【作者】 张玉荣；

【导师】 罗菊春；

【作者基本信息】 北京林业大学 ， 生态学， 2009， 博士

【摘要】 资源冷杉（Abies ziyuanensis L.K.Fu et S.L.Mo）系我国南岭山地新发现的冷杉植物。在《中国珍稀濒危保护植物名录》第一册中被定为濒危种,在《国家重点保护野生植物名录》中,被列为一级保护植物（含大院冷杉A.dayuanensis Q.H.Li）。从已发表的资料看,自资源冷杉定名以来,没有人对其进行全面、系统的研究。在《中国植物志》、《湖南植物志》和《湖南树木志》中都将大院冷杉作为资源冷杉的变种。因此,本研究将大院冷杉并入资源冷杉进行研究。本论文是在野外试验、样地调查、定点观测和室内分析研究的基础上,从地理分布、生态环境、形态解剖、生长规律、生物生态、种群生态、遗传分化等方面进行了资源冷杉的濒危机制和种群保育策略研究,得出如下结论:1、气候变迁致使资源冷杉成为现代濒危种。资源冷杉在明竹老山、大院和都庞岭的分布呈纬向断续连带性,处于南岭的北侧,冷杉在北迁上移中在这里找到了适宜的繁衍地。如果气温继续上升,现有我国亚热带东南部的冷杉群落还会被其它阔叶树种代替。2、资源冷杉的分布呈星散的岛屿状分布。由于环境变迁和地理隔离,资源冷杉只残存于局部生境,形成孤立的残遗分布区。且在不断分化,在湖南几个地段发现的种群都不同程度的存在分化现象。如大院冷杉与资源冷杉在形态特征解剖构造上有显著差异,拟定名为变种。3、资源冷杉是冷杉植物向东南方向扩展的替代分布种。一个物种逐步分化为不同的近缘种,呈现水平或垂直方向的地理替代现象,有时部分分布区又表现重叠,形成了种间演化的进程和生态习性的差异。百山祖冷杉、资源冷杉及元宝山冷杉在系统发育上都表现出强烈的亲缘性,可能均由一共同的祖先分化而来。4、资源冷杉的温度适应性敏感。温度是直接影响资源冷杉的生存和生长的因子,而降雨、湿度、日照是影响其生长快慢的不可缺少的因素。树液流动要求日平均温8.4℃以上,芽膨大要求日均温13℃,最适宜生长的日均温是16-19℃左右,昼夜温差8-10℃左右。月均温超过20℃以上时,资源冷杉的高生长缓慢或基本停止生长。5、资源冷杉生长时间短,速生期只40-50天,从树液流动到停止生长仅为80天左右。5—6月生长快,6月下旬至7月初生长明显缓慢,到7月中下旬基本停止生长。6、资源冷杉的种子发芽率很低,一般在2%-4%。种子萌发时需低温层积1个月左右以打破休眠,恒温25℃和光照条件下有利于种子萌发。苗期和幼树期,资源冷杉对光照的要求有差异,在幼树期对光照的要求比苗期大大增加,虽然在遮阴70%条件下幼树的长势比全光和林下（近于全荫蔽,郁闭度0.95以上）都要好,株高和地径的增加也比其他两种条件下快,但是优势（差异）没有在幼苗期那样明显。资源冷杉在幼树期生长开始进入旺盛阶段,对日照的要求也增加了,各种生境下的差异开始变小。资源冷杉属雌雄同株异花植物,雄花一般开在树冠的中上部较向阴的侧枝上,下部稀少。雌花则开在树主梢附近或健壮的主侧梢上或附近三盘枝条上,五盘枝以下着生少,雌花数量极少,这与结实数量的多少有很大关系。雌花受粉后,约十天左右,形成圆柱形的绿色幼果。资源冷杉结实率低,种子饱满度仅有5.9%。7、资源冷杉群落主要有3个类型:①资源冷杉-褐叶青冈-多脉青冈群落（FormAbies ziyuanensis-Cyclobalanopsis stewardiana-Cy.mutinervis community）;②资源冷杉-亮叶水青冈群落（Form Abies ziyuanensis-Fagus.lucida community）;③资源冷杉、毛竹、银木荷落群（Form Abies ziyuanensis-Phyllostachyspubesoens-Schima argentea community）。群落特征是:古老成分混生,多为第三纪或更远古的残遗属;暖性植物混生,许多喜暖阔叶树种侵入,冷杉被挤为次要树种;阔叶植物混生,常绿壳斗科植物优势种更新好,稳定性好,资源冷杉成为伴生种。8、种群年龄结构差异很大。存在幼龄个体严重不足、老龄化加剧的现象。资源冷杉种群在180a范围内的死亡（q_x）趋势:在1-30龄的死亡率较低,仅为0.224;30-50龄和50-70龄的死亡率增大到0.675和0.673;70-90龄已进入壮龄期晚期,死亡率较30-70两个龄段略有降低;90-110龄者处在壮龄晚期和老年早期,植株的死亡危险降低;110-130龄的植株,生理机能开始衰弱,形成死亡高峰;130-150龄的植株表现出较强的抗性,其死亡率维持在0.444,较死亡高峰期有所下降。种群的生命期望（e_x）在90-110龄时达到最大,表明此阶段资源冷杉的生存质量最高,是资源冷杉的生理活动旺盛期;在1-30龄的e_x值也较高,这主要是在林窗更新方式下资源冷杉个体受到竞争压力小所致;在110～130龄及130龄以上时,资源冷杉种群的平均生命期望陡降,未及90-110龄的50%,显示着资源冷杉种群的生理衰退。9、种群分布具有较强的集聚性,各种格局尺度上都有集群分布倾向,聚块指数较大;集群分布也较多,林窗形成异龄群聚,上层空间生态位的竞争强烈;随机分布是在植株生长旺盛、自然干扰抵抗力强的群落中发生:光因子是影响其生长,进而影响其分布格局的主导因子。10、自然居群的遗传多样性较高,多态位点百分率为77.78%,大院冷杉和资源冷杉分别为50.54%和40.34%;Nei’s基因多样性指数为0.2344,Shannon信息指数为0.3764。从多态位点百分比来看,大院冷杉种群高于资源冷杉种群,其中香菇棚居群最高,舜皇山居群最低。11、资源冷杉自然居群的遗传分化。总基因多样度H_t=0.2346,种群内的基因多样度H_s=0.146,表明种群内的遗传变异多于种群间:基因分化系数G_st=0.3779,即种群间的遗传变异占了总遗传变异的37.79%,而种群内的遗传变异占总遗传变异量的62.21%。说明资源冷杉自然居群间存在一定程度的遗传分化,但是总的遗传分化主要来自群体内部。Shannon表型多样性指数群体间遗传变异所占比率为39.68%,群体内的遗传变异达60.34%,也说明遗传分化来自群体内部。12、Nei’s遗传距离。6个居群UPMGA聚类分析表明,大院冷杉的4个居群聚在一起,而资源冷杉的2个居群聚在一起,对个体和居群的聚类都表明两个种群间存在一定的遗传分化,可以基本确定大院冷杉已成为资源冷杉生殖隔离而分化的变种。13、遗传分化系数G_st=0.3779,略高于Nybom（2004）所统计的植物ISSR遗传分化系数的平均值(G_st=0.34),表明资源冷杉自然居群间存在相当程度的遗传分化,居群间可能已经形成异质居群结构。资源冷杉的基因流Nm=0.6231,表明在进化过程中可能发生了严重的遗传漂变,群体之间的基因流受阻,导致群体分化。群体规模的不断缩小必然会导致遗传漂变,种群的适应能力变差,进化潜力衰弱,处于极度濒危状态。14、资源冷杉种群的濒危是受内外因相互作用而造成的,外因包括气候变迁、人类活动和群落环境影响,内因则主要是开花与结实少、种子发芽率和幼树竞争力低等方面的原因。15、资源冷杉的解危措施:加强对资源冷杉种子繁殖和营养繁殖的研究,突破技术难关,实现迁地保护,提供种苗保障;适度的人为干扰,对阔叶树和楠竹进行适当的疏伐,使其郁闭度保持在0.4-0.5,对下木盖度偏高的林分进行林地抚育伐,促进冷杉自然更新,扩大种群数量;重视周围生境的保护,停止森林破坏,保护濒危植物的栖息生境。对于尚未建立自然保护区的广西资源县明竹老山、湖南双牌县打鼓坪林场等有冷杉分布的地方尽快建立自然保护区,加强对湖南炎陵县桃源洞、湖南新宁县舜皇山与湖南江永县都庞岭及江西井冈山自然保护区的保护,防止资源冷杉这一珍稀濒危种的灭绝。更多还原

【Abstract】 Abies ziyuanensis is a newly discovered species.It was identified as the endangerous species in "Treasure and endangerous plants for protection in China"（volumⅠ）,and was listed as the national first-grade protection plant in National Wild Plants List for Protection （Ⅰ）.However,till to now systematic and comprehensive research on the plant has not yet been conducted and reported,in terms of all the reporters and research papers published. So in this paper,by means of field experiment,sample plots investigation,location observation,and date analysis,endangered mechanism and population conservation were studies based on aspects of Geographic Distribution,Eco-environment,Morphological anatomy,growth pattern,biological and ecological traits,population ecology,and Genetic differentiation and other factors.The results showed as followings.Studies on endangered mechanism and population conservation of Abies ziyuanensis.1 Climatic changes is the main cause leading to endangered of the species.In Mingzhu Lao shang,Daoyuan and Du Pan Lin,the distribution of Abies ziyuanensis shows latitudinal intermittence joint pattern,which distributes on the North side of Nanlin,and the area becomes a suitable reproduction place,when the species transfer toward north.If temperature continues to keep rising,the Abies ziyuanensis community will be replaced by other hardwood species.2 The Abies ziyuanensis distributed starrily and isolated.Since the environmental changes and geographic isolation,the species only exist in some habitats and formed isolated distribution,which resulted in community differentitation.Investigation on different populations in Hunan province indicated the differentiation,such as Abies in Duyuan was quite different from the Abies ziyuanence in Morphological anatomy,so that was named as new species,Abiese dayuanence3 Abiese ziyuanensis was a Abiese species of geographic substituted distribution of extending towards to South-east.The species differentiated into different relative species gradually,which formed geographic substituted distribution at horizontal or vertical direction.However,at some area,its distribution was overlap,which developed different evolution process and ecological traits among different species.Abies beshanzuensis,A. ziyuanensis and A.yuanbaoensis were closely affinity in systematic development,which suggested that the three species developed from the same ancient.4.Abiese ziyuanensis was sensitive to temperature change.Temperature affected growth and development of A.ziyuangensis directly,besides the factors such as rainfall, moist and sunlight that affect its growth rate.When daily average temperature is over 8.4℃,Sap flowing starts.And buds enlarge required temperature of 13℃daily average, optimist temperature for growth was about 16-19℃,and the temperature difference between day and night is about 8-10℃.When monthly average temperature was over 20℃, the tall growth slowed down or stopped completely.Growth time of A.ziyuanensis was short,about 80 days in whole year.During May and June,the species grew fast,and from later June to the early July,its tall growth slowed down,and stopped growing at the later July.5 Abiese was hermaphroditic and monoecious.Usually,the male flower distributed on the middle and top crown to shade side,a fewer male flower grew at the low part of the tree,Female flower were very fewer and grew on the branches closing to main stem or stronger branches（three to five round branches）,which affected the seeds production significantly.About 10 days after pollen,young and green cone developed.The species has low yield of seeds,and only 5.9%seeds were qualified.6.The germination rate of A.ziyuanensis seeds was very low,about 2-4%.The seeds needed to be stratified at low temperature for about 1 month,to break dormancy,before germination.Constant temperature of 25℃and enough sunlight were favorable to germination.Requirement for sunlight between seedlings and young trees was different, young trees needed much more sunlight than seedlings did.Compared with young trees growing at open area or under big tree,young trees growing under shade grew much faster with bigger base diameter,However the difference was not as obvious as that for seedlings. Young trees growing fast required enough sunlight,in contrast,difference resulted from other environmental factors were little.7.A.ziyuanensis community generally has three types:①Abies ziyuanensis,Cyclobalanopsis stewardiana and C.mutinervis community;②Abies ziyuanensis and Fagus lucida community;③Abies ziyuanensis,Phyllostachys pubesoens and Schima argentea community.All the communities characterized with that mixed with ancient species（tertiary or more primeval genera）,mixed with warm species（lot of warm-like hardwood species invade） and Abiese species became the sub-species;mixed with hardwood species,for the evergreen broad-leaved tree of fagaceae species naturally regenerated well,and was stable,the A.ziyuanensis become the accompany species.8 There was great difference of age among different population.There were fewer existing young trees,and trees became aging more and more serious.The trend of death of A.ziyuanensis within 180 years old was as followings:trees of age 0 to 30 has lower death rate,only 0.224;age 30 to 50 and 50 to 70 the death rate increased up to 0.675 and 0.673 respectively.Plant at the age of 70 to 90 was at mature period,and death rate decreased in contrast with plant at age of 30 to 70;90 to 110 years old tree has low death risk;110 to 130 years old tree,the physiological activity became weak,and at the highest risk of death; 130 to 150 years old tree had stronger resistance,the death rate decreased to 0.444Climax of life expectancy was at the age of 90 to 110,it had high living quality and vigor physiological activities;also trees at age of 0 to 30 had higher life expectancy,for the trees regenerating on the forest gap had little competition pressure at this period;at the age 110 to 130 or over 130,the average life expectancy of A.ziyuanensis decreased sharply, which was less than 50%of that for 90 to 110 years old tree,and reflected the decay of the population.9 The population distribution formed clumped pattern.Clumped distribution existed in different population structure,the gathering index was high;there were lot of contagious distribution,forest gap formed uneven-aged population,competition of ecological niche in upper space was strong.Radom distribution occurred in vigorously growing stage,and in the communities with high resistant to natural disaster;Sunlight was the main factor that affected the development of plant,then affected the distribution pattern.10 Natrual population had high genetic diversity.The proportion of polymorphic loci in the natural population was 77.78%,and the proportion of polymorphic loci of A. dayuanensis and A.ziyuanensis populations was 50.54%and 40.34%respectively.The Nei’s index of genetic diversity was 0.2344,Shannon information index was 0.3764.In terms of the proportion of polymorphic loci,genetic diversity of A dayuanensis was higher than that of A.ziyuanensis.For the A dayuanensis,population located at Xianggupeng had highest genetic diversity,while population at Xunhuan Mountain had lowest diversity. Based on other index,the analysis results was the same,that was A.dayuanensis had higher genetic diversity than A ziyuanensis.11 Genetic differentiation of Natural A.ziyuanensis population.The total gene diversity H_t=0.2346,the gene diversity within population was 0.146,which suggested that the gene diversity within population was higher than that of inter populations.The genetic differentiation index(G_st) was 0.3779,that meant 37.79%of gene diversity contributed by interpopulation and 62.21%contributed by intrapopulation.The results also indicated that, genetic differentiation existed among different populations to some extend,but most genetic differentiation came from intrapopulation.Shannon information index of interpopulation was 39.68%,and index of intrapopulation was up to 60.34%,which also indicated that most genetic differentiation came from intrapopulantion12 Nei’s genetic distance.UPMGA cluster analysis on 6 populations indicated that 4 population of A dayuanensis was classfied into a group,and 2 A ziyuanensis population clusted into a group,cluster analysis on both indiviual and population indicated that genetic differentiation existed between the populations of the two species,which confirmed that the two was isolated differentated into two species.13 Index of genetic differentiation(G_st) was 0.3779 in this paper,which was little higher than the average index(G_st=0.34) published by Nybom（in 2004） by means of ISSR analysis.The results indicated genetic differentiation existed in natural population, interpopulation maybe formed heterogeneous population structure.The gene flow（Nm） of A ziyuanensis was 0.6231,that suggested great genetic drift had happened in its evolution process,however the gene flow was blocked between different population,which resulted in populaiotn differentiation.Decrease of population size resulted in genetic drift,and weakened the adaption of population,then evolution capacity declined,which lead to be endangerous.14 Endangered A ziyuanensis was caused by the interaction of interior and exterior factors.The exerrior included climatic change,human beings’ activity and environment of population,the interrior factors included flowing,fruit,seeds germination and competition ability of seedlings.15.Measures for allevating endanger.To enforce the research on sexual propagation and vegetation propagation of A ziyuanensis,overcome the technical difficulty,so as to relize the insit and exit protection,also provide seedlings for afforestation.Do some reasonable activities,such as conduct thin on hardwood species and banboom,keep the crown close between 0.4 to 0.5.also conduct tending on the vegetation under the forest,so as to enhace natural regenation,to increase the number of population.Great attention should be put on the protection of ecological environment,to stop destroying forest,and to protect habitates of endangered plants.更多还原