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1.
植物群落功能多样性对于维持生态系统功能具有十分重要的意义。该研究以青藏高原高寒草甸植物群落为研究对象,运用R软件程序包(FD、Vegan)与单因素方差分析法,分析高寒草甸不同坡向植物群落功能多样性的变化及其与环境因子的关系,以揭示微生境梯度上植物对环境的适应策略以及群落种间功能特征及生态系统内部结构和功能的变化机制。结果显示:(1)青藏高原高寒草甸的北坡和西北坡的物种丰富度、植物株高、比叶面积、叶片有机碳、叶片氮以及叶片磷显著高于其他坡向,且坡向间差异显著(P<0.05)。(2)在北坡到南坡的变化中,功能丰富度差异比较明显(P<0.05),株高、比叶面积、叶片有机碳、叶片氮及叶片磷等功能丰富度均呈递减趋势。(3)北坡的株高功能均匀度、西北坡比叶面积、叶片有机碳、叶片氮及叶片磷等功能均匀度均显著高于南坡,且多元性状功能均匀度在坡向间差异显著(P<0.05)。(4)北坡的比叶面积、叶片氮功能离散度及西北坡的株高、叶片有机碳、叶片磷等功能离散度均高于南坡,且坡向间差异显著(P<0.05)。(5)植物群落功能多样性与土壤含水量、土壤有机碳、土壤全氮、土壤全磷呈显著正相关关系(P<0.05),与坡度、土壤pH、土温、照度呈显著负相关关系(P<0.05)。  相似文献   

2.
干旱胁迫对高山柳和沙棘幼苗光合生理特征的影响   总被引:6,自引:0,他引:6  
蔡海霞  吴福忠  杨万勤 《生态学报》2011,31(9):2430-2436
为了解干旱河谷-山地森林交错带植物光合生理特征对干旱胁迫的响应。以交错带两种典型植物高山柳(Salix paraqplesia)和沙棘(Hippophae rhamnoides)为研究对象,研究其在不同程度的干旱胁迫条件下植株气体交换参数的日变化特征。干旱胁迫显著降低了两种植物叶片数、叶面积、叶片生物量、比叶面积、色素含量、净光合速率(Pn)、气孔导度(gs)和气孔限制值(Ls)等与光合生理过程密切相关的叶片指标,但增大了胞间CO2浓度(Ci)和内禀水分利用效率(WUEi)。植物叶片的气体交换参数(如:Pngs)日变化并未完全随着光合有效辐射的增强和温度的升高而增加,全天以11:00最大,"午休"现象明显。相对而言,沙棘在干旱胁迫条件下表现出相对较高的叶面积、PngsWUEi,具有相对更强的适应干旱环境的能力,而高山柳对干旱胁迫更为敏感。  相似文献   

3.
干旱胁迫对高山柳和沙棘幼苗光合生理特征的影响   总被引:2,自引:0,他引:2  
蔡海霞  吴福忠  杨万勤 《生态学报》2010,30(9):2430-2436
为了解干旱河谷-山地森林交错带植物光合生理特征对干旱胁迫的响应。以交错带两种典型植物高山柳(Salix paraqplesia)和沙棘(Hippophae rhamnoides)为研究对象,研究其在不同程度的干旱胁迫条件下植株气体交换参数的日变化特征。干旱胁迫显著降低了两种植物叶片数、叶面积、叶片生物量、比叶面积、色素含量、净光合速率(Pn)、气孔导度(gs)和气孔限制值(Ls)等与光合生理过程密切相关的叶片指标,但增大了胞间CO2浓度(Ci)和内禀水分利用效率(WUEi)。植物叶片的气体交换参数(如:Pngs)日变化并未完全随着光合有效辐射的增强和温度的升高而增加,全天以11:00最大,"午休"现象明显。相对而言,沙棘在干旱胁迫条件下表现出相对较高的叶面积、PngsWUEi,具有相对更强的适应干旱环境的能力,而高山柳对干旱胁迫更为敏感。  相似文献   

4.
赵文  王雅倩  魏杰  王丽 《生态学报》2011,31(7):2040-2045
采用室内实验生态方法研究了不同软体部干重((1.022 ±0.821)、(0.557±0.266)、(0.303±0.277) g)和盐度(13、18、23、28、33)对中国蛤蜊(Mactra chinensis Philippi)耗氧率和排氨率的影响。结果表明:盐度、个体大小对中国蛤蜊耗氧率的影响极显著(P<0.01),二者的交互作用对中国蛤蜊耗氧率影响显著(P<0.05);中国蛤蜊单位体重耗氧率(R0)与软体部干重(W)负相关,符合幂函数方程R0=aW-b, 其中a值的取值范围是0.695-1.762,平均值为1.449,b值的取值范围是0.446-0.587,平均值为0.542。盐度、个体大小对中国蛤蜊排氨率影响也极显著(P<0.01);随着中国蛤蜊个体的增大,其单位体重排氨率逐渐降低;排氨率与其软体部干重呈负相关,它们之间可以用幂函数RN=a0W-b0表示。单位体重耗氧率和排氨率与盐度(S)、软体部干重(W)的二元线性回归方程分别为: RO=2.111-1.817W+0.49S (R2=0.546, F=34.294, P<0.001);RN=168.186-120.589W+1.734S (R2=0.561, F=36.418, P<0.001)。  相似文献   

5.
三峡库区消落带植物恢复不仅面临长期淹水逆境,还面临泥沙、干旱等环境因素的胁迫。2009年实验、调查研究了三峡库区长寿段低位消落带的狗牙根(Cynodon dactylon L.)种群,探讨了泥、沙沉降对狗牙根种群的影响。结果表明,泥沉降和沙沉降均显著促进了狗牙根芽的萌发,而抑制了狗牙根的芽形成和萌发苗的生长,且前者的抑制作用显著大于后者。泥沉降导致总芽数、萌发苗的茎长和茎宽分别比对照低65.4%(P<0.05)、97.0%(P <0.05)、31.2%(P <0.05),而沙沉降导致前述参数分别比对照低17.1%(P<0.05)、21.2%(P<0.05)、1.0%(P>0.05)。分别将被沉降泥掩埋的狗牙根移植、掩埋于12cm厚的泥和沙中,40d后对照和S'd组(覆盖沙)狗牙根芽萌发后均能在地面上形成正常的分株,而S'l组(覆盖泥)的萌发芽无法穿透覆盖层,形成分株。S'l组狗牙根芽的萌发率显著高于对照和S'd组,但其萌发苗的茎长和茎节数均显著低于对照,分别为对照的30.3%(P<0.05)、80.4%(P<0.05);而S'd组分株的茎长、茎节数、叶片数、叶长和叶宽均显著高于对照组,分别比后者高87.9%(P<0.05)、53.0%(P<0.05)、24.2%(P<0.05)、23.4%(P<0.05)和24.1%(P<0.05)。S'l组萌发苗的鲜质量、干质量和干鲜质量比分别比对照组低83.3%(P<0.05)、86.2%(P<0.05)、15.8%(P<0.05);而S'd组萌发苗的鲜质量、干质量和干鲜质量比分别比对照组高76.8%(P<0.05)、110.1%(P<0.05)、20.0%(P<0.05)。表明,低位消落带的狗牙根对沙沉降具有较强的适应能力,而对泥沉降的适应能力较低,泥沉降是库区低位消落带狗牙根种群恢复的主要影响因素之一。  相似文献   

6.
胡杨异形叶结构型性状及其与胸径关系   总被引:5,自引:0,他引:5       下载免费PDF全文
对胡杨5种类型植株的叶片厚度、叶面积、比叶面积、叶片干重和干物质含量等5个结构型性状指标进行分析,研究叶片的结构型性状与胸径之间及各个结构型性状彼此间相互关系。结果表明:叶面积、叶厚度和叶干重与胸径呈极显著正相关(P0.01),叶片干物质含量与胸径间呈显著正相关(P0.05),比叶面积与胸径之间呈极显著负相关(P0.01),说明随着植株生长发育的进行,叶片的面积、厚度、干重和干物质含量均逐渐增加,而比叶面积逐渐减小。各性状指标间相关性表现为叶面积、叶厚度、叶干物质和叶片干物质含量任意2个指标之间均呈显著或极显著正相关;而比叶面积与这4个指标间均呈显著或极显著负相关。  相似文献   

7.
物种组成对高寒草甸植被冠层降雨截留容量的影响   总被引:2,自引:0,他引:2       下载免费PDF全文
余开亮  陈宁  余四胜  王刚 《生态学报》2011,31(19):5771-5779
高寒草甸退化减少地上生物量、叶面积指数(LAI),因而减少冠层降雨截留容量(S)。但是,未有研究评价物种组成改变对S的影响。用水浸泡法和水量平衡法研究青藏高原高寒草甸3个不同退化阶段下(未退化、轻度退化、中度退化)的S变化规律,并评价物种组成改变对S的影响。结果表明:高寒草甸退化显著减少S(P<0.05)。在未退化、轻度退化、中度退化的高寒草甸,水浸泡法测得的S分别为0.612 mm,0.289 mm 和0.217 mm;水量平衡法测得的S分别为0.979 mm,0.493 mm 和0.419 mm。物种组成改变对S的影响表现为:随着高寒草甸的3个不同退化阶段,S减少的幅度先大于后小于LAI减少的幅度。原因是:(1)在未退化的草甸,鹅绒委陵菜(Potentilla arserina)的叶面积占有显著优势,占总叶面积的31.18%;在轻度退化的草甸,禾本科植物(Graminoid)的叶面积占有显著优势,占总叶面积的44.41%,而鹅绒委陵菜是稀有种,仅占总叶面积的3.76%;在中度退化的草甸,鹅绒委陵菜的叶面积占有显著优势,占总叶面积的19.91%;(2)鹅绒委陵菜的叶单位面积吸附水量(SL)是禾本科植物的大约2.5倍。  相似文献   

8.
植物叶片性状是植物与环境长期互作的结果,对环境变化具有敏锐的捕捉力,而且植物叶片性状影响植物的"投资-收益"关系。本文以天目山不同海拔的檫木叶片为材料,分析檫木叶面积、叶长宽比、叶片干重和比叶面积等叶片形态性状以及叶绿素含量和叶氮含量(N_(area))等叶片生理性状对海拔的响应。结果表明,不同海拔亚群体间叶面积具有显著差异,比叶面积、叶长宽比和叶片干重存在极显著差异;叶长宽比和叶片干重在亚群体内的变异系数小于叶面积和比叶面积,说明檫木叶片形态性状在亚群体间存在着不同程度的变异。比叶面积与叶面积和叶长宽比具有显著正相关,与叶片干重呈显著负相关;叶绿素含量与N_(area)呈显著正相关;通过檫木叶片性状与温度的线性回归表明,叶面积、比叶面积、叶绿素含量和N_(area)随着温度下降而下降,与之相反,叶片干重和叶长宽比则逐渐增加。  相似文献   

9.
植物功能性状种间性状变异反映不同物种的生活史对策,种内性状变异反映了同一物种不同个体应对不同环境的性状应答。人工林均一的环境有利于深入分析不同树种种内和种间变异。该研究以南宁良凤江林场的四种乡土珍贵阔叶树种[观光木(Tsoongiodendron odorum)、红锥(Castanopsis hystrix)、灰木莲(Magnolia blumei)和望天树(Parashorea chinensis)]为研究对象,对其叶功能性状的种内和种间变异进行研究。结果表明:(1)同一高度的不同种植物大部分叶功能形状差异显著,只有极少数叶功能性状差异不显著。相较于其他三种植物,红锥的叶鲜重、叶厚度、叶面积、叶干重、比叶面积和叶含水率较小,但红锥的比叶重、叶干物质量和叶组织密度较大。(2)不同高度的同一树种叶功能性状存在差异,不同的树种差异表现不同。高度对叶功能性状的影响为灰木莲>望天树>观光木>红锥。随着高度的变化,9种叶功能性状中,叶厚度和叶组织密度表现最稳定,叶面积和叶干重变化较大;比叶面积呈下降趋势,比叶重呈上升趋势。(3)随着树龄的增大,灰木莲的叶功能性状变化最大,红锥的叶功能性状表现最稳定,树龄对叶功能性状的影响为灰木莲>观光木/望天树>红锥。9种叶功能性状中,受到树龄影响最大的是叶厚度和叶组织密度,影响最小的是叶鲜重、叶干重和叶面积;四种树种的叶功能性状随树龄的变化差异显著,但不具有明显规律性。(4)叶干物质量与叶厚度相关性不显著,叶含水率与叶厚度、叶面积、叶干重和比叶重相关性不显著,其余各功能性状存在一定的相关性。综上结果可知,植物各功能性状之间存在一定的相关性,彼此相互协调适应环境的变化。该研究结果对于乡土珍贵阔叶树种的人工林种植具有一定的指导意义。  相似文献   

10.
匍匐茎草本金戴戴对盐分梯度的表型可塑性   总被引:14,自引:2,他引:12       下载免费PDF全文
 研究了匍匐茎型克隆草本金戴戴(Halerpestes ruthenica) 4种基株(基因型)对不同盐分处理(0,85.5, 171.0, 256.5和342.0 mM NaCl)的表型可塑性。随着盐分浓度的增加,实验植物与生长相关的性状指标 (如植株干重、总叶面积、分株数和总匍匐茎长度) 显著减小。植株干重、总叶面积和总匍匐茎长度具有显著的基株间差异。实验植物与形态相关的性状指标 (如平均叶柄长和根冠比) 对盐分梯度具有可塑性并具有显著的基株间差异;而其它形态指标 (如平均节间长、比节间长和比叶柄长)  相似文献   

11.
延河流域植物群落功能性状对环境梯度的响应   总被引:3,自引:0,他引:3       下载免费PDF全文
龚时慧  温仲明  施宇 《生态学报》2011,31(20):6088-6097
研究群落水平上的植物功能性状特征及其随环境梯度的变化规律,对认识不同环境梯度下植物群落的形成及其对环境的适应机制具有重要意义。以延河流域不同环境梯度下的稳定的自然植物群落为对象,测量了植物群落组成物种的叶厚度、比叶面积、叶组织密度、比根长、根组织密度、单位质量叶氮含量、单位质量根氮含量、种子质量、种子体积等9个性状,然后以物种重要值为基础加权平均得到各个性状在群落水平上的平均值(即群落性状值);以现有的环境因子栅格图为基础,利用ArcGIS提出各群落对应的环境因子值,同时测定各个群落的土壤水分,分析群落各性状值与环境因子的关系,并建立关系模型。结果表明:在群落水平上,9个植物功能性状分别与13个环境因子存在不同程度的相关性,同时这9个植物功能性状对8个环境因子梯度(土壤水分、年4-10月平均气温、年7-9月总降雨量、降雨季节变化、年平均降雨量、年平均蒸发量、坡度、坡向)的响应特征较好,不同植物功能性状间具有较好相关性。群落水平上植物功能性状及其组合随环境梯度的规律性变化,反映了延河流域植被群落构建过程中环境对功能性状的筛选效应。该研究结果对该区的植被恢复重建的物种选择及植被布局规划具有重要的实践意义。  相似文献   

12.
Intraspecific trait variability plays an important role in species adaptation to climate change. However, it still remains unclear how plants in semi-arid environments respond to increasing aridity. We investigated the intraspecific trait variability of two common Mediterranean annuals (Geropogon hybridus and Crupina crupinastrum) with similar habitat preferences. They were studied along a steep precipitation gradient in Israel similar to the maximum predicted precipitation changes in the eastern Mediterranean basin (i.e. −30% until 2100). We expected a shift from competitive ability to stress tolerance with decreasing precipitation and tested this expectation by measuring key functional traits (canopy and seed release height, specific leaf area, N- and P-leaf content, seed mass). Further, we evaluated generative bet-hedging strategies by different seed traits. Both species showed different responses along the precipitation gradient. C. crupinastrum exhibited only decreased plant height towards aridity, while G. hybridus showed strong trends of generative adaptation to aridity. Different seed trait indices suggest increased bet-hedging of G. hybridus in arid environments. However, no clear trends along the precipitation gradient were observed in leaf traits (specific leaf area and leaf N-/P-content) in both species. Moreover, variance decomposition revealed that most of the observed trait variation (≫50%) is found within populations. The findings of our study suggest that responses to increased aridity are highly species-specific and local environmental factors may have a stronger effect on intraspecific trait variation than shifts in annual precipitation. We therefore argue that trait-based analyses should focus on precipitation gradients that are comparable to predicted precipitation changes and compare precipitation effects to effects of local environmental factors.  相似文献   

13.
侯东杰  陆帅志  王静  郭柯 《生态学报》2020,40(18):6522-6531
植物功能性状反映植物适应环境变化过程中在不同器官形态与功能间的资源权衡与分配策略。典型草原围封后枯落物累积导致群落光照、热量和水分的重新分配并改变微环境特征。在此过程中植物地上功能性状将通过怎样的变化来适应新的环境,目前尚不清楚。2015—2017年每年8月对内蒙古地区3种典型草原共有物种羊草(Leymus chinensis)的植株、叶片和茎干功能性状进行了测量与分析。结果表明:枯落物累积显著增加了羊草的植株高度、单株重量、茎叶比和总叶面积;枯落物累积显著增加了羊草的叶片长度、叶片重量、单叶面积、节间长度和茎干重量,这些性状属于敏感性状;枯落物累积对羊草的叶片数量和节间数量无显著影响,相对而言,这些性状属于惰性性状;羊草的单株重量与植株高度、叶片重量呈极显著的正相关关系(P<0.0001);羊草的植株高度与节间数量、节间长度呈极显著的正相关关系(P<0.0001)。本研究结果从植物地上功能性状的角度阐明了典型草原植物对环境变化的适应方式,可为围封草原的合理管理提供基础数据与理论依据。  相似文献   

14.
Plant functional trait variation in tropical forests results from taxonomic differences in phylogeny and associated genetic differences, as well as, phenotypic plastic responses to the environment. Accounting for the underlying mechanisms driving plant functional trait variation is important for understanding the potential rate of change of ecosystems since trait acclimation via phenotypic plasticity is very fast compared to shifts in community composition and genetic adaptation. We here applied a statistical technique to decompose the relative roles of phenotypic plasticity, genetic adaptation, and phylogenetic constraints. We examined typically obtained plant functional traits, such as wood density, plant height, specific leaf area, leaf area, leaf thickness, leaf dry mass content, leaf nitrogen content, and leaf phosphorus content. We assumed that genetic differences in plant functional traits between species and genotypes increase with environmental heterogeneity and geographic distance, whereas trait variation due to plastic acclimation to the local environment is independent of spatial distance between sampling sites. Results suggest that most of the observed trait variation could not be explained by the measured environmental variables, thus indicating a limited potential to predict individual plant traits from commonly assessed parameters. However, we found a difference in the response of plant functional traits, such that leaf traits varied in response to canopy‐light regime and nutrient availability, whereas wood traits were related to topoedaphic factors and water availability. Our analysis furthermore revealed differences in the functional response of coexisting neotropical tree species, which suggests that endemic species with conservative ecological strategies might be especially prone to competitive exclusion under projected climate change.  相似文献   

15.
Plant functional traits capture important variation in plant strategy and function. Recent literature has revealed that within-species variation in traits is greater than previously supposed. However, we still have a poor understanding of how intraspecific variation is coordinated among different traits, and how it is driven by environment. We quantified intraspecific variation in wood density and five leaf traits underpinning the leaf economics spectrum (leaf dry matter content, leaf mass per unit area, size, thickness and density) within and among four widespread Nothofagus tree species in southern New Zealand. We tested whether intraspecific relationships between wood density and leaf traits followed widely reported interspecific relationships, and whether variation in these traits was coordinated through shared responses to environmental factors. Sample sites varied widely in environmental variables, including soil fertility (25–900 mg kg–1 total P), precipitation (668–4875 mm yr–1), temperature (5.2–12.4 °C mean annual temperature) and latitude (41–46 °S). Leaf traits were strongly correlated with one another within species, but not with wood density. There was some evidence for a positive relationship between wood density and leaf tissue density and dry matter content, but no evidence that leaf mass or leaf size were correlated with wood density; this highlights that leaf mass per unit area cannot be used as a surrogate for component leaf traits such as tissue density. Trait variation was predicted by environmental factors, but not consistently among different traits; e.g., only leaf thickness and leaf density responded to the same environmental cues as wood density. We conclude that although intraspecific variation in wood density and leaf traits is strongly driven by environmental factors, these responses are not strongly coordinated among functional traits even across co-occurring, closely-related plant species.  相似文献   

16.
王瑗  郁万文  周凯  汪贵斌  曹福亮 《广西植物》2019,39(9):1147-1158
该研究以自然分布的内蒙、宁夏、甘肃、新疆、陕西等23个不同地理来源(种源)的野生苦豆子种子及其播种于内蒙古鄂托克前旗同质园内的当年生植株为材料,采用方差分析、主成分分析、聚类分析等方法对种子长、宽、千粒重以及植株的叶长、叶宽、叶面积、叶形指数、苗高、地径及生物量等10个表型性状的多样性进行了研究。结果表明:各个表型性状种源间均呈极显著差异,其中种子表型性状的变异系数为5.24%,植株表型性状的变异系数为18.34%,表明种子性状的稳定性高于植株性状。同时,10个性状的表型分化系数均高于70%,说明苦豆子表型多样性主要来源于种源间的表型变异;各种源苦豆子种子性状的表型分化系数均值高达97.55%,且种长、千粒重分别与采集地经度、纬度和海拔等环境因子呈极显著相关性,说明种子表型性状受环境因素的影响较大;相关性分析显示,苦豆子植株性状叶长(LL)、叶面积(LA)分别与种子性状千粒重(TW)、种长(SL)和种宽(SW)有显著相关性,暗示表型性状中的可遗传变异影响;利用主成分和聚类分析对23个种源苦豆子进行综合评价,筛选出生物量较大、苗高较高、千粒重较重、叶面积较大等综合表现较好的6个种源,共分为两类,分别是DK、JY、WY、WH、ETK和YN,这为苦豆子种质资源定向开发以及选育和栽培提供了一定的理论支撑和基础材料。  相似文献   

17.
Question: Is the assumption of trait independence implied in Westoby's (1998) leaf‐height‐seed (LHS) ecology strategy scheme upheld in a Mediterranean grazing system dominated by annuals? Is the LHS approach applicable at the community level? Location: Northern Israel. Methods: LHS traits (specific leaf area [SLA], plant height and seed mass), and additional leaf traits (leaf dry matter content [LDMC], leaf area, and leaf content of nitrogen [LNC], carbon [LCC], and phosphorus [LPC]), were analyzed at the species and community levels. Treatments included manipulations of grazing intensity (moderate and heavy) and protection from grazing. We focused on species comprising 80% of biomass over all treatments, assuming that these species drive trait relationships and ecosystem processes. Results: At the species level, SLA and seed mass were negatively correlated, and plant height was positively correlated to LCC. SLA, seed mass, and LPC increased with protection from grazing. At the community level, redundancy analysis revealed one principal gradient of variation: SLA, correlated to grazing, versus seed mass and plant height, associated with protection from grazing. We divided community functional parameters into two groups according to grazing response: (1) plant height, seed mass, LDMC, and LCC, associated with protection from grazing, and (2) SLA, associated with grazing. Conclusions: The assumption of independence between LHS traits was not upheld at the species level in this Mediterranean grazing system. At the community level, the LHS approach captured most of the variation associated with protection from grazing, reflecting changes in dominance within the plant community.  相似文献   

18.
We applied the leaf‐height‐seed (LHS) ecology strategy scheme (a combination of three ecologically important traits: specific leaf area (SLA), seed mass and plant height) intraspecifically to two widespread European forest herbs along a latitudinal gradient. The aims of this study were to quantify LHS trait variation, disentangle the environmental factors affecting these traits and compare the within‐species LHS trait relationships with latitude to previously established cross‐species comparisons. We measured LHS traits in 41 Anemone nemorosa and 44 Milium effusum populations along a 1900–2300 km latitudinal gradient from N France to N Sweden. We then applied multilevel models to identify the effects of regional (temperature, latitude) and local (soil fertility and acidity, overstorey canopy cover) environmental factors on LHS traits. Both species displayed a significant 4% increase in plant height with every degree northward shift (almost a two‐fold plant height difference between the southernmost and northernmost populations). Neither seed mass nor SLA showed a significant latitudinal cline. Temperature had a large effect on the three LHS traits of Anemone. Latitude, canopy cover and soil nutrients were related to the SLA and plant height of Milium. None of the investigated variables appeared to be related to the seed mass of Milium. The variation in LHS traits indicates that the ecological strategy determined by the position of each population in this three‐factor triangle is not constant along the latitudinal gradient. The significant increase in plant height suggests greater competitive abilities for both species in the northernmost populations. We also found that the studied environmental factors affected the LHS traits of the two species on various scales: spring‐flowering Anemone was affected more by temperature, whereas early‐summer flowering Milium was affected more by local and other latitude‐related factors. Finally, previously reported cross‐species correlations between LHS traits and latitude were generally unsupported by our within‐species approach.  相似文献   

19.
郑颖  温仲明  宋光  丁曼 《生态学报》2014,34(10):2682-2692
研究环境筛选作用和植物系统发育背景对植物群落构建产生的影响,有助于理解植物在生长过程中对资源的分配利用和对环境的适应规律。以延河流域3个植被带(森林带、森林草原带及典型草原带)稳定的自然植物群落为研究对象,调查了31个样地107种植物,隶属于35个科78个属,测量了6种叶片和3种细根性状。分别对3个植被带和不同植物科植物的叶片和细根性状做单因素方差分析,结果表明:叶片氮含量和细根氮含量在3个植被带间无显著差异,叶厚度、比叶面积、叶组织密度、叶片磷含量、叶片氮磷比、比根长、根组织密度在3个植被带间差异极显著。由南向北随着气候干旱的加剧,植物通过调节叶片和细根性状,表现出了不同的适应策略:森林带植物叶片相对生长速率高,根系防御力强;森林草原带植物叶片防御力强,根系相对生长速率快。不同科的植物在相同的环境条件下,对于资源的竞争力和胁迫的忍耐力也有所不同,比如豆科植物具有远远高于其他科的叶片和细根氮含量,但是对养分的利用效率并不高。GLM分析结果说明,所涉及的植物功能性状的空间变异主要来自于年均降雨量的变化及植物科的差异,如16.26%的比叶面积的变异可由年均降雨量变化解释,4.02%可由植物科的差异解释。物种水平上,叶厚度、比叶面积、叶组织密度、比根长、根组织密度、叶片磷含量是对气候干燥度变化响应敏感的植物功能性状,其空间变异主要由环境差异所致。延河流域的植物群落在形成过程中,存在明显的环境筛选效应。这表明,环境异质性在植被恢复实践中必须予以考虑。  相似文献   

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