森林管理对动物生境影响的模拟研究——以小兴安岭友好林业局为例

理解森林管理对野生动物生境的累积效应，需要对不同森林管理预案作出预测、分析和评价。本文，以小兴安岭友好林业局为研究区，利用空间直观景观模型LANDIS模拟其在6种森林管理预案—无采伐、皆伐、择伐I（禁伐区不采伐，限伐区和商品林区每10年采伐面积分别为5%和10%）、择伐II（限伐区和商品林区10%和15%）、造林I（采伐同择伐I，伐后人工更新）和造林II（采伐同择伐II，伐后人工更新）下200年内的森林景观变化。在查阅文献、野外考察和咨询相关专家的基础上，以GIS为平台，构建有着不同生境需求的3种动物：松鼠（Sciurus vulgaris）、马鹿（Cervus elaphus）和花尾榛鸡（Bonasa bonasia）在景观尺度上的生境适宜度指数（Habitat suitability index, HSI）模型，利用Arc的宏语言AML（Arc Macro Language）将LANDIS的输出结果与3种动物的HSI模型相结合，借助生境单元和类水平（Class level）上的景观指数（结合度指数等）评价动物生境，以反映不同森林管理预案对动物生境的影响。研究结果表明： 1）对于LANDIS的模拟结果而言，不同森林管理预案往往导致不同的森林演替动态：无采伐和2造林方案下，森林逐渐向成、过熟林演替，且造林方案显著增加了营林树种的分布面积；择伐I和择伐II下，由于成、过熟林被采伐，森林向后期演替的速度较为缓慢，而皆伐下，中、幼龄林的比重较大。定性而言，对于偏好早期演替的动物而言，皆伐下的生境适宜性较高；对于偏好中、后期演替森林的动物而言，2种择伐方案下生境适宜性较高；对于偏好后期演替的动物而言，无采伐和2造林方案下生境适宜性较高。 2）对于松鼠，无采伐和2造林预案下的生境单元和适宜生境（HSI≥0.5）结合度指数较高，适宜生境的平均斑块面积较大，表明这3种预案下的生境适宜性较高，而2择伐预案由于移去了大量成、过熟林，导致松鼠生境适宜性的下降，对于皆伐，尽管采伐量比2择伐预案的小，由于其不利于针叶林的天然更新，对松鼠的生境破坏更为严重。 3）对于马鹿，皆伐和2造林预案下的生境单元和结合度指数较高，而无采伐下的生境单元和结合度指数整体上又小于2择伐预案下的，这表明，适当的干扰反而利于提高马鹿的生境适宜性，因为，若没有这些采伐、造林等干扰活动，森林的郁闭度会随着树冠的封闭而逐渐加大，下层的许多不耐荫的树种就会消失或减少，降低马鹿的食物来源。 4）对于花尾榛鸡，若不考虑营林活动对其干扰，2造林预案下的生境单元和结合度指数较高，其次为无采伐预案，而皆伐和2择伐方案下较低，这表明，单纯的采伐的将减小花尾榛鸡的生境适宜性。 生态系统是一复杂的系统，因此，不可能存在适于所有动物的森林管理预案，对于管理预案的选择取决于管理者多方面（经济、生态和社会）的权衡。本文是将LANDIS与HSI相结合模拟评估森林管理预案对动物生境影响的一次尝试，研究结果表明了这一方法的实用性。尽管这一方法存在一定的局限性，但利用这一方法，能够可视化和量化结果，并比较不同森林管理预案，从生物多样性保护出发，为森林管理提供决策支持。最后，需要声明的是，本研究侧重方法的探讨，作为实际应用，还需要大量的野外工作来验证HSI模型。

辽东山区次生林生态系统主要树种幼苗对光环境的响应

辽东山区森林是辽宁省重要的水源涵养基地与用材林资源，在维系区域内生态环境和林产品的可持续供应方面占据十分重要的战略位置。该区的天然林已基本绝迹，因此该区的森林生态恢复具有重要意义。 已有研究表明，影响辽东山区森林更新演替最主要的环境因素是光环境。核桃楸（Juglans mandshurica）、水曲柳（Fraxinus mandshurica）、黄菠萝（Phellodendron amurense）和红松(Pinus koraiensis)是阔叶红松林的优势树种；这些树种幼苗对光环境的适应性差异，在群落演替和森林生态恢复中发挥重要作用。 本论文采用人为控制遮光试验测定了核桃楸、水曲柳和黄菠萝幼苗对光环境的响应，同时，采用自然光环境试验和人为控制遮光试验相结合的手段测定了红松幼苗对光环境的适应性。人为控制遮光试验设置的光环境类似于自然中的典型林窗、林缘和林下的光环境；在人为控制遮光试验中，研究材料于2007年4月末栽植于4个不同光环境（全光、全光的60%、30%和15%，分别记为FI、II、LI和WI处理）下，在2007年7~9月测定了树种幼苗的光合生理、叶片特征、生长和冠层形态特征等方面的变化，结果表明： 1）不同光环境处理区内的光合有效辐射（PAR）具有显著差异，形成一定的光强梯度，而气温，相对湿度和土壤含水量差异并不显著。全光处理区内的日平均PAR为842.4μmol∙m-2∙s-1，最大PAR为1884.1μmol∙m-2∙s-1，显著高于其它处理区。 2）生长在高光强下4个树种幼苗的叶片有较高的光合能力（Amax），随生长光强的下降，Amax显著下降；光补偿点（LCP）和光饱和点（LSP）也表现出随着生长光强的下降而降低的趋势。核桃楸和水曲柳净光合速率Pn的日变化最大值约为16μmol∙m-2∙s-1，黄菠萝的约为13μmol∙m-2∙s-1，这与温带阔叶树种叶片的最大净光合速率Pn在10~15μmol∙m-2∙s-1范围内的结论相符；3个苗龄红松针叶的Pn日变化均呈单峰型，没有光合“午休”现象，峰值出现在11:00~13:00期间。 3）4个树种幼苗的比叶重（LMA）和单位叶面积鲜重（LFA）均随着光环境的降低而下降；三个阔叶树种幼苗的叶长L、叶宽W、叶周长C和单叶面积A均具有随着光强的降低而呈增大的趋势，表明叶片通过调节叶片的形态来适应多变的光环境。 4）不同光环境对阔叶树种幼苗的植株冠形和生长有显著影响，而红松幼苗植株冠形和生长的变化无明显的规律性。 综上，本研究得出以下结论：○1.通过可塑性分析和模糊隶属函数分析，核桃楸和黄菠萝较水曲柳能适应更宽的光强幅度；同时，核桃楸和黄菠萝较水曲柳的需光性更强，核桃楸和黄菠萝的需光性差异不大。○2.与3年、5年生红松相比，7年生红松对光强的适应幅度最小；同时，7年生红松的需光性强于3年和5年生红松。○3.本研究结果支持前人的观点：红松在幼年阶段能耐一定程度的遮光，在全光的20%~60%光条件下生长较好，随着年龄的增大，红松的需光性增加。

大兴安岭冻土湿地泥炭有机碳矿化对气候变化因子的潜在响应

大兴安岭地区是我国地带性多年冻土和冻土湿地的主要分布区，近30年来，大兴安岭地区整体增温显著，气候变化的幅度加大，加之人类活动的频繁，冻土退化严重，冻土湿地出现了原有湿地萎缩和新生湿地扩张的现象。目前，对大兴安岭多年冻土湿地的研究还非常有限，且定性的研究较多，定量的研究极少，多数研究集中于冻土湿地的分布，冻土与湿地之间的机理探讨及描述多年冻土退化对湿地产生的影响等方面。 本论文通过室内培养实验，分析不同温度和湿度梯度及冻融作用下，大兴安岭不同多年冻土区湿地两层泥炭有机碳的矿化状况。结合回归模型，分析大兴安岭多年冻土湿地泥炭有机碳矿化对不同温度和湿度的响应，探讨在气候预案下，大兴安岭多年冻土湿地对气候变化的潜在响应。获得的主要结论如下： （1）大兴安岭多年冻土湿地存在着碳储层，其不同的冻土湿地区由于自然条件、融深等因素的不同，碳储层的厚度也存在着差异。多年冻土湿地含碳量和含氮量都很高，有机碳含量随剖面深度的增加有降低的趋势，泥炭全氮的含量随剖面深度变化复杂，这与湿地土壤形成的气候条件、微地貌和植被类型等有关。大兴安岭连续多年冻土区泥炭，C/N比要高于不连续多年冻土区湿地，并且有机碳含量与全氮含量存在着很好的耦合关系。 （2）大兴安岭多年冻土湿地泥炭有机碳矿化随温度的升高而升高，在培养温度5-20℃下，总的泥炭有机碳矿化量变化范围为18.55~112.91 mg g-1。虽然连续多年冻土区湿地泥炭有机碳矿化率和矿化量都要高于不连续多年冻土区湿地，但经过温度敏感性系数Q10分析，大兴安岭不连续多年冻土区湿地泥炭矿化对温度的响应更显著。从一元动力学方程分析结果来看，大兴安岭多年冻土湿地泥炭有机碳的矿化对15℃响应更显著。 （3）土壤湿度对大兴安岭多年冻土湿地泥炭有机碳矿化产生一定的影响，泥炭总矿化量出现了先随湿度的增加而增加，达到最适宜值后降低的趋势。从本论文的实验设置来看，大兴安岭多年冻土湿地泥炭有机碳矿化的最适宜湿度为60%WHC。利用二元回归模型很好地反映了湿度对大兴安岭多年冻土湿地泥炭矿化的影响，模型推测大兴安岭连续多年冻土区湿地泥炭有机碳矿化的最优湿度为10-20cm层63%WHC，20-30cm层65%WHC；不连续多年冻土区湿地有机碳矿化的最优湿度为10-20cm层65%WHC，20-30cm层59%WHC。 （4）大兴安岭多年冻土湿地泥炭有机碳矿化受温度和湿度的影响显著，其之间的交互作用同样显著。连续多年冻土区湿地有机碳矿化量要高于不连续多年冻土区湿地，这与其含有更高的有机碳和全氮有关。温度和湿度对泥炭有机碳矿化的影响可以用二元二次回归方程很好的表示（P<0.001），通过回归方程和方差分析，结果表明温度和湿度对大兴安岭多年冻土湿地泥炭有机碳矿化都非常重要。 （5）通过培养实验结果显示，虽然温度仍是影响大兴安岭多年冻土湿地泥炭有机碳矿化的主要因子，但随冻融作用处理次数的增加，冻土湿地泥炭有机碳矿化量和温度敏感性系数Q10值有增加的趋势，这意味着冻融作用对大兴安岭多年冻土湿地泥炭矿化产生了不小的影响。虽然冻融作用对大兴安岭多年冻土湿地的影响并不是很大，但大兴安岭处于寒温带，在气候变暖下，冻融过程的频率将加高，冻融作用对大兴安岭多年冻土湿地的影响不容忽视。 （6）大兴安岭地区近30年气候变化趋势分析表明，年均温增长显著，年降水量变化幅度大。在气候变化下，对于不连续多年冻土区，多年冻土不断的退缩及最终的消失，会使冻土湿地萎缩和消失，原有的典型的贫营养的泥炭藓沼泽湿地可能演化为富营养的苔草沼泽湿地或灌丛沼泽湿地，对于大片连续多年冻土区，冻土湿地的变化更加复杂，出现的湿地类型会更多。通过线性气候预案下的大兴安岭多年冻土湿地泥炭有机碳矿化分析，结果显示大兴安岭多年冻土湿地对气候变化响应显著，特别是对于变湿的环境。气候变化下，大兴安岭多年冻土湿地泥炭存在着潜在的分解，多年冻土湿地与气候变化之间存在着正反馈机制。 目前研究表明，大兴安岭地区对气候变化特别敏感，对大兴安岭冻土湿地的研究既填补了国内研究的空白，又对全球的碳循环研究提供了数据支持，并且加深了对冻土湿地生态过程的了解。

长白山主要树种对水氮变化的响应特征

探讨全球及区域性降水变化和大气氮沉降增加对植物的影响，能够为预测未来气候变化背景下植物相对竞争能力的变化及陆地生态系统的植被组成及其演替动态提供科学依据。本实验以我国温带典型红松针阔叶混交林主要组成树种紫椴（Tilia amurensis）、水曲柳（Fraxinus mandshurica）、蒙古栎（Quercus mongolica）和红松（Pinus koraiensis）为研究对象，采用控制试验的方法，在自然条件下模拟降水和氮素变化，研究幼树的光合特征、形态、生长及生物量分配对水氮变化的响应。主要结论如下： (1) 降水变化后，紫椴幼树保持自身的光合、形态、生物量及其分配特征不变；氮素添加后，紫椴幼树通过茎部的快速生长来提高对水分和养分的传输能力，植株的生物量也有较大增长。 (2) 在增加30%自然降水时，水曲柳幼树的光合速率降低，但并没有影响到整个生长季的生物量积累的提高；氮素添加后，水曲柳幼树各器官生物量和植株生物量都有增加。 (3) 蒙古栎幼树的光合碳同化能力受水、氮变化的影响不明显。蒙古栎幼树调节各器官的生物量分配，作为应对降水格局变化的策略，即减少30%自然降水时分配给茎部的同化物也减少，增加30%自然降水时茎干生长加速以适应水分传输的要求；氮素添加后，蒙古栎幼树通过增加对叶的同化物的分配，以调节各器官的生物量分配策略。 (4) 红松幼树的光合碳同化能力受水、氮变化的影响不明显。为适应水分的变化，红松幼树在减少30%自然降水时地上生物量减少、增加30%自然降水时地下生物量增加；氮素添加后，红松幼树总体生物量保持增加。 因此，面对全球变化背景下的水、氮变化，水曲柳幼树和红松幼树能更有效地利用增加的降水和氮素，而氮素增加对这两个树种生长的促进作用在降水减少时将被削弱；紫椴幼树的生长更多地受到氮素添加的促进，对降水格局变化响应不明显；蒙古栎幼树则通过调节生物量分配来适应变化的生存环境，但光合特征和植株生物量变化不大。在同龄的针阔叶幼树的竞争中，针叶树种在光合能力和形态特征等方面均占弱势。因此，在比较适应水氮变化的两个树种中，水曲柳幼树的竞争优势更加明显。

大兴安岭典型区森林景观变化及人为驱动力分析

森林景观在人类活动影响下的变化规律，是森林景观生态学研究的热点和焦点问题之一，也是森林经理学研究的重要内容。本文以大兴安岭呼中林业局为研究区，呼中自然保护区为其对照，充分利用TM数据、森林的资源清查图件资料和采伐设计资料，结合大量的野外调查，以GIS为核心技术，综合空间分析和各种统计方法，剖析呼中林业局1989-2000森林景观变化过程；分析道路、采伐的时空格局对景观格局和生态功能的影响，旨在更准确地揭示人类活动与森林景观变化的关系；同时为森林景观管理和森林经营提供科学依据。主要结论如下： ①呼中林业局1959-2000年的景观变化主要驱动力是采伐活动：优势类型从原有的大面积连续针叶林转变成大面积针阔混交林；森林景观功能指标，从一种高质量的匀质状态（原始状态）经过一个异质化程度增大（1989年）的过程，又形成一种低质量的匀质状态（2000年）。②采伐量、采伐面积、采伐方式和伐区的时空分布影响森林景观的结构和功能，采伐设计不合理甚至无设计的开发早期，主要导致针叶林面积下降，1989年后采伐，主要导致林龄下降。只要合理经营，该林业局森林有望获得较好的恢复，天保工程的实施为此提供了良好契机。③道路分割生境，使景观破碎化程度增加。移动窗口法判定道路对路旁植被影响阑的宽度为24-34m，且各个等级的道路之间无显著区别。④亚里河林场水源涵养、固土保肥、吸收二氧化碳和释放氧气四项服务功能总价值，1989年1.85亿，2000年1.37亿，下降25.9％。1989-1999年采伐当年损失的生态效益0.67亿元；由于道路的影响，该损失增加2％左右；该损失价值为当年生产木材所创造的经济效益的2倍。⑤呼中林业局野生动物的最适宜生境面积十年间减少41％，分布趋于破碎化；道路的存在使野生动物的适宜生境面积分别下降6.7％（1989年）和9.6％（2000年）。

辽宁东部山区天然次生林恢复的研究

辽东山区的天然次生林是辽宁的森林资源宝库和辽中城市群的天然屏障，在辽宁的经济建设和生态建设中发挥着不可替代的重要作用。辽东山区的天然次生林是原生植被阔叶红松林遭破坏后形成的次生群落，现大部分为低产、低质、低效的“三低”林分，因此天然次生林的恢复具有重要意义。本文对辽东天然次生林的演替动态、干扰对天然次生林的影响、恢复目标林分主要树种的生理生态学特性、恢复的生态过程及恢复技术等进行了系统研究，得出以下主要结论：（1）辽东山区的天然次生林，经聚类分析，分成四种主要类型即：柞木林、阔叶混交林、硬阔叶林和杨桦林。杨桦林在演替序列中的定位应属原生群落遭破坏后初级阶段即软阔混交林阶段。阔叶混交林主要是以锻属、榆属、械属、柞属等阔叶树种组成的群落，在演替序列中的定位应为软硬阔混交林阶段。硬阔叶林系指以辽东山区三大硬阔叶树种水曲柳、、黄菠萝、核桃揪等为主要树种组成的群落，在演替序列中的定位应为硬阔叶林阶段。柞木林是以栋属树种为优势树种的森林群落，它与阔叶红松林同时存在，是长白植物区系的一个亚顶极群落；（2）通过放牧对不同林分类型林木生长、森林环境以及部分生态功能的影响研究表明，天然次生林与其它林分类型比较，其抵御外来干扰的缓冲能力较强，具有一定稳定性。因此在天然次生林中可以适当放牧。科学地解决了辽东山区林牧矛盾问题。试验结果证明：不同采伐方式对天然次生林环境因子有明显影响。择伐是天然次生林较好的恢复途径，既不使森林环境发生大变化，同时择伐后还可以在林冠下引进针叶树，形成针阔混交林；（3）对天然次生林恢复所涉及到的主要树种红松、云杉、水曲柳、花曲柳、黄菠萝、蒙古柞、紫锻等进行了生理生态学特性与光环境关系的研究。红松是阳性树种，具有喜光的特性，但同时幼年又有一定的耐荫性。在透光10％条件下最大净光合速率为5.743μmofco2．m-2．s-1，全光条件下为8.233μmolco2．m-2.s-1。随树龄的增长趋于喜光。利用红松等针叶树的幼年耐荫特性，进行林冠下更新，使人工恢复阔叶红松林成为可能：在一定的光照范围内，水曲柳、花曲柳、黄菠萝、蒙古柞、紫锻这五种阔叶树的最大净光合速率随光照强度的增加而提高，在光照极弱的条件下生长不良，多数树种在透光70％条件下净光合速率最大；光饱和点、暗呼吸速率这五种阔叶树有所差异，蒙古柞和黄菠萝相对喜光，花曲柳和水曲柳居中，紫极相对耐荫；（4）天然次生林的人工恢复是多途径的。人工恢复阔叶红松林组成类型主要有：红松杂木林、红松花曲柳和蒙古柞林、红松水曲柳林、红松核桃揪林4种类型。各类型中红松重要值（相对密度＋相对频度十相对优势度）均超过100；在天然次生林下人工栽植红松，经过20年大部分林分已形成三层垂直结构；人工恢复过程中林木的生长，上层保留木随着林冠的伐开，生长加快，迅速郁闭，这对林冠下栽植红松的成活有利。因光照条件改善，林下阔叶树生长迅速，并大量萌生新的个体。林冠下红松的初期高生长与全光条件下比较几乎无差异，巧年后开始低于全光条件下的生长。红松径生长，栽植10年后明显低于全光条件下的；（5）根据辽东山区天然次生林的形成、现状、在群落演替中的定位以及功能定位等确定辽东天然次生林主要恢复目标为：阔叶红松林、柞树林和阔叶混交林，面积比例分别以30％、65％和5％为宜；以对天然次生林现状、人为干扰对其影响、恢复目标群落所需要的引进种和天然次生林中的主要建群种的生理生态学特性以及人工诱导过程中，系统所发生的变化的研究为基础，并结合林龄、密度、立地条件等确定恢复途径，采取人工诱导、抚育间伐、人工营造针阔棍交林以及封育保护等技术措施完成恢复过程，达到恢复目的。天然林保护是我国正在实施的重大生态建设工程，辽宁省也出台了天然次生林禁止商业性采伐的措施，使辽东天然次生林的保护得到了政策保障。本文研究成果将为辽东天然次生林的保护、恢复以及可持续经营提供可靠的理论依据和技术支撑。

云南横断山与吉林长白山赤杨根瘤内Frankia菌遗传多样性

本文应用nifD-nifK IGS及16S-23S rDNAIGSPCR-RFLP方法，系统研究了分布于云南横断山的旱冬瓜以及吉林长白山的西伯利亚赤杨、色赤杨和东北赤杨根瘤内Frankia菌的遗传多样性。该研究可加深对Frankia菌起源与进化的认识，并为保护和利用这一固氮共生资源提供科学依据。从113株赤杨的根瘤样品中共检测到48种基因型的Frankia菌株。首次确切报道了自然条件下不同基因型Frankia菌可与同一宿主植株同时共生，并且这种混乱性在横断山区普遍存在。通过对Frankia菌群体遗传结构的分析，查明云南省横断山旱冬瓜Frankia菌群体内遗传变异水平由高到低的顺序是苍山群体、高黎贡山群体、鸡足山群体、来凤山群体和无量山群体。酶切带型9为云南横断山旱冬瓜Frankia菌群体中最古老的类型；大部分（75.63％）遗传变异发生在Frankia菌的各群体内，同一气候区的Frankia菌群体有较近的亲缘关系。旱冬瓜Fran辰a菌遗传多样性特点与横断山气候特征及冰川运动历史密切相关。宿主赤杨的进化地位不同，其共生Frankia菌的群体遗传多样性水平也不同。古老的旱冬瓜共生Fran舫“菌群体内遗传分化最大，分化最晚的东北赤杨共生Frankia菌群体内遗传变异最小；属同一生活型的西伯利亚赤杨和色赤杨共生Fronkia菌间存在着较近亲缘关系；早冬瓜Fran舫。菌群体可能为其它赤杨共生Fran舫“菌提供祖先，因此认为赤杨与其共生Frankia菌间存在着协同进化。

长白山阔叶红松林生产力对气候变化响应的模拟研究

本论文以长白山阔叶红松林为研究对象，观测了阔叶红松林主要树种的光合生理生态特征，建立了单叶化汁卜片的光合作用模型，上推出群落的生产力模型，采用基于干物质生产过程的模型Sim-CYCLE，模型了该生态系统对·气候变化的响应。得到主要结论如下：（1）、在不同的CO2浓度和光合有效辐射条件下，长白山阔价卜红松林主要树种净光合速率月动态规律不同；气孔导度随着瞬时光合有效辐射强度和C02浓度的增加而有下降趋势。（2）、建立的适用于阔价f一红松林的单叶化气孔导度对环境因子气温（Ta）、光合有效辐射（PAR）、饱和水汽压（VPD）的响应模型：gs＝PAR（-1.606Ta2＋118.192Ta＋1878.67）／（355.700+PAR）（-430.433+VPL），这是一个基于叶片光合机理的群落生产力模型，在模拟了长白山阔叶红松林群落生产力时取得了满意的效果。（3）、采用干物质产量理论的Sim-CYCLE模型，通过样地尺度的参数化模拟表明，长白山阔叶红松林生态系统的总初级生产力（GPP）为14.89Mgcha-1、净初级生产力（NPP）为8.22MgCha-1、净生态系统生产力困EP）为2．67MgCha-1；在CO2倍增和温度上升时碳积累在增加，净初级生产力（NPP）为9.03±1.51MgCha-1、净生态系统生产力（NEP）为2.95±0.47MgCha-1。

长白山典型森林生态系统土壤碳通量研究

森林生态系统是陆地最大的碳储存库，森林土壤呼吸是陆地生态系统土壤呼吸的重要组成部分，其动态变化将刘全球碳平衡产生深远的影响。精确测定土壤呼吸及其各组分的贡献，是目前全球变化研究中最基础和最迫切需要解决的问题。本文对长白山典型森林生态系统土壤碳通量及其过程机理进行了研究，结果表明：（1）阔叶红松林、红松云冷衫林、岳桦云冷杉林和岳桦林有不同的凋落节律；随海拔高度的上升，年凋落物量逐渐减少，分别为4.90、4.51、3.08和2.65thm-2；凋落物分解残留率与时间均呈指数关系，不同类型森林凋落物年分解常数的变化范围是25-47％之间。（2）阔叶红松林土壤总呼吸和断根土壤呼吸速率都存在明显的昼夜变化，为单峰型曲线，与土壤温度的昼夜变化趋势一致；不同森林类型土壤总呼吸和断根土壤呼吸的季节变化都比较明显，阔叶红松林、红松云冷杉林和岳桦云冷杉林变化趋势基本相似，都呈双峰型，岳桦林呈单峰型；土壤呼吸与土壤温度、大气温度之间都呈极显著（P＜0.01）指数相关关系，且与土壤温度的相关性要好于与大气温度的相关性；长白山四种类型森林土壤和根系呼吸的Q10值变化范围是1.8-2.9，根系呼吸的Q10值均大于土壤总呼吸和断根土壤呼吸的Q10值；土壤含水量对呼吸速率影响较为复杂，与土壤呼吸之间没有明显的相关关系；根系对土壤总呼吸贡献的季节变化与根系呼吸的季节变化相似，生长季内测定的阔叶红松林、红松云冷杉林、岳桦云冷杉林和岳桦杉林根系呼吸对土壤总呼吸贡献平均值分别为43.6％、44.1％、45.5％和44.4％。（3）长白山典型森林生态系统土壤碳的年释放量有随海拔高度上升而减小的趋势，且阔价卜林大于针叶林。阔叶红松林、红松云冷杉林、岳桦云冷杉林和岳桦林土壤碳的年释放量分别为7392.43、7181.83、6507.29和6841.09kghm-2a-1；根系的年碳释放量分别为3332.93、2965.68、2708.84和3015.48kghm-2a-1。

青藏高原东部混农季节性放牧及其对高山林线格局的影响

混农季节性放牧（agropastoral transhumance）通过作物种植和畜牧生产相结合的方式对不同海拔高度带上的资源进行相互补充利用，在亚洲兴都库什地区、青藏高原、横断山、东部及南部非洲、南美安第斯地区等具有悠久的历史。这种传统的生计系统几千年以来一直是居住在该地区的人类社会和自然生态系统相互作用的主要形式之一。这种传统的资源利用方式与山地自然植被以及特殊的山地人类文化和社会特征具有密切的协同演变关系。认识和理解这一关系，是山地生态学和人类学的核心科学问题之一。近年来，山地生态系统的多重功能性及动态演变对山区社会经济可持续发展的重要意义受到人们的不断关注。本文通过对云南省德钦县的12个自然村的混农季节性放牧以及对云南德钦、四川壤塘等山地植被格局特别是高海拔地带植被格局的的详细调查，探讨青藏高原东缘地区混农季节性放牧的主要特征、系统构成及相互关系，及其在全球变化、经济全球化和市场化及现代化过程中的变化趋势，分析混农季节性放牧与高山林线格局及生态系统的互动关系，旨在探讨山地地区人类活动与自然生态系统之间的互动关系，从而为山区社会经济可持续发展、环境建设和生物多样性保护等国家战略提供理论依据。 调查结果表明，混农季节性放牧是一种适应青藏高原东部高山峡谷地区环境因子及自然资源呈明显的垂直分布、资源数量稀少而时空分布异质性极高的生存环境的一种传统经济形式。这种传统的畜牧业的主要生产目的仍然是提供当地基本生存所需的产品，饲养牲口的种类和数量取决于农户的当地需求并且受资源的限制，因而维持在比较低的水平的。分布在不同海拔高度的放牧资源在一年中被牲口利用的时间也不同，互为补充，共同构成混农季节性放牧的资源基础。根据各社区永久居住点的位置和该村的土地资源特别是牧草地资源的分布范围，牲口迁移的距离和格局有较大的差异。。天然牧场仍然是最主要的畜牧业生产资源。混农季节性放牧中的农业系统和牧业系统互为补充，共同构成调查地区完整的的生计系统，农耕活动为放牧活动提供精饲料如粮食等和冬季饲料如秸秆， 其数量往往成为家庭畜牧业生产规模的主要决定因子之一。 通过对牲口数量和结构、牲口的时空迁移格局、牧业活动在整个经济活动中的相对重要性以及牧业活动和作物种植的关系方面的研究分析，混农季节性放牧在近几十年发生了深刻的变化。主要表现在牲口数量总体下降，牲口组成发生变化，牲口移动性降低、牧业活动的经济重要性下降以及牧业活动和种植活动之间的相互依存度降低等。上述变化的根本驱动力是发生在当地、地区及全球尺度上的环境、政治、社会经济、技术和文化等的变化，从而造成当地群众畜牧生产目标、土地利用和劳动力的分布等发生了变化。当地生计系统发生的改变可能会带来对方面而深刻的政治、社会经济、文化和生态影响。 混农季节性放牧这种古老的传统生计策略面临着许多挑战，如冬季饲料短缺、草场退化、缺乏市场竞争力、经济重要性降低、对年轻人缺乏吸引力、国家缺乏专门的政策指导等。与此同时，经济全球化、市场经济、新技术的应用、替代生计机会的增加、国家对于山地生态系统的作用的重新定位等也为传统生计系统转型、实现社会与生态共赢创造了机遇。 混农季节性放牧活动对亚高山及树线交错带生态系统系统的互动方式主要体现在以下几个方面：（1）牲口啃食、践踏等影响森林群落更新，改变森林群落的组成和结构，从而影响森林群落的演替进程和植被格局。林线边缘是搭建夏棚的首选地点，因此林线及树线交错地带就成了牲口活动的主要场所之一；（2）利用火烧开辟、维持和改良高山牧场； 3）在亚高山火灾迹地的放牧活动能够阻止火烧迹地的顺向演替； 4）牧民在林线附近获取建材和薪材等活动影响高山林线附近森林的结构和功能。 在调查区域，梅里雪山、白马雪山、甲午雪山的林线海拔高度在4200-4300m之间； 四川雅江、理塘一线，林线位置多在4300-4400m；四川壤塘二林场一带的林线主体在4100-4200m，在个别地区达到4300m； 在贡嘎山的南坡和东坡一带，林线位置在3600-3700m；而在四川松潘一带，林线位置主体在3700-3800米左右。树线高度的分布趋势和林线一致。混农季节性放牧及其有关人类利用活动使研究地区很多地方高山林线降低、树线交错带宽变窄或消失。在研究地区，总体情况是，阳坡和半阳坡（南坡、西南坡等）的林线和树线比阴坡和半阴坡（北坡、东北坡等）低，变化幅度达20-200m。这种差异主要是为了开辟牧场而人为清除了南向坡自然林线及其以上的植被从而使林线位置下降所致。在南坡自然林线保留得比较好的地方，林线和树线依然可以达到甚至超过北坡林线和树线的高度。放牧活动抑制了高山林线带火烧迹地的天然更新，从而使林线位置保持在目前的位置。 放牧活动对高山林线带森林群落更新的影响是显著的。自然林线内的乔木个体密度特别是新生苗和幼苗的密度大大高于非自然林线。没有放牧的自然林线及树线交错带内的I级个体（新生苗）密度达到725-2917株/公顷，而与之相对的处理样地内I级个体的密度只有0-228株/公顷；II级个体（高度10-50cm）也表现出类似的趋势，在没有放牧的自然林线及树线交错带样方内，其密度达到550-5208株/，而在放牧处理样方内只有14-321株/公顷。在非自然林线带样地内，在有正常放牧的样地内，完全缺乏I级个体。 从相对比例来看，没有放牧的样方内的I、II级个体在全部个体中所占的比例显著高于有放牧活动的样方。放牧使林线交错带的乔木幼苗数量显著减少，从而影响林线及树线交错带森林群落的天然更新过程。林线和树线交错带的灌木对乔木幼苗具有重要的保护作用，能够为树线树种如冷杉等幼苗的定居体提供有利的微气候环境，同时保护苗免受牲口的啃食和践踏。火烧以后接着进行放牧能够100%地抑制高山林线带的幼苗更新。 高山牧场放牧强度降低、使用时间缩短而低海拔地带放牧强度增加是研究地区混农季节性放牧系统的一个显著变化。这种变化也必然会引起各海拔带上的生态系统的变化。放牧强度的降低、生产性用火的停止将导致原来通过人工火烧而降低并通过进一步的火烧和放牧活动来维持的林线及其以上地带的灌木盖度和高度的增加，从而为林线森林群落的扩张创造条件。 青藏高原东部高山峡谷地区是我国重要的山地生态系统，在我国的生物多样性保护、生态环境建设、社会经济可持续发展战略中具有举足轻重的作用。正确认识人类特别是当地传统的生计系统与生态环境系统的互动关系是实现上述战略目标的前提。决策者必须以综合、系统的的视角协调促进社会经济可持续发展、保护生物及文化多样性和维持人、牲口和生态系统之间的平衡的多重目标。 Agropastoral transhumance, which makes a complementary exploitation of the natural resources at different altitudinal belts through a combination of migratory animal husbandry and crop cultivation, has a long history in Hindu-Kush Himalaya, Tibet Plateau, Hengduan Ranges, eastern and southern Africa and the Andes region of south America.For millennia, this traditional livelihood strategy has been one of the main forms of interaction between human societies inhabiting in these regions and their natural ecocystems. A close co-evolutionary relationship has been developed between this indigenous resources management systems and the mountain vegetation systems on the one hand and a unique set of cultural values and social features on the other. Understanding this relationship has been one of the core scientific issues in mountain ecology and anthropology. In recent years, the importance of the multiple functions of the mountain ecosystems and their dynamic changes in the sustainable socio-economic development of the mountain regions has gained increasing attention. This paper, which is based on a detailed study on the agropastoral practices of the 12 natural villages in Deqin County of Yunnan, and the mountainnn vegetation patterns in Deqin of Yunnan and Rangtang County of Sichuan, intends to reveal the major characteristics, system composition and the inter-relations of the subsystems of the agropastoral transhumance in Eastern Tibetan Plateau as well as the trends of changes of the system within the context of global changes, economic globalization and modernity process of China and analyze the relations between agropastoral transhumance and alpine ecosystem, ao as to understand the interactions between human activities and natural ecosystems of the mountains and provide theoretical basis for the national strategies in eocioeconomic development, environmental reconstruction and biodiversity conservation in the mountain regions. Results of the survey indicate that agropastoral transhumance in the investigated area is a traditional economic form that is highly adapted to the eastern Tibet Plateau where the topography features high peaks and deep gorges and where the highly variable environmental parameters and scanty natural resources exhibit a distinct vertical spectrum of distribution and great temporal and spatial heterogeneity. The main objective of pastoral management is still aimed at the production of basic goods and services of local people and thus the type and size of animals raised for each household mainly depend on local needs and are limited by the availability of natural resources. The scale of production is relatively low. Pastoral resources at different altidudinal belts are complementarily used at different seasons of a year and thus form the resources basis for agropastoral production of the study area. Migration distances and patterns vary with the location of the permanent settlements, the elevational distribution range of the resources of the villages concerned. Natural pastures (rangelands) are the main fodder resources and sumplement feedings only account for less than 5% of the total fodder consumption. Crop cultivation and pastoral activities support each other to form a complete livelihood system. The ability of the farmig lands (crop cultivation) to provide the pastoral activities with concentrates and sumplements often becomes a main factor limiting the scale of livestock production at household level. Agropastoral transhumance is experiencing drastic changes in recent decades as is reflected in the size and composition of animals, the seasonal migration pattern, the relative importance of pastoralism in the household economy and the interplays of agricultural and pastoral elements of the system. In general, there is a decline in animal population and mobility, a shift in animal composition to meet new needs arising from changed macro-economic situation, a decrease in the relative importance in the household economy and an increasing decoupling of agro&pastoral relations. The fundamental divers of these changes can be traced to environmental, social, economic, technological and cultural changes from local to global levels and such changes have further caused local changes in livestock management objectives, land use and distribution of labor forces. Changes in local livelihood systems could have profound political, socioeconomic, cultural and ecological conseuquences. Agropastoral transhumance, as an age-old traditional livelihood strategy, is facing multifacet challenges, such as winter fodder shortage, rangeland degradation, lack of market competitiveness, decrease in economic importance, lack of appreciation among the young generation and adequate policies from the government. At the same time, economic globalization, market economy, intrdoctution of new technologies, increase of alternative income generating opportunities and the national re-oreitation of policies on mountain ecosystems have all brought about new opportunities for the transformation of the traditional livelihood system and the synchronized development of local society and the environment. Agropastoral transhumance interacts with the ecosystems at the timberline and treeline ecotone mainly through the following aspects: 1)Animal browsing and stamping affect the regeneration process of the forest communities and alters the composition and structure of the forest which in turn affect the succession process and vegetation pattern of the forest communities. Forest edges are the priority locations for summer houses and therefore the timeline and treeline area becomes the major venues of aninal activities; （2）herders create, maintain and improve pastures through burning that remove the forest communities at the timeline and treeline ecotone; 3）immediate grazing on the fire sites can significantly prevent the fire sites from perogressive succession; and 4）herders harvesting of construction timber and firewoods affects the structure and functions of the forest communities at the timberline and treeline zone. Timberline position in the survey region shows geographical variations. It is around 4200-4300m in Meilixueshan, Baimaxueshan and Jiawuxueshan in Northwest of Yunnan and rises to 4300-4400m in Yajiang County and Litang County of Sichuan. In Rangtang of Sichuan, it is between 4100-4200m, though reaching 4300m in localized sites. In the southern and eastern slopes of Gongga Mountain, the timberline is only between 3600m and 3700m and in Songpan County at the upper reach of the Minjiang River the timberline is around 3700-3800m.Treeline pattern follows similar trend. In many places, agropastoral transhumance and related human activities have lowered the timberline and treeline and narrowed or removed the treeline ecotone. In the area of survey, generally speaking, timberlines and treelines are lower on the southern slopes than on the northern slopes, with a difference between 20 and 200m. This is mainly because that the use of fires to crerate pastures has removed the forest vegetation at the previous timberline and above. In fact, in many places, well-preserved forests on the south slopes have even high timberline position that the corresponding northern slopes. At subalpine zone, grazing activities could have prohibited the natural regeneration of many forest fire sites and maintained the forest position at the present level. Grazing has a significant impact on the regernation process of forest communities at the timberline zone. Natural timberline and treeline ecotone has much higher density of treeline species individuals especially the emergents and seedlings than the timberlines that are maintained by human activities. In natural timberline and treelien ecotone without grazing interference, the density of the I Class seedlings (less than 10cm in height) ranges 725-2917 /hm2; while that in the treatment plots (with grazing disturbance) is only 0-228//hm2；II Class seedlings (10-50cm）exhibit similar density trends, reaching 550-5208//hm2 in natural timberline without grazing but only 14-321//hm2 in the plots with grazing treatment. In the man-created timberlines, there is no I Class seedling at all in plots with normal grazing activities. In relative terms, in plots without grazing activities, the propotion of I Class and II Class seedlings is much higher than that in plots with grazing. Grazing activities have significantly reduced the number of seedlings in the timberline ane treeline ecotone, and thus affect the natural regeneration process of the forests. Shrubs at the timberline and treeline ecotone can effectively protect the seedlings from severe climate and animal tramping, thus increasing the survival rate of the seedlings. Grazing following fires can completely inhibit forest regeneration process at timberline. Changes in agropastoral transhumance will have great impact on the timberline and treeline pattern of the studied area. The decrease in grazing intensity on alpine pastrues and the cessation of the use of fires will result an increase in the cover and height of shrubs above the present human-maintained treeline, which will create further condition for the expansion of timberline forest communities. Eastern Tibet Plateau harbors some most important mountain ecosystems of China that are of vital importance to the country’s strategy in biodiversity conservation, environmental construction and sustainable sociaoeconomic development. A proper knowledge of the interactions between traditional livelihood systems and the ecosystems in the region is a precondition to the realization of the above strategic goals. Therefore, the decision-makers must have a holistic and systemic perspective so as to integrate the multiple objectives of promoting sustainable socioeconomic development, conserving biological and cultural diversity and maintaining the balances among people, animal population and the ecosystems.

粗枝云杉( Picea asperata Mast.)天然群体的遗传变异

西南地区在我国的经济发展和生态环境建设中占重要地位，但也是我国生态环境最脆弱的地区之一，生态系统退化，生态功能减弱，严重制约着西南林业的可持续经营与发展。本项目采用DNA 分子标记SSR 研究不同生境条件下粗枝云杉群体的遗传变异及其时空分布格局，考察遗传变异与复杂的山地生态环境间的潜在联系，系统地揭示粗枝云杉天然群体与环境系统相互作用的生态适应与分子进化机制。粗枝云杉适应性强，生长迅速，在植树造林和工业用材方面占有重要地位，研究成果可为中国西南部亚高山天然林的可持续经营及退化生态系统的恢复与重建提供理论依据和科学指导。主要研究结果如下： 1. SSR 位点变异丰富，等位基因频率的分布格局多样。7 个SSR 标记全是多态位点，每位点的等位基因数变化范围为13~24，平均为19.9 个。SSR 位点的等位基因片段长度范围变化较大。73.1%的等位基因变异遵循逐步突变模型(SSM)而发生1 个重复基元的变化，22.3%和4.6%的变异分别按两阶段突变模型(TMP)发生1 个重复基元以上的变化和在SSR 位点侧翼区发生1 个碱基变化的插入-删除事件。 2. 粗枝云杉拥有中等偏高水平的遗传多样性和相对大的群体间遗传分化。通过分析代表10 个群体的250 个个体在7 个SSR位点的变化，调查了源自中国西南山区的粗枝云杉的微卫星变异。相当高的遗传多样性和强烈的群体分化发生在粗枝云杉中， 其群体平均Nei's 期望杂合度为0.707 ， 群体间遗传距离为0.121~0.224(FST)和0.100~0.537(RST)。然而，群体间遗传距离与地理距离之间无相关性，从而排除了简单的距离分离模式并暗示迁移不是影响粗枝云杉遗传变异格局的主要因素。事实上，使用私有等位基因估算的基因流数量非常低，仅等于0.753。等位基因置换检验(Allele permutation tests)揭示逐步突变及遗传漂变都对群体间分化有贡献。另外，在多数位点检测到显著的群体间遗传差异，这个结果说明自然选择，假设通过环境压力，是引起粗枝云杉微地理分化的主要因素之一。根据SSR基因型，250 个粗枝云杉个体的70%被正确地归类入其各自的来源群体，结果表明微卫星(SSR)对区分来自中国不同生态地理位点的粗枝云杉基因型是有效的。 3. 在SSR、RAPD 和AFLP 位点，显著的群体间遗传结构被发现的，但三种标记间遗传分化程度和群体遗传关系有差异。利用来自10 个群体的247 个个体，我们报告了关于样本粗枝云杉群体间遗传关系的总体看法。根据各自对评价遗传关系的信息能力和适用性，SSR、RAPD 和AFLP 标记被选用，三种技术非常有效地区别这些基因型。使用的SSR、RAPD 和AFLP 标记分别估计平均Dice 相似性系数。Mantel 检验产生显著但相对低的共表型适合度(RAPD = 0.63£AFLP = 0.60和SSR = 0.75)。比较三种标记系统，RAPD 和AFLP 共表型指数相对高地相关(r =0.59)，而RAPD 和SSR 及SSR 和AFLP 之间的相关系数分别是0.53 和0.35。所有系统树，包括不同标记资料结合获得的系统树，反映了多数群体依据它们的地理条件而成某种特定关系。结果暗示单个或结合标记系统能用来深入洞察粗枝云杉遗传研究，并且不同标记系统合并资料能提供更可靠的信息。 Southwestern region plays an important role in economic developmentand ecological construction in China. Yet, it is also one of the weak regionsof ecological environment in China with degraded ecosystem and imperfectfunction, which restricts the sustaining management and development ofsouthwestern forestry. The genetic variation and spatial distribution patternof P. asperata populations originating from different habitats wereinvestigated using SSR molecular markers in this study. The correlationsbetween genetic variation and ecological and environmental conditionswere detected, and the interaction between P. asperata populations andenvironmental system and the mechanism of ecological adaption -molecular evolution were revealed. Given the significant ecological andeconomic roles of the fast-growing and wide-adaptive species in reforestation and production of pulp wood and timber, the study couldprovide a strong theoretical evidence and scientific direction for thesustaining management of subalpine natural forest, and the afforestationand rehabilitation of degraded ecosystem. The results are as follows: 1. The genetic variation at SSR loci was abundant and the distributionof allelic frequencies was uneven. All seven loci were polymorphic, and thenumber of alleles per locus varied from 13 to 24 with a mean valueequaling 19.9. The allele sizes at SSR loci were found to vary widely.73.1% of allelic variation followed stepwise mutation model (SSM) whichresults increase or decrease by one repeat type, and 22.3% and 4.6% wereresulted from two-phase mutation model (TMP) with allele size varying bymore than one repeat type and from insertion-deletion events in theflanking regions at SSR loci with a single basepair changing, respectively. 2. P. asperata possessed a moderate to high level of genetic diversityand considerable genetic differentiation. Microsatellite variation of P.asperata. originating from the mountains of southwestern China wasinvestigated by analyzing variation at seven SSR loci in 250 individualsrepresenting ten populations. A fair degree of genetic diversity and strongpopulation subdivision occurred with the mean gene diversity (H) of 0.707,and genetic distances among populations varying between 0.121 and 0.224(FST) and between 0.100 and 0.537 (RST). However, inter-populationgenetic distances showed no correlation with geographic distances between the population sites. This ruled out a simple isolation by distance modeland suggested that migration does not have a great impact. In fact, theamount of gene flow, detected using private alleles, was very low, equalingonly 0.753. Allele permutation tests revealed that stepwise-like mutations,coupled with genetic drift, could contribute to population differentiation.Moreover, significant genetic differences between populations weredetected at most loci. The results indicate that natural selection, presumablythrough environmental stress, may be one of the main factors causingmicro-geographical differentiation in the genetic structure of P. asperata.Based on SSR genotypes, 70% of the 250 individuals were correctlyclassified into their sites of origin. This suggests that microsatellites (SSRs) are effective in distinguishing genotypes of P. asperata originating fromdiverse eco-geographical sites in China. 3. Using a set of 247 individuals from ten P. asperata populations wereport an overview on the genetic relationship among the sampled P.asperata populations. RAPD, AFLP and SSR were used in terms of theirinformativeness and applicability for evaluate relationship and all threetechniques discriminated the genotypes very effectively. Mean Dicesimilarities coefficient were estimated using RAPD, AFLP and SSR,respectively. The Mantel test resulted in a significant but relatively low fit(RAPD = 0.63, AFLP = 0.60 and SSR = 0.75) of cophenetic values.Comparing the three marker systems to each other, RAPD and AFLP cophenetic indices were highly correlated (r = 0.59), while correlationcoefficient between RAPD and SSR was r = 0.53 and between SSR andAFLP was r = 0.35. For all markers a relatively high similarity indendrogram topologies was obtained although some differences wereobserved. All the dendrograms, including that obtained by the combineduse of all the marker data, reflect some relationships for most of thepopulations according to their geographic conditions. The results indicatethat single or combined marker system could be used to insight into geneticstudy in P. asperata and the combined data of different marker systems canprovide more reliable information.

四川九顶山西坡及龙肘山维管植物区系和植物多样性研究

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

克隆植物东方草莓对异质生境的适应对策

克隆植物被认为比非克隆植物更宜于利用异质性环境。在复杂的空间异质环境中，克隆植物可能形成了各种有效利用环境异质性的适应对策。对于克隆植物适应机制的研究，前人已做了大量的工作，特别是从形态和生物量分配等方面对简单异质生境下克隆植物的克隆整合和克隆分工进行了详细的研究。本研究以分布广泛的克隆植物东方草莓（Fragaria orientalis）作为研究对象，应用野外调查和实验生态学方法，采用多对比度单资源模型和不同向双资源模型，从形态和生理生态的角度，研究复杂异质生境下克隆植物的整合和分工及其耗益问题，分析不同类型的生境对克隆植物整合和分工的修饰作用，进而探讨克隆植物对异质生境的适应策略。克隆构型和分株种群特征是植物克隆生长及其生态适应对策研究的基本内容。本文通过野外调查，研究在不同光照条件下东方草莓克隆构型、分株种群特征以及点分布格局。结果表明：东方草莓的克隆构型随光照发生相应的变化，低光照下其匍匐茎节间长和分枝角度均增大而分枝强度减小；随光照减弱，东方草莓分株种群的生物量、根冠比和分株种群密度显著降低；不同光照下东方草莓分株均以随机分布为主但不同尺度下有所差异，其分布格局强度依次为旷地<林缘<林下。结合克隆植物对资源的利用对策，探讨了克隆构型和分株种群特征以及分布格局随环境条件变化的生态适应意义。不同生境斑块条件下克隆植物可能采取不同的适应对策。采用盆栽实验，研究不同水分对比度下克隆整合及其生理生态特征，并对单向和交互资源中东方草莓的克隆整合做了对比研究。结果显示：高的水分对比度能够促进东方草莓的克隆整合，并能刺激相连分株增加光合作用，东方草莓体内的氧化—抗氧化系统也II随对比度做出相应的反应。耗-益分析表明胁迫分株的受益是以供给分株的损耗为代价的，但从克隆片段总体来说是受益的。单向资源中东方草莓生长的绝对值高于交互资源，但耗-益分析表明生长于交互资源下东方草莓的克隆整合获益大于生长于单向资源下东方草莓的克隆整合获益。长期生长于特定生境的克隆植物，在进化过程中其克隆整合和克隆分工在对资源异质性的适应策略方面可能有所侧重。采用盆栽实验对来自不同海拔梯度的东方草莓的克隆整合和克隆分工对异质资源的适应对策进行了研究。实验结果表明，来自高海拔的东方草莓可塑性较差。来自两个海拔的东方草莓对切断匍匐茎的表现有所差异，总体上切断匍匐茎对来自高海拔的东方草莓影响更大些。另外，来自高海拔的东方草莓表现出更高的克隆分工。IIIClonal plants are known to be more suitable for the habitats of heterogeneousresources than nonclonal plants, perhaps due to their well developed adaptivestrategies to environmental heterogeneity. Many studies have been done on theadaptive mechanisms of clonal plants, especially on the clonal integration anddivision of labor with morphology and biomass allocation under simpleheterogeneous habitats. Based on field surveys, laboratory experiments, multi-contrastunidirectional resource model and reciprocal resource model, Fragaria orientalis, aRosaceae stoloniferous herb that widely distributes in China, was used to study thisplant’s morphological and physiological responses to complicated heterogeneoushabitats in terms of its clonal integration, division of labor and cost-benefit, as well astheir modifications by different habitats, so as to better understand the adaptivestrategies of clonal plants under heterogeneous environments.Clonal architecture and ramet population characteristics are of the major concernin the studies on growth and adaptive strategies of clonal plants. Clonal architecture,ramet population characteristics and spatial point pattern of F. orientalis underdifferent light intensity were studied with field observations. The results showed that,clonal architecture changed with light availability: Internode-lengths and branchangels of stolons were larger while branch intensities were smaller under lower lightintensity than those under higher light intensity; Biomass of ramet population,root-shoot ratio and density of ramet population decreased significantly with reduce oflight intensity; Under all light intensities, spatial pattern of ramets was mainlyrandomly distributed but it changed with different scales, with pattern intensity as:open space < forest edge < understory. Adaptation significance of the clonal architecture, the ramet population characteristics and the spatial pattern changing withdifferent environments was discussed according to these results.Clonal plants may take different adaptive strategies under different patches. Withpot culture, clonal integration and physiological parameters of F. orientalis underdifferent water contrasts were studied, and clonal integration under unilateralresources and reciprocal resources were also compared. The results suggested that,high water contrast improve the clonal integration of F. orientalis and increase thephotosynthesis of connected ramets. Oxidative and antioxidative system of F.orientalis also responded with changing water contrasts. According to cost-benefitanalysis, the drought-stressed ramets obtained benefits from the connectedwell-watered ramets, and as a whole, the clonal fragment could also get benefits.Growth of F. orientalis in homogeneous resources was better than that inheterogeneous resources, but the whole plant got more benefit through clonalintegration in heterogeneous resources than in homogeneous resources.Pot culture experiments were also used to study the adaptive strategies inutilizing heterogeneous resources by the plant populations from different altitudes.The results showed that, F. orientalis from alpine zones were shorter and lessexpanded with poorer clonal plasticity than those from middle mountains. F.orientalis from two different altitudes showed different responses to stolon severing,and as a whole, stolon severing had more influence on F. orientalis from alpine zones.In addition, F. orientalis from alpine zones exhibited higher division of labor, whichsuggested that clonal plants from different habitats develop their own adaptivemechanisms in their clonal integration and division of labor in response toenvironmental heterogeneity.

中国西部亚热带常绿阔叶林木本植物小枝功能生态学初步研究

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