【作者】 王志高；

【导师】 王孝安；

【作者基本信息】 陕西师范大学 ， 植物学， 2004， 硕士

【摘要】 太白红杉(Larix chinesis)是分布于我国秦岭山区的特有植物，主要分布于太白山，另外在长安光头山、柞水牛背梁国家级自然保护区、洋县常青国家级自然保护区等也有少量分布。大量野外调查表明太白红杉繁殖能力较弱，自然更新能力较差，在多数地段发育不良，即使球果发育，大多于瘪无子，已被列入国家二级保护植物。因此研究太白红杉的生殖规律及其与环境间关系，对于了解太白红杉的濒危原因具有重要的意义。本文以秦岭特有植物太白红杉为研究对象，首次对其在自然分布状况下生殖构件的空间分布规律、生殖年龄、种实形态特征和数量特征、生殖值以及植株个体大小和环境因素对种子产量和种子大小的影响等生殖生态学特性进行了详细地研究。所得的主要结果如下： 1 太白红杉球花在前一年10月份开始分化，第二年春天开始生长，雌球花一般着生在2～4龄枝上，雄球花主要分布在2～6龄枝上。球花的分布不仅与枝条年龄密切相关，而且与其在冠层中着生的位置有关；雌球花主要分布在树冠中上部，而雄球花基本上是全冠位分布，树冠中下部较多。随树龄的增加，雌雄球花有向上推移的趋势，特别是在林内，球花大多着生于树冠的中上部。 2 太白红杉的平均生殖年龄为78.59龄，最小生殖年龄为28龄，最大生殖年龄为208龄。其中太白山南坡最小生殖年龄26龄、最高生殖年龄153龄、平均生殖年龄72.97龄；北坡种群最小生殖年龄29龄、最高生殖年龄208龄、平均生殖年龄92龄。海拔和年降水与平均生殖年龄呈正相关：坡度与最高生殖年龄呈正相关；最高生殖年龄与最小生殖年龄呈正相关，表明提早生殖会减少太白红杉的生殖寿命。 3 随着海拔的升高，其种子产量、种子大小、球果大小、种子数／球果、种子总重／株、球果总重／株均发生相应的变化，且与海拔均呈负相关。在形念方面，种子宽、种鳞长、种翅宽、种鳞宽、球果长、球果宽和种鳞数也与海拔呈负相关；坡度与种鳞长宽比呈负相关；年降水与球果宽呈正相关，种子长宽比和种翅长宽比与海拔呈负相关。种子长宽比和种翅长宽比与海拔呈负相关，表明种子和种翅的变异可能与种子的扩散能力有关，温度、坡度、坡向和降水也对种实形态和种实数量特征产生影响。此外，坡度与种鳞长宽比呈负相关；年降水与球果宽呈正相关。种实数量特征与海拔、坡度和坡向呈负相关，与植株年龄呈正相关，种子数／球果与1月(最冷月)均温呈正相关，与7月(最热月)均温呈负相关。声卜户种子大小与种子总数呈弱正相关，种子大小和数目不存在均衡现象。 4太白红杉的个体大小对生殖存在着显著的影响，但在不同环境条件下存在着差别。随着年龄的增大太白红杉种群的生育力逐渐增大，但是到一定年龄后开始下降，南坡和北坡情况稍有不同，南坡太白红杉70龄左右开始下降，北坡太白红杉90龄左右开始下降。种子的重量(千粒重)随着个体年龄的增大也逐渐增大，但南坡在60龄左右开始下降。 5太白红杉的生殖值与年龄有关，同时在不同环境条件下也存在着差别，太白山北坡各龄级的生殖值比南坡高，剩余生殖值随年龄下降的速度比南坡小，北坡的生殖适合度比南坡高，第I一VII龄级之间北坡的剩余生殖值要比南坡高，第珊龄级后由于下降速度较快，其值要比南坡小。更多还原

【Abstract】 Larix chinensis is mainly distributed in Mt.Taibai, Shaanxi.lt is also scattered in other areas, such as Mt. Guangtou in Chang’an, Changqing National Nature Reserve in Yang County and Niubeiliang National Nature Reserve in Zhashui county. It is endangered in natural conditions. The main purpose of this thesis is to explore the reason why it was endangered from the angle of reproduction. Reproductive characters of Larix chinensis in were studied, including the spatial distribution of reproductive module, reproductive age, morphological and quantative characters of seeds and cones, reproductive value, the influences of plant size to fecuntity and seed size. The main results are following:1 The strobiles of Larix chinensis begin to differentiate in October, and develop next year. The female strobiles are located at the branch of 2-4 years old, and the male strobiles at the branches of 2-6 years old. The distribution is related not only to the age of a branch, but also to the place which growthed in the crown of a tree. The female strobiles are in the middle and uper layer of the crown. The male strobiles are much more in the middle and down layer. With the age increasing, the distribution of the strobiles has the trend of going up. Especilly inside the forest, almost all of the strobiles are in the upper layer.2 The average reproduction age is 78.59 years, the minimum reproduction age is 28 years, and the maximum reproduction age is 208 years. In south slope, the average reproduction age is 72.97years, the minimum reproduction age is 26 years, and the maximum reproduction age is 153 years. The average reproduction age is 92 years, the minimum reproduction age was 29 years, and the maximum reproduction age is 208 years in north slope. The average reproduction age shows positive correlation to altitude and annual precipitation, the maximum was positive correlation to slope, and negative correlation to minimum reproduction age, this demonstrates that the earlier reproduction decrease the time of reproduction.3 The fecuntity, seed size, cone size, NSC, TW, TWC show negative correlation toaltitude. The seed width, scale length, seed wing width, scale length, cone length, and the number of scale also are negative correlation to slope, The seed length to width and the seed wing length to width show negative to altitude, this means the variation of seed and seed wing is related to the diffuse of seeds. Temperature, slope and slope directionalso have influences on seed and cone morphlogy and quantative characters. SCLW is negative to slope; the cone width is positive to annual precipitation. The quantative characters of seeds and cones is negative correation to altitude, slope and slope direction, while positive to plant size. The seed number in cone showed positive correlation to mean temperature in January, and negative to mean temperature in July. The size of seed show positive correlation to the total number of seeds. There is no trade-off between the size of seed and the total number of seeds.4 Reproduction of Larix chinensis are influenced greatly by plant size. But the fecundity increases with the age while descent at 70 years old in south slope and 90 years in north slope. It also increases with altitude, but in north slope it was beginning to decent at about 3 300 m. The seed weight becomes heavier with the age increasing. But it becomes lighter in South Slope after 60 years old. With the altitude increasing, the seed weights become heavier at first, then lighter, but it become lighter at lower altitude in north slope.5 The reproductive value is correlated to age, but there are differences in different conditions. The reproductive value of north slope is higher than South slope, and the reproductive fitness is also higher in north slope. Before VII age class the RRVis higher in North slope, But the speed ofRRV descending with the age is faster in South slope.更多还原