁迫的生态生理及蛋白质组学反应，研究成果可为我国干旱半干旱地区营造人工林、防止沙漠化提供理论依据，也为恢复与重建盐污染地区退化生态系统提供科学指导。主要研究结果如下： 1 青杨不同种对逐步干旱胁迫的响应差异 将来自喜马拉雅山东缘高海拔的康定杨和低海拔的青杨枝条扦插在温室中，用来检测它们对逐步干旱胁迫的响应。研究结果表明来自不同海拔的杨树对逐步干旱胁迫的适应性反应是不一样的。株高、叶片发育、叶片相对含水量、丙二醛、过氧化氢等指标的显著性变化在青杨中比在康定杨中来得早些，而且随着干旱胁迫程度的增加，这些参数的变化越来越明显，尤其是当青杨受到严重干旱胁迫的时候；而可溶性蛋白、可溶性糖、游离脯氨酸、抗氧化酶活力变化在康定杨中来得早一些。与青杨相比，在干旱胁迫下，康定杨仍能保持较好的植株生长和叶片发育；康定杨也能在逐步干旱条件下积累更多的可溶性蛋白、可溶性糖、游离脯氨酸及抗氧化酶活力，但是在丙二醛和过氧化氢含量方面增加的更少些。而且，我们的研究结果表明高海拔的康定杨有更强的耐干旱能力，杨树对干旱胁迫的适应能力与干旱发生的速度、强度、持续时间及两种杨树的海拔有关。 2 干旱胁迫下青杨不同种的蛋白质组学分析 来自青杨和康定杨雌株的枝条扦插在温室中，用来研究它们对干旱胁迫的蛋白质组学反应。采用TCA-丙酮/酚提取法提取总蛋白，并进行双向电泳分析。在每个处理的重复图像中都能检测到1,000 个以上的蛋白点。在青杨中有58 个蛋白在干旱处理后发生显著变化，其中22 个蛋白通过肽指纹图谱成功鉴定。康定杨中有69 个蛋白的表达量发生了显著变化，其中有25 个蛋白通过肽指纹图谱成功鉴定。这些被鉴定的蛋白主要参与了光合作用、氧化还原平衡、信号传导、能量代谢、蛋白质合成等过程。尽管被鉴定的蛋白只占叶片总蛋白的很少一部分，但这些被鉴定的干旱响应蛋白可能对维持植株内部平衡方面有重要作用。 3 青杨的盐胁迫响应 青杨植株分别用 0、50 和100 mM NaCl 溶液进行处理。叶片相对含水量、叶绿素a、b 含量、CO2 同化速率和气孔导度的降低表明叶绿体受到了盐胁迫的影响。过氧化氢、丙二醛含量及电导率的升高表明细胞受到了伤害。可溶性糖、游离脯氨酸含量及抗氧化酶含量的上升增加了植株耐盐胁迫的能力。在每个处理的重复图像中都能检测到1,000 个以上的蛋白点。其中有38 个盐响应蛋白被成功鉴定，有16 个蛋白(点4、10、11、14、15、21、24、26、27、28、33、34、35、36、37 和38)出现在盐胁迫的植株中；3 个蛋白(点10、11 和35)只出现在重度盐胁迫处理中；而1 个蛋白(点1)只出现在对照处理中。2 个蛋白(点1 和2)表达量下降，其余蛋白点表达量都增加。被鉴定的蛋白一部分参与了生理生化反应，而另一部分则在信号传导、蛋白质合成等方面有重要作用。盐胁迫下的生理生化变化及蛋白质组学的联合研究有利于青杨对盐胁迫的适应性分析。 Soil is the indispensable environment for human survival and important resource for agriculture development. Nowadays soil is threatened by drought stress and salt stress. Poplars (Populus spp.) possess some characters such as strong acclimilation, fast growth and great production of biomass. In this study, different species of Populus section Tacamahaca spach were used as model plants to investigate the ecophysiological and proteomic responses to drought stress and salt stress. Our results can provide theoretical evidence for the afforestation and prevention of desertification in the arid and semi-arid areas, and also can supply scientific direction for the reconstruction and rehalibitation of ecosystems contaminated by salinity. The results are as follows: 1 Adaptive responses to progressive drought stress in two contrasting poplar species originating from different altitudes Cuttings of Populus kangdingensis C. Wang et Tung and Populus cathayana Rehd., originating from high and low altitudes in the eastern Himalaya, respectively, were examined during one growing season in a greenhouse to determine the effects of progressive drought stress. The results manifested that the adaptive responses to progressive drought stress were different in these two species from different altitudes. Significant changes in height increment, leaf development, relative water content (RWC), malondialdehyde (MDA) and hydrogen peroxide (H2O2) appeared earlier in P. cathayana than in P. kangdingensis, whereas changes in soluble protein, soluble sugar, free proline and antioxidant enzymes appeared earlier in P. kangdingensis. In addition, changes in these parameters became more and more significant when the drought stress progressed, especially under severe drought stress in P. cathayana. Compared with P. cathayana, P. kangdingensis was able to maintain a superior height increase and leaf development under drought stress. Also, P. kangdingensis possessed greater increments in soluble protein, soluble sugar, free proline and antioxidant enzymes, but lower increments in MDA and H2O2 than did P. cathayana when the cuttings were exposed to progressive drought stress. Our results suggest that P. kangdingensis originating from the high altitude has a better drought tolerance than does P. cathayana originating from the low altitude. Furthermore, this study manifested that acclimation to drought stress are related the rapidity, severity, duration of the drought event and the altitude of two contrasting species. 2 Proteomic responses to drought stress in two contrasting poplar species originating from different altitudes The cuttings from a female clone of P. kangdingensis and P. cathayana were used to determine proteomic response to drought stress, respectively. Total proteins of the leaves were extracted by a combination of TCA-acetone and phenol, and separated by two-dimensional gel electrophoresis. More than 1,000 protein spots were reproducibly detected on each gel. 58 differentially expressed spots were detected under drought stress in P. cathayana and 22 drought-responsive proteins were identified by peptide mass fingerprint. 69 differentially expressed spots were detected under drought stress in P. kangdingensiss and 25 drought-responsive proteins were identified by peptide mass fingerprint. The identified proteins are involved in several processes, i.e., signal transduction, protein processing, redox homeostasis, CO2 fixation and energy metabolism. Although the proteins identified in this investigation represent only a very small part of the poplar leaf proteins, some of the novel drought-responsive proteins identified here may be involved in the establishment of homeostasis in response to drought stress in the woody plants. 3 Responses to salt stress in P. cathayana Cuttings from a female clone of P. cathayana were treated by Hoagland’s solution: 0, 50, 100 mM NaCl, respectively. Salinity significantly decreased the relative water content of leaves, the contents of chlorophyll a and chlorophyll b, CO2 assimilation rate (A) and stomatal conductance (gs) in both salt stress treatments，which suggested the chloroplast was affected by salt stress. The observed increases of H2O2 and malondialdehyde contents and electrolyte leakage suggested that salinity caused cellular damage, whereas the increases in compatible solutes and in the activities of antioxidant enzymes enhanced the salt tolerance. More than 1,000 protein spots were reproducibly detected on each gel, and 38 salt-responsive proteins were successfully identified by peptide mass fingerprint (PMF). 16 spots (spot 4, 10, 11, 14, 15, 21, 24, 26, 27, 28, 33, 34, 35, 36, 37 and 38) absent in the control sample were induced by the salt treatment, and three spots (spot 10，11 and 35) were present only in the severely salt-stressed treatment. The %vol of the differentially expressed proteins generally increased with progressing salt stress, except for the decreased %vol of two proteins (spot 1 and 2) under salt stress and the presence of spot 1 only in the control sample. Some of the novel salt-responsive proteins identified here may be involved in physiological, biochemical response to salt stress in P. cathayana, the other identified proteins play a role in numerous cellular functions, including signal transduction and protein processing. An integrated physiological, biochemical and proteomic approach was used here to systematically investigate salt acclimation in poplar.

岷江干旱河谷三种蔷薇植物繁殖更新研究

繁殖更新是植物生活史的重要阶段，在退化生态系统中，植物繁殖更新能力往往较差，是植被恢复的限制环节，因而也成为恢复研究重点和核心。本研究选择岷江干旱河谷广泛分布的三种蔷薇：多苞蔷薇（R. multibracteata）、黄蔷薇（R. hugonis）和川滇蔷薇（R. soulieana）为研究对象，通过野外调查，在查明其生长、繁殖更新状况的基础上，采用控制和模拟实验，对种子和幼苗阶段进行了深入研究，综合分析更新潜力，并提出相对应的促进更新和植被恢复措施。主要结论如下： 1）三种蔷薇在岷江干旱河谷广泛分布，生长和繁殖状况良好，结实量大。各生长指标：株高、基径和冠幅，繁殖指标：结实数量、重量和单果重量都具有显著的空间差异性。基径对多苞蔷薇结实量影响最大；而冠幅对黄蔷薇结实量影响最大。海拔和纬度是对蔷薇生长和繁殖影响最大的环境因素，随着海拔和纬度的升高，植株生长更高大，结实量增加；坡度和坡向对其生长和繁殖也有一定影响，随着坡度 和坡向增加，蔷薇生长和结实受到抑制。 2）三种蔷薇在岷江干旱河谷更新现状不佳, 但更新潜力大。活力种子比率低，动物取食以及两年生幼苗的大量死亡是蔷薇更新的主要限制因素。多苞蔷薇和黄蔷薇的结实率低，川滇蔷薇较高。三种蔷薇种子产量大，但种子质量较差，更新具有充足的种源。三种蔷薇都能形成持久种子库，种子库中种子总量大，但有效种子少，黄蔷薇被动物啃食的比例很高，多苞蔷薇和川滇蔷薇也有一部分种子受到动物破坏。三种蔷薇幼苗库组成特征表现为，当年生幼苗所占比例很高，年龄较大幼苗所占比例小。 3）三种蔷薇都具有不同程度休眠，未经处理种子的发芽率极低。黄蔷薇休眠程度最深，为深度生理休眠；多苞蔷薇为中度生理休眠；川滇蔷薇为非深度生理休眠。三种蔷薇种子在形态上发育成熟，种皮具有透水性。蔷薇果果肉和瘦果中含有抑制物质，其浸泡液抑制了油菜种子萌发，果肉抑制作用更强，果肉和瘦果浸泡液的抑制程度分别为：川滇蔷薇>黄蔷薇>多苞蔷薇。切割和硫酸腐蚀提高了川滇蔷薇种子的发芽能力，而对多苞蔷薇和黄蔷薇没有影响。完全去除瘦果果皮和种皮提高了多苞蔷薇种子发芽率，但对黄蔷薇没有影响。赤霉素和烟水对蔷薇种子萌发没有促进作用。三种蔷薇打破休眠所需低温层积时间分别为：黄蔷薇>多苞蔷薇>川滇蔷薇。对于多苞蔷薇和川滇蔷薇，层积前对种子进行硫酸腐蚀或暖温层积能缩短低温层积时间，提高发芽率。对于多苞蔷薇，变温层积中暖温层积和低温层积具有一定的负补性，即延长暖温层积可以缩短种子萌发对低温层积的需要。 4）多苞蔷薇种子形态特征和种子休眠与萌发在不同海拔梯度间存在较大差异。种子采集时间、采集季节和干藏影响多苞蔷薇和川滇蔷薇的种子休眠。多苞蔷薇果实大小、种子大小和千粒重、种皮厚度随海拔升高而增加，而种子饱满率和活力随海拔升高而降低，种子休眠程度也随海拔升高而增加。种皮厚度与种子大小、千粒重成正相关关系，硫酸腐蚀后的种子经过不同时间的低温层积后，种子发芽率与种皮厚度、种子大小、千粒重、海拔成正相关关系。2006 年采集川滇蔷薇和多苞蔷薇种子休眠程度较2005 年低。种子休眠随种子年龄增加而减弱。高温和干旱能减轻多苞蔷薇和川滇蔷薇种子休眠。 5）三种蔷薇的生长和生物量积累在干旱胁迫条件下受到抑制，而生物量分配、叶片形态特征和水分利用特征等都发生了变化。三种蔷薇的根、茎、叶各器官生物量以及总生物量等在干旱胁迫下明显减小，叶片脱落数量增加。在干旱胁迫条件下，较多的生物量分配到地下部分，从而这使R/S 明显增加。比叶面积（SLA）和冠层面积比（LAR）对干旱胁迫的反应不敏感，仅有部分物种在干旱胁迫条件下发生了变化，并且其变化特点在不同年龄幼苗之间有一定差异。干旱胁迫对WUE 的影响在不同物种间存在差异。多苞蔷薇和黄蔷薇的WUE 随着干旱胁迫的增加而增大， 而川滇蔷薇的WUE 则随干旱胁迫增加而减小。在干旱胁迫条件下，多苞蔷薇和黄蔷薇叶片脱落量和生物量减小幅度较川滇蔷薇大，表明其抗旱能力较强。在干旱胁迫条件，三种蔷薇两年生幼苗的生物量减小幅度较当年生幼苗小，表明两年生幼苗的抗旱能力更强。 6）两种植被恢复措施中，幼苗移栽比播种具有更好的植被恢复效果。播种后，蔷薇种子的发芽率较高，但出苗率都很低，即使出苗，幼苗也几乎在一月内全部死亡。 三种微生境条件下（灌木、半灌木和裸地），种子出苗和幼苗成活没有差异。移栽幼苗总体死亡率都比较低，小于20％。特别是两年生幼苗死亡率更低，小于2％。移栽后的幼苗生长状况良好，在整个生长季中，各生长指标不断增加。生境对幼苗的存活率没有显著影响，但对于幼苗的生长和生物量积累有一定影响，裸地更有利于幼苗生长和生物量积累。与当年生幼苗相比，两年生幼苗具有更高的成活率。总之，三种蔷薇在干旱河谷分布广泛、生长繁殖状况良好，结实量大，具有丰富种源，繁殖更新潜力大，但繁殖更新状况不佳；种子散布后动物对种子的取食、种子的深度休眠过程、种子出苗以及当年生幼苗的存活和定居是更新的主要限制环节。水分是影响结实、种子休眠解除和萌发，幼苗存活和定居的最主要的限制因素。在植被恢复中，应在种子成熟季节大量采集种子，在室内打破休眠后进行人工播种，培育两年生幼苗，通过幼苗移栽方式进行植被恢复。川滇蔷薇应栽种在相对湿润的过渡区，而多苞蔷薇和黄蔷薇可以应用于核心区植被恢复。 Regeneration is an important phase in plant life cycle. It has been a key component of ecological restoration in degradation ecosystem in which plants commonly has poor regeneration. In this paper, we investigated the natural growth, propagation and regeneration status of native three rose species, Rosa multibracteata, R. hugonis and R. soulieana, and analysis the limitation in seed germination and seedling establishment stages. Advice on facilitating the use of these plants in restoration based on the results has been proposed. The results were as follows: 1) Three rose plants widely distributed in the dry valley of the Minjiang River, and made a good performance in growth and propagation. There were significant spatial differences in each growth parameter, such as ramet height, basal diameter, crown diameter and propagation parameters including hip number of a clump, hip mass of a clump and a hip mass. Basa diameter was the most important growth parameter influencing fruit number for R. multibracteata and crown diameter was for R. hugoni. Altitude and latitude had the greatest effect on the growth and propagation of rose plants among environmental conditions. Each parameter of growth and propagation increased with the increase of altitude and latitude. In addition, the increase of slope and aspect limited the growth and propagation. 2) Three rose plants had poor natural regeneration, but great regeneration potential. Low seed viability, predation and higher mortality of current year old seedlings were the limitation in regeneration. R. multibracteata and R. hugonis had higher fruiting rates than R. souliean. All three plants produced a great number of seeds, while their viability was poor. Three rose plants had persistent seed banks, with high total seed number but very low viable seed density. Predation was most severe in R. hugonis, and it also existed to some degree in R. multibracteata and R. soulieana. The seedling age-structure was characteristic of current-year seedlings predominating and few older seedlings were observed. 3) Three rose seeds were dormant and untreated seeds germinated with very low germination percentages. The rose seeds had morphological mature embryos, and achenes were permeable. Some inhabit substances existed in hips and achenes for the extracts of hips and achenes inhibited germination of Brassica campestris. The inhibition effect of the extracts of three rose hip and achenes was R. soulieana>R. hugonis>R. multibracteata. Mechanical and H2SO4 scarification increased R. soulieana germination but had no effect on germination of R. hugonis and R. multibracteata seeds. Full removal of pericarp and testa improved the germination of R. multibracteata but did not affect R. hugonis germination. GA3 and smoke water had no positive effect on rose seed germination. The periods of cold stratification required to released seed dormancy was R. hugonis > R. soulieana >R. multibracteata. H2SO4 scarification and warm stratification shortened cold stratification to release dormancy for R. soulieana and R. multibracteata. Warm stratification had complementary effect for cold stratification, i.e. the longer warm stratification seeds received, the shorter cold stratification were required to obtain the same germination percentage. Three rose seeds had different kinds of dormancy; R. hugonis has deep physiological dormancy, R. multibracteata with intermediate physiological dormancy and R. souliean non-deep physiological dormancy. 4）The seeds traits and dormancy of R. multibracteata showed significant difference across altitudes. Year and season of seed collection had significant effect on seed dormancy for both R. souliean and R. multibracteata. Hip size, seed size, seed weight, seed coat thickness and seed dormancy level increased with the increase of the altitude. There were positive relations between seed coat thickness with seed size and seed weight. Germination percentage of seeds treated with H2SO4 scarification following different periods of cold stratification showed positive relation with seed coat thickness, seed size, seed weight and altitude. Seeds of R. souliean and R. multibracteata collected in 2006 had low dormancy level than those collected in 2005. Seed dormancy decreased with increasing seeds age. High temperature and drought were associated with low dormancy level. 5) Seedling growth, the total dry mass and their components of seedlings were reduced, while leaf senescence accelerated under drought stress. More biomass allocation to root system resulted in higher R/S ratio under drought. Water-use efficiency (WUE) of R. multibracteata and R. hugonis increased, while it declined for R. soulieana under drought stress. R. soulieana seedlings had poor drought-resistance capacity it had more senescent leaves, and its reduction of biomass was stronger than two other rose plants under drought. The reduction degree of one year old seedlings under drought stress was slighter than that of current year seedlings. Therefore, one year old seedling was more drought-resistent compared to current year seedlings. 6）Planting seedlings may have better effect in comparison with direct seeding. Most seeds germinated after seeding, but seedling emergence was very low. More than 80 % seedlings from direct seeding died within a months after emergence. Seedling emergence and survival rate did not show difference among microhabitats. Mortality rates of seedlings artificially planted in microhabitats were general lower than 20 %, and the mortality rate of one year old seedlings was lower than 2 %. Each grow parameter including plant height, leaf number and branch number continually increased after planting. Microhabitat type had effect on the growth parameter and biomass production, but it did not influence the seedling survival. Bare land tended to facilitate seedling growth. One year old seedlings had higher survival rate than current year seedlings. In conculsion, the three rose had wide distribution in the dry valley of the Minjiang River. They produced many seeds and had tolerance to drought stress to some degree. But they had poor regeneration in habitats may be caused by predation, seed dormancy，and high mortality in current year seedlings. We recommend that rose plants should be utilized in restoration by planting two-year old seedlings in spring. A large quantity of seeds should be collected artificially in autumn, release seed dormancy in room, and then cultivate two-year old seedlings by seeding in particular container. R. soulieana seedling probably be planted in transition area, and R. multibracteata and R. hugonis can be used in core area of the dry valley of the Minjiang River.

增强UV-B辐射对粗枝云杉(Picea asperata Mast.)和青杨(Populus cathayana Rehd.)的影响

光是植物赖以生存的重要环境因子，但是植物在获得光的同时不可避免的会受到紫外辐射的伤害。尤其是近年来，人类向大气中排放的大量氮氧化合物和氟氯烃类化合物(CFC’s)引起臭氧分子的分解，导致到达地球表面的紫外辐射增加，特别是UV-B辐射增强。而另一方面，植物对UV-B辐射反应的敏感性在种间和品种间存在差异，主要受植物基因型，生态型和生活型的控制。本项目分别以粗枝云杉和青杨组杨树为模式植物，从形态和生理生化方面分别研究了来自不同水分背景下的粗枝云杉种群和来自不同UV-B背景下的青杨种群在增强UV-B下的反应及其反应差异,并探讨了干旱、喷施外源脱落酸(ABA)对它们抗UV-B能力的影响。研究成果可为生态系统的恢复与重建提供理论依据和科学指导。主要研究结果如下： 1. 粗枝云杉的两个种群，湿润种群(来自四川黑水)和干旱种群(来自甘肃迭部)在水分良好和干旱状况下表现出对增强UV-B的不同响应。同时，干旱对粗枝云杉抗UV-B能力的影响也得到研究：两种胁迫共同作用时，干旱表现出在一定程度上减弱了增强UV-B对粗枝云杉的生理特性的影响。 干旱胁迫显著降低了两个粗枝云杉种群的光合同化速率(A), 气孔导度(gs)和PSII的有效光量子产量(Y), 同时，提高了非光化学猝灭效率(qN)和超氧化物歧化酶(SOD)的活性。与湿润种群相比，干旱种群抗旱性更强，表现为干旱种群拥有更高的SOD和干旱进一步加剧了UV-B的胁迫效应。 本研究中，干旱胁迫单独作用时，显著降低了青杨两个种群的生物量积累和气体交换，具体包括A、gs、蒸腾速率(E)和光合氮利用效率(PNUE)，提高了两个种群的瞬时水分利用效率(WUEi)、长期水分利用效率(WUET)、碳同位素组分(δ13C)和氮含量(N)。同时，UV吸收物质和ABA含量也得到积累。另一方面，增强UV-B对青杨两个种群各个指标的影响，同干旱所引起的效应有着相似的趋势。同低海拔种群相比，高海拔种群有着更强的抗旱和抗UV-B能力，具体表现在高海拔种群有着更多的生物量积累，更强的气体交换和水分利用效率及更高水平的ABA和UV吸收物质含量。相比干旱诱导的生物量积累和气体交换的降低，在干旱和增强UV-B两个胁迫同时作用于青杨时，这种降低表现的更为明显。显著的干旱和UV-B的交互作用还表现在WUEi, WUET, δ13C, 可溶性蛋白含量, UV吸收物质含量, ABA, 叶片和茎中的N含量以及C/N比中。 3. 经过一个生长季的试验观察，增强UV-B、外源ABA及两因子共同作用对青杨的生物量积累、气体交换、内源ABA和UV吸收物质含量、抗氧化系统以及碳、氮含量和碳/氮比均产生显著影响。本试验中，青杨的两个种群分别来自中国西南部的不同海拔地区，高海拔种群来自青海大通而低海拔种群来自四川九寨。外源ABA的胁迫为直接喷施ABA到青杨叶片，而增强UV-B胁迫是利用平方波系统分别保证青杨苗暴露于外界UV-B强度和两倍于外界UV-B强度下。 研究结果显示，增强UV-B显著的降低了两个青杨种群的株高、基茎、总叶面积和总生物量等生长指标，同时也导致其A、gs、E和叶片中碳含量的减少。而显著增加了SOD和过氧化物酶(GPx)活性水平，诱导了过氧化氢(H2O2)和MDA的显著增加，促进了UV吸收物质和不同器官中内源ABA含量的显著积累。另一方面，外源ABA引起了青杨光合同化速率的下降，SOD和GPx酶活性的增强，H2O2 和 MDA含量也表现出显著增加，同时，内源ABA含量得到显著累积。同低海拔种群相比，高海拔种群具有更加抗UV-B和外源ABA的特性。显著的UV-B和ABA的交互作用表现在A, E, SOD和GPx活性，以及叶片和根部的内源ABA等一系列指标中。在所有胁迫下，叶片中的碳和氮含量同其在茎和根中的含量显著相关，另外，叶片和茎中的氮含量同茎中的碳含量显著相关。 Sunlight is an indispensable environment factor for plants survival and development. Meanwhile, photosynthetic organisms need sunlight and are thus, inevitably, exposed to UV radiation. Especially for recent years, ultraviolet radiation, especially UV-B reaching the Earth’s surface increased because of depletion of ozone layer resulted from emission of NxO and CFC’s from human activities. On the other hand, the sensitivity of plants to UV-B radiation depends on the species, developmental stage and experimental conditions. In this experiment, two populations of Picea asperata Mast from different water background and two populations of Populus cathayana Rehder from different altitude background were selected as model plants to assess the effects of enhanced UV-B radiation. Morphological and physiological traits induced by enhanced UV-B in each plant species were observed and the different responses were discussed, furthermore the influences of drought and exogenous ABA on responses induced by enhanced UV-B were studied. The study could provide a strong theoretical evidence and scientific direction for the afforestation and rehabilitation of ecosystem. The results are as follows: 1. Different responses of two contrasting Picea asperata Mast. populations to enhanced ultraviolet-B (UV-B) radiation under well-watered and drought conditions were investigated. And the effects of enhanced UV-B on tolerance of drought were also observed in our study that the UV-B exposure may have alleviated some of the damage induced by drought. Two contrasting populations, originating from a wet and dry climate region in China, respectively, were employed in our study. Drought significantly decreased CO2 assimilation rate (A), stomatal conductance (gs) and effective PSII quantum yield (Y), while it significantly increased non-photochemical quenching (qN) and the activity of superoxide dismutase (SOD) in both populations. Compared with the wet climate population, the dry climate population was more acclimated to drought stress and showed much higher activities of SOD and ascorbate peroxidase (APX), and much lower levels of malondialdehyde (MDA) and electrolyte leakage. On the other hand, enhanced UV-B radiation also induced a significant decrease in the chlorophyll (Chl) content in both populations under well-watered conditions, and a significant increase in UV-absorbing compounds in the wet climate population. After one growing season of exposure to different UV-B levels and watering regimes, the increases in MDA and electrolyte leakage, as induced by drought, were less pronounced under the combination of UV-B and drought. In addition, an additive effect of drought and UV-B on A and gs was observed in the wet climate population, and on the activity of APX and qN in the dry climate population. 2. The significant effects of drought, enhanced UV-B radiation and their combination on Populus cathayana Rehd. growth and physiological traits were investigated in two populations, originating from high and low altitudes in south-west China. Our results showed that UV-B acts as an important signal allowing P. cathayana seedlings to respond to drought and that the combination of drought and UV-B may cause synergistically detrimental effects on plant growth in both populations. In both populations, drought significantly decreased biomass accumulation and gas exchange parameters, including A, gs, E and photosynthetic nitrogen use efficiency (PNUE). However, instantaneous water use efficiency (WUEi), transpiration efficiency (WUET), carbon isotope composition (δ13C) and nitrogen (N) content, as well as the accumulation of soluble protein, UV-absorbing compounds and abscisic acid (ABA) were significantly increased by drought. On the other hand, cuttings from both populations, when kept under enhanced UV-B radiation conditions, showed very similar changes in all above-mentioned parameters, as induced by drought. Compared with the low altitude population, the high altitude population was more tolerant to drought and enhanced UV-B, as indicated by the higher level of biomass accumulation, gas exchange, water-use efficiency, ABA concentration and UV-absorbing compounds. After one growing season of exposure to different UV-B levels and watering regimes, the decrease in biomass accumulation and gas exchange, induced by drought, was more pronounced under the combination of UV-B and drought. Significant interactions between drought and UV-B were observed in WUEi, WUET, δ13C, soluble protein, UV-absorbing compounds, ABA and in the leaf and stem N, as well as in the leaf and stem C/N ratio. 3. During one growing season, significant effects induced by enhanced UV-B radiation, exogenous ABA and their combination on biomass accumulation, gas exchange, endogenous ABA and UV-absorbing compounds concentrations, antioxidant system as well as carbon (C) content, nitrogen (N) content and C/N ratio were investigated in two contrasting Populus cathayana populations, originating from high and low altitudes in south-west China. Exogenous ABA was sprayed to the leaves and enhanced UV-B treatment was using a square-wave system to make the seedlings under ambient (1×) or twice ambient (2×) doses of biologically effective UV-B radiation (UV-BBE). Enhanced UV-B radiation significantly decreased height, basal diameter, total leaf area, total biomass, A, gs, E and carbon (C) content in leaves, and significantly increased activities of SOD and guaiacol peroxidase (GPx), hydrogen peroxide (H2O2) and malonaldehyde (MDA) content as well as the accumulation of UV-absorbing compounds and endogenous ABA concentrations among different organs in both populations. In contrast, exogenous ABA showed significant decrease in A and significant increases in activities of SOD and GPx, H2O2, MDA content and the endogenous ABA concentrations. Compared with the low altitude population, the high altitude population was more tolerant to enhanced UV-B and exogenous ABA. Significant interactions between UV-B and ABA were observed in A, E, activities of SOD and GPx, as well as in endogenous ABA in leaves and roots of both populations. Across all treatments, C and N content in leaves was strongly correlated with those were in stems and roots, respectively. Additionally, leaf and stem N content were significant correlated with stem C content.

九寨沟核心景区湖泊硅藻的组成及其密度与环境因子的关系

九寨沟自然保护区地处四川盆地北部岷山山脉南段，属川西高原气候中的暖温带。保护区内分布着118 个串珠状排列的高山湖泊，核心景区共有湖泊20 个（组），集中在海拔2000 米到3000 米之间。水资源是九寨沟的灵魂，保护水生生态系统是九寨沟生态旅游可持续发展的立足之本。本研究以九寨沟湿地生物多样性保护项目为依托，于2007 年5 月～2008 年4 月对九寨沟核心景区湖泊水体硅藻植物进行调查，分析了其密度与环境因子的相互关系，旨在为九寨沟湖泊生态系统保护提供科学依据和基础资料。主要有以下几点结论： （1）九寨沟硅藻植物丰富，调查统计为2 纲6 目10 科35 属159 种（包括变种和变型），水体硅藻中真性浮游种类较少，着生种类多，羽纹纲的脆杆藻属、舟形藻属、桥弯藻属、异极藻属、曲壳藻属的种类最多，常为优势属组成湖泊硅藻群落，只在长海是小环藻属占绝对优势。 （2）九寨沟水体中硅藻细胞密度不大，多在4×104～30×104 个/L，长海最高，五花海最低。在年变化上，不同的湖泊水体中硅藻的生长高峰季节不尽相同，在夏季、秋末和冬末春初均有可能出现高密度。在空间上，整体看来密度与海拔有一定的正相关，但由于水温不是单一主导因素，密度受多种环境因子影响，在海拔梯度上呈现一定的波浪状变化。 （3）影响九寨沟湖泊水体硅藻细胞密度较重要的环境因子是海拔、水温和pH。硅藻细胞密度年变化幅度大的湖泊水体，年平均细胞密度大。因此，环境因素不太稳定的湖泊水体，更可能出现高的硅藻细胞密度。11 月份响应于水量剧烈的减少，细齿菱形藻大量出现在五彩池成为优势种群，造成水体硅藻细胞密度的大幅增加。 （4）九寨沟湖泊水体水质几乎达到国家地表水I 类标准，但是，硅藻商指数以及代表多样性的Cairns 指数计算的结果不能反映水质的情况，这是由于水质状况不是决定九寨沟湖泊水体中硅藻生存的种类和数量的主要因素。因此在用各种指数分析水质的时候，都应该先判断计算该指数的参数是否主要由水质状况决定，然后再综合理化性质等其他指标分析和比较。 （5）人类的活动对九寨沟湖泊水生态系统有一定的影响。一方面，在低海拔景点人类活动的干扰比海拔高处相对要大，干扰引起低海拔景点湖泊硅藻Cairns指数较高；另一方面，旺季的影响比淡季大，水体中出现了典型富营养种类。因此，应加强低海拔景点和旺季的管理，并限制淡季的人类活动以保证九寨沟生态系统的自我恢复。 Jiuzhaigou nature reserve is located in north Sichuan, at the south section of Minshan Mountain, having a warm temperate climate which belongs to West Sichuan plateau climate. It includes 118 mountain lakes, and 20 of them between 2000 and 3000 altitude degree constitute the core area of Jiuzhaigou. The water is Jiuzhaigou's soul, so it is the basis of sustainable tourism development of Jiuzhaigou to protect the water ecological environment. Research depends on Jiuzhaigou wetland biodiversity protection program in this paper, invested the diatom plants in 17 lakes at the core area from May 2007 to April 2008. The composition and the correlation of diatom density and the environment were studied, which could provide scientific and basic information for the protection of the ecological environment of Jiuzhaigou. The main conclusions were: 1 The diatom species were in abundance, investigation showed that there were 159 species belong to 10 families and 35 genera. Most diatoms were benthos, euplankton were less. Genera Fragilaria, Navicula, Cymbella, Gomphonema and Achnanthes had the most species, which always were the dominant genera. Only in The Long Lake genus Cyclotella possessed a predominant status. 2 The diatom cell density was not very high, always between 4×104 cell/L and 30×104 cell/L, highest in The Long Lake and lowest in The Colorful Lake. In one year's time, diatom in different lakes had different growth type. The maximum could be in summer, late autumn and late winter early spring. The cell density showed a positive correlation to altitude in the whole, but fluctuated in details along altitude because of comprehensive influence by many environmental factors. 3 Altitude, water temperature and pH were the more important factors to determine the cell density. There was a positive correlation between the range of cell density in one year and the average cell density. So high annual cell average density probably will appear in lakes which has an unstable environmental condition. The boom of Denticula elegans in The Jade-Colored Lake in November was corresponding to the large decrease in water quantity. 4 The water quality of Jiuzhaigou was near the National Surface Water Standard rank I, but the Diatom Quotient and the Cairns Index didn't reflect the water quality accordingly. It was because the water quality wasn't the most important factor here which determined the species number and species quantity, so the index based on these items would not reflect it. Therefore, it is recommended that, when we use indices to evaluate the water quality, we should know first whether the water quality is the main determinative factor inflects the items used to compute the indices, and then combined with other chemical indices to analyze and do comparison. 5 The tourists' activities had influenced the water ecosystem of Jiuzhaigou. On the one hand, disturbance was relatively high at the lower altitude, it resulted in higher Cairns index; on the other hand, influence in high season was more severe than in low season, some typical species indicating eutrophication were observed in the water. It is suggested that the management at lower altitude and in high season must be strengthen, and less people activity in low season is necessary to fulfill the recovery of the water ecosystem.

青杨(Populus cathayana Rehd.)对逆境胁迫的反应及lea基因的表达分析

杨树具有分布广、适应性强，在生态环境治理和解决木材短缺方面均占有重要位置。青杨(Populus cathayana Rehd.)是青杨派树种的重要成员之一，也是我国的特有种。本研究通过对不同水分梯度的干旱胁迫下青杨形态和生理生化的反应，不同pH值盐碱胁迫下不同海拔和不同气候地区的四个青杨种群在生理生态上的反应差异，以及在干旱和低温胁迫下青杨lea2, lea3组基因表达差异的研究，从形态、生理、生化和分子生物学水平系统地研究了青杨在不同逆境胁迫下的反应和青杨不同种群在盐碱胁迫下的反应差异。主要研究结果如下： 1. 青杨在干旱胁迫下的反应机制：中度和重度干旱胁迫下植株的生长受到明显抑制。表现在光合系统上青杨的净光合同化速率(A)下降，主要原因是气孔导度(gs)，胞间二氧化碳浓度(Ci)下降。另外最大量子产量(Fv/Fm)、光化学猝灭效率(qP)降低反应了干旱胁迫下光合系统II(PSII)受到严重损伤, 而且非光化学猝灭效率(qN)上升，导致可利用化学能产量下降，叶绿体产生淀粉的量减少。qP降低qN上升导致产生的过量电子对光合系统的伤害造成活性氧以及丙二醛(MDA)的含量增加。超微解剖结构显示，干旱胁迫增强时，叶绿体内淀粉粒的数目减少，而且叶绿体、线粒体等细胞器中嗜锇颗粒的数目增加。为清除细胞内的活性氧，植物一般的反应是抗氧化系统酶活性增加，对青杨来讲超氧化物歧化酶(SOD), 抗坏血酸过氧化物酶(APx)活性的增加远大于过氧化物酶(POD)，这显示了在青杨中SOD、APx酶在清除活性氧的作用上大于POD。另外同工酶研究结果显示这些酶活性的升高主要是由于各条同工酶带表达量的增加，而不是诱导新酶带的产生。另外，75% FC水分处理下有些指标非但没有下降，像A和有效光量子产量(Y)的值都略有增加，而且gs同时增加。另外，100% FC比75% FC细胞内淀粉粒的数目少一些，但有少量的嗜锇颗粒。这证明100% FC土壤水分也许并非最适合青杨生长。 2. 盐碱胁迫对不同海拔地区青杨种群的反应差异：青杨高海拔和低海拔种群的各种生理特性随着pH值上升都受到了很大的影响。两种群叶和根中Na+、K+ 含量, Na+/K+比率随着pH值的上升影响显著。在pH值高于10.4时高海拔种群叶和根中Na+/K+比率急剧下降但是低海拔种群中却一直维持在较高水平。两种群中MDA、脯氨酸(Proline)的含量，抗氧化系统酶的活性都受到了严重的影响，证明两个种群都属于盐碱胁迫敏感类型但是高海拔的种群对盐碱胁迫的耐性要高于低海拔。这主要是由于高海拔种群一般具有耐干旱、低温胁迫的能力，而植物的抗逆机制一般都有共通之处。 3. 盐碱胁迫对不同气候地区青杨种群的反应差异：盐碱胁迫下两种群的光合作用受到明显的抑制，具体表现在叶绿素的含量和A 显著下降。净光合速率的下降主要是由于叶片gs，Ci 值降低引起的。与湿润地区的种群相比盐碱胁迫增强时，干旱地区的种群叶绿素含量和光合能力的升高与K+离子含量增加有关。植物维持细胞质高K+/Na+值对植物的抗盐性有很重要的作用。为清除盐碱胁迫产生的活性氧，抗氧化系统酶活性增加。盐碱胁迫下干旱地区的种群在SOD、CAT 和谷胱甘肽还原酶(GR)等酶的活性均显著上升，而湿润地区种群只有谷胱甘肽氧化酶(GST)的活性明显增加，说明干旱种群的抗氧化酶系统在较高盐碱胁迫下的保护作用要强于湿润种群。这主要是由于植物抗盐碱胁迫与抗干旱胁迫在一些方面的机制是一致的，抗旱种群一般也能抵抗一定程度的盐碱胁迫。 4. 青杨lea2、lea3 基因在干旱和低温胁迫下的表达差异：通过荧光定量PCR 分析，lea2、lea3 组基因在干旱和低温胁迫下在mRNA 水平的瞬时表达量明显升高，说明了两基因在青杨耐干旱和低温胁迫上都起显著的作用。而且两基因在干旱胁迫下，表达量的升高和降低的时间近乎同步，表明两基因在干旱胁迫下对植物应急保护机制的启动都发挥着重要的作用。低温胁迫下lea3 基因在mRNA 水平上表达量显著上升的时间要早于lea2，而且lea3 基因的持续作用时间明显长于lea2 组基因，说明了低温胁迫开始时lea3基因在植物应对逆境的作用上要大于lea2 基因。 Poplars play an important role in lumber supply, and are important components of ecosystems due to their wide distribution and well adaptation. Populus cathayana Rehd., which belongs to Populus Sect. Tacamahaca Spach, is one of the most important resources of poplars and is specialist to china. In this study, different altitudes and climates populations of P. cathayana were used as experiment materials to investigate the adaptability to drought and salt-alkali stresses. And the cultures of P. cathayana were used to analyze the lea2 and 3 group genes expression when exposed to drought and low temperature stresses. The results are as follows: 1. A large set of parallel responses to drought stress: Drought stress caused pronounced growth inhibition. A decreased significantly and was mainly the result of gs and Ci down. Besides, Fv/Fm, qP decreased and that reflected the harmful effects to PSII of drought stress. In accordance with qN increasing, decreased useful energy production caused the starch numbers reduction in chloroplast. The qP up and qN down improved the levels of ROS and MDA. Starch numbers in chloroplast reduced and plastoglobuli numbers increased when soil water content decreased. To reduce ROS, the activities of SOD, APX, CAT and PPO were activated. The isozymes results show that the rising activities of the antioxidant enzymes resulted from certain isoform content increased, and not from the new band produced. Interestingly, morphological results show 100%FC maybe wasn’t the favorite water content for P. cathayana growth. 2. Effect of salt-alkali stress on morphological and physiological changes in two different altitudes populations of P. cathayana: We compared the physiological responses of two populations of Populus cathayana Rehder, originating from altitudes 2,840 m and 1,450 m. Our results demonstated that Na+ and K+ contents, and Na+/K+ ratios in leaves and roots are greatly affected by pH values. At pH 10.4, the Na+/K+ ratios in both leaves and roots sharply dropped in the higher altitude population but were always maintained at higher levels in the lower altitude population. The pH values causing maximum malondialdehyde (MDA) level, free proline content and antioxidant enzyme activities were significantly different in two populations. These results indicated that the higher altitude population exhibits greater tolerance to alkalinity stress than does the lower altitude population. 3. Morphological and physiological changes in two different climates populations of P. cathayana when exposed to salt-alkali stress. Salt-alkali stress caused pronounced inhibition of the growth and especially in photosystem. Pigments content and A decreased significantly and at the same time gs and Ci decreased too. Compared with wet climate population, the Chlorophyll content and A increased in drought climate population as pH value rising was related to the K+ content increasing. It is important to resist salt-alkali stress that the K+/Na+ ratio matained at high level in cytoplasm. To reduce ROS content, the SOD, CAT and GR activities rised significantly in drought population but only GST increased in wet population. The drought population showed higher salt-alkali tolerance than the wet population mainly resulted from the fact that drought tolerance was in accordance with salt-alkali tolerance to some extent. 4. The different expressional model of lea2 and lea3 gene when P. cathayana was exposed to drought and cold stress. RT-PCR results show both lea2 and lea3 suddenly expressed significantly in mRNA level under drought and cold stress. The expression level of two genes reached optimal level at the same time. But under cold stress, the earlier significantly rising expressional time and the longer maintained higher level time in lea3 than lea2 elucidated that lea3 may be more important than lea2 in resisting cold stress in short time in P. cathayana.

贡嘎山植物小枝功能性状在不同生活型和不同海拔间的比较研究

植物功能生态学研究不仅提供了植物生理生态学与生态系统生态学的连接，还为植物种群生活史对策研究提供了材料。Westoby 等 (2002) 提出了利用植物功能性状变量的主导维度来确定和量化植物生活史的生态适应策略。在他们所提出四个主导维度中，叶大小－小枝大小是研究相对较少的一维；其内部各组分的关系、对环境的响应，以及与其它重要维度的关系，目前的理解非常有限。 本研究以贡嘎山不同海拔不同功能群物种为研究对象，采用种间比较和系统发生独立性比较等研究方法，系统研究了植物的功能特征及其相关性在不同生境及不同功能群间的差异，旨在分析不同功能群物种的叶大小－小枝大小的成本和收益。其研究结果将有助于我们理解植物生活史对策的进化，进而理解物种共存和维持物种多样性的机制。主要研究结果如下： 1. 叶大小－小枝大小关系 小枝茎横截面积与单叶面积和总叶面积均呈异速生长关系，即总叶面积和单叶面积的增加比茎横截面积的增加速度快。但是，总叶面积和叶片干重的增加却基本上与小枝茎干重的增加等速。系统发生独立性比较研究的结果与此相一致。表明，在某一给定的茎投入时，至少大叶大枝物种不比小叶小枝物种在支撑叶面积和叶片干重方面具有优势。同时，在某一给定的小枝茎投入时，常绿阔叶物种比落叶阔叶物种支撑更少的叶面积。在茎干重与总叶面积的关系中，落叶复叶物种比落叶单叶物种具有更高的y轴截距，表明复叶物种比单叶物种在展叶面积方面更有效。复叶物种与单叶物种相比，通常具有较大的叶大小和小枝大小。 2. 叶大小－叶数量关系 叶大小与数量间在不同的叶片习性、不同的叶片形态以及不同的生境类型的物种间均存在稳定的负的等速生长关系，且这种关系在系统发生独立性比较时依然成立。然而，在某一给定的出叶强度 (单位小枝的叶数量) 时，常绿阔叶物种比落叶物种具有更小的叶面积。而在给定体积基础上的出叶强度时，落叶复叶物种的叶面积显著大于落叶单叶物种，且复叶物种比单叶物种具有更大的叶大小和更小的出叶强度。但是，叶大小与数量间的关系在不同的海拔间并没有显著的差异。 3. 小枝大小－总叶面积关系 在不同的生活型或不同的生境下，小枝上总叶面积与茎干重和小枝干重均呈正的异速生长关系，且斜率显著小于1.0，表明小枝上总叶面积的增加都不能赶上小枝及茎大小的增加。这种“收益递减”表明随着小枝干重的增加，光截取的收益递减。此外，叶面积比 (总叶面积与小枝干重的比值) 与单叶干重呈显著负相关关系，系统发生独立性比较的结果与此相一致。根据以上结果，可以推测，大叶的物种在质量较好的生境中出现，而群落内部小枝茎的寿命较长的物种可以拥有较大的叶片。 4. 叶片色素浓度－LMA关系 随着海拔的升高，阔叶木本植物和草本植物的叶片色素浓度减少，叶绿素a/b和类胡萝卜素/叶绿素比值以及比叶重 (LMA) 增加。然而，在草本植物中的色素浓度、色素比值和LMA的变化比阔叶木本植物的更明显。同时，LMA与叶片色素浓度呈负相关关系，但是在落叶物种中的LMA对色素浓度的影响比常绿阔叶物种更强烈。总之，草本植物的叶片特征对海拔梯度的变化似乎比木本植物更敏感，LMA对叶片色素的保护作用在落叶物种中比在常绿阔叶物种显得更重要。这些结果表明不同生活型物种可能采取不同的保护机制来降低叶绿体器官的损伤和增加他们的碳获取能力。 Studies on plant functional ecology not only bridge plant eco-physiology and ecosystem functioning, but also enrich plant population biology. As pointed out by Westoby et al (2002), plant life history strategies can be identified and quantified by four leading dimensions of variations in plant functional traits, i.e., seed size/output, leaf mass per area and leaf life span, plant height, and leaf size-twig size. Compared to the other dimensions, the cost/benefit of the leaf size-twig size spectrum has scarcely been analyzed in relation to environmental gradients and life form types, and the adaptive significance of this spectrum is not fully understood. In the present study, the relationships between functional traits of plant twigs are determined for the species with different life forms along an altitudinal gradient of Gongga Mountain with both cross-species analysis and evolutionary divergence analysis. The primary objective of this study is to examine the cost/benefit of leaf size-twig size in plants. The study results are supposed to provide insights into the understanding of the mechanism of species coexistences. The results are shown in the following. 1. The relationship between leaf size and twig size Twig cross-sectional area allometrically scaled with both individual leaf area and total leaf area supported by the twigs. However, the increase in total lamina mass/area was generally proportional to the increase in stem mass. These correlations between trait variations were significant in both interspecies analysis and phylogenetically independent comparison (PIC) analysis, which indicated that thick-twigged/large-leaved species, at least, do not have an advantage in supporting leaf/lamina area and lamina mass for the same twig stem investment than thin-twigged/ small-leaved species. Meanwhile, the evergreen broad-leaved species supported a smaller leaf area for the same twig stem investment in terms of both cross-sectional area and stem mass than the deciduous species. The deciduous compound-leaved species have a higher y-intercept in the scaling relationship of twig stem mass versus total leaf area than the deciduous simple-leaved species, indicating that compound-leaved species were more efficient in displaying leaf area. The compound-leaved species were larger in both leaf size and twig size than their counterpart in the present study. 2. The relationship between leaf size and leaf number Significantly negative and isometric scaling relationships between leaf size and leafing intensity (leaf number per twig mass or volume) were found to be consistently conserved across species independent of leaf habit, leaf form and habitat type. The negative correlations between leaf size and leafing intensity were also observed across correlated evolutionary divergences. However, leaf area was smaller in the evergreen broad-leaved species at a given leafing intensity than in the deciduous species. The deciduous compound-leaved deciduous species were higher in leaf area than deciduous simple-laved species at a given volume-based leafing intensity. Moreover, the compound-leaved deciduous species were larger in leaf size but smaller in leafing intensity than their simple counterparts. No significant difference was found in the scaling relationships between altitudes. 3. The relationship between twig size and total leaf area Leaf area was found to scale positively and allometrically with both stem and twig mass (stem mass plus leaf mass) with slopes significantly smaller than 1.0, independent of life form and habitat type, indicating that the increase in total leaf area fails to keep pace with increasing twig size and stem size. This ‘diminishing returns’ suggests that the benefit of light intercept decreased with increasing twig mass. Moreover, the leaf area ratio (the ratio of total leaf area to stem or twig mass) correlated negatively with individual leaf mass. The results of PIC were consistent with the correlations. According to the results, it is speculated that large-leaved species may be favored when habitat is good and when stem longevity are long within community. 4. The relationship between leaf pigment concentrations and leaf mass per area With increasing altitude, the concentrations of pigments decreased, but the ratios of chlorophyll a/b and carotenoid/chlorophyll, and LMA increased, in both the broad-leaved woody species and herbaceous species groups. However, the changes in the pigment concentrations, ratios and LMA were more profound in the herbaceous species than in the woody species. In addition, pigment concentrations were negatively correlated with LMA in each life form type and in the pooled dataset. However, the LMA effect on leaf pigment concentrations was more profound in the deciduous species than in the evergreen braode-leaved species. In general, herbaceous species seemed more sensitive to the increasing altitude compared to woody species, and LMA seemed to be a more important mechanism for protecting leaf pigments in deciduous species than in evergreen broad-leaved species. These results suggested that the species with different life forms may employ different protective mechanisms to decrease the chloroplast apparatus damage and increase their carbon gain.

川西云杉(Picea balfouriana)天然群体的遗传变异

青藏高原东南缘由于特殊的生态地理条件，有着丰富的森林资源，这些资源是长江上游涵养水源、保持水土的生态屏障，是生物多样性的资源宝库。但随着过量的森林采伐，使该区曾经丰富的生物多样性资源遭受了前所未有的破坏，天然林的质量严重下降，生态系统退化，功能减弱。与此同时，许多物种的种群规模正在锐减，物种的遗传多样性也严重丧失。川西云杉是西部地区分布最广的云杉树种之一，在较高海拔的地区有着重要的生态学功能，是一种适应性很强的乡土树种。本项目采用简单序列重复标记(SSR)和特定序列位点(STS)研究不同生境条件下川西云杉群体的遗传变异及其时空分布格局，考察遗传变异与复杂的山地生态环境间的潜在联系，系统地揭示川西云杉天然群体与环境系统相互作用的生态适应与分子进化机制。研究成果能有效地为该树种遗传资源的科学保护与合理利用提供理论依据和科学指导，可为中国西南部亚高山天然林的可持续经营及退化生态系统的恢复与重建提供依据。主要研究结果如下： 1 STS和SSR两种分子标记的研究结果表明：川西云杉群体拥有中等水平的遗传多样性(基于SSR标记，平均He = 0.640；基于STS标记，平均He = 0.553)。造成这种中等水平的遗传多样性，可能是由于历史原因，川西云杉天然林被大量采伐，导致了遗传多样性的丧失。两种方法都检测出群体BT有着最高水平的遗传多样性。 2 两种标记的结果都一致说明：检测的10个川西云杉群体间遗传分化比较高，其存在群体间的遗传变异比例要明显地高于广泛分布的挪威云杉、横贯大陆的黑云杉以及兼有连续分布和不连续分布的西加云杉等，但要低于分布范围狭窄且呈不连续分布的粗枝云杉。青藏高原东南部的片段化生境可能是导致高水平遗传分化的主要原因。 3 基于两种标记的UPGMA 聚类和PCA分析结果，以及基于SSR标记的FCA分析结果都显示：群体BY遗传上明显区别于其它群体，其可能原因是青藏高原东南缘山脉阻隔而导致的生殖隔离的结果。 4 根据软件Bottleneck 1.2.02的检测以及不依赖哈迪一温伯格平衡的M比率检测结果：川西云杉种群很有可能经历了近期的遗传瓶颈效应。在本研究中遗传瓶颈效应并没有显著影响到物种的遗传多样性。然而，在这些片断化群体未来的子代群体中很可能出现遗传瓶颈导致的遗传多样性下降的效应。 Due to the extremely complex topography and climatic conditions, the southeast of the Qinghai-Tibet Plateau is region abundant in forest resource, which is benefit to the upper reaches of the Yangtze River water conservation, and protecting natural environment and biodiversity resources. However, by the reason of a plenty of trees were cut in these yeas, the biodiversity resource was destroy with degraded ecosystem and imperfect funcation. Picea balfouriana is one of the regionally distributed conifer species in the southeast of the Qinghai-Tibet Plateau and considered as a constructive species within its distribution area. It is an optimal species for the production of biomass. Moreover, it is well adapted to stressful environments at high altitude, especially to cold and drought conditions which are generally harsh for other trees. In our study, two types of molecular markers (SSR and STS) were used to estimate the genetic diversity and genetic structure of P. balfouriana populations originating from the southeast of the Qinghai-Tibet Plateau with varying climatic and geographical conditions. The results will not only provide a deep insight into its genetic diversity and population genetic structure but also valuable information for further management and breeding programs in P. balfouriana. In summary, the results obtained in this study revealed that: 1 A moderate degree of genetic variation is present in P. balfouriana in the southeast of the Qinghai-Tibet Plateau and it may caused by many trees were cut in the past. Population BT owns the highest level of genetic diversity by both two types of markers. 2 Considerable population differentiation exists among the ten P. balfouriana populations based on both SSR and STS markers, possibly caused by habitat fragmentation and heterogeneous environments. 3 The UPGMA clustering and PCA analyses based on SSR and STS marker, and FCA analyses based on SSR marker congruously separated population BY from other populations, which is likely due to the presence of mountain barriers. 4 The results of bottleneck analysis indicated that P. balfouriana populations that have undergone recent declines. In our research, the bottleneck effect don’t have a significant impact on the genetic diversity of species, however, the level of genetic diversity of P. balfouriana offspring populations growing in the fragmented habitats will decline in the future.

西藏齿突蟾蝌蚪冷适应策略研究

本文通过对高海拔两栖类西藏齿突蟾(Scutiger boulengeri)蝌蚪在实验室特定低温条件下的冷适应微空间行为分布的动态变化分析、温度耐受性实验及在不同适应温度的乳酸脱氢酶(LDH)同工酶的酶量与活性比较分析, 探讨了高海拔两栖类蝌蚪的部分冷适应策略。 西藏齿突蟾蝌蚪在不同温度的行为分布是一连续、动态过程，需用多种检验方法综合利用才能进行判断；在15℃, 除低海拔分布的西藏齿突蟾种群外所有实验物种蝌蚪均符合负二项分布、NeymanⅡ型分布；在10℃, 高海拔两栖类蝌蚪均符合负二项分布、NeymanⅡ型分布；在5℃、0℃低温时，高海拔两栖类不同分组的西藏齿突蟾蝌蚪的负二项分布、NeymanⅡ型分布均呈现明显差异, 这可能与高海拔两栖类蝌蚪在低温条件下通过不断地改变其行为分布方式来避免自身被冻伤有关。野外观察表明：高海拔两栖类蝌蚪常选择与流动河水相连的静水水体这种微生境中生存, 蝌蚪应对环境温度极端变化会不断改变其行为分布方式来选择最佳生存温度以避免极端高、低温对自身身体的伤害, 这种对微生境的利用能力对高海拔两栖类蝌蚪耐受极端环境温度的变化极其重要。 两栖类蝌蚪的温度耐受性实验表明不同的驯化温度可以改变西藏齿突蟾蝌蚪、两栖类仙琴水蛙蝌蚪的最适温度、逃避温度，并具有显著影响。 随着驯化温度5℃、10℃逐渐升高, 其最适温度、逃避温度也在一定范围内升高，但驯化温度对低海拔的仙琴水蛙蝌蚪的最适温度、逃避温度的改变效应大于高海拔的西藏齿突蟾蝌蚪的改变效应, 仙琴水蛙蝌蚪对温度的耐受范围、最适温度和逃避温度的ARRS值都大于西藏齿突蟾蝌蚪, 这说明仙琴水蛙蝌蚪对环境温度变化的适应能力大于西藏齿突蟾蝌蚪。 高海拔地区不同分组的两栖类蝌蚪, 在0℃适应温度时, LDH5条带的酶相对含量最高，而在5℃、10℃、15℃适应温度时，LDH5条带的酶相对含量明显都降低, 这表明酵解作用是高海拔两栖类蝌蚪的一些组织在低温﹑缺氧环境中的重要供能方式。高海拔两栖类蝌蚪同一分组的LDH总酶活性总是表现为10℃适应温度的总酶活性最高，而对低海拔的两栖类蝌蚪则是0℃适应温度的总酶活性最高, 这说明高海拔两栖类蝌蚪的LDH同工酶A、B两亚基基因活性在10℃时最高, 而低海拔两栖类蝌蚪的LDH同工酶A、B两亚基基因活性在0℃时最高。同时发现在15℃适应温度组的高海拔两栖类蝌蚪的LDH电泳图谱都有第6条带,有可能由LDH - C亚基组成, 对高海拔两栖类蝌蚪的LDH - C亚基只在15℃适应温度下才表达的机理还有待进一步的研究。 高海拔两栖类西藏齿突蟾蝌蚪通过行为分布方式的改变来选择最佳的生存温度, 这种温度选择过程与野外特定的微生境的存在密切相关, 现在由于人类对河道的不合理利用正在导致高海拔两栖类蝌蚪赖以生存的这种微生境逐渐消失, 这种微生境的消失将加速高海拔的两栖类种群数量衰退的进程。高海拔两栖类物种蝌蚪在低温（0℃）上表现出的同工酶多谱带说明，其A、B两亚基都有所表达，及其参与代谢的方式也是正常的，而低海拔两栖类物种蝌蚪只有A亚基表达的LDH5存在，因此其主要参与酵解过程，这种通过动物自身生理代谢方式的改变来适应极端环境温度条件的变化是高海拔两栖类蝌蚪能适应低温环境的重要策略。但高海拔物种的适应温度变化范围显著小于低海拔物种，对环境温度的变化适应能力有限，特别是对高温区域，因此全球气候变化可能对高海拔物种影响更为显著。 The partly cold-adaptation stratagem of the high altitude amphibian tadpole were researched in the laboratory by analyzing the high altitude amphibian tadpole of Scutiger boulengeri mainly on endpoints related to the dynamic variation of the micro-spatial behavior distribution patterns, the experiment of the temperature tolerance, and the enzyme content and activity of the lactic acid dehydrogenase(LDH) isozyme in special temperature condition. The behavior distribution of the Scutiger boulengeri tadpole is continuous and variable, but it can be figured out by multple testing ways. At 15℃, all of the experiment amphibian tadpoles behavior distribution fit both for the negative binomial distribution and NeymanⅡtype distribution except for the low altitude Scutiger boulengeri tadpoles. At 10℃, all of the high altitude amphibian tadpoles behavior distribution fit both for the negative binomial distribution and NeymanⅡtype distribution. At lower temperature, 5℃ and 0℃, the high altitude amphibian tadpoles of the Scutiger boulengeri at different groups behavior distribution fit for or don’t fit for behavior distribution respectively. It is denoted that the high altitude amphibian tadpoles probably avoid frostbiting by varying the behavior distribution patterns at low temperature condition. The high altitude amphibian tadpoles often actively select the special microhabitat which has the connected still water body and the flowing water body in the wild. It is important that tadpoles can endure the extreme temperature variety in this kind of microhabitat, because tadpoles can be better survival through select temperature condition through migrating in these kinds of microhabitats by varying their own behavior distribution patterns. Different acclimation temperature causes the significant change of preferred temperature(PT)、 avoiding temperature(AT) both in high altitude amphibian Scutiger boulengeri tadpoles and in low altitude amphibian Rana daunchina tadpoles in the temperature endurance experiment. With the acclimation temperature growing from 5℃ to 10℃. the PT and the AT of them would be uprise to some extent, but the effect of acclimation temperature on the PT and the AT of the tadpoles of Rana daunchina is more significant than the ones on the tadpoles of Scutiger boulengeri, at the same, the effects on the temperature endurance range, the ARRs of the tadpoles of Rana daunchina would be stronger than the ones on the tadpoles of Scutiger boulengeri. It is implied that the adaptation ability of tadpoles of Rana daunchina to the surroundings temperature alternation preferred to tadpoles of Scutiger boulengeri. At 0℃ acclimation temperature, the LDH5 enzyme comparative content of the high altitude amphibian tadpoles at different groups was highest, but it becomes lower at 5℃、10℃、15℃ acclimation temperature. It indicated that the alcoholysis role was the important ways of applying energy for special tissue of the high altitude amphibian tadpoles in low-temperature and low-oxygen condition. The total enzyme activity of the LDH of the high altitude amphibian tadpoles in the same group always keeps the highest at 10℃ acclimation temperature, but the low altitude amphibian tadpoles’ was maximum at 0℃. It was denoted that the gene activity of LDH -A and LDH – B submit was highest at 10℃ acclimation temperature for the high altitude amphibian tadpoles, but the low altitude amphibian tadpoles’ was maximum at 0℃. Meanwhile, the LDH electrophoretogram of the high altitude amphibian tadpoles always composed of 6 stripes at 15℃ acclimation temperature，the extra stripe probably was composed by LDH-C submit。It is unknown why LDH-C expresses only under high temperature。. The high altitude amphibian tadpoles can select the most optimal temperature by changing their behavior distribution patterns ceaselessly, but this course of selecting the most suitable temperature correlated with the special microhabitat in the wild closely. Nowadays, this kind of microhabitat which the high altitude amphibian tadpoles rely on are lossing gradually for human being exploit the riverway unreasonably. The disappearing of the microhabitat would accelerate the decline of the high altitude amphibian population. Compare to one band of LDH5, which only composed by the LDH-A submit, presents in the low altitude amphibian at 0℃, the five bands which composed by the LDH-A and LDH-B are checked out, this means the species which occurred in the highland is more adaptable to the low temperature. It is an important stratagem for the high altitude amphibian tadpoles adapt to the limited low temperature depends on the animal energy metabolism change.However, this kind of adaption is restricted, the adaption range to the temperature is much norrow in the high altitude amphibian than in the low one, especially for the high temperature side. The global climate change will be more serious for the high altitude species.

长白山地区曲尾藓属植物生态分化的排序研究

The relationships of eight moss species of Dicranum in 31 sites in main ecological systems in the Changbai Mountain with environmental factors were studied by canonical correspondence analysis (CCA). The results showed that altitude, soil sand percentage, water percentage, acidity and canopy density were important environmental factors influencing the distribution of the species of Dicranum . The relationships between Dicranum elongatum Schleich. ex Schwaegr ., D.groenlandicum Brid. and altitude,between D.japonicum Mitt., D.scoparium Hedw. and canopy density,between D.polysetum Sw., D. undulatum Schrad. ex Brid. and soil acidity and water percentage,were positively correlative. The niche overlaps among the eight species of Dicranum were calculated. The minimal spanning tree of the eight species on the two-dimensional scatter plot were also drawn based on their niche overlaps, which clearly revealed the ecological similarities of eight species.

大巴山北坡垂直带土壤特性及系统分类

通过野外考察与室内分析相结合 ,对大巴山北坡不同海拔高度的土壤特性进行研究 ,确定了各剖面的诊断层和诊断特性及其在系统分类中的位置。结果表明大巴山北坡各垂直带土壤在系统分类中可划归 2个土纲的 6个土类 ,系统分类中土壤的分类位置与发生分类位置并不具有简单的一一对应的关系。

Changes in individual plant traits and biomass allocation in alpine meadow with elevation variation on the Qinghai-Tibetan Plateau

Plant traits and individual plant biomass allocation of 57 perennial herbaceous species, belonging to three common functional groups (forbs, grasses and sedges) at subalpine (3700 m ASL), alpine (4300 m ASL) and subnival (>= 5000 m ASL) sites were examined to test the hypothesis that at high altitudes, plants reduce the proportion of aboveground parts and allocate more biomass to belowground parts, especially storage organs, as altitude increases, so as to geminate and resist environmental stress. However, results indicate that some divergence in biomass allocation exists among organs. With increasing altitude, the mean fractions of total biomass allocated to aboveground parts decreased. The mean fractions of total biomass allocation to storage organs at the subalpine site (7%+/- 2% S.E.) were distinct from those at the alpine (23%+/- 6%) and subnival (21%+/- 6%) sites, while the proportions of green leaves at all altitudes remained almost constant. At 4300 m and 5000 m, the mean fractions of flower stems decreased by 45% and 41%, respectively, while fine roots increased by 86% and 102%, respectively. Specific leaf areas and leaf areas of forbs and grasses deceased with rising elevation, while sedges showed opposite trends. For all three functional groups, leaf area ratio and leaf area root mass ratio decreased, while fine root biomass increased at higher altitudes. Biomass allocation patterns of alpine plants were characterized by a reduction in aboveground reproductive organs and enlargement of fine roots, while the proportion of leaves remained stable. It was beneficial for high altitude plants to compensate carbon gain and nutrient uptake under low temperature and limited nutrients by stabilizing biomass investment to photosynthetic structures and increasing the absorption surface area of fine roots. In contrast to forbs and grasses that had high mycorrhizal infection, sedges had higher single leaf area and more root fraction, especially fine roots.