子午岭辽东栎天然林土壤种子库研究

结合野外调查与室内试验对子午岭辽东栎天然林的种群生长状况,枯落层种子库,不同坡位土壤种子库物种组成、数量特征、生活型及其与地上植被的相似性进行了较为系统的研究。结果表明:(1)试验萌发鉴定出的幼苗共有24种,隶属于16科,其中多年生草本和落叶灌木物种比例最高,分别占种子库物种总数的58.33%和12.5%;(2)整个子午岭天然辽东栎林土壤种子库总密度为12 761.44粒/m2,种子主要分布在枯枝落叶层和0-2.5 cm土层中,其中,辽东栎种子密度为752.5粒/m2,占整个样地土壤种子库总密度的5.89%,表明辽东栎种子萌发能力很差,该林分群落天然更新缓慢。(3)子午岭天然辽东栎林的下坡位物种多样性指数较其它坡位高,但各个样地物种多样性指数均高于对照;(4)天然辽东栎纯林的种群生长状况良好,树龄均为成年树种;(5)方差分析表明:辽东栎的胸径、地径在不同坡位之间均具有显著性差异(P>0.05);(6)相关分析表明:枯枝落叶层厚度,重量与土壤种子库密度之间具无显著相关性(P<0.05)。

广西主要林区多孔菌生物多样性与资源的初步研究

广西壮族自治区是中国多孔菌资源比较丰富的区域之一，本研究对广西主要林区进行了初步调查，并根据形态学研究方法对广西地区的多孔菌进行了系统分类学研究。 结果显示，广西地区的多孔菌共有15科，60属，140种。研究过程中发现两个新种，分别是菌索容氏孔菌Junghuhnia rhizomorpha H.S. Yuan & Y.C. Dai和小孔大孢卧孔菌Megasporoporia microporela X.S. Zhou &Y.C. Dai；发现7个中国新记录种：萨拉氏灵芝Ganoderma sarasinii Steyaert，唐氏胶囊革菌Gloeocystidiellum donkii S.S. Rattan，线浅孔菌Grammothele lineata Berkeley & M.A. Curtis，粉状捷克革菌Jacksonomyces furfurellus (Bres.) Sheng H. Wu & Z.C. Chen，半伏容氏孔菌Junghuhnia separabilima (Pouzar) Ryvarden，非洲纵隔担孔菌Protomerulius africanus (Ryvarden) Ryvarden和日本芮氏孔菌Wrightoporia japonica Núñez & Ryvarden；78种为广西地区新记录种，占该地区已报道种类的55.7%。 依据分类学的研究结果，对广西地区的多孔菌的种类组成和地理成分进行了初步分析，结果显示，优势科为多孔菌科Polyporaceae（33.3%），其次为皱孔菌科Meripilaceae（10%），优势属为多孔菌属Polyporus（7.9%%）和针层孔菌属Phellinus（5.7%）；属的地理成分以世界广布属（68.3%）和热带–亚热带分布属（23.3%）为主，种的地理成分以泛热带分布成分（35%）和世界广布种（30%）为主。 经研究表明广西地区共有森林干基腐朽病原多孔菌21种，食用多孔菌菌有5种，药用多孔菌32种，工业用多孔菌17种，多孔菌资源较丰富。 对重要种类木蹄层孔菌Fomes fomentarius (L.:Fr.) Fr.进行了固体培养研究，结果显示木蹄层孔菌的营养菌丝生长最适培养温度为28℃，最适培养pH值为7，最适培养碳源为蔗糖，最适培养氮源为蛋白胨。

施肥和海洋微生物调控对桉树人工林土壤质量的影响

本文研究施化肥和海洋微生物制剂对桉树人工林土壤质量的影响。研究结果表明：施用不同的化肥对桉树人工林土壤质量影响具有明显差异；从海洋植物根际分离得到的微生物菌株制成的微生物制剂中的活性微生物菌株能够在桉树人工林土壤中定殖，对桉树生长具有一定促进作用。桉树凋落叶分解过程中是否释放化感物质是桉树人工林发展过程中人们普遍关注的问题之一，本论文也对该部分做了初步研究。 对施用长效尿素、芬兰复合肥、高峰复合肥三种不同化肥对桉树人工林土壤质量的的影响进行了初步研究，研究结果表明长效尿素在保障土壤氮素供应、促进土壤纤维素分离能力提高和增强土壤对磷元素吸收方面具有重要作用；芬兰复合肥在增强土壤呼吸作用和促进土壤酶活性提高方面优于长效尿素和高峰复合肥。 以两株海洋来源的枯草芽孢杆菌(Bacillus subtilis 3512, Bacillus subtilis 3728)和一株海洋木霉(Trichoderma TF4)为研究材料，在实验室条件下对其生防机理进行了研究，研究表明:两株枯草芽孢杆菌通过产生脂肽和蛋白酶对植物病原菌产生抑制作用；海洋木霉TF4则能够产生HCN，IAA类植物生长激素，同时还具有一定的解磷能力，具有很好的应用前途，采用传统分类学方法和分子系统学方法鉴定为棘孢木霉(T.asperellum)。这三株海洋菌株制成微生物菌剂，在原位条件和盆栽条件下考察了其对桉树生物量和土壤质量指标的影响，研究结果表明将三株海洋微生物混合后添加少量三叶草作辅剂，能有效改善桉树人工林土壤质量，并促进桉树树高和胸径的增加，具备进一步研究和开发成产品的价值。 用高效液相色谱(HPLC)对桉树凋落叶中毒性物质进行分离、纯化，以小麦、绿豆、大速生菜为指示植物，对分离到的物质进行毒性跟踪，分离到一个毒性较强的组分，经1H氢谱和NMR鉴定为3–β甲酰基–乌索酸。

长白山暗叶林苔藓植物生态功能的研究

本文以长白山暗针叶林中苔藓植物为研究对象，通过野外调查和实验分析，对苔醉植物在暗针叶林生态系统中的生态功能进行了系统地研究。研究内容包括长白山暗针叶林苔藓植物的生物量、对降雨的截留能力、在养分循环中的作用以及苔醉植物浸提液对乔木种子萌发的影响四个方面。研究结论将加强人们对苔藓植物的认识，促进对苔藓植物资源的保护，为进一步研究森林生态系统的生态服务功能和长白山自然保护区的生态价值提供科学依据。主要结论：1）长白山暗针叶林苔藓植物的生物量除海拔1100m夕卜都在2×103kg·hm~(-2)以上。苔醉植物分布并不均匀，随海拔变化生物量差异很大。塔藓和拟垂枝藓的生物量随海拔的变化趋势与暗针叶林优势种臭冷杉和鱼鳞云杉的重要值变化规律相似。2）苔藓一枯落物的成层结构能够大大提高持水能力。苔一枯落物层在一次降雨过程中截留量为4.46mm。通常在降雨发生时苔鲜一枯落物层便开始大量吸水，苔藓-枯落物层含水量逐渐达到饱和，降雨继续增加，持水量出现下降的现象。这种现象随降雨的发生而往复出现。3）随倒木腐烂程度的加深，上面着生的苔醉植物不断发生着演替变化，演替序列被给出。采用C/N随腐烂程度的变化规律对倒木腐烂程度分级进行检验和修正，排序结果更加准确4）苔藓植物体内磷含量较高，是重要的磷库，对维持整个系统的磷平衡有非常重要的作用。不同苔藓盖度的土壤中养分含量有差异，尤其磷差异显著。5）苔藓植物浸提液处理条件下，对红松和鱼鳞云杉的种子发芽有促进作用。

涡动相关法估算森林生产力及与测树学方法的比较

大气中CO2、CH4和其它温室气体浓度升高导致的全球气候变化引起了人们对全球碳循环和碳收支的关注，植被与大气间CO2通量的长期测定能够加深对陆地生态系统在全球碳循环作用的科学理解。本文以我国北方典型的温带植被类型长白山阔叶红松林为研究对象，利用观测塔上的涡动相关系统对长白山阔仆卜红松林进行长期的CO2通量监测，并分析CO2通量的周年动态，估算森林净生态系统生产力；同时基于测树学方法，进行群落调查，根据已有的经验公式，估算森林净生态系统生产力，综合评价长白山阔汗卜红松林碳收支，为森林碳收支的研究提供基础。主要结论有：（1）FSAM模型的分析结果表明，观测塔上40m高度的涡动相关仪器测量的信息中，76％来自于西北至西南方相对均质的阔叶红松原始林，其中footprint最大的源区在塔西南方100m-400m范围内。因此，森林群落调查选择在此区内进行，使得涡动相关法和测树学方法估算的生产力具有可比性。（2）2003-2004年碳通量季节变化趋势基本一致，从年初到4月上旬该森林生态系统保持较弱的正的碳通量（释放CO2），5月开始表现为净的碳吸收，且吸收量迅速增加，到6月达到最大值，然后又逐渐减小；9月末到10月末随着生长季的结束，净生态系统COZ交换（NEE）开始由负转为正，11-12月NEE为正，生态系统以呼吸为主。净生态系统COZ交换的年累计量表明长白山阔叶红松林为明显的碳汇，2003年和2004年净生态系统生产力NEP分别为-217±75gcm-2a-1和-190±85gcm-2a-1，相当于-2.17±0.75tCha-1a-1和-1.90±0.85tCha-1a-1。（3）根据经验公式和材积法得到阔汗卜红松林的生物量在343．9-362．3tha－l之间，应用两种方法得到2003一2004年群落的净初级生产力在10.22-10.40tCha-1a-1之间，净生态系统生产力在2.50±1.12tCha-1a-1-2.68±1.20tCha-1a-1之间。（4）测树学方法与涡动相关法测得的净生态系统生产力略有差异，但在误差有效范围内基本一致。

川西亚高山森林生态系统辐射传输研究

辐射传输研究是贯穿森林生态系统的纽带，太阳辐射为植物的生长发育提供光合能量、适宜的环境温度以及发育信息。一方面，气候变化使到达地面辐射能的质和量发生变化，影响到植被的生长发育，改变森林的结构，而森林结构的变化又会影响林冠内辐射能的分配和质量，这些变化会进一步影响到林下土壤温度，改变森林根系活性以及土壤营养转化的效率；连锁反应的结果有可能会使森林生态系统的生产力发生变化，改变碳素和氮素源库的调节方向，从而反馈影响地球气候系统。另一方面，人类作为生态系统的成员，必然需要森林生态系统为其提供更多的原材料和更好的生态服务功能，如何实现这些目标，就需要人类适度调整干预方式和频度，达到预期的目的。本文在建立适合于川西亚高山森林的叶面积测量技术、光照辐射模型和土壤温度变化模型的基础上，对川西亚高山地带森林生态系统的辐射传输特征进行了分析，并从森林结构的角度探讨了林分内的辐射分布以及对土壤温度的影响。主要成果如下： 1. 提出了一种照相法测量叶面积的方法。通过对摆放在平面上的叶片照相，利用投影变化，把非正射图像转化为正射图像，然后经过计算机图像处理得到每一片叶片的面积、周长、长度、宽度等信息。这种方法可使用户以任意方向和距离拍摄处于平面上的叶片，能同时处理大量的叶片，适于野外离体或活体叶片测量。叶片面积分辨率可调，分辨率可以与常用的激光叶面积仪相近甚至更高，而且叶片图像可以存档查询。 2. 提出一种模拟林内光照变化的模型。利用林冠半球照片，记录视点以上半球内的林冠构件空间分布，作为林冠子模型；天空辐射子模型采用国际照明委员会(CIE)的标准晴天和阴天以及插值模型。该模型能够模拟林下某一位点处的实时光斑变化。 3. 提出一种土壤温度变化模型。把土壤视为具有容量和阻力性质的结构，利用电阻和电容器件构建土壤能量分布模型。外界太阳辐射能经过植被以及其它一些能量分配器后进入土壤，其中有一部分转化为土壤势能，即土壤温度。土壤温度的变化类似于电池的充放电过程。在已知模型参数的情况下，可以从太阳辐射计算土壤温度的变化。在模型参数未知的情况下，通过输入和输出值推算模型的参数，而模型参数中的时间常数与土壤组成和含水量有关，这样就可以知道土壤水分的变化情况。 4. 从王朗亚高山森林典型样地林分结构的测量获得林地三维结构图、树冠形态、叶面积密度等参数，这些参数输入到Brunner (1998)开发的tRAYci 模型中计算出一段时间内林分任意位置处的光照值。与林下辐射计测量值以及半球照片计算结果的比较，该模型基本上能够满足对林分光环境了解的要求。 5. 从川西亚高山森林生产力的角度，探讨了森林生产力研究的方法以及川西地区的研究历史和成果，发现了其中的一些规律和问题，特别是在叶面积测量上，还没有使用标准的叶面积指数定义。综合来看，川西地区针叶林叶面积指数(单位土地面积上植物冠层总叶面积的一半) 应在4-5 之间。降雨丰富的华西雨屏带是川西地区森林生产力最高的地区，而向西北森林生产力逐渐降低。川西地区云冷杉林森林生产力平均约为600 gDM m-2 a-1，但是根据辐射能计算的潜在生产力则达到1800 gDM m-2 a-1。实际与潜在森林生产力的巨大差异说明其它因子对生产力的影响。 6. 王朗亚高山3 个典型森林林分中，白桦林样地(BF) 林下草本以糙野青茅、牛至、紫菀等喜阳性物种为主，林下透光度较高；冷杉林样地(FF) 林下透光度最低，以喜阴性物种水金凤、蟹甲草、囊瓣芹等为主；而云杉林样地(SF)林分林龄最大，林下透光度介于冷杉林和白桦林之间，草本层仍然以喜阴性物种东方草莓、紫花碎米芥、酢浆草等为主。冷杉林和云杉林的灌木层也很丰富，卫矛属、五加属、茶藨子属、忍冬属植物很丰富，而在白桦林则以栒摘要子属、榛子属、鹅耳枥属等植物为主。藓类植物在云杉林中最丰富，并且形成毯状层，其它两个林分则很稀少。3 个样地林分结构与林下光环境有很强的相关性，从光环境特征可以在一定程度上推测林分的结构。各样地单纯从乔木层材积推算的NPP 排列顺序为BF>FF>SF，与林下辐射透射率和林分年龄的顺序相同，暗示辐射对群落演替过程的驱动作用。 7. 用半球照相法测得BF、FF 和SF 3 个样地的有效叶面积指数以SF 样地最高，BF 最低。如果考虑针叶树叶片在小枝上的丛聚分布，利用北方针叶林的数值进行校正，则SF 样地LAI 显著增加(达到89%)，其它样地的LAI 基本不变甚至有所下降。校正后的数值与文献中地面测量的结果较相近，说明在使用半球照相法测量川西亚高山针叶林LAI 时必须加以校正。 8. 在3 个样地中，白桦、岷江冷杉和方枝柏种群为丛聚分布，紫果云杉在FF和SF 样地中基本上为随机分布。3 个物种出现丛聚分布的最短距离约为2m，在最短距离以内则为随机分布。最短距离可能与树冠大小有关，种子传播特征以及对光照的需求状况可能是造成这种分布格局类型的原因。 Radiative transfer plays a key role in forest ecosystems. Solar radiation providesenergy for photosynthesis, appropriate ambient temperature and development informationfor plants. However, quality and quantity of radiation reaching land surface are affected byweather and subsequently influence the growth and development of plants, which in turnchanges the budget of radiation in forest. Soil temperature changes with the variation ofradiation under forest canopy and influences the activity of roots and rate of nutrientturnover. Thus, any changes of radiation will induce chain reactions in the entireecosystem and display in the value of net primary productivity which will possibly shiftthe relationship between carbon source and sink at local or regional scale and feed back tothe global climate system. On the other hand, as a component of ecosystems, humanbeings of course need to demand more materials and better service from ecosystems. Forthese purpose, man must adapt their pattern and frequency of interference to ecosystems.This paper aims to research on the canopy structure, the radiation distribution and theirinfluence on soil temperature from the process of radiative transfer in subalpine forestecosystem of western Sichuan. The main results are: 1 Present a new photogrammetric method for leaf area. The main idea is to convertnon-vertically taken images of planar leaves to orthoimages through projectivetransformation. The resultant images are used to get leaf morphological parametersthrough image processing. This method enables users to take photos at almost anyorientation and distance if only the leaves are placed on same plane, and to processlarge quantity of leaves in a short time, which is suitable for field measurement. Theresolution of leaf area is adjustable to fit for special requirement. 2 A model using hemispherical photos combining with solar tracks and radiation courseis provided to simulate light variation in forest. The hemispherical photos of canopyrecord the real spatial distribution of each element of plants viewed from a point. Skyradiance is simulated with CIE standard clear sky or cloudy sky model. This modelcan be used to simulate real time light variation under canopy. 3 Present a soil temperature model. Soil could be regarded as a body of resistor andcapacitor. Some of the budget of solar radiation in soil body is transformed into soilpotential energy, the soil temperature. Variation of soil temperature is driven by solarradiation, vegetation, soil properties, etc. This model has two parameters, one of whichis time constant and is related to soil water content. The inversed model can be used tosimulate the variation of soil water. 4 By using model tRAYci developed by Brunner (1998), the 3-D distribution of light inthree subalpine forest stands of Wanglang Nature Reserve has been simulated andvalidated with value of radiometers in these stands. This model can basically satisfythe need for understanding light regimes of these stands. 5 Present some principles and questions of NPP (net primary of productivity) researchesin western Sichuan. The standard leaf area index (LAI) defined by Chen and Black(1997) has not been used in this region. Total leaf area and projected leaf area indexare still used in NPP researches which may differ around 1-fold in magnitude. Thestandard LAI which is a half of total leaf area above unit land area should be between4 and 5 for typical subalpine coniferous forest of western Sichuan concluded fromliteratures. The maximum forest NPP occurs in West China rain belt and decreasesnorthwestwards. Average NPP of spruce-fir forest in western Sichuan is about600gDM m-2 a-1, which is below the potential NPP of 1800gDM m-2 a-1 based onmeasured radiation in this region. The significant difference between potential and realNPP suggests that other factors influence the growth of stands. 6 In the three subalpine forest stands of Wanglang Nature Reserve, herbage layer ofAbstractbirch stand (BF) with age of 40 is dominated by heliophytes of Deyeuxia scabrescens,Origanum vulgare, Aster tongoloa etc.. However, both of the other two stands aredominated by shade tolerent species, such as Impatiens noli-tangere, Impatiensdicentra, Cacalia deltophylla and Pternopetalum tanakae etc. in fir stand (FF) withage of 180 and Fragaria orientalis, Cardamine tangutorum and Oxalis corniculata etc.in spruce stand (SF) with age of 330. Shrub species in the latter two stands arerelatively rich, typical dominant genera being Euonymus, Acanthopanax, Ribes andLonicera. Birch stand has relatively sparse shrubs dominated by genera of Cotoneaster,Corylus and Carpinus. Mosses are significant only in spruce stand. The canopystructure controls the light regime of stand, which influence the composition of herblayers beneath the canopy. This light regime-community structure relationship can beused to infer the herb community from canopy structure. The NPP derived from timbervolume of arbor layer of the three stands decreases from BF to SF, which is in thesame order of transmitted total radiation under canopy and age of these stands,suggesting the driving effect of radiation in the succession of community. 7 The highest effective LAI of the three stands obtained by hemispherical photos is inplot SF and lowest in plot BF. After rectification of the clumping effect of leaves onshoot, the real LAI in plot SF increases significantly (89%) and approximate to theaverage LAI of coniferous forest in western Sichuan. Therefore, the LAI obtainedfrom hemispherical photos needs rectification for clumping effect. 8 Spatial distribution pattern for Betula platyphylla, Abies faxoniana and Sabinasaltuaria is clumpy, but Picea purpurea almost random in plot FF and SF. The shortestdistance for clumpy distribution for Betula platyphylla and Sabina saltuaria is 1.5m,and 2m for Abies faxoniana. And random pattern for these trees is exhibited within thisrange which almost coincides with the diameter of crown. Seed dispersalcharacteristics and light requirement may be the reason for different spatial pattern.

增温对川西亚高山针叶林不同光环境下几种幼苗生长的影响

由于人类活动所引起的地球大气层中温室气体的富集已导致全球地表平均温度在20 世纪升高了0.6 ¡æ，并预测在本世纪将上升1.4-5.8 ¡æ。气候变暖对陆地植物和生态系统产生深远影响，并已成为全球变化研究的重要议题。位于青藏高原东部的川西亚高山针叶林是研究气候变暖对陆地生态系统影响的重要森林类型。森林采伐迹地和人工云杉林下作为目前该区人工造林和森林更新的两种重要生境，二者截然不同的光环境对亚高山针叶林不同物种更新及森林动态有非常重要的影响。 本文以青藏高原东部亚高山针叶林几种主要森林树种为研究对象，采用开顶式增温法（OTCs）模拟气候变暖来研究增温对生长在两种不同光环境下（全光条件和林下低光环境）的几种幼苗早期生长和生理的影响，旨在从更新角度探讨亚高山针叶林生态系统不同树种对气候变暖在形态或生理上的响应差异，其研究结果可在一定程度上为预测气候变暖对亚高山针叶林物种组成和演替动态提供科学依据，同时也可为未来林业生产管理者提供科学指导。 1、与框外对照相比，OTCs 框内微环境发生了一些变化。OTCs 框内与框外对照气温年平均值分别为5.72 ¡æ和5.21 ¡æ，而地表温度年平均值分别为5.34 ¡æ和5.04 ¡æ，OTCs 使气温和地表年平均温度分别提高了0.51 ¡æ和0.34 ¡æ；OTCs框内空气湿度年平均值约高于框外对照，二者分别为90.4 %和85.3 %。 2、增温促进了三种幼苗生长和生物量的积累，但增温效果与幼苗种类及所处的光环境有关。无论在全光或林下低光条件下，增温条件下云杉幼苗株高、地径、分支数、总生物量及组分生物量（根、茎、叶重）都显著地增加；增温仅在全光条件下使红桦幼苗株高、地径、总生物量及组分生物量（根、茎、叶重）等参数显著地增加，而在林下低光条件下增温对幼苗生长和生物量积累的影响效果不明显；冷杉幼苗生长对增温的响应则与红桦幼苗相反，增温仅在林下低光条件下对冷杉幼苗生长和形态的影响才有明显的促进作用。 增温对三种幼苗的生物量分配模式产生了不同的影响，并且这种影响也与幼苗所处的光环境有关。无论在全光或林下低光环境下，增温都促使云杉幼苗将更多的生物量分配到植物地下部分，从而导致幼苗在增温条件下有更高的R/S 比；增温仅在林下低光条件下促使冷杉幼苗将更多的生物量投入到植物叶部，从而使幼苗R/S 比显著地降低；增温在全光条件下对红桦幼苗生物量分配的影响趋势与冷杉幼苗在低光条件下相似，即增温在全光条件下促使红桦幼苗分配更多的生物量到植物同化部分—叶部。 3、增温对亚高山针叶林生态系统中三种幼苗气体交换和生理表现的影响总体表现为正效应（Positive），即增温促进了几种幼苗的生理活动及其表现：（i）无论在全光或林下低光环境下，增温使三种幼苗的光合色素含量都有所增加；（ii）增温在一定程度上提高了三种使幼苗的PSII 光系统效率（Fv/Fm），从而使幼苗具有更强的光合电子传递活性；增温在一定程度使三种幼苗潜在的热耗散能力（NPQ）都有所增强，从而提高幼苗防御光氧化的能力；（iii）从研究结果来看，增温通过增加光合色素含量和表观量子效率等参数而促进幼苗的光合作用过程。总体来说增温对幼苗生理过程的影响效果与幼苗种类及所处的光环境有关，增温仅在全光条件下对红桦幼苗光合过程的影响才有明显的效果，而冷杉幼苗则相反，增温仅在低光条件下才对幼苗的生理过程有显著的影响。 4、增温对三种幼苗的抗氧化酶系统产生了一定的影响。从总体来说，增温使几种幼苗活性氧含量及膜脂过氧化作用降低，从而在一定程度上减轻了该区低温对植物生长的消极影响；增温倾向表明使三种幼苗体内抗氧化酶活性和非酶促作用有所提高，从而有利于维持活性氧代谢平衡。但增温影响效果与幼苗种类所处的光环境及抗氧化酶种类有关，增温对冷杉幼苗抗氧化酶活性的影响仅在林下低光环境下效果明显，而对红桦幼苗抗氧化酶活性的影响仅在全光条件下才有明显的效果。 总之，增温促进了亚高山针叶林生态系统中三种幼苗的生长和生理表现，但幼苗生长和生理对增温的响应随植物种类及所处的光环境不同而变化，这种响应差可能异赋予了不同植物种类在未来气候变暖背景下面对不同环境条件时具有不同的适应力和竞争优势，从而对亚高山针叶林生态系统物种组成和森林动态产生潜在的影响。 Enrichment of atmospheric greenhouse gases resulted from human activities suchas fossil fuel burning and deforestation has increased global mean temperature by 0.6¡æ in the 20th century and is predicted to increase it by 1.4-5.8 ¡æ. The globalwarming will have profound, long-term impacts on terrestrial plants and ecosystems.The ecoologcial consequences arising from global warming have also become thevery important issuses of global change research. The subalpine coniferous forests inthe eastern Qinghai-Tibet Plateau provide a natural laboratory for the studying theeffects of climate warming on terrestrial ecosystems. The light environment differssignificantly between clear-outs and spruce plantations, which is particularlyimportant for plant regeneration and forest dynamics in the subalpine coniferous forests. In this paper, the short-term effects of two levels of air temperature (ambient andwarmed) and light (full light and ca. 10% of full light regimes) on the early growthand physiology of Picea asperata, Abies faxoniana and Betula albo-sinensis seedlingswas determined using open-top chambers (OTCs). The aim of the present study wasto understand the differences between tree species in their responses to experimentalwarming from the perspective of regeneration. Our results could provide insights intothe effects of climate warming on community composition and regeneration behavior for the subalpine coniferous forest ecosystem processes, and provide scientificdirection for the production and management under future climate change. 1. The OTCs manipulation slightly altered thermal conditions during the growingseason compared with the outside chambers. The annual mean air temperature andsoil surface temperature was 5.72 and 5.34 ¡æ (within the chambers), and 5.21 and5.04 ¡æ (outside the chambers), respectively. The OTCs manipulation increased airtemperature and soil surface temperature by 0.51 and 0.34 ¡æ on average, respectively.Air relative humidity was slightly higher inside the OTCs compared with the controlplots, with 90.4 and 85.3 %, respectively. 2. Warming generally stimulated the growth and biomass accumulation of thethree tree species, but the effects of warming on growth and development variedbetween light conditions and species. Irrespective of light regimes, warmingsignificantly increased plant height, root collar diameter, total biomass, componentbiomass (stem, foliar and root biomass) and the number of branches in P. asperataseedlings; For A. faxoniana seedlings, significant effects of warming on all the tested parameters (plant height, root collar diameter, total biomass, and component biomass) were found only under low light conditions; In contrast, the growth responses of B.albo-sinensis seedlings to warming were found only under full light conditions. Warming had pronounced effects on the pattern of carbon allocation. Irrespectiveof light regimes, the P. asperata seedlings allocated relatively more biomass to rootsin responses to warming, which led to a higher R/S. Significant effects of warming onbiomass allocation were only found for the A. faxoniana seedlings grown under lowlight conditions, with significantly increased in leaf mass ratio (LMR) and decreasedin R/S in responses to warming manipulation. The carbon allocation responses of B.albo-sinensis seedling to warming under full light conditions were similar with theresponse of A. faxoniana seedlings grown under low light conditions. Warmingsignificantly decreased root mass ratio (RMR), and increased leaf mass ratio (LMR)and shoot/root biomass ratio (S/R) for the B. albo-sinensis seedlings grown under full light conditions. 3. Warming generally had a beneficial effect on physiological processes of dominant tree species in subalpine coniferous forest ecosystems: (i) Warming markedincreased the concentrations of photosynthetic pigments in both tree species, but theeffects of warming on photosynthetic pigments were greater under low lightconditions than under full light conditions for the two conifers; (ii) Warming tended toenhance the efficiency of PSII in terms of increase in Fv/Fm, which was related tohigher chloroplast electron transport activity; and enhance non-radiative energydissipation in terms of in increase in NPQ, which may reflect an increased capacity inpreventing photooxidation; (iii) Warming may enhance photosynthesis and advancephysiological activity in plants by increasing photosynthetic pigment concentration,the efficiency of PSII and apparent quantum yield (Φ) etc. From the results, theeffects of warming on seedlings’ physiological performance varied between lightenvironment and species. The effects of warming on photosynthesis performance of B.albo-sinesis seedlings were pronounced only under full light conditions, while thephysiological responses of A. faxoniana seedlings to warming were found only underthe 60-year plantation. These results provided further support for the observationsabove on growth responses of seedlings to warming. 4. Warming had marked effects on antioxidative systems of the three seedlings.Warming generally decreased H2O2 accumulation and the rate of O2- production, andalleviated degree of lipid peroxidation in terms of decreased MDA content, whichalleviated to some extent the negative effects of low temperature on the plant growthand development in this region; Warming tended to increase the activities ofantioxidative enzymes and stimulate the role of non-enzymatic AOS scavenging,which helped to create an balance in maintaining AOS metabolites for the threeseedlings. Nevertheless, the effects of warming on antioxidative defense systems werepronounced only under the 60-year plantation for the A. faxoniana seedlings. Incontrast, the marked effects of warming on antioxidative defense systems for the B.albo-sinesis seedlings were found only under the full light conditions. In sum, warming is considered to be generally positive in terms of growth andphysiological process. However, the responses of growth and physiology performanceto warming manipulation varied between species and light regimes. Competitive and adaptive relationships between tree species may be altered as a result of responsedifferences to warming manipulation, which is one mechanism by which globalwarming will alter species composition and forest dynamics of subalpine coniferousforest ecosystems under future climate change.