王瑞丽
, 于贵瑞, 何念鹏
WANG Ruili, YU Guirui, HE Nianpeng
通讯作者:
收稿日期: 2015-07-20
修回日期: 2015-08-21
网络出版日期: 2015-11-20
版权声明: 2015 《地理学报》编辑部 本文是开放获取期刊文献，在以下情况下可以自由使用：学术研究、学术交流、科研教学等，但不允许用于商业目的.
基金资助:
作者简介:
作者简介：王瑞丽(1988-), 女, 博士, 主要从事植物功能属性研究。E-mail:loverain.88@163.com
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摘要
为了探究森林植物叶片功能属性的地理格局及其影响因素,在2013年7-8月期间系统调查了中国东部南北样带9个森林生态系统的847种植物的叶片面积（LA）、叶片厚度（LT）、比叶面积（SLA）和叶片干物质含量（LDMC）,并结合群落结构计算了各属性的群落加权平均值（LACWM、SLACWM、LTCWM和LDMCCWM）。结果显示：847种植物的LA、LT、SLA和LDMC的平均值（±标准误）分别为2860.01±135.37 mm2、0.17±0.003 mm、20.15±0.43 m2 kg-1和 316.73±3.81 mg g-1。SLA和LDMC表现出了明显的纬度格局,随着纬度增加,SLA逐渐增加,LDMC降低;然而,LA和LT沿纬度的变化趋势不明显（R2 = 0.02 ~ 0.06）。不同植物类型之间叶片属性的差异是影响LA、LT、SLA和LDMC空间变化的主要因素;叶片功能属性的群落加权值表现出了更加明显的纬度分布格局（R2 = 0.46 ~ 0.71）,这主要受到了气候因素和土壤N含量的影响。本文结果完善了中国区域森林生态系统叶片功能属性地理分布的数据库,同时强调了在研究植物属性空间格局时,考虑群落结构在尺度扩展中的重要性。
关键词：
Abstract
To explore the large-scale changes in leaf functional traits from the species level to community level and their influencing factors in Eastern China, we investigated leaf area (LA), leaf thickness (LT), specific leaf area (SLA) and leaf dry matter content (LDMC) across 847 species from nine typical forest ecosystems along the North-South Transect of Eastern China (NSTEC) between July and August in 2013, and we also calculated the community weighted means (CWM) of leaf traits on the basis of the relative dominance of each species within the community. Our results showed that, for all 847 species, the means (± SE) of LA, LT, SLA, and LDMC were 2860.01 ± 135.37 mm2, 0.17 ± 0.003 mm, 20.15 ± 0.43 m2 kg-1 and 316.73 ± 3.81 mg g-1, respectively. In addition, SLA increased and LDMC decreased with the increasing latitude, whereas no clear latitudinal trends of LA and LT were found (R2 = 0.02-0.06), as latitudinal changes were mainly affected by plant functional types. At the community level, more significant spatial patterns of leaf traits were observed (R2 = 0.46-0.71). Generally, as latitude increased, LACWM and SLACWM varied nonlinearly, while LTCWM increased and LDMCCWM decreased linearly, which were influenced by climate and soil N. This study improved the biogeographical database of leaf functional traits from tropical to cold-temperate forests in eastern China and emphasized the importance of scaling-up in the study of plant traits.
Keywords：
植物叶片功能属性作为各种植物功能属性中重要的定量指标,能够反映植物光合能力、资源利用策略及植物对生长环境的适应性[1-2],具有重要的生态学和生物进化意义[2-4]。与叶片化学和生理属性相比,叶片大小（Leaf area, LA）、叶片厚度（Leaf thickness, LT）、比叶面积（Specific leaf area, SLA）和叶片干物质含量（Leaf dry matter content, LDMC）简单易测,已经被作为研究叶片功能属性大尺度空间变化的主要参数[5-7]。
在过去的几十年内,许多研究者已经探讨了自然条件下叶片功能属性沿环境梯度的变化规律,并认为环境因子的空间格局影响了植物叶片功能属性的地理分布[8-11]。例如,在平均温度较高、辐射强度较高或干旱地区生长的植物,具有高的LT[12]和LDMC[13]及低的SLA[9, 12]。然而,尽管全球范围内叶片功能属性的地理分布规律已有详细统计[5-6, 14-15],但这些研究普遍缺乏中国区域森林生态系统的实测数据或者仅仅涵盖少数森林类型[15]。
目前,一些有关中国森林叶片功能属性地理格局的研究仅仅以优势乔木或少数物种为研究对象[10-11, 16]。因此,有关中国森林叶片功能属性的地理分布的数据仍然十分匮乏,本研究通过系统调查中国东部9个森林生态系统847种植物的叶片功能属性,试图弥补这一知识的空缺。
此外,目前有关叶片功能属性的研究多是在物种水平（即比较不同物种的平均值）,并不能反映植物群落通过群落构建来适应大尺度环境条件的生态学机制,也难以建立植物群落的叶片功能属性与生态系统功能的生理生态学联系。近年来,研究者提出以群落结构数据为基础计算叶片属性的群落加权平均值（community weighted mean, CWM）,来代表群落水平的叶片功能属性值[17-18]。已有研究结果表明,叶片功能属性的加权平均值沿着土壤养分和水分梯度[19]、光照梯度[20]以及不同的演替阶段[17-18, 21]表现出了明显的变化趋势。然而,遗憾的是,这些研究多在局部尺度上进行,且大多只关注草地生态系统,关于横跨多个气候带的大陆或次大陆尺度的森林植被叶片属性的空间格局以及其影响机制的研究仍未报道。
中国东部南北样带（North-South Transect of Eastern China, NSTEC）具有丰富的气候区,包含了热带、亚热带、暖温带和寒温带等气候区,相应地森林植被类型从热带雨林、常绿阔叶林、针阔混交林到北方针叶林[22-23],因此为研究跨越多个气候区的次大陆尺度的森林生态系统的植物叶片功能属性沿环境梯度的变化规律提供了理想条件。在此,沿中国东部南北样带选择了9个典型的森林生态系统,系统调查和分析了847种植物的叶片功能属性（LA、LT、SLA和LDMC）和它们的群落加权平均值（LACWM、LTCWM、SLACWM和LDMCCWM）的地理分布,旨在：① 考察物种和群落水平的叶片功能属性的纬度变化规律;② 探究物种和群落水平的叶片功能属性空间变化的驱动因子。
中国东部南北样带北起大兴安岭北端,向东南方向经小兴安岭到长白山,再折向西南至海南岛,其纬度范围18°44′N~53°N,经度横跨109°30′E~128°E[22]。沿样带从南到北依次分布着热带雨林、季雨林、亚热带常绿阔叶林、暖温带落叶阔叶林、温带针阔叶混交林和寒温带针叶林,形成了地球上独特而完整的以热量梯度驱动的森林地带系列[22, 24]。以中国东部南北样带为研究平台,沿纬度从南到北分别选择尖峰岭、鼎湖山、九连山、神农架、太岳山、东灵山、长白山、凉水和呼中等9个典型的森林生态系统类型进行野外调查和采样（表1）。
表1 野外取样地点的环境和植被类型概况
Tab. 1 Environmental characteristics and vegetation types of sampling sites
| 地点 | 纬度(°N) | 经度(°E) | 年均温(°C) | 年降水量(mm) | 土壤类型 | 植被类型 | 物种数量 |
|---|---|---|---|---|---|---|---|
| 尖峰岭 | 18.7 | 108.9 | 19.8 | 2449.0 | 砖黄壤 | 热带季雨林 | 139 |
| 鼎湖山 | 23.2 | 112.5 | 20.9 | 1927.0 | 砖红壤 | 亚热带常绿阔叶林 | 158 |
| 九连山 | 24.6 | 114.4 | 16.7 | 1954.0 | 红壤 | 亚热带常绿阔叶林 | 172 |
| 神农架 | 31.3 | 110.5 | 10.6 | 1330.0 | 黄棕壤 | 亚热带常绿落叶阔叶混交林 | 120 |
| 太岳山 | 36.7 | 112.1 | 6.2 | 662.0 | 褐土 | 暖温带落叶阔叶林 | 76 |
| 东灵山 | 40.0 | 115.4 | 4.8 | 539.1 | 棕壤 | 暖温带落叶阔叶林 | 79 |
| 长白山 | 42.4 | 128.1 | 2.6 | 691.0 | 暗棕壤 | 温带红松阔叶混交林 | 109 |
| 凉水 | 47.2 | 128.9 | -0.3 | 676.0 | 暗棕壤 | 温带红松阔叶混交林 | 104 |
| 呼中 | 51.8 | 123.0 | -4.4 | 481.6 | 棕色针叶 林土 | 寒温带针叶林 | 88 |
2.2.1 群落调查 野外调查与取样在2013年7-8月期间进行。参照方精云等[25]有关植物群落清查的方法和技术规范,在9个森林站点内开展了群落结构清查。首先,在每个森林站点内,随机设置了3~4个30 m×40 m的样方,用于乔木层的调查,共计32个样方,记录每个样方的海拔、地理位置、地形、坡度和坡向等。选取乔木样方的对角处设置2个5 m×5 m的灌木样方;在乔木样方的四角和中心设置5个1 m×1 m的小样方,用于草本层的调查。随后,在乔木样方中调查所有胸径≥ 2 cm的个体,记录种名、胸径和树高;在灌木和草本样方中,记录植物的种名、株高、基径、多度和盖度。
2.2.2 叶片样品采集 叶片取样方法参照Cornelissen等[3]。对于乔木和灌木植物,在样方内选择健康成熟、长势均匀的植株,每个物种选择3~5个个体,利用高枝剪选取能最大程度地接收阳光照射、完全成熟、无病虫害损坏的叶片20片。一些高大乔木的阳生叶由专业人员爬到树的顶部来获取。采集到的叶片样品立即将放入自封袋内,在4~8小时内扫描确定其叶面积。对于草本植物,进行全株采集。
在整个样带的9个森林站点中,共取样847种植物,隶属于467属、159科,部分出现在不同地点的相同物种进行了重复测定。9个森林站点取样的物种数量具体见表1。将所有物种按照不同的功能型（Plant functional type, PFT）划分为草本、灌木和乔木,乔木又细化为针叶、常绿阔叶和落叶阔叶乔木。不同功能型植物的物种数量详见图1。
图1 中国东部叶片属性在不同植物功能型之间的差异（字母不同代表具有显著差异P < 0.05;n为物种数量。）
Fig. 1 Differences in leaf traits among plant functional types in Eastern China
2.2.3 土壤样品采集 利用随机布点法在每个森林站点的4个样方内采集土壤样品,作为4次重复。在去除土壤表面的枯枝落叶层后,利用内径6 cm的土钻对0~10 cm的土层进行取样,每个样方内随机设置30个取样点,混合均匀后带回实验室用于土壤理化性质的测定。
2.3.1 叶片功能属性的测定 每个物种随机选取5~10个叶片,将叶片平铺在坐标纸上,用透明塑料板压平,确保叶片完全伸张,用扫描仪进行扫描获得待测叶片的平面图像。利用Adobe Photoshop CS4软件（Adobe Systems, San Jose, USA）统计图像中叶片所占的像素数,乘以每个像素所占的面积就可以计算出叶片的实际面积（LA,mm2）。叶片图像处理的测定步骤详见肖强等[26]。随后,将扫描后的叶片放入纸信封内,在70 ℃的烘箱内烘干48 h,用万分之一天平称重,用来计算比叶面积（SLA,m2 kg-1）。
叶片厚度（LT,mm）的测定使用游标卡尺测量（精确到0.01 mm）,选取5~10个新鲜叶片,测量时避开叶脉,并尽量选择叶片中心部位,每个个体在不同部位测量5次,最后取平均值为该个体的叶片厚度。
叶片干物质含量（LDMC,mg g-1,叶片干重与叶片饱和鲜重的比值）的测定：每个物种选择5~10片,将其浸泡在清水中12小时以上,进行饱和鲜重的测量,随后将其置于70 ℃的烘箱中烘干48 h,测量干重。
2.3.2 土壤养分的测定 在实验室内,土壤样品风干后除去根系和石块,用球磨仪（MM400 ball mill; Retsch, Germany）研磨后全部过2 mm筛,装入自封袋中供测试使用。利用元素分析仪（Elementar,Vario Max CN,Germany）测定土壤总C和N含量。
2.3.3 群落水平的叶片属性的计算 依据群落结构的数据,计算了叶片功能属性的群落加权平均值（CWM）[17],用来代表群落水平的叶片属性值。
式中：
生物量方程来源于中国生态系统研究网络（CERN）（http://159.226.111.42/pingtai/cernc/index.jsp）和文献搜集。文中一共采用246个生物量方程（R2 = 0.52~1.00）,其中乔木的生物量方程为235个,灌木为21个,混合生物量方程为12个（具体的生物量方程详见Wang等[27]）。对于生物量方程缺失的物种采用同一属或同一功能型的方程来代替。
2.3.4 气象数据来源 气象数据来自中国生态系统研究网络。该气象数据库以国家气象局1961-2007年740个站点的观测数据为基础,包括太阳总辐射、日照时数、温度、降水、风向、风速、平均气压等气象数据,以及1:250000的500 m×500 m的数字高程数据,经过数据处理后,生成的全国尺度各种气候要素的1 km×1 km栅格数据库[28]。根据每个取样点的经纬度坐标,提取出各取样点的年均温（MAT）和年均降水量（MAP）数据。
由于叶片属性呈右偏态分布,所以在数据分析时,对叶片属性数据进行了Log10的对数转换,以满足正态分布的要求。
利用单因素方差分析（One-way ANOVA）和LSD多重比较,分析了不同功能型（乔木、灌木和草本;针叶和阔叶;常绿阔叶植物和落叶阔叶植物）之间叶片功能属性的差异。
为了探讨叶片属性参数的纬度变异性,首先利用回归分析考察了物种水平上乔木、灌木和草本（由站点内每个物种的平均值组成）和群落水平（由叶片属性的群落加权平均值组成）的叶片属性的空间格局。然后,利用巢式方差分析（nested ANOVA）,将物种水平所有物种的LA、LT、SLA和LDMC的纬度变异性区分为样地间和样地内的变异性。
接下来,进一步利用R语言lme4程序包中的混合效应模型来定量评估植物功能型（包括草本、灌木、针叶植物、常绿阔叶和落叶阔叶乔木）、气候和土壤因子对物种叶片属性空间变异的解释程度;群落水平的叶片属性空间变化的解释因子只包括气候和土壤因素。在混合效应模型中,植物功能型、气候和土壤因子作为固定因素,地点作为随机变量能够将同一地点内各叶片属性之间的非独立性考虑进去[29]。同时,由于各环境因子之间具有较高的相关性,相关性显著的两个因子中的一个进入主效应模型,来避免解释变量之间的共线性,将具有显著作用的因子和交互作用进入到最终的模型中。如果有多个环境因子都显著,则利用逐步回归来筛选出AIC值（Akaike's Information Criterion, AIC）最小的模型作为最终的拟合模型。
数据分析在SPSS 13.0（SPSS Inc., Chicago, IL, USA, 2004）和R 2.15.2（version 2.15.2,R Development Core Team 2012）中完成。
本研究系统分析了中国东部南北样带9个森林生态系统中847个物种LA、LT、SLA和LDMC的统计特征,并分别从物种水平和群落水平考察了叶片功能属性的纬度变异性及其影响因素。
叶片功能属性特征主要包括叶片面积（LA）、叶片厚度（LT）、叶面积指数（SLA）和叶片干物质含量（LDMC）以及这4个叶片属性的群落加权值,即LACWM、LTCWM、SLACWM和LDMCCWM。
3.1.1 叶片功能属性的物种水平概况 中国东部森林生态系统中847个物种的统计特征,LA、LT、SLA和LDMC的平均值（±标准误）分别为2860.01±135.37 mm2、0.17±0.003 mm、20.15±0.43 m2 kg-1和316.73±3.81 mg g-1,变化范围分别为4.09~56085.43 mm2、0.01~0.78 mm、1.89~94.99 m2 kg-1和44.46~775.68 mg g-1（表2）,在全球叶片功能属性值的变化范围之内（数据范围：LA为1~946070 mm2、LT为0.03~7.5 mm、SLA为2.3~122.8 m2 kg-1和LDMC为48~517 mg g-1）[13]。4个叶片属性中LA的变异程度最大（变异系数= 1.51）,LDMC的变异程度最小（变异系数= 0.38）。
3.1.2 叶片功能属性的群落水平概况 在群落水平上,LACWM、LTCWM、SLACWM和LDMCCWM的平均值分别为1443.80±169.35 mm2、0.34±0.03 mm、9.83±0.71 m2 kg-1和421.78±8.76 mg g-1。LACWM的变异程度最大（变异系数= 0.66）,LDMCCWM的变异程度最小（变异系数 = 0.12）（表2）。
表2 中国东部森林叶片功能属性在物种水平和群落水平的统计特征
Tab. 2 Statistics for forest leaf functional traits at the species and community levels in Eastern China
| 水平 | 属性 | 数量* | 平均值 | 最小值 | 最大值 | 标准误 | 变异系数 | 偏度 |
|---|---|---|---|---|---|---|---|---|
| 物种 | LA (mm2) † | 847 | 2860.01 | 4.09 | 56085.43 | 135.37 | 1.51 | 5.54 |
| LT (mm) | 847 | 0.17 | 0.01 | 0.78 | 0.003 | 0.56 | 2.71 | |
| SLA (m2·kg-1) | 847 | 20.15 | 1.89 | 94.99 | 0.43 | 0.68 | 1.29 | |
| LDMC (mg·g-1) | 847 | 316.73 | 44.46 | 775.68 | 3.81 | 0.39 | 0.27 | |
| 群落 | LACWM (mm2) | 32 | 1443.80 | 22.98 | 3547.5 | 169.35 | 0.66 | 0.49 |
| LTCWM (mm) | 32 | 0.34 | 0.18 | 0.69 | 0.03 | 0.46 | 1.00 | |
| SLACWM (m2·kg-1) | 32 | 9.83 | 5.08 | 18.34 | 0.71 | 0.41 | 0.68 | |
| LDMCCWM (mg·g-1) | 32 | 421.78 | 364.16 | 544.01 | 8.76 | 0.12 | 0.72 |
3.1.3 不同类型植物叶片属性的差异 单因素方差分析被用来较不同植物功能型（PFT）之间叶片属性的差异（图1）,结果表明,在不同生长型中,灌木的LA显著低于草本和乔木（F = 6.90,P = 0.001）,SLA的大小依次为草本>灌木>乔木（F = 201.13,P < 0.001）,而LT和LDMC均为乔木最大,草本最小（LT：F = 18.39,P < 0.001;LDMC：F = 231.02,P < 0.001）;与针叶相比,阔叶乔木具有较大的LA（F = 8.34,P = 0.004）和SLA（F = 22.55,P < 0.001）,以及较小的LT（F = 213.61,P < 0.001）,而LDMC在二者之间差异不显著（F = 0.36,P = 0.549）;与落叶阔叶植物相比,常绿阔叶植物具有较高的LT（F = 37.34,P < 0.001）和LDMC（F = 5.06,P = 0.025）,以及较低的SLA（F = 83.13,P < 0.001）,LA在二者之间差异不显著（F = 0.48,P = 0.487）。
叶片属性的纬度格局在物种水平和群落水平上存在差异（图2）。物种水平上,乔木、灌木和草本植物的叶片属性表现出了相似的纬度变化格局（图2a）,具体表现为：随纬度增加,LA、LT和LDMC均显著降低（P < 0.05,图2a）,SLA增加（P < 0.05）,然而LA和LT沿纬度梯度的变化趋势较弱（R2 = 0.02~0.06,图2a）。群落水平上,LACWM和SLACWM的纬度变化趋势呈抛物线性,具体表现为：随着纬度增加,LACWM和SLACWM先增加到最大值,而后降低（P < 0.05,图2b）。LTCWM随纬度增加而增加（P < 0.05,图2b）,LDMCCWM随纬度的变化趋势则与之相反（P < 0.05,图2b）。
图2 中国东部森林叶片功能属性的纬度变异性（只给出了显著的回归关系P < 0.05;*：P < 0.05;**：P <0.01）
Fig. 2 Latitudinal trends of forest leaf functional traits in Eastern China
利用巢式方差分析,将物种水平上叶片功能属性的纬度变异性区分为样地内和样地间的变异性（图3）。结果表明,物种水平的叶片功能属性38.15%~50.87%的变异性存在于样地内部共存物种之间,只有15.96%~37.20%的变异性能够被样地之间的差异所解释。此外,与SLA和LDMC相比,LA和LT较多的变异性存在于样地内部（> 49%）。
图3 中国东部森林物种水平的叶片功能属性的变异性区分
Fig. 3 Variance partitioning of the total variance of species-level leaf functional traits in Eastern China
进一步利用混合效应模型来定量分析各因素对物种水平和群落水平的叶片功能属性纬度变异的解释率（表3,表4）,结果显示：物种水平上,植物功能型是影响LA、LT、SLA和LDMC空间变化的主要因素,能够解释物种水平的叶片属性19.43%~41.57%的变异性,而环境因素仅仅解释了总变异的1.65%~9.13%（表3）。
表3 中国东部环境因素和植物功能型对叶片属性纬度变化的作用
Tab. 3 Influences of the plant functional type and environmental factors on species-level leaf traits in Eastern China
| 影响因素 | LogLA | LogLT | ||||
|---|---|---|---|---|---|---|
| 自由度 | F值 | 解释率(%) | 自由度 | F值 | 解释率(%) | |
| 植物功能型 | 4 | 56.79** | 19.43 | 4 | 1.26** | 41.57 |
| 年均温 | 1 | 98.16** | 6.72 | |||
| 年降水量 | 1 | 25.22** | 1.65 | |||
| 土壤氮 | 1 | 30.49** | 2.09 | 1 | 139.73** | 9.13 |
| 功能型×年均温 | ||||||
| 功能型×年降水量 | 4 | 4.45** | 1.16 | |||
| 功能型×土壤氮 | 4 | 3.90** | 1.02 | |||
| 年均温×土壤氮 | ||||||
| 年降水量×土壤氮 | 1 | 80.67** | 5.27 | |||
| 地点 | 8 | 6.31** | 3.46 | 8 | 5.14** | |
| 残差 | 997 | 68.31 | 1001 | |||
| LogSLA | LogLDMC | |||||
| 自由度 | F值 | 解释率(%) | 自由度 | F值 | 解释率(%) | |
| 植物功能型 | 4 | 163.24** | 36.83 | 4 | 129.50** | 34.18 |
| 年均温 | 1 | 41.41** | 2.19 | |||
| 年降水量 | 1 | 127.55** | 5.76 | |||
| 土壤氮 | 1 | 197.69** | 8.92 | 1 | 77.47** | 4.09 |
| 功能型×年均温 | 4 | 9.90** | 2.09 | |||
| 功能型×年降水量 | 4 | 6.73** | 1.21 | |||
| 功能型×土壤氮 | 4 | 2.67* | 0.48 | 4 | 4.30** | 0.91 |
| 年均温×土壤氮 | 1 | 10.18** | 0.54 | |||
| 年降水量×土壤氮 | 1 | 12.48** | 0.56 | |||
| 地点 | 8 | 3.86** | 1.39 | 8 | 4.51** | 1.90 |
| 残差 | 992 | 44.85 | 1022 | 54.11 | ||
表4 中国东部环境因素对群落水平的叶片属性纬度变化的影响
Tab. 4 Influences of environmental factors on community-level leaf traits in Eastern China
| 影响因素 | LogLACWM | LogLTCWM | |||||
|---|---|---|---|---|---|---|---|
| 自由度 | F值 | 解释率(%) | 自由度 | F值 | 解释率(%) | ||
| 年均温 | 1 | 3.34* | 25.08 | ||||
| 年降水量 | 1 | 5.30** | 32.75 | ||||
| 土壤氮 | |||||||
| 年均温×土壤氮 | |||||||
| 地点 | 8 | 14.09** | 58.43 | 8 | 14.99** | 54.87 | |
| 残差 | 22 | 16.49 | 22 | 12.38 | |||
| LogSLACWM | LogLDMCCWM | ||||||
| 自由度 | F值 | 解释率(%) | 自由度 | F值 | 解释率(%) | ||
| 年均温 | 1 | 7.77* | 16.51 | 1 | 22.56** | 48.04 | |
| 年降水量 | |||||||
| 土壤氮 | 1 | 7.75** | 36.41 | ||||
| 年均温×土壤氮 | 1 | 0.003 | 1.79 | ||||
| 地点 | 8 | 5.86* | 15.42 | 8 | 1.471 | 3.01 | |
| 残差 | 20 | 29.87 | 22 | 48.95 | |||
群落水平上,气候条件和土壤N含量的变化是影响叶片属性的群落加权值变化的主要因素（表4）。其中,年均温的空间变化是影响LACWM和LDMCCWM的纬度变化的主要因素,分别解释了LACWM和LDMCCWM的25.08%和48.04%变异性;年降水量是LTCWM纬度变化的主要影响因素,解释了其32.75%的变异性;土壤N含量是影响SLACWM纬度变化的主要因素,解释了其变异性的36.41%。
本研究系统调查了中国东部9个森林生态系统内847种植物叶片的LA、LT、SLA和LDMC在自然环境梯度下的变异规律,完善了中国森林叶片功能属性地理分布的数据集。与全球范围的数据集相比[3, 13],结果在全球区域的数据范围之内。
中国东部森林中乔木、灌木和草本植物叶片功能属性沿纬度梯度的变化格局一致,均表现为SLA随纬度增加而增加,LDMC随纬度增加而降低（图2a）。然而,LA和LT的纬度变化趋势较弱（R2 = 0.02~0.06）。这主要是由于与SLA和LDMC相比,LA和LT大部分变异性存在于样地内部共存物种之间（> 49%,图3）,这部分变异不能被大尺度条件下不同区域之间的环境差异所解释,从而导致了LA和LT沿着环境梯度较弱的地理格局。类似地,全球范围内的叶片经济学属性（SLA、叶片寿命、光合速率以及叶片氮磷含量）的研究也证明,叶片功能属性20%~67%的空间变异性存在于同一样地内的共存物种之间[5, 30]。
植物功能型的空间格局解释了叶片功能属性19.43%~41.57%的纬度变异性（表3）,而气候和土壤因素对叶片属性空间变异性的作用较弱（1.65%~9.13%）,这和全球和区域尺度上植物功能型（PFT）对叶片形态、养分和生理属性空间变异的解释程度大于环境因素的结论一致[31-33]。不同植物功能型之间叶片功能属性的差异,是植物自身遗传因素及其对生境的适应的共同结果[12, 34]。例如,在养分贫瘠或动物危害严重的生态系统（如低纬度地区）中,植物优先把碳分配到储存和防御器官,产生高的LDMC和较低的SLA,而低SLA往往会导致较长的叶片寿命,因此,这类植物多为硬叶或常绿植物[12, 35]。本研究中具有高LDMC和低SLA的常绿阔叶植物多分布在低纬度地区,而高SLA和低LDMC的落叶阔叶分布在土壤肥沃的中高纬度地区。最终,这种物种组成的分布格局导致了SLA随着纬度增加而增加,LDMC随着纬度增加而降低（图2a）。
尽管气候和土壤因素对物种水平的叶片属性纬度格局的解释程度较低,但它们对叶片属性的空间分布具有一定程度的直接和间接作用。一方面,环境因子可以直接影响植物叶片的形态构建及与代谢活动相关的碳分配[4]。另一方面,自然条件下,气候条件塑造了植被类型的大尺度地理格局[36-37],同时也调节了土壤资源的可利用性[30, 38]。
本研究中,用叶片功能属性的群落加权平均值来代表群落水平的叶片属性值,结果发现它们表现出了与物种水平上乔木、灌木和草本叶片属性不同的纬度变异性（图2）。随着纬度增加,LACWM和SLACWM呈抛物线型的变化趋势,而LTCWM线性增加,LDMCCWM线性降低（图2b）,并且当考虑物种的相对生物量比例时,叶片功能属性的群落加权平均值随纬度的变化趋势更加明显（R2 = 0.46~0.71）。类似地,Domínguez等[20]和Vile等[18]也发现,与物种水平的均值相比,植物的相对生长速率和叶片形态、化学属性的群落加权平均值沿着光环境梯度或不同的演替阶段的变化趋势更加明显。这些结果表明,物种水平的结果或所有物种属性的算术平均值不能反映森林生态系统内群落水平上真实的属性值,即使采用乔木层植物的叶片属性值（或平均值）也无法代替群落的属性值。这是因为生态系统过程和功能主要是由群落内优势物种的功能属性来决定的（质量比率假说）[2, 17]。在物种丰富的群落内,非优势的物种对生态系统功能的影响较小,如果简单计算群落内所有物种的算术平均值则会削弱优势物种的作用[18]。相反,群落加权平均值融合了群落结构和物种信息[17-18, 20],能够更好地解释群落对环境因素的响应。
气候和土壤N含量是影响群落水平的叶片功能属性沿纬度变化的主要因素（表4）,表明气候和土壤养分条件作为主要的环境滤镜,通过改变群落内的物种组成和群落结构,进而决定了叶片功能属性的群落加权平均值在不同环境条件下的差异[20, 39]。根据群落构建理论,物种对外界环境的适应性差异是群落内物种组成沿着环境梯度变化的主要原因[39-40]。本研究中,从南到北,环境梯度的一端是高温、高湿和土壤养分贫瘠的低纬度地区,具有低SLA但高LDMC特征的常绿植物占优势（因而导致低的SLACWM和高LDMCCWM）;另一端,在中纬度地区,较高的土壤肥力和季节明显的环境则倾向于选择具有高SLA特征的落叶植物（产生高的SLACWM）;而随着纬度增加,在寒冷的高纬度地区,针叶植物（具有低LA和SLA、高LT的特征）逐渐成为群落内的优势物种,这导致了植物群落具有低的LACWM、SLACWM和高的LTCWM（图2b）。
（1）中国东部南北样带9个森林站点中847个物种的叶片面积（LA）、叶片厚度（LT）、比叶面积（SLA）和叶片干物质含量（LDMC）的平均值（±标准误）分别为2860.01 ± 135.37 mm2、0.17 ± 0.003 mm、20.15 ± 0.43 m2 kg-1和316.73±3.81 mg g-1,变化范围分别为4.09~56085.43 mm2、0.01~0.78 mm、1.89~94.99 m2 kg-1和44.46~775.68 mg g-1。
（2）叶片属性的群落加权平均值中,LACWM、LTCWM、SLACWM和LDMCCWM的平均值（±标准误）分别为1443.80 ± 169.35 mm2、0.34 ± 0.03 mm、9.83 ± 0.71 m2 kg-1和421.78 ± 8.76 mg g-1。
（3）叶片功能属性的纬度格局在物种水平和群落水平存在差异。具体表现为：在物种水平上随着纬度增加,SLA增加,LDMC降低,而LA和LT变化不明显,这主要是由于LA和LT的纬度变异性大多存在于样地内共存物种之间,从而削弱了LA和LT在大尺度的空间变异性;群落水平的叶片属性的纬度变化趋势明显（R2 = 0.46~0.71）。随着纬度增加,LA和SLA表现为先增加后降低的趋势,LT线性增加,而LDMC降低。
（4）不同因素驱动了叶片属性在物种水平和群落水平的纬度格局。植物功能型的空间变化是调控物种水平上叶片属性纬度变异性的主要因子,而气候和土壤N含量作为主要的环境滤镜通过调控群落内的物种组成,导致了群落水平的叶片属性的纬度格局。
The authors have declared that no competing interests exist.
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Leaf traits as indicators of resource-use strategy in floras with succulent species. https://doi.org/10.1046/j.1469-8137.2002.00357.x URL [本文引用: 1] 摘要
Summary 61 68Associations between specific leaf area (SLA), leaf water content (LWC) and leaf thickness (LT) in 77 species were analysed to identify which of these traits gave a better indicator value of general plant resource-use strategy within the flora of central-western Argentina, in which succulent species are common. 61 68When all species were considered together,
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A trait-based approach to comparative functional plant ecology: Concepts, methods and applications for agroecology. A review. https://doi.org/10.1007/s13593-011-0036-y URL Magsci [本文引用: 3] 摘要
Abstract<br/>Comparative functional ecology seeks to understand why and how ecological systems and their components operate differently across environments. Although traditionally used in (semi)-natural situations, its concepts and methods could certainly apply to address key issues in the large variety of agricultural systems encountered across the world. In this review, we present major advances in comparative plant functional ecology that were made possible over the last two decades by the rapid development of a trait-based approach to plant functioning and prospects to apply it in agricultural situations. The strength of this approach is that it enables us to assess the interactions between organisms and their environment simultaneously on a large number of species, a prerequisite to address questions relative to species distribution, community assembly and ecosystem functioning. The trait concept will be first defined, before presenting a conceptual framework to understand the effects of environmental factors on plant community structure and ecosystem properties via plant traits. We will then argue that leading dimensions of variation among species can be captured by some selected traits and show that a combination of three easily measured traits—specific leaf area (the ratio of leaf area to leaf dry mass), plant height and seed mass—enables us to assess how different species use their resources, interact with neighbours and disperse in time and space. The use of traits to address central questions in community ecology will be reviewed next. It will be shown that traits allow us to (1) understand how plant species are sorted according to the nature of environmental gradients, (2) evaluate the relative importance of habitat filtering and limiting similarity in the process of community assembly and (3) quantify two main components of community functional structure, namely, community-weighted means of traits and community functional divergence. The relative impacts of these two components on ecosystem properties will then be discussed in the case of several components of primary productivity, litter decomposition, soil water content and carbon sequestration. There is strong support for the biomass ratio hypothesis, which states that the extent to which the traits of a species affect those ecosystem properties depends on the abundance of this species in the community. Assessing the role of functional divergence among species on ecosystem properties will require major methodological breakthroughs, both in terms of metrics and statistical procedures to be used. In agricultural situations, we show that trait-based approaches have been successfully developed to assess the impacts of management practices on (1) the agronomic value of grasslands and (2) the functional composition and structure of crop weed communities and how these could affect the functioning of the crop. Applications in forestry are still poorly developed, especially in temperate regions where the number of species in managed forest remains relatively low. The last decades of research have led to the constitution of large data sets of plant traits, which remain poorly compatible and accessible. Recent advances in the field of ecoinformatics suggest that major progress could be achieved in this area by using improved metadata standards and advancing trait domain ontologies. Finally, concluding remarks, unanswered questions and directions for research using the functional approach to biodiversity made possible by the use of traits will be discussed in the contexts of ecological and agronomical systems. The latter indeed cover a wide range of environmental conditions and biological diversity, and the prospect for reducing environmental impacts in highly productive, low-diversity systems will certainly imply improving our skills for the management of more diverse systems prone to a trait-based approach as reviewed here.<br/>
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Which is a better predictor of plant traits: Temperature or precipitation? https://doi.org/10.1111/jvs.12190 URL [本文引用: 2] 摘要
Abstract Question Are plant traits more closely correlated with mean annual temperature, or with mean annual precipitation? Location Global. Methods We quantified the strength of the relationships between temperature and precipitation and 21 plant traits from 447,961 species-site combinations worldwide. We used meta-analysis to provide an overall answer to our question. Results Mean annual temperature was significantly more strongly correlated with plant traits than was mean annual precipitation. Conclusions Our study provides support for some of the assumptions of classical vegetation theory, and points to many interesting directions for future research. The relatively low R 2 values for precipitation might reflect the weak link between mean annual precipitation and the availability of water to plants.
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The worldwide leaf economics spectrum. https://doi.org/10.1038/nature02403 URL PMID: 15103368 [本文引用: 3] 摘要
Bringing together leaf trait data spanning 2,548 species and 175 sites we describe, for the first time at global scale, a universal spectrum of leaf economics consisting of key chemical, structural and physiological properties. The spectrum runs from quick to slow return on investments of nutrients and dry mass in leaves, and operates largely independently of growth form, plant functional type or biom
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A review of leaf morphology plasticity linked to plant response and adaptation characteristics in arid ecosystems. https://doi.org/10.3724/SP.J.1258.2012.00088 URL Magsci [本文引用: 1] 摘要
<p>叶片形态是指示植物适应特定环境的重要指标。由于植物叶片形态不仅对时空环境变化具有极强的敏感性和可塑性, 而且能够通过叶片形态的调整调节自身的生存适应能力, 所以叶片形态学研究一直是植物生理及植物生态学研究中的热点。该文在总结前人叶片形态学研究成果的基础上, 探索建立了简单的叶片形态指标分类体系; 结合物质能量交换的物理学原理, 回顾总结了叶片表观形态变化与叶片物质能量交换之间的相关关系; 应用叶片形态影响物质能量交换的物理学原理, 重点分析了干旱区植物叶片表观形态对低水分环境、高辐射(或高温)的响应与适应特征; 最后, 在回顾分析的基础上, 对叶片形态研究中存在的几个问题进行了讨论。</p>
干旱区叶片形态特征与植物响应和适应的关系 .https://doi.org/10.3724/SP.J.1258.2012.00088 URL Magsci [本文引用: 1] 摘要
<p>叶片形态是指示植物适应特定环境的重要指标。由于植物叶片形态不仅对时空环境变化具有极强的敏感性和可塑性, 而且能够通过叶片形态的调整调节自身的生存适应能力, 所以叶片形态学研究一直是植物生理及植物生态学研究中的热点。该文在总结前人叶片形态学研究成果的基础上, 探索建立了简单的叶片形态指标分类体系; 结合物质能量交换的物理学原理, 回顾总结了叶片表观形态变化与叶片物质能量交换之间的相关关系; 应用叶片形态影响物质能量交换的物理学原理, 重点分析了干旱区植物叶片表观形态对低水分环境、高辐射(或高温)的响应与适应特征; 最后, 在回顾分析的基础上, 对叶片形态研究中存在的几个问题进行了讨论。</p>
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Research advances on canges of leaf traits along an altitude gradient. https://doi.org/10.11820/dlkxjz.2011.11.014 URL Magsci [本文引用: 1] 摘要
由于在海拔梯度上各种环境因子表现出连续的梯度性变化,以海拔梯度为平台研究植物叶片性状的适应特征有助于揭示植物对气候变化的响应,进而可以为研究全球变化与陆地生态系统的关系提供研究基础。本文重点分析了植物的叶寿命、比叶面积、叶氮含量、叶绿素含量等叶片结构性状和气孔导度、叶片羧化效率、水分利用效率和叶片δ<sup>13</sup>C等叶片功能性状随海拔梯度的变化规律和特点,探讨了植物叶片性状的研究不足及未来发展方向,以便为国内相关研究的开展提供参考。
植物叶片性状沿海拔梯度变化研究进展 .https://doi.org/10.11820/dlkxjz.2011.11.014 URL Magsci [本文引用: 1] 摘要
由于在海拔梯度上各种环境因子表现出连续的梯度性变化,以海拔梯度为平台研究植物叶片性状的适应特征有助于揭示植物对气候变化的响应,进而可以为研究全球变化与陆地生态系统的关系提供研究基础。本文重点分析了植物的叶寿命、比叶面积、叶氮含量、叶绿素含量等叶片结构性状和气孔导度、叶片羧化效率、水分利用效率和叶片δ<sup>13</sup>C等叶片功能性状随海拔梯度的变化规律和特点,探讨了植物叶片性状的研究不足及未来发展方向,以便为国内相关研究的开展提供参考。
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Relative effects of phylogeny, biological characters and environments on leaf traits in shrub biomes across central Inner Mongolia, China. https://doi.org/10.1093/jpe/rts028 URL [本文引用: 1] 摘要
Aims Understanding the drivers for leaf traits is critical to improving our predictions on ecosystems’ responses to global changes. Geographic patterns of leaf traits are shaped by phylogenetic, biological and environmental factors simultaneously. However, till now few studies have examined how these factors influenced leaf traits together, and how their effects differed at the within- and among-site levels. Methods We sampled leaf traits from a 1100 km shrub-biome transect across central Inner-Mongolia, including leaf mass per area (LMA), mass-based photosynthetic rate, nitrogen (N) and phosphorus (P) concentrations. We examined the effects of phylogenetic, biological (height and growth rate) and environmental (climate and soil) factors on leaf traits with mixed-model analyses of variance. Variation partitioning method was used to separate the joint and independent effects of these three types of factors. Important Findings (i) Climate and soil fertility (total or available nutrient concentrations) together explained 11.4–41.4% of among-site variations, with remarkable difference among traits. (ii) Height and height growth rate together explained 0.4–31.9% of trait variations (mostly among-site variations). Our results could only weakly support the ability of leaf traits as predictors for whole-plant growth. (iii) LMA was negatively related to height, which was consistent with the resource-use strategy hypothesis but inconsistent with the hypotheses proposed for coexisting trees, suggesting that the LMA–height relationship is shaped by rather different mechanisms between the within- and among-communities levels. (iv) The variation partitioning analysis showed that, the relationships between leaf traits and biological characters largely reflected the differences in both leaf traits and biological characters among species that occupying different sites. The relative importance of phylogenetic, biological and environmental factors differed remarkably among leaf traits, between the within- and among-communities levels, and between different biomes. (v) Our results strongly suggest the necessity of examining the three types of factors simultaneously, and at both the within- and among-communities levels, for a better understanding of the drivers for leaf traits patterns.
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A global study of relationships between leaf traits, climate and soil measures of nutrient fertility. |
| [10] |
Relationships among functional traits of Quercus species and their response to meteorological factors in the temperate zone of the North-South Transect of Eastern China. https://doi.org/10.3773/j.issn.1005-264x.2010.06.001 URL Magsci [本文引用: 1] 摘要
<FONT face=Verdana>在南北样带温带区选择11个栎属(<EM>Quercus</EM>)树种的核心分布区, 对各分布区内栎属建群树种的功能性状进行了测定,并对功能性状间的关系及其对气象因子的响应进行了分析, 以期为气候变化背景下植物-环境关系的深入研究奠定基础。结果表明: 虽然比叶重(<EM>LMA</EM>)和叶片干物质含量(<EM>LDMC</EM>)在反映栎属树种生活策略上有着异曲同工的作用, 但是相比之下, <EM>LMA</EM>的作用略胜一筹; 基于面积的叶片养分含量间的关系较基于质量的更为显著; 除叶片单位面积磷含量(<EM>P</EM><SUB>area</SUB>)和单位面积钾含量(<EM>K</EM><SUB>area</SUB>)间关系外, 无论是基于面积还是质量的叶片氮(N)、磷(P)含量间的正相关, 均较两者与钾(K)含量间的正相关显著, 这可能与K元素并不直接参与任何稳定结构物质的合成有关。温度和日照时数是影响功能性状间关系的主要气象因子, 与基于质量的养分含量相比, 基于面积的养分含量更易于受温度和日照时数的影响; 降水仅仅影响叶片<EM>P</EM><SUB>area</SUB>与其他性状间的关系。</FONT>
南北样带温带区栎属树种功能性状间的关系及其对气象因子的响应 .https://doi.org/10.3773/j.issn.1005-264x.2010.06.001 URL Magsci [本文引用: 1] 摘要
<FONT face=Verdana>在南北样带温带区选择11个栎属(<EM>Quercus</EM>)树种的核心分布区, 对各分布区内栎属建群树种的功能性状进行了测定,并对功能性状间的关系及其对气象因子的响应进行了分析, 以期为气候变化背景下植物-环境关系的深入研究奠定基础。结果表明: 虽然比叶重(<EM>LMA</EM>)和叶片干物质含量(<EM>LDMC</EM>)在反映栎属树种生活策略上有着异曲同工的作用, 但是相比之下, <EM>LMA</EM>的作用略胜一筹; 基于面积的叶片养分含量间的关系较基于质量的更为显著; 除叶片单位面积磷含量(<EM>P</EM><SUB>area</SUB>)和单位面积钾含量(<EM>K</EM><SUB>area</SUB>)间关系外, 无论是基于面积还是质量的叶片氮(N)、磷(P)含量间的正相关, 均较两者与钾(K)含量间的正相关显著, 这可能与K元素并不直接参与任何稳定结构物质的合成有关。温度和日照时数是影响功能性状间关系的主要气象因子, 与基于质量的养分含量相比, 基于面积的养分含量更易于受温度和日照时数的影响; 降水仅仅影响叶片<EM>P</EM><SUB>area</SUB>与其他性状间的关系。</FONT>
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Traits variations along a climatic gradient in hilly area of Loess Plateau.
选取黄土丘陵区延河流域147个物种,对10个与植物形态、生理相关的叶片和细根功能性状(叶大小、叶长宽比、叶厚度、叶干重、比叶面积、叶组织密度、叶氮含量、细根比根长、细根组织密度和细根氮含量)进行了测定,并对功能性状与气候因子的关系进行了分析。结果表明:(1)水热条件是影响研究区植物功能性状的重要因子,其中降雨为主导因子。物种水平上,植物功能性状随着环境的变化而变化,如叶氮含量随着温度指标(最冷月均温、生长季均温、年均温、最热月均温、温度季节变化的增加而增加;(2)不同生长型功能性状在环境梯度下存在差异,表现为草本植物相对木本植物有更小的叶组织密度以及更大的叶面积、比叶面积、叶片氮含量、根氮含量和比根长,表明不同生活型植物对环境的适应能力明显不同;(3)不同类群植物对环境条件变化的响应不同,表现为适应方式的分异和趋同。该结果为探究黄土高原植物对环境的适应机制提供理论依据。
黄土丘陵区植物功能性状沿气候梯度的变化规律 .
选取黄土丘陵区延河流域147个物种,对10个与植物形态、生理相关的叶片和细根功能性状(叶大小、叶长宽比、叶厚度、叶干重、比叶面积、叶组织密度、叶氮含量、细根比根长、细根组织密度和细根氮含量)进行了测定,并对功能性状与气候因子的关系进行了分析。结果表明:(1)水热条件是影响研究区植物功能性状的重要因子,其中降雨为主导因子。物种水平上,植物功能性状随着环境的变化而变化,如叶氮含量随着温度指标(最冷月均温、生长季均温、年均温、最热月均温、温度季节变化的增加而增加;(2)不同生长型功能性状在环境梯度下存在差异,表现为草本植物相对木本植物有更小的叶组织密度以及更大的叶面积、比叶面积、叶片氮含量、根氮含量和比根长,表明不同生活型植物对环境的适应能力明显不同;(3)不同类群植物对环境条件变化的响应不同,表现为适应方式的分异和趋同。该结果为探究黄土高原植物对环境的适应机制提供理论依据。
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Causes and consequences of variation in leaf mass per area (LMA): A meta-analysis. https://doi.org/10.1111/j.1469-8137.2009.02830.x URL PMID: 19434804 [本文引用: 4] 摘要
ABSTRACT Here, we analysed a wide range of literature data on the leaf dry mass per unit area (LMA). In nature, LMA varies more than 100-fold among species. Part of this variation (c. 35%) can be ascribed to differences between functional groups, with evergreen species having the highest LMA, but most of the variation is within groups or biomes. When grown in the same controlled environment, leaf succulents and woody evergreen, perennial or slow-growing species have inherently high LMA. Within most of the functional groups studied, high-LMA species show higher leaf tissue densities. However, differences between evergreen and deciduous species result from larger volumes per area (thickness). Response curves constructed from experiments under controlled conditions showed that LMA varied strongly with light, temperature and submergence, moderately with CO2 concentration and nutrient and water stress, and marginally under most other conditions. Functional groups differed in the plasticity of LMA to these gradients. The physiological regulation is still unclear, but the consequences of variation in LMA and the suite of traits interconnected with it are strong. This trait complex is an important factor determining the fitness of species in their environment and affects various ecosystem processes.
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| [13] |
Is leaf dry matter content a better predictor of soil fertility than specific leaf area? https://doi.org/10.1093/aob/mcr225 URL PMID: 21948627 [本文引用: 3] 摘要
Background and Aims Specific leaf area (SLA), a key element of the `worldwide leaf economics spectrum', is the preferred `soft' plant trait for assessing soil fertility. SLA is a function of leaf dry matter content (LDMC) and leaf thickness (LT). The first, LDMC, defines leaf construction costs and can be used instead of SLA. However, LT identifies shade at its lowest extreme and succulence at its highest, and is not related to soil fertility. Why then is SLA more frequently used as a predictor of soil fertility than LDMC? Methods SLA, LDMC and LT were measured and leaf density (LD) estimated for almost 2000 species, and the capacity of LD to predict LDMC was examined, as was the relative contribution of LDMC and LT to the expression of SLA. Subsequently, the relationships between SLA, LDMC and LT with respect to soil fertility and shade were described. Key Results Although LD is strongly related to LDMC, and LDMC and LT each contribute equally to the expression of SLA, the exact relationships differ between ecological groupings. LDMC predicts leaf nitrogen content and soil fertility but, because LT primarily varies with light intensity, SLA increases in response to both increased shade and increased fertility. Conclusions Gradients of soil fertility are frequently also gradients of biomass accumulation with reduced irradiance lower in the canopy. Therefore, SLA, which includes both fertility and shade components, may often discriminate better between communities or treatments than LDMC. However, LDMC should always be the preferred trait for assessing gradients of soil fertility uncoupled from shade. Nevertheless, because leaves multitask, ind
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| [14] |
Global-scale climatic controls of leaf dry mass per area, density, and thickness in trees and shrubs. https://doi.org/10.2307/2679872 URL [本文引用: 1] 摘要
ABSTRACT Leaf dry mass per unit area (LMA) is a product of leaf thickness (T) and of density (D). Greater T is associated with greater foliar photosynthetic rates per unit area because of accumulation of photosynthetic compounds; greater D results in decreased foliage photosynthetic potentials per unit dry mass because of lower concentrations of assimilative leaf compounds and decreases in intercellular transfer conductance to CO2. To understand the considerable variation in T and D at the global scale, literature data were analyzed for 558 broad-leaved and 39 needle-leaved shrubs and trees from 182 geographical locations distributed over all major earth biomes with woody vegetation. Site climatic data were interpolated from long-term world climatologies (monthly precipitation, surface temperature) or modeled using the Canadian Climate Center Model (monthly global solar radiation). Influences of total annual precipitation (W-T), precipitation of the driest month (W-min), monthly mean precipitation of the three driest months in the year (W-3min), highest monthly precipitation (W-max), precipitation index ([W-max - W-min]/W-T), mean, minimum, and maximum annual monthly temperatures, and daily annual mean global solar radiation (R) on LMA, D, and T were tested by simple and multiple linear and log-linear regression analyses. In broad-leaved species, LMA and T increased with increasing R and mean temperature and scaled weakly and negatively with precipitation variables, but D was negatively related only to precipitation. Similar relationships were also detected in needle-leaved species, except that, in multiple regression analysis, precipitation did not significantly influence leaf thickness, and R was positively related to D. Given that increases in LMA and T are compatible with enhanced photosynthetic capacities per unit leaf area, but also with greater costs for construction of unit surface area, positive effects of solar irradiance and surface temperature on these variables are indicative of shorter leaf pay-back times in conditions of higher irradiance and temperature allowing construction of leaves with higher photosynthetic potential. To gain insight into the scaling of leaf density with site aridity, correlations of D with the leaf elastic modulus close to full turgor (epsilon) and with the leaf osmotic potentials (pi) at full and zero turgor were analyzed. Both low pi, which is compatible with low leaf water potential, and high epsilon, which permits large adjustment of leaf water potential with small changes in leaf water content, may facilitate water uptake from drying soil. Leaf elastic modulus was independent of T and was weakly related to LMA; but there were close positive associations of epsilon with D and leaf dry to fresh mass ratio, which is an estimate of apoplastic leaf fraction. Consequently, changes in D bring about modifications in leaf elasticity and allow tolerance of water limitations. Across all the data, epsilon and the estimates of pi were negatively related. However, given that pi varied only fourfold, but epsilon 10-fold, I conclude that osmotic adjustment of leaf water relations is inherently limited, and that elastic adjustment resulting from changes in leaf structure may be a more important and general way for plants to adapt to water-limited environments.
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Putting plant resistance traits on the map: A test of the idea that plants are better defended at lower latitudes. https://doi.org/10.1111/j.1469-8137.2011.03732.x URL PMID: 21539574 [本文引用: 2] 摘要
61 It has long been believed that plant species from the tropics have higher levels of traits associated with resistance to herbivores than do species from higher latitudes. A meta-analysis recently showed that the published literature does not support this theory. However, the idea has never been tested using data gathered with consistent methods from a wide range of latitudes. 61 We quantified the relationship between latitude and a broad range of chemical and physical traits across 301 species from 75 sites world-wide. 61 Six putative resistance traits, including tannins, the concentration of lipids (an indicator of oils, waxes and resins), and leaf toughness were greater in high-latitude species. Six traits, including cyanide production and the presence of spines, were unrelated to latitude. Only ash content (an indicator of inorganic substances such as calcium oxalates and phytoliths) and the properties of species with delayed greening were higher in the tropics. 61 Our results do not support the hypothesis that tropical plants have higher levels of resistance traits than do plants from higher latitudes. If anything, plants have higher resistance toward the poles. The greater resistance traits of high-latitude species might be explained by the greater cost of losing a given amount of leaf tissue in low-productivity environments. 08 2011 The Authors. New Phytologist 08 2011 New Phytologist Trust.
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Response of leaf morphometric traits of Quercus species to climate in the temperate zone of the North-South Transect of Eastern China. https://doi.org/10.3724/SP.J.1258.2013.00083 URL Magsci [本文引用: 1] 摘要
<p>植物叶片的形态性状能够有效地反映生存环境的变化, 并且影响植物的基本行为和功能。该研究通过获取植物标本提供的叶片形态信息, 结合相关分析和标准化主轴分析, 探讨了南北样带暖温带区栎属(<em>Quercus</em>)树种叶片形态性状对气候条件的响应及适应策略。结果表明: 在南北样带暖温带区, 随着气候条件的变化, 栎属树种的叶片形态性状发生显著的变化。随着年平均气温的降低和年日照时数的增加, 栎属树种叶面积增加, 以利于吸收更多的光照辐射, 并增加叶片的边界层阻力, 减少叶片热量的散失; 而叶片分裂程度的增加不仅可以降低热量的散失, 也可以提高叶片液流的波动以增强叶片的生理活动; 叶脉密度随温度的升高、光照强度和降水量的增加而增加, 以响应叶片蒸腾作用的增强, 提高水分的运输能力和叶片的支撑能力。此外, 为适应南北样带暖温带区气候条件的变化, 栎属树种的叶片形成了一系列的形态性状组合, 随着叶面积的增加, 叶柄长度和叶片分裂程度逐渐增加, 而叶脉密度降低; 随着叶片倾向于向长条状发展, 叶柄长度和叶脉密度也随之增加。</p>
中国东部南北样带暖温带区栎属树种叶片形态性状对气候条件的响应 .https://doi.org/10.3724/SP.J.1258.2013.00083 URL Magsci [本文引用: 1] 摘要
<p>植物叶片的形态性状能够有效地反映生存环境的变化, 并且影响植物的基本行为和功能。该研究通过获取植物标本提供的叶片形态信息, 结合相关分析和标准化主轴分析, 探讨了南北样带暖温带区栎属(<em>Quercus</em>)树种叶片形态性状对气候条件的响应及适应策略。结果表明: 在南北样带暖温带区, 随着气候条件的变化, 栎属树种的叶片形态性状发生显著的变化。随着年平均气温的降低和年日照时数的增加, 栎属树种叶面积增加, 以利于吸收更多的光照辐射, 并增加叶片的边界层阻力, 减少叶片热量的散失; 而叶片分裂程度的增加不仅可以降低热量的散失, 也可以提高叶片液流的波动以增强叶片的生理活动; 叶脉密度随温度的升高、光照强度和降水量的增加而增加, 以响应叶片蒸腾作用的增强, 提高水分的运输能力和叶片的支撑能力。此外, 为适应南北样带暖温带区气候条件的变化, 栎属树种的叶片形成了一系列的形态性状组合, 随着叶面积的增加, 叶柄长度和叶片分裂程度逐渐增加, 而叶脉密度降低; 随着叶片倾向于向长条状发展, 叶柄长度和叶脉密度也随之增加。</p>
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| [17] |
Plant functional markers capture ecosystem properties during secondary succession. https://doi.org/10.1890/03-0799 URL [本文引用: 5] 摘要
Although the structure and composition of plant communities is known to influence the functioning of ecosystems, there is as yet no agreement as to how these should be described from a functional perspective. We tested the biomass ratio hypothesis, which postulates that ecosystem properties should depend on species traits and on species contribution to the total biomass of the community, in a successional sere following vineyard abandonment in the Mediterranean region of France. Ecosystem-specific net primary productivity, litter decomposition rate, and total soil carbon and nitrogen varied significantly with field age, and correlated with community-aggregated (i.e., weighed according to the relative abundance of species) functional leaf traits. The three easily measurable traits tested, specific leaf area, leaf dry matter content, and nitrogen concentration, provide a simple means to scale up from organ to ecosystem functioning in complex plant communities. We propose that they be called “functional markers,” and be used to assess the impacts of community changes on ecosystem properties induced, in particular, by global change drivers.
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| [18] |
Ecosystem productivity can be predicted from potential relative growth rate and species abundance. https://doi.org/10.1111/j.1461-0248.2006.00958.x URL PMID: 16925655 [本文引用: 5] 摘要
We show that ecosystem-specific aboveground net primary productivity (SANPP, g g(-1) day(-1), productivity on a per gram basis) can be predicted from species-level measures of potential relative growth rate (RGRmax), but only if RGRmax is weighted according to the species' relative abundance. This is in agreement with Grime's mass-ratio hypothesis. Productivity was measured in 12 sites in a French Mediterranean post-agricultural succession, while RGRmax was measured on 26 of the most abundant species from this successional sere, grown hydroponically. RGRmax was only weakly correlated (r2 = 0.12, P < 0.05) with field age when species abundance was not considered, but the two variables were str
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| [19] |
Evidence for a 'plant community economics spectrum' driven by nutrient and water limitations in a Mediterranean rangeland of southern France. |
| [20] |
Relationships between leaf morphological traits, nutrient concentrations and isotopic signatures for Mediterranean woody plant species and communities. https://doi.org/10.1007/s11104-012-1214-7 URL [本文引用: 4] 摘要
ABSTRACT Background and aims Soil factors are driving forces that influence spatial distribution and functional traits of plant species. We test whether two anchor morphological traits—leaf mass per area (LMA) and leaf dry matter content (LDMC)—are significantly related to a broad range of leaf nutrient concentrations in Mediterranean woody plant species. We also explore the main environmental filters (light availability, soil moisture and soil nutrients) that determine the patterns of these functional traits in a forest stand. Methods Four morphological and 19 chemical leaf traits (macronutrients and trace elements and 未13C and 未15N signatures) were analysed in 17 woody plant species. Community-weighted leaf traits were calculated for 57 plots within the forest. Links between LMA, LDMC and other leaf traits were analysed at the species and the community level using standardised major axis (SMA) regressions Results LMA and LDMC were significantly related to many leaf nutrient concentrations, but only when using abundance-weighted values at community level. Among-traits links were much weaker for the cross-species analysis. Nitrogen isotopic signatures were useful to understand different resource-use strategies. Community-weighted LMA and LDMC were negatively related to light availability, contrary to what was expected. Conclusion Community leaf traits have parallel shifts along the environmental factors that determine the community assembly, even though they are weakly related across individual taxa. Light availability is the main environmental factor determining this convergence of the community leaf traits.
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| [21] |
Relationships between plant functional traits at the community level and environmental factors during succession in a tropical lowland rainforest on Hainan Island, South China. https://doi.org/10.3724/SP.J.1003.2013.10012 URL Magsci [本文引用: 1] 摘要
<p>以功能性状为基础的方法可以用来探讨植物群落中功能性状如何响应环境并揭示植物生态策略的潜在驱动力, 但有关功能性状与环境因子之间的关系随植物群落演替变化的研究仍然匮乏。作者以海南岛热带低地雨林刀耕火种弃耕后处于不同演替阶段的次生林(包括弃耕后恢复15年、30年及60年的次生林)和老龄林为对象, 通过群落学调查和对木本植物的功能性状及样地环境因子的测定, 分析了群落水平植物功能性状与环境因子关系随演替阶段的变化规律。结果表明, 随着演替的进行, 林冠开阔度、土壤养分、比叶面积、叶片氮含量、叶片磷含量和叶片总有机碳含量逐渐降低, 叶片干物质含量、木材密度、潜在最大高度逐渐升高, 而土壤水分和叶片钾含量变化不大。多元逐步回归分析表明, 影响群落水平植物功能性状的主要环境因子随演替阶段而发生显著的变化, 在15年、30年和60年的次生林及老龄林中, 对群落水平植物功能性状影响最大的环境因子依次为土壤有机质和pH值、林冠开阔度和土壤总磷含量、土壤总钾和有效磷含量, 以及土壤有机质含量和磷含量。同一功能性状在不同演替阶段受到不同环境因子的控制, 同时各功能性状又能够对不同演替阶段所处的特殊环境产生一定的适应性。</p>
海南岛热带低地雨林群落水平植物功能性状与环境因子相关性随演替阶段的变化 .https://doi.org/10.3724/SP.J.1003.2013.10012 URL Magsci [本文引用: 1] 摘要
<p>以功能性状为基础的方法可以用来探讨植物群落中功能性状如何响应环境并揭示植物生态策略的潜在驱动力, 但有关功能性状与环境因子之间的关系随植物群落演替变化的研究仍然匮乏。作者以海南岛热带低地雨林刀耕火种弃耕后处于不同演替阶段的次生林(包括弃耕后恢复15年、30年及60年的次生林)和老龄林为对象, 通过群落学调查和对木本植物的功能性状及样地环境因子的测定, 分析了群落水平植物功能性状与环境因子关系随演替阶段的变化规律。结果表明, 随着演替的进行, 林冠开阔度、土壤养分、比叶面积、叶片氮含量、叶片磷含量和叶片总有机碳含量逐渐降低, 叶片干物质含量、木材密度、潜在最大高度逐渐升高, 而土壤水分和叶片钾含量变化不大。多元逐步回归分析表明, 影响群落水平植物功能性状的主要环境因子随演替阶段而发生显著的变化, 在15年、30年和60年的次生林及老龄林中, 对群落水平植物功能性状影响最大的环境因子依次为土壤有机质和pH值、林冠开阔度和土壤总磷含量、土壤总钾和有效磷含量, 以及土壤有机质含量和磷含量。同一功能性状在不同演替阶段受到不同环境因子的控制, 同时各功能性状又能够对不同演替阶段所处的特殊环境产生一定的适应性。</p>
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| [22] |
Allocation and study on global change transects in China.
<p>为研究中国全球变化与陆地生态系统（GCTE）关系及过去全球变化（PAGES）需要，我国全球变化样带（CENT）将分别按经向（E110-120°）和纬向（N40°）设置。第一样带（CENTI）系中国东部森林生态系统样带，是沿着热量梯度，在东亚季风控制下的各个森林地带的生态系列。第二样带（CENTZ）系中国北温带森林-草原-荒漠生态系统样带，是沿着湿度梯度，由大陆性气候向海洋性气候过渡的生态系列。在样带上进行生物地球化学过程、能量交换、植被结构与动态、气候-植被关系、土地利用格局、模型测试和遥感校验等研究。</p>
中国全球变化样带的设置与研究 .
<p>为研究中国全球变化与陆地生态系统（GCTE）关系及过去全球变化（PAGES）需要，我国全球变化样带（CENT）将分别按经向（E110-120°）和纬向（N40°）设置。第一样带（CENTI）系中国东部森林生态系统样带，是沿着热量梯度，在东亚季风控制下的各个森林地带的生态系列。第二样带（CENTZ）系中国北温带森林-草原-荒漠生态系统样带，是沿着湿度梯度，由大陆性气候向海洋性气候过渡的生态系列。在样带上进行生物地球化学过程、能量交换、植被结构与动态、气候-植被关系、土地利用格局、模型测试和遥感校验等研究。</p>
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| [23] |
Patterns and driving factors of WUE and NUE in natural forest ecosystems along the North-South Transect of Eastern China. https://doi.org/10.1007/s11442-011-0870-5 URL Magsci [本文引用: 1] 摘要
<p>From July 2008 to August 2008, 72 leaf samples from 22 species and 81 soil samples in the nine natural forest ecosystems were collected, from north to south along the North-South Transect of Eastern China (NSTEC). Based on these samples, we studied the geographical distribution patterns of vegetable water use efficiency (WUE) and nitrogen use efficiency (NUE), and analyzed their relationship with environmental factors. The vegetable WUE and NUE were calculated through the measurement of foliar <em>δ</em><sup>13</sup>C and C/N of predominant species, respectively. The results showed: (1) vegetable WUE, ranging from 2.13 to 28.67 mg C g<sup>-1</sup> H<sub>2</sub>O, increased linearly from south to north in the representative forest ecosystems along the NSTEC, while vegetable NUE showed an opposite trend, increasing from north to south, ranging from 12.92 to 29.60 g C g<sup>-1</sup> N. (2) Vegetable WUE and NUE were dominantly driven by climate and significantly affected by soil nutrient factors. Based on multiple stepwise regression analysis, mean annual temperature, soil phosphorus concentration, and soil nitrogen concentration were responding for 75.5% of the variations of WUE (<em>p</em><0.001). While, mean annual precipitation and soil phosphorus concentration could explain 65.7% of the change in vegetable NUE (<em>p</em><0.001). Moreover, vegetable WUE and NUE would also be seriously influenced by atmospheric nitrogen deposition in nitrogen saturated ecosystems. (3) There was a significant trade-off relationship between vegetable WUE and NUE in the typical forest ecosystems along the NSTEC (<em>p</em><0.001), indicating a balanced strategy for vegetation in resource utilization in natural forest ecosystems along the NSTEC. This study suggests that global change would impact the resource use efficiency of forest ecosystems. However, vegetation could adapt to those changes by increasing the use efficiency of shortage resource while decreasing the relatively ample one. But extreme impacts, such as heavy nitrogen deposition, would break this trade-off mechanism and give a dramatic disturbance to the ecosystem biogeochemical cycle.</p>
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| [24] |
Terrestrial transect study on the responses of ecosystem to global change.
<p>为从机理上理解、评估和预测陆地生态系统对全球变化的响应，国际地圈生物圈计划在全球共启动了15条全球变化陆地样带，其中2条在中国, 即中国东北样带和中国东部南北样带。从植物碳氮代谢、生物多样性、生态系统功能与碳收支及样带生态系统的变化趋势等方面较系统地总结了围绕中国这2条全球变化陆地样带的最新研究进展，加深了全球变化与陆地生态系统相互作用过程与机制的理解，提出未来中国全球变化陆地样带研究应充分利用我国特殊的生态与环境及区域特色，重点针对陆地生态系统对全球变化的适应性、地球系统相互作用的生物—物理—化学—社会过程与管理、土地利用变化的动力学过程与机制、灾害性天气气候的生态效应及其调控机制和全球变化模拟预警系统开展研究，做出一些在国际上既有显示度又服务于我国社会经济可持续发展的研究成果。</p>
生态系统响应全球变化的陆地样带研究 .
<p>为从机理上理解、评估和预测陆地生态系统对全球变化的响应，国际地圈生物圈计划在全球共启动了15条全球变化陆地样带，其中2条在中国, 即中国东北样带和中国东部南北样带。从植物碳氮代谢、生物多样性、生态系统功能与碳收支及样带生态系统的变化趋势等方面较系统地总结了围绕中国这2条全球变化陆地样带的最新研究进展，加深了全球变化与陆地生态系统相互作用过程与机制的理解，提出未来中国全球变化陆地样带研究应充分利用我国特殊的生态与环境及区域特色，重点针对陆地生态系统对全球变化的适应性、地球系统相互作用的生物—物理—化学—社会过程与管理、土地利用变化的动力学过程与机制、灾害性天气气候的生态效应及其调控机制和全球变化模拟预警系统开展研究，做出一些在国际上既有显示度又服务于我国社会经济可持续发展的研究成果。</p>
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| [25] |
Methods and protocols for plant community inventory. https://doi.org/10.3724/SP.J.1003.2009.09253 URL Magsci [本文引用: 1] 摘要
植物群落是不同植物在长期环境变化中相互作用、相互适应而形成的组合。它提供着人类赖以生存的主要物质资源, 维系着地球生态系统的健康和功能, 也为各种动物和其他生物提供食物来源和栖息地, 是人类生存和发展不可或缺的物质基础, 具有不可替代的作用。我国植物群落类型多样, 在世界上首屈一指, 但我国至今尚没有一次全面和系统的植物群落清查, 不仅影响了人们对我国植物资源的了解、利用和保护, 也不利于我国生态学、环境科学和地理学等相关学科的发展。采用统一的方法体系和技术规范开展我国植物群落的清查工作势在必行, 并具有紧迫性。本文基于作者长期的野外工作实践和国内外的群落调查方法, 首先简要定义了与植物群落清查有关的重要概念, 在此基础上, 论述了调查样地的设置原则和体系、群落清查的技术指标和方法、主要优势种生态属性的测定方法和规范, 并介绍了大样地调查的主要步骤。通过本文的介绍、归纳和总结, 试图为制定我国植物群落清查的技术规范提供基础材料和技术储备。
植物群落清查的主要内容、方法和技术规范 .https://doi.org/10.3724/SP.J.1003.2009.09253 URL Magsci [本文引用: 1] 摘要
植物群落是不同植物在长期环境变化中相互作用、相互适应而形成的组合。它提供着人类赖以生存的主要物质资源, 维系着地球生态系统的健康和功能, 也为各种动物和其他生物提供食物来源和栖息地, 是人类生存和发展不可或缺的物质基础, 具有不可替代的作用。我国植物群落类型多样, 在世界上首屈一指, 但我国至今尚没有一次全面和系统的植物群落清查, 不仅影响了人们对我国植物资源的了解、利用和保护, 也不利于我国生态学、环境科学和地理学等相关学科的发展。采用统一的方法体系和技术规范开展我国植物群落的清查工作势在必行, 并具有紧迫性。本文基于作者长期的野外工作实践和国内外的群落调查方法, 首先简要定义了与植物群落清查有关的重要概念, 在此基础上, 论述了调查样地的设置原则和体系、群落清查的技术指标和方法、主要优势种生态属性的测定方法和规范, 并介绍了大样地调查的主要步骤。通过本文的介绍、归纳和总结, 试图为制定我国植物群落清查的技术规范提供基础材料和技术储备。
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| [26] |
A simple non-destruction method to measure leaf area using digital cameral and Photoshop software.
采用数码相机获取叶片的数字图像,用Photoshop图像处理软件计算叶面积,并与目前常用的剪纸法和叶面积仪测定法进行比较分析.结果表明,本方法和 上述传统测定方法测定结果存在极显著线性相关;不同拍摄分辨率、单位叶面积存贮像素个数和拍摄角度对测定结果无显著影响.和其它方法相比,本方法具有准 确、快速、成本低廉、适合非破坏性动态连续观测等优点,适用于植物生理生态学研究中叶面积的测定.
利用数码相机和Photoshop 软件非破坏性测定叶面积的简便方法 .
采用数码相机获取叶片的数字图像,用Photoshop图像处理软件计算叶面积,并与目前常用的剪纸法和叶面积仪测定法进行比较分析.结果表明,本方法和 上述传统测定方法测定结果存在极显著线性相关;不同拍摄分辨率、单位叶面积存贮像素个数和拍摄角度对测定结果无显著影响.和其它方法相比,本方法具有准 确、快速、成本低廉、适合非破坏性动态连续观测等优点,适用于植物生理生态学研究中叶面积的测定.
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| [27] |
Latitudinal variation of leaf stomatal traits from species to community level in forests: Linkage with ecosystem productivity.
ABSTRACT To explore the latitudinal variation of stomatal traits from species to community level and their linkage with net primary productivity (NPP), we investigated leaf stomatal density (SDL) and stomatal length (SLL) across 760 species from nine forests in eastern China, and calculated the community-level SD (SDC) and SL (SLC) through species-specific leaf area index (LAI). Our results showed that latitudinal variation in species-level SDL and SLL was minimal, but community-level SDC and SLC decreased clearly with increasing latitude. The relationship between SD and SL was negative across species and different plant functional types (PFTs), but positive at the community level. Furthermore, community-level SDC correlated positively with forest NPP, and explained 51% of the variation in NPP. These findings indicate that the trade-off by regulating SDL and SLL may be an important strategy for plant individuals to adapt to environmental changes, and temperature acts as the main factor influencing community-level stomatal traits through alteration of species composition. Importantly, our findings provide new insight into the relationship between plant traits and ecosystem function.
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| [28] |
Spatio-temporal variation of photosynthetically active radiation in China in recent 50 years.
<p>基于中国陆地区域1961-2007 年逐年/季节平均光合有效辐射(PAR) 的空间化数据(10km×10km)，结合GIS 空间分析技术与Mann-Kendall 趋势分析方法对近50 年年/季节平均PAR进行时空变化特征分析。结果表明：① 全国PAR的空间分布差异明显，总体上呈现东南低、西部高的特点，年均PAR在17.7~39.5 mol m<sup>-2</sup> d<sup>-1</sup>之间。② 全国像元平均的年/季节平均PAR表现出一个较明显的波动下降过程，年均PAR降幅为0.138 mol m<sup>-2</sup> d<sup>-1</sup>/10a，不同季节下降幅度存在差异，夏季降幅最大。③ 逐像元分析显示全国大部分地区PAR呈现显著下降趋势(<em>α </em>= 0.05)，东部趋势变化较西部明显，夏冬两季在PAR年际变化中的贡献最大。华北地区在不同季节都是下降区域，而青藏高原西北地区在不同季节都表现为上升趋势。④ PAR年际变化率空间分布在不同时段差异明显，同一地区PAR年际变化率不仅在不同季节存在差异，而且在不同时段也不相同，总体上1990年代之前PAR下降较快，之后下降趋势变缓。</p>
近50年中国光合有效辐射的时空变化特征 .
<p>基于中国陆地区域1961-2007 年逐年/季节平均光合有效辐射(PAR) 的空间化数据(10km×10km)，结合GIS 空间分析技术与Mann-Kendall 趋势分析方法对近50 年年/季节平均PAR进行时空变化特征分析。结果表明：① 全国PAR的空间分布差异明显，总体上呈现东南低、西部高的特点，年均PAR在17.7~39.5 mol m<sup>-2</sup> d<sup>-1</sup>之间。② 全国像元平均的年/季节平均PAR表现出一个较明显的波动下降过程，年均PAR降幅为0.138 mol m<sup>-2</sup> d<sup>-1</sup>/10a，不同季节下降幅度存在差异，夏季降幅最大。③ 逐像元分析显示全国大部分地区PAR呈现显著下降趋势(<em>α </em>= 0.05)，东部趋势变化较西部明显，夏冬两季在PAR年际变化中的贡献最大。华北地区在不同季节都是下降区域，而青藏高原西北地区在不同季节都表现为上升趋势。④ PAR年际变化率空间分布在不同时段差异明显，同一地区PAR年际变化率不仅在不同季节存在差异，而且在不同时段也不相同，总体上1990年代之前PAR下降较快，之后下降趋势变缓。</p>
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| [29] |
Leaf nitrogen and phosphorus concentrations of woody plants differ in responses to climate, soil and plant growth form. https://doi.org/10.1111/j.1600-0587.2011.06833.x URL Magsci [本文引用: 1] 摘要
Leaf chemistry is important in predicting the functioning and dynamics of ecosystems. As two key traits, leaf nitrogen (N) and phosphorus (P) concentrations set the limits for plant growth, and leaf N:P ratios indicate the shift between N- and P-limitation. To understand the responses of leaf chemistry to their potential drivers, we measured leaf N and P concentrations of 386 woody species at 14 forest sites across eastern China, and explored the effects of climate, soil, and plant growth form on leaf N, P and N:P ratios. In general, leaf N and P were both negatively related to mean annual temperature and precipitation, and positively related to soil N and P concentrations. Leaf N:P ratios showed opposite trends. General linear models showed that variation in leaf N was mainly determined by a shift in plant growth form (from evergreen broadleaved to deciduous broadleaved to conifer species) along the latitudinal gradient, while variations in leaf P and N:P were driven by climate, plant growth form, and their interaction. These differences may reflect differences in nutrient cycling and physiological regulations of P and N. Our results should help understand the ecological patterns of leaf chemical traits and modeling ecosystem nutrient cycling.
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| [30] |
Global to community scale differences in the prevalence of convergent over divergent leaf trait distributions in plant assemblages. https://doi.org/10.1111/j.1466-8238.2011.00651.x URL [本文引用: 2] 摘要
ABSTRACT Aim  The drivers of species assembly, by limiting the possible range of functional trait values, can lead to either convergent or divergent distributions of traits in realized assemblages. Here, to evaluate the strengths of these species assembly drivers, we partition trait variance across global, regional and community scales. We then test the hypothesis that, from global to community scales, the outcome of co-occurring trait convergence and divergence is highly variable across biomes and communities. Location  Global: nine biomes ranging from subarctic highland to tropical rain forest. Methods  We analysed functional trait diversity at progressively finer spatial scales using a global, balanced, hierarchically structured dataset from 9 biomes, 58 communities and 652 species. Analyses were based on two key leaf traits (foliar nitrogen content and specific leaf area) that are known to drive biogeochemical cycling. Results  While 35% of the global variance in these traits was between biomes, only 15% was between communities within biomes and as much as 50% occurred within communities. Despite this relatively high within-community variance in trait values, we found that trait convergence dominated over divergence at both global and regional scales through comparisons of functional trait diversity in regional and community assemblages against random (null) models of species assembly. Main conclusions  We demonstrate that the convergence of traits occurring from global to regional assemblages can be twice as strong as that from regional to community assemblages, and argue that large differences in the nature and strength of abiotic and biotic drivers of dominant species assembly can, at least partly, explain the variable outcome of simultaneous trait convergence and divergence across sites. Ultimately, these findings stress the urgent need to extend species assembly research to address those scales where trait variance is the highest, i.e. between biomes and within communities.
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| [31] |
Predicting leaf physiology from simple plant and climate attributes: a global GLOPNET analysis. https://doi.org/10.1890/06-1803.1 URL PMID: 17974336 [本文引用: 1] 摘要
Knowledge of leaf chemistry, physiology, and life span is essential for global vegetation modeling, but such data are scarce or lacking for some regions, especially in developing countries. Here we use data from 2021 species at 175 sites around the world from the GLOPNET compilation to show that key physiological traits that are difficult to measure (such as photosynthetic capacity) can be predicted from simple qualitative plant characteristics, climate information, easily measured ("soft") leaf traits, or all of these in combination. The qualitative plant functional type (PFT) attributes examined are phylogeny (angiosperm or gymnosperm), growth form (grass, herb, shrub, or tree), and leaf phenology (deciduous vs. evergreen). These three PFT attributes explain between one-third and two-thirds of the variation in e
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| [32] |
Floral, climatic and soil pH controls on leaf ash content in China's terrestrial plants. https://doi.org/10.1111/j.1466-8238.2011.00677.x URL 摘要
ABSTRACT Aim68 To investigate broad-scale patterns of plant le
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| [33] |
Responses of leaf morphological traits for broadleaved woody plants along the altitudinal gradient of Changbai Mountai, northeastern China. https://doi.org/10.13332/j.cnki.jbfu.2014.04.012 URL [本文引用: 1] 摘要
植物叶片的形态性状,如叶片大小、叶片形状和叶缘分裂程度等,是植物在长期进化过程中适应环境的结果,与植物的基本功能有密切的关系.本文通过沿长白山海 拔梯度对阔叶木本植物的叶片形态性状进行测定,分析了气候对叶片形态性状的影响.结果表明:随着海拔的升高和温度的下降,叶片长度、叶宽、叶周长和叶面积 减小,有利于叶片降低热量损失;而叶缘分裂程度(周长/面积比)和叶片长宽比增加,增大了叶片边界层阻力,不仅可以降低植物叶片水分蒸发和热量散失并适应 低温环境,还可以提高叶片液流速度以加强叶片生理活动.此外,采用一般线性模型和方差变异分离分析,探讨了气候条件和物种特性对叶片形态性状的相对解释 力,结果表明:叶片形态性状的变异在很大程度上由物种遗传特性所决定,其独立解释力为47.08％ ～ 76.07％;环境因子对叶片形态性状也有显著影响,但仅独立解释了1.22％～3.82％的变异.
长白山阔叶木本植物叶片形态性状沿海拔梯度的响应特征 .https://doi.org/10.13332/j.cnki.jbfu.2014.04.012 URL [本文引用: 1] 摘要
植物叶片的形态性状,如叶片大小、叶片形状和叶缘分裂程度等,是植物在长期进化过程中适应环境的结果,与植物的基本功能有密切的关系.本文通过沿长白山海 拔梯度对阔叶木本植物的叶片形态性状进行测定,分析了气候对叶片形态性状的影响.结果表明:随着海拔的升高和温度的下降,叶片长度、叶宽、叶周长和叶面积 减小,有利于叶片降低热量损失;而叶缘分裂程度(周长/面积比)和叶片长宽比增加,增大了叶片边界层阻力,不仅可以降低植物叶片水分蒸发和热量散失并适应 低温环境,还可以提高叶片液流速度以加强叶片生理活动.此外,采用一般线性模型和方差变异分离分析,探讨了气候条件和物种特性对叶片形态性状的相对解释 力,结果表明:叶片形态性状的变异在很大程度上由物种遗传特性所决定,其独立解释力为47.08％ ～ 76.07％;环境因子对叶片形态性状也有显著影响,但仅独立解释了1.22％～3.82％的变异.
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| [34] |
Mechanisms underlying global temperature-related patterns in leaf longevity. https://doi.org/10.1111/geb.12042 URL Magsci [本文引用: 1] 摘要
Aim At a global scale, the relationship of leaf longevity (LL) to mean annual temperature (MAT) is positive for deciduous species but negative for evergreen species. The aim of this paper is to understand the mechanisms underlying these contrasting patterns of leaf longevity, from a cost-benefit perspective.<br/>Location Global.<br/>Methods We tested our hypothesis that contrasting LL-MAT relationships in evergreen and deciduous species result from differing adaptations to variation in the length of the annual favourable period. We defined f as the portion of the year when monthly temperature and water availability were favourable. We examined whether the contrasting LL patterns with MAT can be also seen with f. Next, we calculated the optimal LL that maximizes carbon gain per unit time across a range of f.<br/>Results The contrasting LL patterns across MAT were also found across f. Our optimization model successfully reproduced the contrasting LL patterns across f for the evergreen (LL longer than 1 year) and deciduous plants. The model shows that longer LL is required to maximize carbon gain for evergreen plants in shorter f, while LL of deciduous plants decreases with decreasing f. Without any a priori trait association, the model reproduced the well-known LL-leaf mass per area (LMA) relationship. The model also reproduced observed shifts in LL-LMA relationships across MAT or f. Evergreen leaves in long f need greater LMA to maintain LL than those in shorter f.<br/>Main conclusions Observed contrasting LL-MAT patterns in deciduous and evergreen species can be reproduced via the simple rule of maximizing carbon gain across different lengths of favourable periods. Our model provides a mechanistic explanation for the empirical global patterns of several key leaf traits and their relationships.
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| [35] |
A standardized protocol for the determination of specific leaf area and leaf dry matter content. https://doi.org/10.1046/j.0269-8463.2001.00563.x URL [本文引用: 1] 摘要
Summary 68The impact of sample preparation, rehydration procedure and time of collection on the determination of specific leaf area (SLA, the ratio of leaf area to leaf dry mass) and leaf dry matter content (LDMC, the ratio of leaf dry mass to fresh mass) of mature leaves was studied in three wild species growing in the field, chosen for their contrasting SLA and LDMC. 68Complete rehydration was achieved 602h after samples were placed into water, but neither of the procedures tested – preparation of samples before rehydration or temperature applied during rehydration – had a significant effect on the final values of SLA or LDMC. 68As expected, water-saturated leaves had a lower LDMC than non-rehydrated leaves; more surprisingly, their SLA was also higher. The impact of rehydration on SLA was especially important when the SLA of the species was high. 68There was no significant effect of time of sampling on either trait in any species over the time period covered (09·00–16·3002h). 68These results suggest that SLA
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| [36] |
The Ecology of Plants. https://doi.org/10.1658/1100-9233(2003)014[0623:BR]2.0.CO;2 URL [本文引用: 1] 摘要
This book contains 22 chapters which are divided into 5 parts providing various ecological processes in individual plants within biomes and communities. In part 1 (chapters 1-4), the interactions of individuals with the physical environment, including light, water and temperature, soils, mineral nutrients, and belowground activities are considered. Part 2 (chapters 5-9) focuses the ways on how ...
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| [37] |
Biogeography and variability of eleven mineral elements in plant leaves across gradients of climate, soil and plant functional type in China. https://doi.org/10.1111/j.1461-0248.2011.01641.x URL PMID: 21692962 [本文引用: 1] 摘要
ABSTRACT Understanding variation of plant nutrients is largely limited to nitrogen and to a lesser extent phosphorus. Here we analyse patterns of variation in 11 elements (nitrogen/phosphorus/potassium/calcium/magnesium/sulphur/silicon/iron/sodium/manganese/aluminium) in leaves of 1900 plant species across China. The concentrations of these elements show significant latitudinal and longitudinal trends, driven by significant influences of climate, soil and plant functional type. Precipitation explains more variation than temperature for all elements except phosphorus and aluminium, and the 11 elements differentiate in relation to climate, soil and functional type. Variability (assessed as the coefficient of variation) and environmental sensitivity (slope of responses to environmental gradients) are lowest for elements that are required in the highest concentrations, most abundant and most often limiting in nature (the Stability of Limiting Elements Hypothesis). Our findings can help initiate a more holistic approach to ecological plant nutrition and lay the groundwork for the eventual development of multiple element biogeochemical models.
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| [38] |
Principles of Terrestrial Ecosystem Ecology. https://doi.org/10.1007/b97397 URL [本文引用: 1] 摘要
The ecosystem approach to ecology treats organisms and the physical elements of their environment as components of a single, integrated system. This comprehensive textbook outlines the central processes that characterize terrestrial ecosystems, tracing the flow of water, carbon, and nutrients from their abiotic origins to their cycles through plants, animals, and decomposer organisms. As human activity becomes an increasingly dominant factor in natural processes around the globe, landscape dynamics over time and space have become the focus of recent attention. This book synthesizes current advances in ecology with established theory to offer a complete survey of ecosystem pattern and process in the terrestrial environment. 搂Featuring review questions at the end of each chapter, suggestions for recommended reading, and a glossary of ecological terms, Principles of Terrestrial Ecosystem Ecology will be an important text suitable for use in all courses on ecosystem ecology. Resource managers, land use managers, and researchers will also welcome its thorough presentation of ecosystem essentials.
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| [39] |
Community assembly and shifts in plant trait distributions across an environmental gradient in coastal California. https://doi.org/10.1890/07-1134.1 URL [本文引用: 2] 摘要
Community assembly processes are thought to shape the mean, spread, and spacing of functional trait values within communities. Two broad categories of assembly processes have been proposed: first, a habitat filter that restricts the range of viable strategies and second, a partitioning of microsites and/or resources that leads to a limit to the similarity of coexisting species. The strength of both processes may be dependent on conditions at a particular site and may change along an abiotic gradient. We sampled environmental variables and plant communities in 44 plots across the varied topography of a coastal California landscape. We characterized 14 leaf, stem, and root traits for 54 woody plant species, including detaile
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| [40] |
Trait-based community assembly of understory palms along a soil nutrient gradient in a lower montane tropical forest. https://doi.org/10.1007/s00442-011-2112-z URL PMID: 21894517 Magsci [本文引用: 1] 摘要
Abstract<br/>Two opposing niche processes have been shown to shape the relationship between ecological traits and species distribution patterns: habitat filtering and competitive exclusion. Habitat filtering is expected to select for similar traits among coexisting species that share similar habitat conditions, whereas competitive exclusion is expected to limit the ecological similarity of coexisting species leading to trait differentiation. Here, we explore how functional traits vary among 19 understory palm species that differ in their distribution across a gradient of soil resource availability in lower montane forest in western Panama. We found evidence that habitat filtering influences species distribution patterns and shifts community-wide and intraspecific trait values. Differences in trait values among sites were more strongly related to soil nutrient availability than to variation in light or rainfall. Soil nutrient availability explained a significant amount of variation in site mean trait values for 4 of 15 functional traits. Site mean values of leaf nitrogen and phosphorus increased 37 and 64%, respectively, leaf carbon:nitrogen decreased 38%, and specific leaf area increased 29% with increasing soil nutrient availability. For <em class="a-plus-plus">Geonoma cuneata</em>, the only species occurring at all sites, leaf phosphorus increased 34% and nitrogen:phosphorus decreased 42% with increasing soil nutrients. In addition to among-site variation, most morphological and leaf nutrient traits differed among coexisting species within sites, suggesting these traits may be important for niche differentiation. Hence, a combination of habitat filtering due to turnover in species composition and intraspecific variation along a soil nutrient gradient and site-specific niche differentiation among co-occurring species influences understory palm community structure in this lower montane forest.<br/>
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