井冈山鹿角杜鹃群落灌木层植物叶功能性状对海拔梯度的响应

为揭示鹿角杜鹃(Rhododendron latoucheae)群落灌木层植物叶功能性状及其对环境变化的响应趋势,对分布于井冈山不同海拔梯度鹿角杜鹃群落灌木层植物的叶功能性状进行了研究。结果表明,海拔梯度对灌木植物的叶功能性状有显著影响。随海拔的升高,叶片的干物质含量(LDMC)、厚度(LT)、氮含量(LNC)、磷含量(LPC)呈显著上升趋势,比叶面积(SLA)和N/P呈显著下降趋势,而叶大小(LS)呈先上升后下降的变化趋势;灌木植物叶片的LDMC与SLA、LS呈负相关,与LT、LNC、LPC呈正相关;SLA与LT、LNC呈负相关;LS与LT呈负相关;LNC与LPC呈正相关;N/P与LPC呈负相关;环境因子对灌木植物叶功能性状有重要影响,除受海拔的影响外,LPC、N/P还受坡位的影响,LS、LNC则分别还受到坡向和坡度的影响。因此,井冈山地区鹿角杜鹃群落灌木层植物通过改变叶功能性状来适应海拔和其它环境因子的变化。     

滨海沙地主要造林树种叶片功能性状及养分重吸收特征

为探讨不同树种对滨海沙地干旱贫瘠环境的适应策略,以滨海沙地主要造林树种木麻黄、湿地松、厚荚相思和尾巨桉为对象,研究了不同树种叶片功能性状及养分重吸收特征.结果表明:阔叶树种(厚荚相思和尾巨桉)的叶面积、比叶面积显著高于针叶树种(木麻黄和湿地松),而针叶树叶干物质含量、叶厚度最高.成熟叶和凋落叶的N、P含量表现为阔叶树高于针叶树,成熟叶高于凋落叶,但凋落叶N∶P较高.针叶树种的N、P养分重吸收效率大于阔叶树种,P重吸收效率明显高于N,木麻黄、湿地松、厚荚相思和尾巨桉的N、P吸收效率分别为64.2%、63.1%、47.0%、16.8%和92.5%、81.6%、80.3%、18.0%.比叶面积与叶片N、P含量呈显著正相关,与叶干物质含量,叶厚度以及N、P养分重吸收效率呈显著负相关;叶干物质含量与叶厚度及N、P养分重吸收效率呈显著正相关.就叶片功能的权衡关系而言,木麻黄和湿地松属于缓慢投资-收益型物种,具有较高的养分重吸收效率,而厚荚相思和尾巨桉属于快速投资-收益型物种,养分的重吸收效率较低.不同滨海沙地造林树种通过叶片功能性状及养分重吸收之间的相互协调实现对滨海沙地特殊生境的适应性.     

同期生长在种源地与异地同质园刨花楠叶性状分析

为辨别环境变化与遗传因素对植物叶片主要功能性状的影响,以同期生长在4种源地母树林下及异地同质园的1.5年生刨花楠苗木为研究对象,对其叶片表型及养分性状进行对比分析。结果显示：(1)刨花楠叶面积、叶厚、叶干物质含量等叶片表型性状受遗传与环境因素共同影响;叶片碳(C)含量受遗传因素调控,环境对其影响较小;叶片氮、磷(N、P)含量主要受环境因素影响;(2)不同种源刨花楠比叶面积、叶厚、叶干物质含量、叶形指数等性状变异系数较大(8.85%—37.03%),其中江西遂川种源变异系数相对较大,而湖南茶陵种源则相对较小,各种源都倾向于通过调节比叶面积、叶厚、叶片氮磷含量等性状以适应生境变化;(3)种源地与同质园刨花楠的比叶面积虽均与叶厚呈显著负相关,但同质园刨花楠比叶面积与叶形指数呈显著正相关,与叶片氮含量无明显相关,而种源地刨花楠比叶面积则与叶形指数无明显相关,与叶片氮含量则呈显著负相关;(4)不同种源苗木叶性状指标在种源地与同质园间存在不同的协调与权衡,体现了植物在不同生境下的适应策略。其中湖南茶陵种源在两种生境下都具有更保守的资源获取策略,而江西安福种源对环境变化则更为敏感,资源获取策略更为灵...     

引种期同质园翅荚木主要叶功能性状与种源地环境关系

从比叶面积(SLA)、叶片相对含水量(LRWC)、叶组织密度(LTD)、叶片干物质含量(LDMC)、叶片碳(C)氮(N)磷(P)含量及其化学计量比等方面对在引种期同质园的广西桂林市(GGL)、广西靖西市(GJX)、湖南江华县(HJH)、湖南通道市县(HTD)、广东英德市(GYD)等5翅荚木种源叶片主要功能性状进行差异分析及相关性分析,并研究翅荚木叶功能性状与种源地环境因子的关系。结果显示,(1)不同种源间叶片C、N含量及C/N差异显著,5种源间叶片C含量GYD最高、GGL最低,N含量GJX最高、GYD最低,C/N为GYD最高、GJX最低。(2)比叶面积与叶组织密度呈显著负相关;叶片N含量与C/N和C/P呈显著负相关,与N/P呈显著正相关;C/P与P含量呈显著负相关,与C/N呈显著正相关;C/N与N/P呈显著负相关。(3)翅荚木叶功能性状主要受七月均温、年均温和相对湿度等地理环境因子影响。七月均温与C/P、比叶面积呈正相关,与叶片N含量、叶片干物质含量、叶组织密度呈负相关;年均温与C/N呈正相关,与N/P呈负相关;相对湿度与叶片P含量、叶组织密度呈正相关,与C/P、比叶面积呈负相关。研究结果有助于理解翅荚木对引种区的环境适应特征及其在引种期的生长与生存策略,对探究翅荚木的养分利用策略、揭示其对环境变化的响应机制等具有重要意义,并为相关部门选择适宜的翅荚木引种栽培种源及开展其优良种源的遗传改良等提供理论指导与决策参考。     

干热河谷石漠化区顶坛花椒叶片功能性状的海拔分异规律

为阐明顶坛花椒人工林叶片功能性状的海拔分异规律,探讨顶坛花椒对不同海拔生境的适应策略,该研究测定了叶片厚度、比叶面积、叶全氮含量等9个功能性状和土壤有机碳、全氮、全磷等8个环境因子,揭示了顶坛花椒人工林叶片功能性状的内在关联及其随海拔的分异规律。结果表明:(1)随海拔升高,顶坛花椒比叶面积、叶全磷、叶全钾含量先升高后降低,叶干物质含量、叶全氮含量先降低后逐渐升高,叶片厚度、叶面积及叶片含水率逐渐增大。(2)顶坛花椒叶片功能性状间具有显著的相关性,叶全氮与叶全磷呈显著负相关,与叶片厚度的关系则相反;叶干物质含量与比叶面积、叶片含水率呈显著的抑制效应。(3)土壤因子对顶坛花椒叶片的影响表现为速效氮>速效钾>有机碳,其他土壤因子的影响较小。研究显示顶坛花椒主要通过增强防御功能性状、协调叶片养分含量的生存策略来提高获取资源和抵御外界环境胁迫的能力,对土壤养分具有强烈的依赖性,其干旱适应属性为干旱避免,该研究为顶坛花椒人工林复壮、高产与稳定,及喀斯特石漠化区生态修复提供科学依据。     

冠层垂直高度对植物叶片功能性状的影响: 以鼎湖山南亚热带常绿阔叶林为例

植物功能性状能够反映植物对环境变化的响应, 从而影响生态系统功能。叶片是植物功能性状的重要研究对象, 但随着树冠垂直高度的增加, 植物叶片功能性状的变化规律仍不清楚。为了更好地解释植物对所处环境的响应机制, 本研究以鼎湖山南亚热带常绿阔叶林6个优势树种为研究对象, 对这些树种不同冠层高度的叶片比叶面积(SLA)、叶绿素相对含量(SPAD)、叶干物质含量(LDMC)、叶片碳含量(LCC)、叶片氮含量(LNC)、叶片磷含量(LPC)、叶片氮磷比(N : P)、等效水厚度(EWT)、氮平衡指数(NBI)、类黄酮含量(FLAV)共10个功能性状指标进行比较分析。结果表明: (1)随树冠垂直高度的增加, 叶干物质含量、类黄酮含量、等效水厚度和叶片磷含量呈增加趋势, 比叶面积和氮平衡指数呈减小趋势; 在冠层垂直方向上, 类黄酮含量与氮平衡指数、比叶面积与等效水厚度呈极显著负相关, 叶片氮含量与叶片磷含量呈极显著正相关。(2)不同树种叶片功能性状差异显著, 可能受植物自身特性和群落树种演替进程的影响。(3)叶片功能性状的种内差异沿垂直层次呈现不同的变化趋势。其中, 67%的树种的类黄酮含量随树冠垂直高度增加而显著增加, 67%的树种的氮平衡指数随树冠垂直高度增加而显著减小。南亚热带常绿阔叶林不同树种叶片功能性状随树冠垂直高度增加产生的变化, 反映了植物对光环境的适应以及对水资源和能量利用的不同策略。     

檫木叶片性状沿海拔梯度的响应特征

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。     

浙江四明山沼泽湿地植物功能性状研究

为理解浙东亚高山沼泽湿地不同植物的生态策略,收集了浙江四明山12种典型沼泽湿地植物,对其主要功能性状进行了统计比较。结果表明：(1)不同沼泽湿地植物功能性状变异程度不同,变异系数(CV)最大为叶片密度(216.16%),最小为相对叶绿素含量(22.84%),平均变异为112.86%。(2)叶周长分别和叶面积、叶干重、叶长和叶长宽比呈显著正相关(P<0.05);叶形指数与叶面积、叶长、叶长宽比和叶片密度呈显著负相关(P<0.05);棘刺与比叶面积呈显著正相关(P<0.05);生活史与相对叶绿素含量呈显著正相关(P<0.05);根状茎或匍匐茎与叶形指数呈显著负相关(P<0.05);生活型与异形叶性呈显著负相关(P<0.05)。(3)17项功能性状主成分分析(PCA)的前3大主成分累计贡献率达到71.47%,可综合表征和概述为：植物叶片的质量和大小(35.72%)、对水分和氮素的吸收(18.74%)、植物抵御草食动物的能力和强光下的自我保护能力(17.01%)。(4)物种-功能性状排序图结合UPGMA聚类分析均支持将12种植物划分为2个功能组,第1功能组包...     

松嫩草地66种草本植物叶片性状特征

植物叶片功能性状及其相互关系越来越受到关注.以松嫩草地66种草本植物为研究对象,测量叶片干物质含量、比叶面积、叶片厚度、叶片氮含量、叶片磷含量、叶绿素含量和类胡萝卜素含量,检验性状间的相互关系,比较不同功能群(多年生根茎禾草,多年生丛生禾草,多年生杂类草,1年生或2年生草本)间性状的差异性.结果表明,叶片厚度变异系数最大,比叶面积、叶片氮含量、叶片磷含量、叶绿素含量和类胡萝卜素含量之间存在显著的正相关关系;叶片于物质含量与叶片磷含量没有显著的相关关系,与其它叶片性状呈显著的负相关关系;叶片厚度只与叶片干物质含量和比叶面积呈显著的负相关关系,与其它叶片性状不相关.叶片干物质含量、比叶面积、叶片厚度、叶片氮、磷含量在4个功能群间差异显著,叶绿素含量和类胡萝卜素含量在各个功能群间差异不显著;多年生根茎禾草和多年生丛生禾草叶片的7个性状差异不显著;多年生根茎禾草和多年生丛生禾草的叶片干物质含量高于多年生杂类草和1年生或2年生草本,其它性状小于这两个功能群.     

地形因子对黄土高原山杏叶片功能性状的影响

坡向和坡度是重要的地形因子,调控水、热组合可以影响植物生长及叶片功能性状,研究叶片功能性状对不同地形因子的响应,有助于了解植物对环境的适应策略.以阳坡(半阳坡)和阴坡(半阴坡)2个坡向,以及15°~20°、21°~25°和26°~30°3个坡度为环境梯度,对比研究了其对黄土高原主要造林树种山杏叶片功能性状(包括叶面积、比叶面积、叶干物质含量和叶片含水量)的影响,结果表明:1)坡向与坡度分别对所有叶片功能性状的影响均显著,坡向和坡度仅对叶片含水量具有交互作用.2)坡向梯度上,阳坡叶片的叶面积与阴坡相当,但叶干物质含量(0.24 g·g^-1)和叶片含水量(59.6%)均小于后者(0.27 g·g^-1和67.0%);阳坡叶片的比叶面积显著高于阴坡,其值分别为183.72和163.05 cm2·g^-1.3)坡度梯度上,叶片的比叶面积和叶面积均随坡度增大呈先减后增趋势,二者分别在15°~20°和26°~30°上达最大值,分别为184.04 cm^2·g^-1和21.14 cm2.4)除15°~20°与26°~30°的土壤水分无差异外,其余坡度以及坡向之间的土壤水分均存在显著差异,且土壤水分是造成叶片功能性状差异的主要原因之一,其中0~10 cm土层含水量对叶片功能性状的影响最大.5)叶片比叶面积与叶片含水量、叶干物质含量呈负相关,与叶面积呈正相关;叶干物质含量与叶片含水量呈正相关,与叶面积呈负相关;土壤含水量仅与叶片含水量呈正相关,与其他叶片功能性状均不相关.     

海岸草本植物细根、叶片功能性状及其与土壤因子的关系

植物根、叶是对环境敏感性最高的器官,探究根叶功能性状之间的相互关系以及对环境因子的响应,有助于揭示植物对资源的利用状况及其对环境的适生策略。为探讨沿海植物的适应策略,该文以平潭岛砂质海岸草本植物为研究对象,由海及陆设置了3个距离梯度,选取6个叶功能性状和5个细根功能性状指标,分析海岸植物叶片与细根功能性状及其对土壤因子的响应。结果表明:(1)根、叶功能性状变异系数幅度在潮间带最小,在距高海潮线30～60 m的梯度上最大。单叶面积、叶磷含量、根平均直径、根组织密度、根磷含量随着由海到陆的距离增加呈上升趋势; 叶干物质含量、叶组织密度、比根长、比根面积呈下降趋势。(2)植物通过性状组合,在生长与防御间进行资源分配的权衡,表现在叶性状间、根性状间以及根-叶性状间具不同程度的相关性。其中,在地上-地下对应性状中,叶厚与根平均直径、叶磷含量与根磷含量呈极显著正相关; 而比叶面积与比根面积、比根长,叶组织密度与根组织密度均未表现出显著的相关性。(3)土壤因子对海岸植物功能性状变化的解释度为52.05%,其中土壤含盐量的影响最大,其次是土壤含水量、电导率、pH值。总体而言,在恶劣的海岸环境下,由海向陆土壤含盐量、电导率、含水量及pH值逐渐下降,整体为低磷高盐碱,植物表现为不同的生存策略:距海近的植物采取“叶片资源保守型、根系资源获取型”策略; 距海远的植物则采取“叶片资源获取型、根系资源保守型”。该研究结果为了解海岸草本植物对环境梯度变化的响应机制和适应性提供了一定参考价值,同时也利于通过分析土壤等环境特性按梯度筛选栽种适宜的物种,促进海岸植物的恢复和保护。     

CSR analysis of plant functional types in highly diverse tropical grasslands of harsh environments

The classification of plant species according to the CSR ecological strategy scheme has been proposed as a common language that allows comparison among species, communities, and floras. Although several studies on European continent have demonstrated a consistent association between CSR strategies and key ecosystem processes, studies of this type are still lacking in other ecoregions worldwide. For the first time, the CSR strategy scheme is applied in a tropical plant community. In a Brazilian mountain grassland ecosystem characterized by both high biodiversity and environmental stress, we sampled various functional traits of 48 herbaceous species in stony and sandy grasslands, and evaluated the relationship between CSR strategies and functional traits with several environmental parameters. The extremely infertile soils in the two studied habitats may have acted as a major environmental filter leading to a clear predominance of the stress-tolerant strategy in both communities. However, fine-scale environmental differences between the two communities resulted in the filtering of distinct functional trait values. The sites with coarser soil texture, lower percentage of plant cover and (paradoxically) higher mineral nutrient concentrations favored plants with narrower leaves, higher stress tolerance, lower competitiveness, and higher sclerophylly (i.e., lower specific leaf area and higher leaf dry matter content). The comparison between the functional character of stony and sandy communities evidenced the influence of soil texture and water availability in the environmental filtering. This study highlighted the validity of the CSR classification outside the temperate region where it was originally developed and corroborated.     

狗娃花叶片生态化学计量特征及功能性状对坡向的响应

坡向对植物叶片生态化学计量特征及功能性状有显著影响。研究不同坡向上植物叶片生态化学计量特征与功能性状有助于了解植物对环境变化的响应及适应。以兰州地区狗娃花叶片为研究对象,分析其生态化学计量及功能性状随坡向的变化特征。结果显示:阳坡叶片C含量(408.12 g·kg^-1)、C∶P(348.61)与N∶P(29.71)均显著高于阴坡(其值分别为400.75 g·kg^-1、196.69和16.60),N含量(34.81 g·kg^-1)和C∶N(11.72)与阴坡无显著差异(其值分别为34.07 g·kg^-1和12.24),而P含量(1.67 g·kg^-1)显著小于阴坡(2.56 g·kg^-1);阳坡比叶面积及叶片含水量(10.55 cm2·g^-1、59.06%)与阴坡(9.70 cm2·g^-1、60.65%)无显著差异,叶干物质含量(0.14 g·g^-1)和叶面积(0.31 cm2)均显著低于阴坡...     

Plant functional traits under cattle grazing and fallow age scenarios in a tropical dry forest of Northwestern Mexico

Evaluating plant functional traits helps to understand how plants respond to changing environmental conditions and resource availability associated with disturbance events. Livestock production is one of the primary drivers of tropical forest loss and degradation. Livestock alter environmental conditions within the forest by grazing, trampling and nutrient inputs, which in turn can influence species composition and functional traits of species. Understanding how livestock influence functional traits along a successional gradient is poorly understood. Here, we studied the effect of cattle grazing and fallow age on plant functional traits and soil nutrients in secondary and old-growth tropical dry forests. We analyzed plant functional traits of the most important species in successional and old-growth forest communities in both cattle present and cattle excluded plots. Our results showed the effects of cattle grazing and fallow age on plant functional traits, with fallow age explaining more variation than cattle grazing. In early succession, functional traits were associated with water conservation (thicker leaves, lower specific leaf area), and in later successional they were linked with sunlight conservation (larger height, higher specific leaf area). The presence of large fruits and seeds in advanced successional sites suggests high resource availability, which may help plants to successfully reproduce. Moreover, under cattle grazing some functional traits are associated with herbivory defense (high foliar dry weight and thick leaves). Even though N and C increased as succession advanced, the sites with cattle grazing had higher NH4 and NO3 concentrations as a result of fecal deposition. Plant functional traits responded to fallow age than to cattle grazing. Our study showed that cattle exclusion, as a management and biodiversity conservation strategy, contributes positively to soil nutrition. Thus, fallow age and cattle exclusion facilitate soil recovery and allows establishing species with suitable functional attributes for overcoming environmental filters in abandoned cattle fields.     

Foliar demand and resource economy of nutrients in dry tropical forest species

Important phenological activities in seasonally dry tropical forest species occur within the hot‐dry period when soil water is limiting, while the subsequent wet period is utilized for carbon accumulation. Leaf emergence and leaf area expansion in most of these tree species precedes the rainy season when the weather is very dry and hot and the soil cannot support nutrient uptake by the plants. The nutrient requirement for leaf expansion during the dry summer period, however, is substantial in these species. We tested the hypothesis that the nutrients withdrawn from the senescing leaves support the emergence and expansion of leaves in dry tropical woody species to a significant extent. We examined the leaf traits (with parameters such as leaf life span, leaf nutrient content and retranslocation of nutrients during senescence) in eight selected tree species in northern India. The concentrations of N, P and K declined in the senescing foliage while those of Na and Ca increased. Time series observations on foliar nutrients indicated a substantial amount of nutrient resorption before senescence and a ‘tight nutrient budgeting’. The resorbed N‐mass could potentially support 50 to 100% and 46 to 80% of the leaf growth in terms of area and weight, respectively, across the eight species studied. Corresponding values for P were 29 to 100% and 20 to 91%, for K 29 to 100% and 20 to 57%, for Na 3 to 100% and 1 to 54%, and for Ca 0 to 32% and 0 to 30%. The species differed significantly with respect to their efficiency in nutrient resorption. Such interspecific differences in leaf nutrient economy enhance the conservative utilization of soil nutrients by the dry forest community. This reflects an adaptational strategy of the species growing on seasonally dry, nutrient‐poor soils as they tend to depend more or less on efficient internal cycling and, thus, utilize the retranslocated nutrients for the production of new foliage biomass in summer when the availability of soil moisture and nutrients is severely limited.     

Litter decomposition of woody species in shrublands of NW Patagonia: how much do functional groups and microsite conditions influence decomposition?

The study examined the effects of leaf traits, soil microsite, and microclimate characteristics on litter decomposition of the dominant species in two functional groups (FG), deciduous and evergreen, in shrublands in NW Patagonia, Argentina. Leaf traits considered were nutrient concentration (C, N, P, C/N, and N/P) and physical characteristics (area, strength, specific leaf area, and dry matter content). Soil microsite characteristics measured were pH, C, N, P, C/N and water retention capacity, while soil microclimate characteristics recorded were soil and air, temperature and moisture, and solar radiation. Five evergreen and five deciduous woody shrub species were selected. During 1 year, litter and microsite properties were measured below canopy: (i) senescent leaf chemical and physical properties, and the quantity as well as field decomposition of litter and (ii) soil chemistry, and soil and air physical properties. The factors controlling litter decomposition were different for each FG. In deciduous species, C/N ratio had a negative effect on decomposition. In evergreen species, decomposition was affected negatively by leaf carbon and dry matter content. Litter decomposition depended exclusively on the inherent senescent leaves traits. The common decomposition pattern between species of both FG could be attributed to similar leaf traits and the correlation between variables that control decomposition in both groups. Plant nutrient inputs associated with the litter decomposition process did not explain the soil nutrient content. These results suggest that other organic matter sources (roots, branches, and fruits) are more important than leaves on soil fertility.     

基于叶片解剖性状探究29种植物对热带珊瑚岛的适应策略

为探究植物对热带珊瑚岛高温、强光照、干旱、盐碱等极端环境的适应策略，分别以生长于海南文昌苗圃和移栽至热带珊瑚岛的29种植物为研究对象，对其叶片性状进行测定和比较分析。结果表明，与海南文昌的同种植物相比，热带珊瑚岛的草本植物除干物质含量增加外其他性状均无显著改变；而木本植物的比叶面积显著下降，叶片厚度和叶片干物质含量显著增加，海绵组织更厚且栅栏组织排列更紧密，但气孔长度、气孔密度及气孔面积指数无显著差异。岛上木本植株采取慢速投资-收益的资源获取策略，将更多的资源投入到叶片构建中从而增强逆境下的适应性，并且通过非气孔调节的方式提高光合与储水的潜力以抵御胁迫。栽植于热带珊瑚岛的29种植物能够采用更保守的资源利用策略，较好地适应干旱、强光照等胁迫环境，可用于热带珊瑚岛植被构建。     

重庆石灰岩地区主要木本植物叶片性状及养分再吸收特征

以重庆石灰岩地区15种常绿木本植物和14种落叶木本植物为研究对象,对两种生活型植物叶片衰老前后叶干物质含量(LDMC)、比叶面积(SLA)和叶片厚度(LT)进行了比较,并采用不同的计算方法(单位质量叶片养分含量、单位面积叶片养分含量)分析了两类植物叶片衰老前后养分含量及再吸收特征,最后对养分再吸收效率与其他叶性状因子之间的关系进行了相关分析。结果表明:常绿植物成熟叶LDMC、LT及衰老叶LT显著低于落叶植物,落叶植物成熟叶和衰老叶SLA均显著高于常绿植物(P0.05);基于单位质量叶片计算的养分含量,常绿植物成熟和衰老叶N、P量均低于落叶植物,而基于单位面积叶片计算的N、P含量则表现出相反的趋势;基于不同方法计算的N、P再吸收效率差异不明显,其中常绿植物基于单位质量叶片养分含量计算的N、P平均再吸收效率为39.42%、43.79%,落叶植物的为24.08%、33.59%;常绿和落叶植物N、P再吸收效率与LDMC、SLA、LT和成熟叶N、P含量之间没有显著相关性,但与衰老叶养分含量存在显著负相关(P0.05)。研究发现,无论是常绿植物还是落叶植物,衰老叶N、P含量均较低,表明石灰岩地区植物具有较高的养分再吸收程度。     

热带珊瑚岛不同生活型植物叶片性状及其生态适应性意义

为探究热带珊瑚岛植物对高温、高光照、土壤贫瘠生境的适应性,对热带珊瑚岛不同生活型植物叶片功能性状及其生态适应策略差异进行研究。结果表明,不同生活型植物叶片全N、纤维素含量,C/N、水分利用效率和比叶面积存在显著差异;叶片功能性状间的显著相关性表明植物在资源分配和生长投资间存在权衡;不同物种在珊瑚岛生境中采取不同的生态策略,且呈现明显趋异性。在热带珊瑚岛植被恢复实践中,可优先选择的乔木树种为抗风桐(Pisonia grandis),灌木为银毛树(Tournefortia argentea),但同时要防范飞机草(Chromolaena odorata)、孪花蟛蜞菊(Wollastonia biflora)和南美蟛蜞菊(Sphagne- ticola trilobata)的扩张。