【作者】 何中声；

【导师】 刘金福； 洪伟；

【作者基本信息】 福建农林大学 ， 野生动植物保护与利用， 2012， 博士

【摘要】 格氏栲（Castanopsis kawakamii）为壳斗科生长周期长常绿高大乔木，是分布于我国中亚热带地区南缘的第三纪孑遗植物，属国家重点保护珍稀植物，自然分布范围狭窄。象福建三明小湖一带有近700hm~2呈纯林状态的格氏栲林，介于中亚热带与南亚热带的一种常绿阔叶林过渡类型，是较为罕见的天然群落。目前，福建三明格氏栲天然林格氏栲种群已过熟，林冠层破碎化加剧导致林窗数量增多，同时由于物种竞争和人为干扰导致格氏栲林已处于衰退之中，种群数量下降，中一代个体数少，野外格氏栲种子萌发困难且幼苗生长缓慢，如何避免格氏栲种群退化，对其进行有效地科学保护，促进格氏栲种群更新与复壮成为亟待解决的问题。通过开展格氏栲天然林林窗基本特征、微环境特征、群落更新与幼苗更新动态研究，揭示格氏栲幼苗自然更新阈值，提出切实可行的格氏栲人促更新对策与恢复技术。结果表明：在所调查的格氏栲天然林林窗中，实际林窗面积（Canopy gap，CG）最小为29.03m~2，最大为98.92m~2，CG平均面积为61.89m~2；扩展林窗（Expanded gap，EG）面积最大为487.42m~2，最小为180.66m~2，EG平均面积为327.83m~2。格氏栲天然林林窗边界木主要组成树种为格氏栲，所占比例为74.75%；林窗边界木胸径结构为尖峰呈左偏，符合正态分布、Weibull分布和β分布；边界木高度级结构呈正态分布，主要集中在15-30m；林窗边界木存在明显的偏冠现象，偏冠率主要在0.5~0.8之间（70.71%）。林窗边界木主要由发育良好的中、高径级树木组成，与非林窗相比林窗边界木大部分已过熟，仅存较少小径级的边界木，表明仅依靠林窗边界木完成林窗更新存在困难，需加强对林窗幼苗和幼树的保护，实现林窗更新。格氏栲天然林林窗光照度在春季、夏季、秋季和冬季从林窗中央、实际林窗、扩展林窗到非林窗光照度逐渐下降，林窗中央光照度最高，非林窗最低；不同季节实际林窗和扩展林窗光照度较高值出现的方位不同。春季、夏季、秋季和冬季格氏栲天然林林窗平均光照度日变化呈正态分布曲线。早晚光照度较低，在正午光照度达到最大值。不同面积大小格氏栲天然林林窗光照度存在差异，大林窗光照度最高，其次是中林窗，小林窗太阳光照度最低。格氏栲天然林林窗空气温湿度在春、夏、秋、冬季节之间差异极显著（P<0.01）。季节对土温0、土温5和土温10影响极显著（P<0.01）。格氏栲天然林林窗空气与土壤温湿度的日变化呈现单峰型，林窗内空气温度与土壤温度（土温0、土温5、土温10）日变化趋势相同，林窗空气湿度与土壤含水量日变化呈高-低-高变化趋势。不同面积大小格氏栲天然林林窗空气温湿度之间差异极显著。中林窗空气温度最高，空气湿度最低；小林窗空气温度最低，空气湿度最大。不同面积大小格氏栲天然林林窗土壤温度之间差异极显著；小林窗土壤含水量与大林窗、中林窗之间差异极显著。不同位置格氏栲天然林林窗空气温湿度、土壤温度与土壤含水量由林窗中央、实际林窗、扩展林窗变化到非林窗温度逐渐降低。不同季节格氏栲天然林林窗风速变化平缓，秋季风速最低，春季、夏季和冬季风速基本趋于一致。秋季风速与春季、夏季和冬季风速之间存在极显著差异（P<0.01）。春季、夏季林窗风速日变化呈单峰凸型曲线；秋季和冬季白天风速变化基本趋于稳定。不同面积大小林林窗风速变化存在差异，中林窗风速变化最高，其次是小林窗，大林窗风速变化最低。不同位置林窗风速变化以实际林窗和扩展林窗较高，林窗中央和非林窗相对较低。对不同大小和发育期的格氏栲天然林林窗的土壤理化性质的研究表明：不同面积大小和发育期的林窗提高了土壤的孔隙组成和水分性质，可有效促进植物根系吸水能力和生长发育，在植物更新过程中扮演着重要角色。小林窗对土壤水分和孔隙组成的改善更明显，中林窗其次；林窗发育晚期对土壤水分和孔隙组成的改善较为明显，林窗发育早期其次。不同面积大小与发育期的林窗的水解性N、速效K含量均高于非林窗，全N、全P、有效P、有机质和有机碳含量均低于非林窗。中林窗的全N、水解性N、速效K、有机质、有机碳含量高于大林窗和小林窗。林窗发育早期土壤中全N、水解性N、全P、有效P、有机质和有机碳含量高于林窗发育中期和晚期。林窗与非林窗土壤平均呼吸速率分别为1.5211μmol CO2·m-2·s-1和1.5220μmol CO2·m-2·s-1，林窗与非林窗土壤呼吸速率差异不显著。林窗土壤呼吸速率与土壤温湿度之间关系不显著（p>0.05）；非林窗土壤呼吸速率与土壤温度之间关系极显著（p<0.01），最优回归方程为y=0.0109e0.2761x。林窗的土壤呼吸速率与土壤全P含量呈显著正相关（p<0.05），最优回归方程为y=17.821x2-7.9157x+2.3536。采用改进的M. Godron稳定性法研究林窗干扰对格氏栲自然保护区天然林更新层物种稳定性的影响。结果表明：林窗乔木层植物处于稳定状态，林下乔木层植物不稳定；林窗和林下灌木层植物均处于稳定状态。林窗和林下乔木层树种中以桂北木姜子（Litsea subcoriacea）重要值最高，说明其在森林更新中占有重要地位，可能对格氏栲种群更新产生较大影响。林下乔木层中格氏栲重要值较低，格氏栲更新存在困难，而林窗干扰促进了格氏栲的向上生长和重要值的提升，可有效实现格氏栲种群的更新和恢复。采用改进更新生态位宽度和更新生态位重叠模型分析林窗干扰对格氏栲天然林更新层物种生态位的影响。林窗格氏栲的更新生态宽度值显著高于非林窗，林窗和非林窗更新生态位宽度最大的是桂北木姜子，与格氏栲更新生态位重叠值也较大。林窗形成早期可利用资源丰富，格氏栲与更新生态位重叠较大的物种在空间上不是竞争，而是对资源利用存在共享趋势；在林窗晚期由于可利用资源逐渐减少，更新生态位重叠较大的物种间将产生明显的竞争关系，将限制格氏栲在林窗中更新，导致格氏栲优势地位进一步下降。格氏栲天然林未来树种组成中，主要由桂北木姜子、木荷、矩圆叶鼠刺（Itea chinensis）与格氏栲等组成的混交群落，整个群落正向物种组成多样化的复杂方向演变。对格氏栲天然林林窗和非林窗格氏栲种子雨、种子库的分布特征与幼苗更新状况研究表明，格氏栲种子雨历时3个月，高峰期在11月中下旬至l2月中旬，林窗和非林窗高峰期种子雨数量分别占种子雨总量的77.13%和74.5%。格氏栲天然林土壤中植物种子种类较少，以格氏栲占绝对优势。林窗和非林窗总的种子数量和格氏栲种子数量的垂直分布均表现为枯落物层（约占2/3）>腐殖质层（0~5cm）（约占1/3）>心土层（5~10cm）（小于1%）。种子雨散布过程中格氏栲种子总量到完好格氏栲种子数量的转化率相对较高，再到土壤种子库中完好格氏栲种子数量和野外幼苗密度其转化率呈急剧下降趋势，格氏栲种子到幼苗转化率极低，应加强对格氏栲种子和幼苗的保护。为了提高格氏栲种子萌发，根据不同粒级、不同温度、不同浓度赤霉素、不同种皮处理等对格氏栲种子发芽率、发芽势、发芽指数和平均发芽速度的影响研究表明：大粒和中粒格氏栲种子的萌发率高于小粒种子；40℃和50℃处理有利于格氏栲种子萌发，温度过高会抑制其种子萌发；不同浓度赤霉素处理均能促进格氏栲种子萌发，赤霉素浓度为10、20和50mg/L时格氏栲种子发芽率均高于70%；去除种皮可提高格氏栲种子的发芽率。格氏栲种子野外发芽率在30%以下，其野外发芽主要为小粒种子、虫蛀或被啃食遗留下的尚具活力种子，而室内格氏栲种子发芽率在60%左右，说明格氏栲种子野外发芽率低可能受到自然或人为干扰影响。在格氏栲天然林中，依据改进Hegyi单木竞争模型计算林窗和非林窗格氏栲幼苗的竞争强度，林窗和非林窗格氏栲幼苗平均竞争强度随着竞争距离增大而逐步降低，初期下降较快，下降到一定程度后明显变缓，存在一变化幅度的转折点，即为幼苗的竞争范围。林窗和非林窗格氏栲幼苗竞争强度的三次指数平滑值在最佳平滑系数α为0.83和0.79时其均方误差值最小，单一斜率变点分析得出林窗和非林窗格氏栲幼苗最佳竞争范围分别是距对象木1.68m和2.00m。野外调查中可调查距对象木2m样圆内的所有竞争木，既能实际反映格氏栲幼苗的竞争格局，又可提高调查效率。采用Hegyi单木竞争指数模型对格氏栲幼苗种内和种间竞争强度进行定量分析表明：格氏栲幼苗种内竞争强度随幼苗高度的增大而逐渐减少。初期格氏栲幼苗种内竞争强度处于中等水平，随着高度的增加，种内竞争强度逐渐减弱，种间竞争强度越来越明显，种群呈衰退趋势。随着对象木高度的增加，林窗和非林窗格氏栲幼苗的种内竞争强度逐渐减少。林窗种间竞争强度的顺序为：梨茶（Camellia octopetala）>褐毛石楠（Photinia hirsuta）>黄润楠（Machilus grijsii）>桂北木姜子（Litsea subcoriacea）>毛鳞省藤（Calamusthysanolepis）>酸味子（Antidesma japonicum）>少叶黄杞（Engelhardtia fenzelii）>矩圆叶鼠刺（Itea chinensis）>小叶赤楠（Syzygium grijsii）>山黄皮（Randia cochinchinensis）>光叶山矾（Syplocos lancifolia）>沿海紫金牛（Ardisia punctata）>丝栗栲（Castanopsis fargesii）>狗骨柴（Diplospora dubia）>木荷（Schima superba）>赤楠（Syzygium buxifolium）>杜茎山（Maesa japonica）。非林窗种间竞争强度的顺序为：桂北木姜子>梨茶>黄润楠>木荷>毛冬青（Ilex pubescens）>狗骨柴>毛鳞省藤>香港新木姜子（Neolitsea cambodiana）>酸味子>沿海紫金牛>山黄皮>光叶山矾>赤楠>小叶赤楠>尖叶水丝梨（Distyliopsis dunnii）>杜茎山>丝栗栲。格氏栲幼苗幼树的竞争主要来自种间竞争，种内竞争对格氏栲影响不大，林窗格氏栲幼苗幼树的种内竞争强度和种间总体竞争强度大于非林窗。在林窗格氏栲幼苗生长初期应加强对其保护，非林窗格氏栲幼苗高度达到100~150cm后适当创造林窗环境以实现其快速生长，从而有效促进林窗和非林窗格氏栲种群保护与更新。不同季节格氏栲天然林林窗和非林窗不同龄级格氏栲幼苗净光合速率日变化研究表明：春季、夏季、秋季和冬季格氏栲天然林林窗和非林窗5个不同龄级格氏栲幼苗的净光合速率日变化均呈单峰型。上午由于光合有效辐射强度（PAR）和空气温度相对较低，净光合速率不高。午间，格氏栲幼苗未出现明显“午休”现象。净光合速率（Pn）的峰值皆出现在上午12：00前后，此后净光合速率持续下降，林窗形成对格氏栲幼苗生长有促进作用。格氏栲天然林林窗和非林窗不同龄级格氏栲幼苗光响应研究表明：林窗环境下5种不同龄级的格氏栲幼苗光补偿点（Lcp）大小顺序为：3-4龄级>5-6龄级>7-8龄级>9-10龄级>1-2龄级；格氏栲幼苗光饱和点（Lsp）大小顺序为：5-6龄级>7-8龄级>3-4龄级>9-10龄级>1-2龄级。非林窗生境5种不同龄级格氏栲幼苗Lcp的大小顺序为：3-4龄级>5-6龄级>7-8龄级>1-2龄级>9-10龄级；格氏栲幼苗Lsp的大小顺序为：5-6龄级>3-4龄级>7-8龄级>9-10龄级>1-2龄级。非林窗不同龄级格氏栲幼苗光补偿点均小于林窗，表现出较强耐荫能力，但非林窗的弱光生境，格氏栲幼苗生长缓慢，甚至停止生长，其耐荫能力是以牺牲生长为代价。林窗不同龄级格氏栲幼苗光饱和点均大于非林窗，非林窗荫蔽条件不利于格氏栲幼苗的光合作用，非林窗格氏栲幼苗在群落竞争中处于不利地位，对格氏栲种群更新十分不利。林窗生境与非林窗生境相比，格氏栲幼苗具有较好的生长表现和竞争能力，更有利于天然格氏栲林的更新演替。格氏栲天然林林窗和非林窗不同龄级格氏栲幼苗CO2响应研究表明：林窗格氏栲幼苗在CO2浓度较低的起始阶段，7-8龄级的表观羧化反应效率大于其他4个龄级，林窗7-8龄级的格氏栲幼苗更有效的利用低浓度的CO2。而当CO2达到饱和时，林窗3-4龄级的格氏栲幼苗的最大净光合速率最大。非林窗格氏栲幼苗在CO2浓度较低的起始阶段，5-6龄级羧化反应效率小于其他4个龄级，当CO2达到饱和时，非林窗5-6龄级格氏栲幼苗的最大净光合速率也最小。除林窗5-6龄级格氏栲幼苗CO2饱和点和补偿点小于非林窗外，其余龄级CO2饱和点和补偿点均为林窗大于非林窗，可能是林窗CO2浓度低于非林窗及林窗中央、实际林窗、扩展林窗到非林窗风速逐渐降低。格氏栲成年叶片长×宽和叶面积呈极显著性对数函数模型，为y=4383.232lnx-34519.789；林窗和非林窗格氏栲幼苗叶片长×宽和面积均呈极显著幂函数关系，分别为y=0.255(lnx)1.092和y=0.866(lnx)0.944。林窗与非林窗5种龄级格氏栲叶片叶绿素相对含量均呈先上升后下降趋势。林窗与非林窗5-6龄级格氏栲叶片叶绿素相对含量最高，1-2龄级含量最低。林窗各龄级叶片叶绿素相对含量低于非林窗。叶绿素相对含量在3个部位的分布总体表现为：叶尖<叶中<叶基，以叶中的叶绿素相对含量对平均叶绿素相对含量的解释度最高。格氏栲天然林林窗和非林窗格氏栲幼苗生物量及养分分配研究表明：林窗和非林窗不同龄级格氏栲幼苗生物量和养分含量存在差异。幼苗生物量随着年龄增加而增大。林窗1-2龄级、3-4龄级格氏栲幼苗总干重低于非林窗，幼苗生长到5-6龄级后林窗幼苗总干重高于非林窗。由于格氏栲幼苗初期需耐荫，林窗3-6龄格氏栲幼苗全N养分含量小于非林窗，生长放缓。随着幼苗生长对光照要求更高，林窗提供了更适宜其生存的环境，林窗幼苗7-8龄幼苗全N养分含量提高，植物生长加快，在9-10龄格氏栲幼苗养分中得到体现。对格氏栲幼苗更新阈值影响因子差异分析表明，由于格氏栲幼苗初期需耐荫，林窗3-6龄幼苗生长不如非林窗，幼苗生长到7-8龄后，林窗格氏栲幼苗总干重、根干重、茎干重、叶干重和全N含量均大于非林窗，林窗9-10龄对格氏栲幼苗更新的影响因子均大于非林窗。采用粗糙集的属性约简算法对评价指标进行重要程度筛选，依据突变级数法对格氏栲幼苗生长评价结果表明，林窗环境中，光照对1-2龄级格氏栲幼苗生长产生存在一定限制作用，其生长速度低于同龄级的非林窗幼苗。由于林窗微环境的异质性，且能提供更多的可利用养分，促进了不同龄级格氏栲幼苗生长且生长速度呈持续增长趋势。非林窗为格氏栲幼苗初期提供较好的郁闭环境，其生长速度较快，而在幼苗5-6龄级后非林窗难以满足幼苗对光照的需求，生长速度逐渐下降。研究表明7-8龄级格氏栲幼苗为幼苗更新的关键阶段，即幼苗更新阈值。对于非林窗格氏栲幼苗，幼苗生长到7-8龄，可在形成的林窗内采取一定抚育措施促进格氏栲幼苗更新。更多还原

【Abstract】 Castanopsis kawakamii Hayata, a broad-leaved evergreen species of Fagaceae and of long growth periodcycle, is a relic plant of the Territory and endangered plant in the southern edge of mid-subtropics in China, whosedistribution is comparatively narrow. C. kawakamii natural forest, which is almost pure forest above700hm~2areain Fujian province of China, is a transitional type between central and southern subtropical evergreen broadleavedforests. The over mature population，species competition and human disturbance all could affect the dynamicperiodic fluctuations of C. kawakamii populations．Moreover, this forest has entered into a decline stage as a resultof severe fragmentation in the canopy layer, with increasing gaps in the forest canopy, the decreasing quantity ofmiddle age structure of C. kawakamii population, low germination rate of seeds and growth of seedlings in theforest and difficulties in regeneration of forest understory, which makes efficient protection, construct the optimalecological environment for its natural regeneration and improvement in its regeneration an urgent matter at thistime. The research of forest gap basic characteristics, micro-environmental characteristics, populationregeneration characteristics and seedlings regeneration dynamic were studied in this paper. The forest gapregeneration characteristics and restoration technology of C. kawakamii natural forest were firstly conducted andrevealed the C. kawakamii seedlings regeneration threshold, and propose the artificial practical measurements toimprove C. kawakamii regeneration.The minimum, maximum and average areas of canopy gaps were29.03m~2,98.92m~2and61.89m~2, and themaximum, minimum and average areas of expanded gaps were487.42m~2m~2,180.66m~2and327.83m~2in thecollected C. kawakamii natural forest gaps. The main tree species of gap border trees (GBTs) were C. kawakamiiwhose proportion was74.75%; the structure of DBH of GBTs showed a left-skew distribution, which consistentedwith the normal distribution, Weibull distribution and β distribution; the structure of tree height classes showed anormal distribution and mainly from15to30m; the GBTs’ crown inclination was obvious, which was mainlyfrom0.5to0.8(70.71%). With exception for a few low diameter GBTs，most of GBTs were composed ofwell-developed medium or high diameter trees which were over mature compared with those of non-gaps, whichindicated that it was difficult to accomplish the forest gap regeneration by solely relying on GBTs and it wasindispensable to strengthen the protection of seedlings and young trees.Spatial and temporal distribution characteristics of illumination intensity were measured in C. kawakamiinatural forest gaps. The results showed that the illumination intensity in four seasons decreased form the gapcenter, canopy gap, expanded gap to non-gap, and the highest in gap center and lowest in non-gap. The directions of relatively high illumination intensity in canopy gap and expanded gap were different in four seasons. Thediurnal variation of average illumination intensity in C. kawakamii natural forest gaps demonstrated as normaldistribution curve and presented a low-high-low trend. The illumination intensity was low in the morning andevening, whereas reached the peak value in the noon. The illumination intensity was different among the smallgaps, medium gaps and large gaps, which were highest in large gaps, secondly with the medium gaps and thelowest average illumination intensity in small gaps.The differences between air temperature and relative humidity in spring, summer, autumn and winter wereextremely significant in forest gaps (P<0.01). The effects of four seasons on soil temperature0, soil temperature5and soil temperature10were highly significant (P<0.01). The diurnal variation of air and soil temperature andhumidity showed a single peak curve. The diurnal variations of relative humidity and soil water content werehigh-low-high trend. The differences between air temperature and relative humidity were extremely significant indifferent gap sizes of forest gaps. The air temperature of medium gaps was the highest, while with the lowestrelative humidity; the air temperature of small gaps was the lowest, while with the highest relative humidity. Thedifferences between soil temperature and moisture were extremely significant in different gap sizes of forest gaps.The difference of soil water content between small gaps and large gaps, moderate gaps were extremely significant.The air temperature, relative humidity, soil temperature and soil water in different locations of forest gaps weregradually decreased form the gap center, canopy gap, expanded gap to non-gaps.The results indicated that the wind speed of four seasons changed slowly in different points of C. kawakamiinatural forest gap, while the wind speed was the lowest in autumn and basically the same in spring, summer andwinter. The wind speed in autumn was significantly lower than in spring, summer and winter (P<0.01). Thediurnal variation of wind speed showed as a single convex peak curve in spring and summer of forest gaps, andthe diurnal variation of wind speed tended to be stable in autumn and winter during the daytime. The differencesof wind speed among the small gaps, medium gaps and large gaps were various, and the medium gaps were thehighest, secondly with the small gaps and large gaps the lowest. The wind speed in different locations of forestgaps showed that the canopy gap and expanded gap were relatively high, whereas relatively low in the gap centerand non-gap.Forest gaps in various sizes and development stages could improve soil pore space structure and watercharacteristics which may effectively promote water absorbing capacity of plant roots and plant growth, whichplayed an important role in plant regeneration. Soil pore space structure and water characteristics in small gapswere more obvious improvement, followed by the medium gaps. Soil pore space structure and watercharacteristics in late development stage gaps were more relatively improved, followed by the early developmentstage gaps. The contents of hydrolyzable N and available K in various sizes and development stages of forest gapswere higher than those of non-gaps, whereas the contents of total N, total P, available P, organic matter andorganic carbon were lower. The contents of total N, hydrolyzable N, available K, organic matter and organiccarbon in medium gaps were higher than those of large and small gaps. The contents of pH, hydrolyzable N andthe ratio of carbon to nitrogen(C/N) of forest gaps in various development stages were higher than those ofnon-gaps. The contents of total N, hydrolyzable N, total P, available P, organic matter and organic carbon in medium gaps were higher than those of medium and late development stage gaps.The average soil respiration rate in forest gaps and non-gaps were1.5211μmol CO2·m-2·s-1and1.5220μmolCO2·m-2·s-1, which had no significance with each other. There was no significant difference between soilrespiration rate with soil temperature and soil water content in forest gaps (p>0.05). There was no significantdifference between soil respiration rate with soil water content in non-gaps (p>0.05), whereas the extremelysignificant difference between soil respiration rate with soil temperature (p<0.01), the optimal regressionequation was y=0.0109e0.2761x. There was significance between soil respiration rate with Total P in forest gaps,whose the optimal regression equation was y=17.821x2-7.9157x+2.3536.The effect of forest gap disturbance on the stability of species in the regeneration layers of natural C.kawakamii forest were studied by improved M. Godron’s stability methods in C. kawakamii natural reserve. Theplants in the tree layer of the forest gap were stable, but were unstable in the understory. The plants in the shrublayer of both the forest gap and understory were stable. The importance value of Litsea subcoriacea was thehighest in the tree layer of the forest gap and understory, which occupied an important role in forest regenerationand would likely have a greater impact on the regeneration of C. kawakamii population. The importance value ofC. kawakamii was relatively low in the tree layer of the forest understory, which affected its regeneration.However, forest gap disturbance improved the upward growth and importance value of C. kawakamii, whichcould achieve the regeneration and restoration of the C. kawakamii population effectively.The effect of forest gaps on species regeneration niche in regeneration layers was conducted by improvedmodels of regeneration niche width and niche overlap of C. kawakamii natural forest. Regeneration niche width ofC. kawakamii in forest gaps was higher than that of non-gaps. The regeneration niche width of Litsea subcoriaceain forest gaps and non-gaps was the most, while the regeneration niche overlaps between the population of L.subcoriacea and C. kawakamii were relatively high in forest gaps and non-gaps. High regeneration niche overlapsbetween the population of C. kawakamii and other species with sufficient available resources in early phase afterthe formation of forest gaps showed that the relationship of main tree populations in C. kawakamii forest gapswere not competition but a tendency of resource sharing. However, the main species with high regeneration nicheoverlaps may bring an obvious competition with the shortage of available resources in late phase of forest gaps.The further differentiation of niche width lead the species composition of forest gaps were under the situation ofdynamic balance and gradually filled the forest gaps to accomplish the forest regeneration finally. The future treespecies composition in C. kawakamii natural forest was a mixed community which mainly consisted by L.subcoriacea, Schima superba, Itea chinensis and C. kawakamii population. The whole community now ischanging in complex direction with diversity species composition.Seed rain, seed bank distribution characteristics and seedlings regeneration status in forest gaps and non-gapswere analyzed in C. kawakamii natural forest. Seed rain continued about2months and peaked at last ten-dayperiod of November to second ten-day of December. The seed rain quantities in the peak period occupied77.13%and74.5%of total seed rain quantities in forest gaps and non-gaps separately. Seed species in soil were low anddominated by C. kawakamii in forest. The vertical distribution of total seed bank quantities and C. kawakamii seedquantities both demonstrated with liter layer (about2/3)>humus layer (about1/3)> subsoil layer (less than1%). Conversion rate from total seed rain quantities to intact seed numbers in seed rain dispersal were relative high, andthen turned to intact seed numbers in seed bank and seedlings density in field practice presented a decreasingtrend. It should strengthen the protection of C. kawakamii seeds and seedlings for its extremely low conventionrate from seeds to seedlings.The effects of different treatments (seed sizes, temperatures, concentrations of gibberellins and seed capsules)on germination percentage, germination potential, germination index and average germination rate of C.kawakamii seeds were studied to improve the germination ability. The results showed that germination percentageof the large and medium C. kawakamii seeds were higher than that of small seeds; the favorable temperature were40℃and50℃and extreme temperature restrained the germination; different concentration of gibberellinspromoted the germination and the germination percentage of C. kawakamii seeds were over70%when treatedwith10、20and50mg/L gibberellins solution; removal of the seed capsule could improve the germinationpercentage. The germination rate of C. kawakamii seeds in wild was less than30%, and germinated seeds mainlywere small seeds, worm-eaten seeds and eaten by animals but have vigorous, whereas the germination rate wasabout60%during the indoor experiment, which indicated that low germination rate of C. kawakamii seeds in wildwas possibly affected by natural and human disturbance.The competition intensity of C. kawakamii seedlings were calculated by the improved competition model forindividual tree of Hegyi, which were optimized by the exponential smoothing model. The optimum competitionranges were confirmed by using the method of single slope change point. The results showed that: The averagecompetition intensity of C. kawakamii seedlings decreased with the increasing of competition distance withcompetition intensity decreased quickly at early stage while it had a slow down obviously after in a certain extentand existed a turning point in the change range called the seedlings competition zone of C. kawakamii naturalforest gaps and non-gaps. The minimum mean square errors of the third index smooth values of C. kawakamiiseedlings competition intensity in forest gaps and non-gaps were the least when the smoothing coefficient α=0.83and α=0.79respectively. By applying the method of single slope change point，the optimal sampling plotscompetition zone of C. kawakamii seedlings competition intensity were1.68and2.00meters distance from theobjective trees. We could investigated the competition trees around2meters distance from the objective trees tocalculate the competition intensity in field practice, which could demonstrated the competition pattern of C.kawakamii seedlings and improve the survey efficiency.The intraspecific and interspecific competitions intensity of C. kawakamii seedlings in C. kawakamii NatureReserve were quantitatively analyzed by using Hegyi’s competition index model. The results showed that theintraspecific competition intensity in C. kawakamii seedlings decreased gradually with the increasing of heightclass. The intraspecific competition intensity of C. kawakamii seedlings at the early growth stage was at a mediumlevel. With the seedlings’ height rising, the intraspecific competition of C. kawakamii seedlings was weakgradually, the interspecific competition of C. kawakamii seedlings was obvious increasingly and the C. kawakamiipopulation has the tendency of deterioration. In C. kawakamii natural forest gaps and non-gaps, the intraspecificcompetition intensity in C. kawakamii seedlings decreased gradually with the increasing of height class indifferent habitats. The order of the interspecific competition intensity in forest gaps was: Camellia octopetala> Photinia hirsute> Machilus grijsii> Litsea subcoriacea> Calamus thysanolepis> Antidesma japonicum>Engelhardtia fenzelii> Itea chinensis> Syzygium grijsii> Randia cochinchinensis> Syplocos lancifolia> Ardisiapunctata> Castanopsis fargesii> Diplospora dubia> Schima superba> Syzygium buxifolium> Maesa japonica.The order of the interspecific competition intensity in non-gaps was: L.subcoriacea＞C.octopetala＞M. grijsii＞S.superba＞Ilex pubescens＞D. dubia＞C.thysanolepis＞Neolitsea cambodiana＞A. japonicum＞A. punctata＞C.dentata＞S. lancifolia＞S. buxifolium＞S. grijsii＞C. kawakamii＞Distyliopsis dunnii＞M. japonica＞C. fargesii.The competition of C. kawakamii seedlings and samplings was mainly from interspecific competition whileintraspecific competition had little effect on it. Intraspecific competition and overall interspecific competition inforest gaps were higher than those of non-gaps. it should strengthen the protection of C. kawakamii seedlings inthe early stage of forest gaps and the gap environment should be created to accelerate the growth of C. kawakamiiseedlings and samplings after the height up to100~150cm in non-gaps which could effectively improve theconservation and regeneration of C. kawakamii population in forest gaps and non-gaps.The diurnal variation of net photosynthetic rate in5age classes of C. kawakamii seedlings of forest gapsand non-gaps in C. kawakamii natural forest showed that:5age classes of C. kawakamii seedlings of forest gapsand non-gaps showed single peak in four seasons. Photosynthetic rate was not high in the morning due to the lowphotosynthetically active radiation (PAR) and air temperature. Moreover, there was no obvious midday depressionat noon. Net photosynthetic rate (Pn) appeared after12:00and decreased gradually thereafter. The seedlingsgrowth rate of C. kawakamii seedlings in forest gaps was faster than that in non-gaps for the improvement oflight-temperature-water in forest gaps could promote the growth of C. kawakamii seedlings.The light response in5age classes of C. kawakamii seedlings of forest gaps and non-gaps in C. kawakamiinatural forest showed that: the orders of light compensation point (Lcp) in5age classes of C. kawakamii seedlingsof forest gaps were:3-4age class>5-6age class>7-8age class>9-10age class>1-2age class; the size order of Lspsof C. kawakamii seedlings were:5-6age class>7-8age class>3-4age class>9-10age class>1-2age class. Innon-gaps, the size order of Lcps in5age classes of C. kawakamii seedlings were:3-4age class>5-6age class>7-8age class>1-2age class>9-10age class; the size order of Lsps of C. kawakamii seedlings were:5-6age class>3-4age class>7-8age class>9-10age class>1-2age class. All of Lcps in5age classes of non-gaps were lower thanthose of forest gaps, shade-tolerant performed, however, C. kawakamii seedlings grew slowly in dim light, evenstoped growth, whose shade-tolerant ability cost of its growth. All of light saturation points in5age classes ofnon-gaps were lower than those of gaps, which showed that shading condition was not good for photosynthesis ofC. kawakamii seedlings which could be in disadvantage under community competition and very unfavorable forpopulation regeneration. Hence, C. kawakamii seedlings in forest gaps were more favorable for the regeneration.The CO2response in5age classes of C. kawakamii seedlings of forest gaps and non-gaps in C. kawakamiinatural forest showed that: When C. kawakamii seedlings in forest gaps were in initial period of low CO2concentration, apparent carboxylation reaction efficiency of7-8age class seedlings is higher than other four ageclasses, which showed that7-8age class seedlings could make use of low concentration CO2more efficiently. Netphotosynthetic rate of3-4age class seedlings was the highest in forest gaps when CO2saturated. When C.kawakamii seedlings in non-gaps were in initial period of low CO2concentration, apparent carboxylation reaction efficiency of5-6age class seedlings is lower than other four age classes, which indicated that5-6age classseedlings could take use of low concentration CO2for photosynthesis more efficiently. Net photosynthetic rate of5-6age class seedlings was the lowest in non-gaps when CO2saturated. Both of the CO2saturation points and CO2compensation points of C. kawakamii seedlings in forest gaps were higher than those in non-gaps with5-6ageclass seedling contrary, which might due to the decrease of wind speed from gap center, canopy gap and thenexpanded gap gradually and intercellular CO2concentration decreased in forest gaps.There was a very significant logarithmic functional relation between the length×width and area of adultleaves, presented as y=4383.232lnx-34519.789. There were extremely significant power functional relationsbetween the length×width and area of C. kawakamii seedlings’ leaves in forest gaps and non-gaps, presented asy=0.255(lnx)1.092and y=0.866(lnx)0.944, respectively. The relative chlorophyll contents of C. kawakamii seedlings’leaves in different age classes of forest gaps and non-gaps both tended to increase firstly and then decrease. Therelative chlorophyll contents in5-6age class of C. kawakamii seedlings’ leaves were the highest, whereas1-2ageclass the lowest in forest gaps and non-gaps. The relative chlorophyll contents of C. kawakamii seedlings’ leavesin same ages of forest gaps were lower than those of non-gaps. The relative chlorophyll contents in three parts ofC. kawakamii seedlings’ leaves generally shower as: leaf apex>leaf middle>leaf base. The explanation of relativechlorophyll contents in leaf middle to the average relative chlorophyll contents were the highest.The biomass and nutrition content of C. kawakamii seedlings in different age classes of forest gaps andnon-gaps were different, and the biomass of seedlings increased with the increasing of age. The total dry weight in1-2age class,3-4age class in forest gaps were lower than those of non-gaps, whereas the total dry weight werehigher than those of non-gaps during the5-6age class and thereafter. As a result of the initial stages of C.kawakamii seedlings need to live in shade and humid environment, the total N content of3-6age class of C.kawakamii seedlings in forest gaps was lower than that of non-gaps, while with slow growth rate. With thegrowing of seedlings and the demanding to light increasing, because of forest gaps could provide moreappropriate environment for the survival of seedlings, the total N content of7-8age class and growth rate of C.kawakamii seedlings in forest gaps was developing, which also illustrated in the9-10age class of C. kawakamiiseedlings in forest gaps.The difference analysis of regeneration threshold affected factors of C. kawakamii seedlings indicated thatthe growth rate of3-6age class of C. kawakamii seedlings in forest gaps was lower than that of non-gaps due tothe initial stages of C. kawakamii seedlings need to live in shade and humid environment. The Seedlings total dryweight, root dry weight, stem dry weight, leaf dry weight and total N content of7-8age class and growth rate of C.kawakamii seedlings in forest gaps were higher than those of non-gaps. Moreover, the all regeneration impactfactors of9-10age class of C. kawakamii seedlings in forest gaps were higher than those of non-gaps. Using theattribute reduction algorithm method of rough set to screen the degree of importance of evaluation indices, and theevaluation of C. kawakamii seedlings’ growth was studied by using the Catastrophe Progression Method. Theresults showed that the light illumination may have certain limitation to the C. kawakamii seedlings growthduring the1-2age class, which growth rate was lower than that of non-gaps. As a result of micro-habitatheterogeneity of forest gaps, it could provide more sufficient available nutrition which could promote the C. kawakamii seedlings growth and continues increasing of the growth rate. In non-gaps, it could provide betterclosed environment for the initial growth period of C. kawakamii seedlings and had a relatively fast growth rate.However, the growth rate of C. kawakamii seedlings during5-6age class later decreased gradually as a result ofthe light illumination hardly satisfied the demand of seedlings growth. With the growing of seedlings andthe demanding to light and temperature increasing, meanwhile the improvement of light-temperature-water inforest gaps could promote the growth of C. kawakamii seedlings, it indicated that7-8age class of C. kawakamiiseedlings was the critical stage of seedlings regeneration, called as seedlings regeneration threshold. As for7-8age class of C. kawakamii seedlings in non-gaps, it should take certain of tending measures to created a forestgaps to improve the regeneration of C. kawakamii seedlings.更多还原