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1.
基于功能性状的研究方法广泛地应用于生态学研究, 用于解释不同层次的复杂的生态学过程, 而绿色植物叶片的功能性状长期被认为对植物的生存、生长和繁殖具有重要的影响。该研究对玛曲高寒沼泽化草甸51个植物种(分属于14科)的叶片形态和光合性状进行测量, 比较不同物种和不同功能群(莎草科、禾本科和双子叶类杂草)的差异, 分析叶片形态特征和叶片光合性状之间的相关性。结果表明: 1)不同物种、不同功能群之间在比叶面积、净光合速率和水分利用效率等叶片形态和光合特征方面有着显著的差异, 例如禾本科植物具有较高的比叶面积和水分利用效率, 双子叶类杂草具有较大的叶面积, 而莎草科植物具有较高的净光合速率。2)相关性分析结果显示, 无论在物种水平还是功能群水平, 叶片形态和叶片光合性状之间都具有显著的相关关系。该研究揭示了高寒沼泽化草甸植物物种在叶片功能性状上的显著分化, 进而使得这些物种能在同一个草地群落中共存, 而群落中不同功能群物种的组成差异将会对群落的结构、功能和资源利用产生显著的影响。该研究将为进一步研究高寒沼泽化草甸提供基础研究数据并为其保护和恢复提供生理生态学依据。  相似文献   

2.
为探究截干与否对杉木老龄化母树光合特性的影响,以杉木种子园老龄化截干与未截干母树为试验对象使用LI 6400XT便携式光合测定系统对其净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)和水分利用效率进行了比较研究。结果表明:与未截干母树相比,截干可极显著提高母树净光合速率、气孔导度、蒸腾速率以及水分利用效率,其中净光合速率提高了0.3~5.6倍,叶片气孔导度提高了0.4~2.7倍,蒸腾速率提高了0.2~2.1倍,水分利用效率提高了0.02~2.6倍。枝条朝向对光合特性有显著影响,总体表现为东面枝叶的净光合速率、叶片气孔导度和蒸腾速率大于南面和西面。  相似文献   

3.
杂草稻是一类重要的稻属种质资源,具有耐寒、耐旱、耐瘠薄等优良特性.本文以88份中国北方杂草稻资源和4份栽培稻为材料,研究了中国北方杂草稻的光合速率、蒸腾速率、气孔导度等光合与水分生理特性及其相互关系.结果表明: 北方杂草稻资源的光合和水分生理特性存在较大差异,具有丰富的多样性.杂草稻的光合速率变化范围在12.47~28.67 μmol CO2·m-2·s-1,瞬时水分利用效率的变化范围在1.39~3.40 mg·g-1.光合参数中,胞间CO2浓度的变异系数最小,气孔导度的变异系数最大.光合速率与蒸腾速率、气孔导度呈极显著的二次曲线关系,光合速率与胞间CO2浓度呈显著的直线关系,瞬时水分利用效率与蒸腾速率、气孔导度呈极显著的二次曲线关系.可用杂草稻材料的优越性能对栽培稻进行品种改良.  相似文献   

4.
以兰州银滩黄河湿地的千屈菜、芦苇、酸模叶蓼、稗草、龙葵、反枝苋、曼陀罗、红豆草、藨草和水莎草10种植物为材料,采用美国CI-340便携式光合测定系统在晴朗天气下测定了各植物成熟叶片的光合有效辐射(PAR)、净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、胞间CO2浓度(Ci)以及大气温度(Ta)、大气CO2浓度(Ca)等指标的日变化,以探讨其光合生理生态特性。结果表明:有7种湿地植物的净光合速率呈不对称的双峰曲线,光合"午休"现象明显,分别是由气孔和非气孔2个因素引起;通过相关分析、逐步回归分析发现,大多数植物的Pn与Tr、Gs、PAR有较好的相关性,各生态因子对Pn的贡献系数不同,说明影响它们光合速率的主要生理生态因子各不相同;午间强光、高温导致湿地植物的蒸腾速率加剧。本研究对了解湿地植物优势种的光合特性及其与环境因子关系、人工种植湿地植物物种选择有重要意义。  相似文献   

5.
干旱胁迫对夏蜡梅光合特性的影响   总被引:7,自引:0,他引:7  
柯世省 《西北植物学报》2007,27(6):1209-1215
以2年生夏蜡梅(Sinocalycanthus chinensis)苗木为材料,通过盆栽试验,研究土壤干旱胁迫对夏蜡梅叶片光合特性的影响,结果显示:随着干旱胁迫程度的加重,夏蜡梅叶片净光合速率、蒸腾速率、气孔导度显著降低;胞间CO2浓度在轻度和中度胁迫下显著低于对照,但在重度胁迫下显著高于对照;水分利用效率在胁迫下提高,且以中度胁迫为最大.温度升高使叶片净光合速率和水分利用效率降低、蒸腾速率升高,加重了干旱对光合作用的不利影响.对照及轻度和中度干旱胁迫处理的净光合速率、气孔导度和水分利用效率日变化曲线均为双峰型,但重度胁迫下净光合速率和气孔导度日变化转变为峰值很小的单峰型;各处理的蒸腾速率日变化曲线为单峰型并以午间最高.表明夏蜡梅光合作用对干旱胁迫有一定的适应能力,但重度胁迫对其造成严重影响.  相似文献   

6.
运用开放式气体交换C I-310便携式光合作用测定系统,研究了重庆石灰岩地区适生灌木十大功劳(Maho-nia fortunei)光合特性的动态变化和对CO2的响应。结果表明:十大功劳的净光合速率和气孔导度的日变化为双峰曲线,蒸腾速率的日变化为单峰曲线,净光合速率出现了光合午休现象,主要由非气孔因素影响,水分利用效率的日变化呈“L”型。在季节变化中净光合速率、蒸腾速率和气孔导度都呈现双峰曲线,而水分利用效率呈现“W”型。气体交换的日动态和季节动态变化是与植物生存的气候环境相适应的,在石灰岩地区表现出低光合低蒸腾和高水分利用效率的节水特性。净光合速率随着CO2浓度的升高而表现出升高趋势,其CO2补偿点为90μmol.mol-1左右,羧化效率为0.0125,较低的羧化效率是十大功劳净光合速率较低的一个原因。  相似文献   

7.
利用大型移动防雨棚开展了玉米水分胁迫及复水试验,通过分析玉米叶片光合数据,揭示了不同生育期水分胁迫及复水对玉米光合特性及水分利用效率的影响。结果表明:水分胁迫导致玉米叶片整体光合速率、蒸腾速率和气孔导度下降以及光合速率日变化的峰值提前;水分胁迫后的玉米叶片蒸腾速率、光合速率和气孔导度为适应干旱缺水均较对照显著下降,从而提高了水分利用效率,缩小了与水分充足条件下玉米叶片的水分利用效率差值;在中度和重度水分胁迫条件下,玉米叶片的水分利用效率降幅低于光合速率、蒸腾速率和气孔导度的降幅, 有时甚至高于正常供水条件下的水分利用效率;适度的水分胁迫能提高玉米叶片的水分利用效率,从而增强叶片对水分的利用能力,抵御干旱的逆境;水分亏缺对玉米光合速率、蒸腾速率及水分利用效率的影响具有较明显滞后效应,干旱后复水,光合作用受抑制仍然持续;水分胁迫时间越长、胁迫程度越重,叶片的光合作用越呈不可逆性;拔节-吐丝期水分胁迫对玉米叶片光合作用的逆制比三叶-拔节期更难恢复。  相似文献   

8.
柯世省 《生物学杂志》2007,24(4):37-40,61
云锦杜鹃净光合速率和气孔导度日变化曲线为"双峰"型,光合效率午间明显降低,主要由非气孔限制引起。表观量子效率和实际光化学效率的降低是非气孔限制形成和发展的深层原因。蒸腾速率的日变化为"单峰型",午间最高。水分利用效率早晚较高、午间较低。净光合速率、蒸腾速率、气孔导度和水分利用效率分别与一些环境因子的相关性达到0.01或0.05显著水平。利用多元逐步回归方法分别得到了净光合速率、胞间CO2浓度、蒸腾速率、气孔导度和水分利用效率与环境因子的最优方程。  相似文献   

9.
28种园林植物对大气CO2浓度增加的生理生态反应   总被引:6,自引:0,他引:6  
通过对28种园林植物在不同CO2浓度水平下的气体交换参数的观测,分析了净光合速率、气孔导度、蒸腾速率和水分利用效率等生理生态指标的变化趋势与规律.结果表明,所测植物净光合速率和水分利用效率随CO2浓度升高而线性增加,但不同植物种类对高CO2浓度的反应存在较大差异.气孔导度和蒸腾速率与CO2浓度呈线性负相关关系.当CO2浓度倍增(350~700 μmol·mol-1)时,28种园林植物净光合速率平均提高31.2%,气孔导度降低16.5%,蒸腾速率下降11.7%,而水分利用效率则提高了49.2%.不同光合途径的植物净光合速率和水分利用效率受CO2浓度增加的影响程度为C3植物较大,C4植物较小, CAM植物介于两者之间.对不同生活型植物而言,影响程度则为草本C3植物较大,乔木C3植物较小,灌木C3植物居于两者之间.  相似文献   

10.
为探究单播与混播人工草地对羊草和紫花苜蓿光合特性的影响,测定2种牧草光合特性日变化进程,比较不同处理下羊草和紫花苜蓿光合特征。结果表明:单播处理下,羊草和紫花苜蓿的净光合速率、蒸腾速率、叶片温度呈单峰型,紫花苜蓿的气孔导度呈单峰型,羊草的气孔导度和水分利用效率呈双峰型。混播处理下,羊草和紫花苜蓿的净光合速率、蒸腾速率、叶片温度日变化呈单峰型,羊草的气孔导度和水分利用效率呈单峰型,紫花苜蓿的气孔导度呈双峰型。混播处理下,羊草净光合速率峰值显著高于单播,分别为17.72和13.65μmol CO2·m-2·s-1。单播和混播处理下,羊草叶绿素含量均高于紫花苜蓿,羊草叶片氮含量均低于紫花苜蓿,且混播羊草叶片氮含量显著高于单播羊草,二者分别为27.60和22.55 g·kg-1。不同种植方式下,羊草和紫花苜蓿的净光合速率与气孔导度、蒸腾速率呈显著正相关,与胞间CO2浓度呈显著负相关,紫花苜蓿的净光合速率与叶片温度、水分利用效率呈显著正相关。混播处理有利于增加羊草叶片氮含量。试验结果为牧...  相似文献   

11.
Aims Terrestrial carbon (C), nitrogen (N), phosphorus (P) stoichiometry will reflect the effects of adjustment to local growth conditions as well as species' replacements. However, it remains unclear about the hierarchical responses of plant C:N:P to P addition at levels of species and functional groups in the N-limited alpine meadow. Methods A field experiment of P enrichment was conducted in an alpine meadow on the Qinghai-Xizang Plateau during 2009-2013. The stoichiometric patterns of four functional groups (grass, sedge, legume and forb) and five representative species, Elymus nutans (grass), Kobresia humilis (sedge), Oxytropis ochrocephala (legume), Taraxacum lugubre (rosette forb), Geranium pylzowianum (upright forb) were investigated in 2013, and the effects of P addition on species dominance and plant biomass were also analyzed. Important findings Both plant nutrition content and C:N:P varied significantly after five years' P addition, and the responses were consistent at species-And functional group (exemplar species excluded)-levels in the alpine meadow. P addition had neutral effect on C concentrations of grasses, sedges and forbs at both species-And functional group (exemplar species excluded)-levels. P fertilization increased plant P concentrations and thus decreased C:P and N:P of the four functional groups (exemplar species excluded) and the corresponding species. N concentrations significantly decreased and C:N increased in grasses and sedges after P addition, and the species-level responses were consistent with the functional group (exemplar species excluded) level. P addition significantly increased N contents and decreased C:N in Oxytropis ochrocephala, but had neutral effect on N contents and C:N at the functional group (exemplar species excluded) level of the legumes. While N contents and C:N in forbs responded to P addition differently at species and functional group (exemplar species excluded) levels. In the N-limited alpine meadow, species dominance of grasses increased gradually after P addition due to the increased N and P use efficiencies, while the biomass proportion of forbs decreased because of the lowered nutrition use efficiency. © 2018 Editorial Office of Chinese Journal of Plant Ecology. All rights reserved.  相似文献   

12.
Aims The alpine meadow degradation could have profound effects on the grassland productivity. The aim of our study is to clarify the dynamic response of community productivity and species diversity in the process of alpine meadow degradation. Methods In the Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Northern Tibetan Grassland Ecosystem Research Station (Nagqu station), we conducted stages experiments with multiple degradation levels: control, mild degraded meadow, moderate degraded meadow, severe degraded meadow and serious sandy meadow. Important findings The response of aboveground biomass to alpine meadow degradation showed a linear or nonlinear increased response patterns, but the belowground biomass and total biomass decreased nonlinearly. As observed in measurement of aboveground biomass, Margalef index, Simpson index, Shannon-Wiener index and Pielou evenness index also exhibit a nonlinear increased response to degradation. The results of structural equation models showed that belowground biomass has a positive relationship with soil carbon content (p < 0.05) and volume water content (p < 0.1). However, soil nutrient and soil physical properties had no significant impact on aboveground biomass (p < 0.1). Compared with soil physical properties, soil nutrition is an important factor influencing the diversity index. In our study, the nonlinear responses of productivity and diversity of alpine meadow were described by using the multiple levels of degradation in space. The results suggested that aboveground productivity cannot interpret the degree of degradation of alpine meadow, and by contrast, alpine meadow degradation should be measured by the change of plant functional groups, such as edible grasses and poisonous forbs. © 2018 Editorial Office of Chinese Journal of Plant Ecology. All rights reserved.  相似文献   

13.
高寒矮嵩草草甸植物类群对模拟降水和施氮的响应   总被引:13,自引:1,他引:12       下载免费PDF全文
 研究了青藏高原高寒矮嵩草(Kobresia humilis)草甸植物类群对模拟夏季增减雨量、冬春增雪以及增施氮肥下的响应。结果表明:1999年模拟减少降雨20%~40%和增加雨量20%~40%下禾草类、杂类草和莎草类的综合优势比(SDR)和地上生物量变化均不显著。冬春增雪100%有利于禾草类夏季的生长,冬春增雪对植物类群的影响大于夏季雨量的增加。夏季增施氮150 kg·hm-2和增施氮300 kg·hm-2禾草类的盖度比、高度比、SDR和地上生物量明显增大,而杂类草的盖度比和高度比、SDR及地上生物量在施氮300 kg·hm-2下显著减低,在施氮150 kg·hm-2水平上禾草类的生物量的增加与杂类草生物量的降低存在相互补偿的作用机制。在水分资源不利的(如减少雨量)的干扰下,其敏感性表现为杂类草大于禾草类,莎草类最小。莎草类植物对各种处理下响应不敏感,也说明它对资源环境的波动有很强的适应性。缺水年(1999年)模拟增加雨量20%~40%的条件下,可缓解降水量减少的影响,相反模拟减少雨量20%~40%会增强干旱的影响程度。  相似文献   

14.
Coppedge  B.R.  Engle  D.M.  Toepfer  C.S.  Shaw  J.H. 《Plant Ecology》1998,139(2):235-246
We used univariate and multivariate techniques to evaluate vegetation-environment relationships for plant functional groups on a tallgrass prairie site in northern Oklahoma, USA burned seasonally and grazed by bison (Bison bison L.). The objective of the study was to identify important environmental variables associated with variation in residual aboveground standing crop (phytomass) and abundance of plant functional groups. Phytomass was predictably linked to season, with highest levels found in the latter portion of the growing season when the warm-season tallgrasses that dominated the site were most actively growing. When the effects of seasonal phenology were removed, stepwise regression revealed that phytomass variation was best explained by year-to-year climatic variation, seasonal burn type, and bison grazing. Phytomass was negatively related to bison grazing under all conditions. A number of plant functional groups responded to individual environmental variables: relative abundance levels of tallgrasses, little bluestem, annual grasses, forbs and legumes all varied with burn season; little bluestem, annual grasses, and sedges varied by topoedaphic position, while forbs exhibited a positive relationship with bison grazing intensity. Canonical Correspondence Analysis (CCA) was used to directly relate composition patterns of functional groups to environmental variables. CCA bi-plot of the ordination revealed that annual grasses were most closely associated with summer fires; sedges were associated with fall burns and the 1995 sampling year; legumes associated with a gradient representing the length of time since fire; while tallgrasses and little bluestem ordinated nearest a gradient representing bison grazing. Forbs and perennial grasses did not clearly associate with any particular environmental gradient, suggesting they were either simultaneously affected by several parameters or that environmental attributes important to these groups were not measured. Total phytomass and sedges were strongly influenced by yearly climatic variation. Relative abundance of some plant functional groups was principally determined by a single factor, while others were equally influenced by a suite of environmental interactions.  相似文献   

15.
许华磊  王溪  刘伟 《兽类学报》2019,39(5):537-545
在高寒草甸生态系统中,大型草食动物放牧是重要的管理方式之一,对草地生物多样性起着关键的驱动作用。高原鼠兔是高寒草甸生态系统中生物多样性的重要组成成分,对生态系统的食物网结构以及其功能与稳定性起着关键作用。探明放牧条件下高原鼠兔扰动对高寒草甸的影响,对于高寒草甸建立合理的放牧提供理论依据,为鼠害的防治提供科学依据有一定的现实意义。2017年5—9月在青海省海北州祁连县矮嵩草草甸,以高原鼠兔为研究对象,通过小区控制研究放牧条件下高原鼠兔扰动对高寒草甸植物功能群植物特征的影响。结果显示高原鼠兔扰动降低了除杂类草以外的各植物功能群的高度;同时显著降低了禾本科、豆科功能群盖度及总盖度,而杂类草功能群的盖度有增加的趋势。另外,我们的结果也发现高原鼠兔扰动对各植物功能群生物量和重要值的影响不显著。该研究表明放牧条件下高原鼠兔扰动在一定程度上对杂草群落特征具有积极的作用,对其它功能群的群落特征具有抑制作用。  相似文献   

16.
土壤碳输入与输出之间的收支差决定土壤有机碳(SOC)含量。若尔盖湿地高寒草甸退化过程中, 土壤碳输入和输出哪个过程对SOC含量的影响占主导作用还不明确。该研究用空间序列代替时间序列的方法研究了若尔盖湿地高寒草甸不同退化阶段(高寒草甸(AM)、轻度退化高寒草甸(SD)和重度退化高寒草甸(HD)) SOC含量变化及原因。首先, 通过测定高寒草甸退化阶段上主要的土壤理化性状、微生物生物量、植物生物量和功能群组成的变化, 分析了退化阶段上土壤碳输入量的变化及原因; 其次, 结合室内土壤碳矿化培养实验结果和研究区的月平均气温以及土壤呼吸温度敏感性(Q10)估算了该区域土壤碳输出, 并分析了其变化原因; 最后, 分析了造成SOC含量变化的主要原因和过程。结果表明: 在退化梯度上, 土壤含水量(SWC)、SOC和全氮(TN)含量、微生物生物量碳氮含量降低; 植物群落组成逐渐从莎草科、禾本科占优势过渡到杂类草占优势, 且植物生物量降低; SOC矿化量降低; 有机碳潜在积累量降低(与AM阶段相比, SD和HD阶段有机碳潜在输入量、输出量和积累量分别降低了16%、18%、15%和59%、63%、41%)。SWC降低引起土壤容重、SOC含量、TN含量、全磷含量、C:N的改变, 进而导致植物功能群分布模式和土壤微生物的变化, 最终引起SOC输入和输出量的降低。SWC降低导致的植物碳潜在输入量的降低是若尔盖湿地高寒草甸退化过程中SOC含量下降的主要原因。  相似文献   

17.
青藏高原区域不同功能群植物氮磷生态化学计量学特征   总被引:7,自引:4,他引:3  
于海玲  樊江文  钟华平  李愈哲 《生态学报》2017,37(11):3755-3764
生态化学计量学为揭示植物养分利用状况及植物对环境的适应策略提供了重要手段,研究不同功能群植物在区域尺度生态化学计量学特征中所产生的贡献,有助于揭示区域尺度植物元素特征的形成机制。已有研究多是从不同功能群植物元素生态化学计量学特征的比较上进行分析,未能对每种功能群植物元素含量随地理因子和气候因子的变化规律展开探讨。基于生态化学计量学理论,对青藏高原区域不同功能群植物(豆科、禾本科、莎草科、杂类草)叶片水平N、P元素含量随纬度、海拔、年降水量、年均温度的变化规律展开研究,探讨不同植物功能群在区域尺度植物生态化学计量学特征中所产生的贡献,尝试从植物功能群角度揭示青藏高原高寒区域N、P元素含量特征的形成机制。结果显示,1)不同功能群植物叶片元素含量差异显著,豆科植物N、P元素含量最高,禾本科植物N、P含量最低,N/P比值在不同功能群间差异不显著;2)随纬度变化,莎草科植物P元素及杂类草N元素含量变化显著;随海拔变化,豆科、禾本科植物及杂类草叶片N元素含量变化较为显著;随年降水量和年均温度的变化,杂类草和莎草科植物叶片N、P含量变化显著;3)莎草科植物N、P含量对纬度和降水的响应趋势与区域内所有植物叶片N、P含量对纬度和降水的响应趋势一致,豆科、禾本科及杂类草植物叶片元素含量对海拔和温度的响应趋势与区域内所有植物叶片元素平均含量对海拔和温度的响应趋势一致。研究表明,不同功能群植物元素特征对环境因子的响应不同,植物功能群组成对区域尺度植物生态化学计量学特征有重要作用,但在较大的植物结构层次上(如植物群落、生态系统、区域或全球尺度等),不同功能群植物之间的相互组合会抵消或掩盖掉某一类群的特性,从而对区域尺度植物元素特征的变化规律产生影响。  相似文献   

18.
为了解纳帕海流域高山环境中优势乔木树种光合速率特征及其对环境因子的响应规律,运用LI-6400便携式光合测定仪,分别测定了香格里拉纳帕海流域5种优势乔木树种净光合速率(Pn)、蒸腾速率(Tr)、水分利用效率(WUE)等主要光合生理参数日变化,并对其与环境因子的相关性进行统计分析。结果表明:(1)所测定的5种优势树种中,除川滇高山栎以外,其他4个树种的Pn均呈双峰型;5种树种Pn峰值大小依次为云杉高山松山楂清溪杨川滇高山栎,分别为21.58、21.57、15.21、14.18、11.87μmol·m~(-2)·s~(-1)。(2)树种气孔导度(Gs)和蒸腾速率(Tr)在一天之内都呈现出早晚低、中午高的规律,胞间CO2浓度(Ci)与Pn基本呈相反趋势。(3)树种WUE和LUE日均值与Pn值表现出基本一致的顺序特征,云杉和高山松相对较高,WUE分别为3.27和5.82 mmol·m~(-2)·s~(-1),LUE分别为4.42%和2.99%,川滇高山栎最低,仅为0.92 mmol·m~(-2)·s~(-1)和0.74%。(4)树种Pn对PAR和Gs的变化具有显著的响应特征。该区域树种的Pn最大值高于低海拔区域的同类树种;区域内针叶树种的WUE和LUE显著大于阔叶树种,对高山区域内相对较高的辐射环境具有更高效的适应策略;当地环湖面山上种植的大面积云杉树对区域植被的恢复具有高效的现实意义。  相似文献   

19.
矮嵩草草甸生长季节生产者亚系统分室模型   总被引:3,自引:0,他引:3       下载免费PDF全文
本文报道了高寒矮嵩草草甸生产者亚系统六分室模型(GCS 01模型)。六分室包括地上部分的禾草类(V1)、莎草类(V2)、杂类草(V3)、枯枝落叶(V4)四个分室以及地下部分的活根(V5)、死根(V6)两个分室。并建造了相应的微分方程组数学模型,用含有龙格库塔法的BASIC程序可求其数值解。本模型可供高寒草甸生态系统研究人员研究系统行为、探索系统内部规律使用。  相似文献   

20.
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.  相似文献   

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