云南红豆杉人工林萌枝特性

萌枝是许多木本植物维持种群稳定和延续的重要机制之一。本文通过对云南红豆杉人工林萌枝情况的调查,分析了云南红豆杉萌枝特征及其对生长的影响。结果表明：（1）云南红豆杉萌枝现象明显,萌枝率达到88.1%,萌枝类型有树基萌枝和树干萌枝两种,其中树基萌枝是最主要的类型,有树基萌枝的个体达到了总株数的80.0%,树干萌枝率仅为39.6%,约为树基萌枝率的一半,两种萌枝都有的比率为31.5%;（2）云南红豆杉的树基萌枝数量与树高呈正相关关系,与地径呈负相关关系,而树干萌枝数量与树高和地径都没有显著的相关关系。总萌枝数量与树高及地径的相关关系与树基萌枝的一样,但相关性略低。（3）树基萌枝和树干萌枝都会影响云南红豆杉枝叶的空间分布格局,但从植株总体上说,它们对云南红豆杉的枝叶生长量没有显著的影响。

Sprouts characteristic structure of Taxus yunnanensis plantation

Sprouting regeneration is one important mechanism of many woody plants, it plays an important role in the process of maintaining population stability and continuity. Sprouting is a part of "regeneration niche" and a highly evolutionary labile trait of many ancient plant species, it has important physiological function on the regulating of plant individual life history strategies. Taxus yunnanensis is one of the relic species of the Tertiary Period and also is the endangered plants. Taxus yunnanensis is the first-class protective plants in China, which is mainly distributed in Yunnan, Sichuan, Chongqing and Tibet.In this paper, the sprouting phenomenon of six-year-old artificial cultivated Taxus yunnanensis was investigated. Its occurrence mechanism was also studied. Simultaneously, we analyzed the reasons spatial distribution of branches and leaves was affected by different sprouting types. The results showed that: (1) The sprouting phenomenon of Taxus yunnanensis was very obvious, sprouting rate was up to 88.1%. Taxus yunnanensis had two sprouting types, they were stem basal sprouts and stem epicormic sprouts. Of the two, stem basal sprouts was the more important one, it reached 80.0% of total quantity, while stem epicormic sprouts only occupied 39.6%, only about half of the rate of stem basal sprouts, 31.5% of these surveyed trees had both stem basal sprout and stem epicormic sprout. (2) Correlative analysis showed that there was a positive correlation between the quantity of stem basal sprouts and height, a negative correlation between the quantity of stem basal sprouts and collar diameter. Nevertheless, neither height nor collar diameter had significant correlation with the quantity of stem epicormic sprouts. Total sprouts number and stem basal sprouts had the same relationship with height and collar diameter, but the correlation coefficients of the former were slightly lower. (3)Both stem basal sprouts and stem epicormic sprouts changed spatial distribution pattern of branches and leaves, however, as a whole, sprouts number did not have significant influence on the output of the weight of branches and leaves, in other words, neither of these two sprouting types had too much relationship with the yield of the whole tree.Our experiment results collectively suggest that the state of sprouting had a notable effect on the growth and developmental tendency of Taxus yunnanesis. However, the current study did not make it clear what is the influence factor of the sprouting situation. In order to fully function the part sprouting plays after interference of Taxus yunnanesis, future research need to find out every possible influencing factor. Furthermore, the study on sprout regulating should be carried out, it's a promising way to promote the production of branches and leaves.