【作者】 刘彤；

【导师】 胡海清；

【作者基本信息】 东北林业大学 ， 生态学， 2007， 博士

【摘要】 东北红豆杉是第三纪孑遗树种和国家Ⅰ级重点保护的野生濒危物种,开展天然东北红豆杉种群生态学的研究,对于揭示其濒危机理,有效保护与恢复天然东北红豆杉种群及进行东北红豆杉人工培育等方面,有着重要的理论意义和应用价值。本文从种群的基本特征、种内和种间竞争关系、群落学特征、生殖生态及年轮学等方面,揭示了东北红豆杉种群的相关规律。研究结果表明:1.在黑龙江省穆棱东北红豆杉保护区范围内,天然东北红豆杉种群数量相对较多,但种群结构不合理,处于更新层的东北红豆杉幼苗、幼树占种群数量的76.81%,处于演替层的东北红豆杉仅占种群数量的2.32%,处于乔木层的东北红豆杉占种群数量的20.87%,且严重老龄化,这将影响种群的未来发展。天然东北红豆杉种群分布对海拔、坡向、坡位和坡度等生态因子具有选择性。700～800m是种群的最适海拔范围;分布在阴坡的种群数量明显高于阳坡;山地的中部和上部更适合东北红豆杉生长;东北红豆杉种群多数分布在坡度15°以下的山地,随着坡度的增加,种群数量明显减少。2.天然东北红豆杉的种内竞争强度不大,占总竞争的4%,种间竞争占总竞争的96%。更多的竞争压力来自种间。现实林分中,种间竞争压力主要来自紫椴、臭冷杉、色木槭、红松等地带性植被的优势树种。随着胸径的增大,东北红豆杉种群所受到的竞争压力逐渐减小,胸径在20cm以前受到的竞争压力最大,竞争强度与对象木胸径符合y=289.03x^-1.5012的幂函数关系。海拔、坡度、坡向、坡位等生态因子对种间竞争强度或主要竞争树种的排序有明显影响。3.应用TWINSPAN、DCA和CCA多元分析的方法,对东北红豆杉生存群落进行了数量分类和排序。根掘72块样地调查资料,TWINSPAN群落数量分类结果显示,可将东北红豆杉生存群落分为粗茎鳞毛蕨、毛榛子、东北红豆杉、冷杉、红松林,猴腿蹄盖蕨、毛榛子、东北红豆杉、冷杉、红松林,木贼、毛榛子、东北红豆杉、冷杉、红松林,羊胡子苔草、毛榛子、东北红豆杉、冷杉、红松林4个类型。DCA排序较好地验证了TWINSPAN的数量分类结果,DCA排序的第一轴基本上反映了群落随坡位和坡度的变化趋势,第二轴基本上反映了群落随海拔高度和坡向的变化趋势。CCA排序结果表明,海拔、坡位和坡度依次是限制东北红豆杉生存群落分布的主要生态因子,并进一步量化了群落类型随上述生态因子变化的状况。4.在天然东北红豆杉的生活史中,生殖生长最为旺盛的时期为胸径（DBH）20cm～60cm的区间。调查样株中,胸径10cm以上各径级的开花株数与未开花株数的比例大致为1:1,开花植株的雌雄比例接近1:2,开花植株中胸径最小的是雄株,胸径为1.5cm。大小孢子叶球多着生在当年生小枝上,其数量在林冠层由上至下明显递减,小孢子叶球数量约为大孢子叶球数量的1.5～5倍。大小孢子叶球的数量在东南西北四个朝向上的分布呈现相反的规律,即东向和南向的大孢子叶球数量分别高于西向和北向的数量,而西向和北向的小孢子叶球数量分别高于东向和南向的数量。调查的大小孢子叶球数量随胸径增加呈指数增长,大、小孢子叶球数量与胸径之间,分别符合♂株Y=8.0021X^2.3872（R=0.8755,P＜0.001）和♀株Y=2.5892X^2.3826（R=0.6871,P＜0.001）的幂函数模型。天然东北红豆杉种子的千粒重在45.41g—55.60g之间,较少受胸径、坡向、坡位等因子影响。种子的含水率和胚发育,年度间差异明显。粗脂肪、粗蛋白和淀粉3类物质为东北红豆杉种子的主要成分,与同属的南方红豆杉相比,东北红豆杉种子所含的可溶性糖类、淀粉和粗蛋白均高于南方红豆杉。土壤中东北红豆杉种子的数量在东南西北四个方向上的分布无显著差异,在距母树最近的1m范围内,种子数量最多,随着距母株距离的增加,种子数量有减少的趋势。土壤中种子数量随土层深度增加明显减少,5cm以上土层中集中了最大量的种子（83.97%）。土壤中种子损失的主要因素来自于腐烂及啃食,二者占80.46%,有活力的种子数量非常少,不到土壤中种子总量的1%。5.天然东北红豆杉年轮与区域气候重建的相关研究表明,东北红豆杉每年的径向生长主要受生长季前期（前一年10月到当年1月）和生长期的春季最低温度影响,而降水影响相对较弱。利用东北红豆杉年轮指数重建黑龙江穆棱地区近300年的春季最低温度,重建方程是:Y=8.6564X-30.23（F=20.67,P＜0.0001,r²=0.32）,该方程得到的重建值与实测值趋势和极值基本吻合。黑龙江穆棱地区在过去300年间,可能受ENSO、亚洲季风和太阳黑子周期性活动的影响,春季最低温度存在较为明显的周期性变化规律,变化周期基本符合2—4年和8年两个周期类型,个别时段存在20年的长周期。更多还原

【Abstract】 The Japanese yew（Taxus cuspidata Sieb.et.Zucc.） is a survivor tertiary species and national level endangered species.Study on the natural population ecology of Japanese yew will be helpful to reveal its endangered mechanism,and it is greatly important in theory and applied values on conservation,plantation and restoration of the population effectively.This study revealed corresponding regulations about the scalar and stucture characteristics, intraspecific and interspecific competition,community characteristics,reproductive and treering characteristics of Japanese yew population.The results showed:1.Although the scalar of natural Japanese yew population in Muling Nature Reserve was pretty large,the age structure of the natural population was not optimal.The number of seedlings（76.81%） and trees（20.87%） was much more than that of saplings（2.32%）,and the trees were mostly old.This kind of structure would affect the population development in the future.The scalar of Japanese yew（Taxus cuspidata） population and the relationship between individual distribution and site factors were analyzed,The result showed that the distribution rules of Japanese yew population were correlated to elevation, slope position,slope aspect and slope gradient.The optimal distribution range in elevation for the natural Japanese yew population was at the attitudes of 700-800 m.The amounts of Japanese yew individuals on shady slope were more than those on sunny slope.On top slope and mid-slope,the individual amounts of Japanese yew were more than those on toe slope.Most of Japanese yew individuals occurred on slope gradient of less than 15.The scalar of the population was decreased with the slope gradient increasing.2.The intraspecific competition of Japanese yew population was weak,accounting for 4 percent of total competition,and the main stress to the Japanese yew population came from interspecific competition,which accounted for 96 percent of the total.The main competitors were the dominant species of the zonal vegetation types,including Abies nephrolepis,Tilia amurensis,Acer mono and Pinus koraiensis.The competition intensity of Japanese yew declined with increasing DBH,and the stress was more intense for trees less than 20 cm in DBH.The relationship between competition intensity and individual growth of target trees followed the equation y = 289.03x^-1.5012.Along the site gradient such as elevation,slope gradient,slope aspect and slope position,the competition intensity and competitor type changed notably.3.Quantitative classification（Two-way Indicator Species Analysis.TWINSPAN） and ordination analysis（detrended correspondence analysis,DCA:canonical correspondence analysis,CCA ） were used to examine the ecological characteristics of Japanese yew communities.From TWINSPAN analysis,we classified the 72 plots into 4 types,that was Dryopteris crassirhizoma-Corylus mandshurica-Taxus cuspidata-Abies nephrolepis-Pinus koraiensis,Athyrium multidentatum-Corylus mandshurica-Taxus cuspidata-Abies nephrolepis-Pinus koraiensis,Hippochaete hyemale- Corylus mandshurica- Taxus cuspidata-Abies nephrolepis-Pinus koraiensis,Carex callitrichos- Corylus mandshurica-Taxus cuspidata-Abies nephrolepis-Pinus koraiensis.The DCA analysis provided us with similar results.Both classification and ordination analysis of the plots reflected the spatial distribution of shrub communities.The first axis of DCA appeared to be related to slope position and slope gradient,the second axis to the changes of elevation and aspect.The result of CCA showed,elevation,Slope location and slope gradient were three important factors restrict the distribution of Japanese yew communities,and reflected the relationships between community types and ecology factors.4.In the life history of Japanese yew population,the hearty reproduction for tree was during 20cm～60cm in DBH.The number of blooming individuals was about the same as that of unblooming individuals for sampled trees more than 10cm in DBH,the ratio of blooming female and male was near to 1:2,a male tree with 1.5cm in DBH was the youngest blooming tree.Most of female and male strobilus grew in young twigs,The quantity of female and male strobilus in crown declined downward,and the quantity of male strobilus was about 1.5～5 times than that of female strobilus.The quantity of female strobilus in east and south crown more than that of in west and south crown,the quantity of male strobilus was on the contrary.The relationship between quantity of male strobilus and DBH of male trees followed the equation:Y = 8.0021X^2.3872（R = 0.8755, P<0.001）,for female trees it followed the equation:Y= 2.5892X^2.3826（R = 0.6871, P<0.001 ）.1000-seed weight of Japanese yew was 45.41g～55.60g,and hardly affected by trees in DBH,slope aspect and slope position.Seed moisture content and embryo development varied in different years.Crude fat,crude protein and starch were main components in the seeds.The contents of soluble carbohydrate,crude protein and starch in Japanese yew seeds were higher than that of in Taxus mairei.The quantity of Japanese yew seeds in soil existed unnotably variance in orientation,most of them existed in the range of 1m to the female trees,and the quantity decreased with the distance increasing. The quantity of Japanese yew seeds in soil declined following the depth increasing,most of them（83.97%） existed in soil less than 5cm in depth.The most important factors affecting soil seed bank were predation by insects and animals,the proportion of the viable seeds accounted for less than 1%.5.Based on the relationship between the tree-ring data and temperature from 1961 to 2004of Muling in Heilongjiang Province,the minimum spring temperature from October of prior year to January of current year was the primary factor affecting radial growth of Japanese yew,and annual precipitation was a relative lesser factor.the minimum spring temperature was reconstructed for 300 years from 1700 to 2004 using a standard tree-ring chronology of Muling in Heilongjiang Province,the equation was Y=8.6564X-30.23（F = 20.67,P < 0.0001,r²= 0.32 ）,the retrieve values matched the measured values in tendency and the extreme values basically.In the past 300 years in Muling,the minimum spring temperature existed obviously periodical change with periods of 2-4 years and 8 years,it had also longer periods of 20 years in a few series,this might be affected by ENSO,Asian Monsoon and abnormal activities of macula.更多还原