濒危植物翠柏为柏科高大珍贵用材树种,通过对翠柏主要分布区墨江、昌宁翠柏植株树干解析,研究了两地翠柏的生长特性,结果表明:(1)翠柏在20年前生长缓慢,20—60年进入快速生长期,70年以后达到数量成熟,材积生长量开始下降并趋于稳定;(2)翠柏幼苗期具有耐荫性和长大后有喜光特性,墨江地区翠柏生长好于昌宁地区,其生长表现与两地自然条件相符合;(3)针对翠柏特点,提出幼苗时搭建荫棚,幼树时期进行疏伐,数量成熟时期进行间伐或疏伐等促进生长经营措施,为翠柏资源培育与保护奠定基础。

The annual growth rhythm of Litsea cubeba seedling was studied. The average thousand-grain weight of L. cubeba was 35 g, and the germination rate was higher than 70%. The results of cluster analysis showed that, the growth period could be divided into 4 stages, i.e. the stage of seedling emergence (from March 2 to March 17), the initial stage of growth (from March 18 to May 31), the vigorous growth stage (from June 11 to August 29) and the late growth stage (from August 30 to December 27). The height and diameter of one-year-old seedling were fit with logistic curve law, and the growth process followed a "slow-fast-slow" curve. The equation of average daily growth showed that the fastest growth appeared in July which had the highest monthly average temperature. This conclusion provided a reference for the seedling stage management of L. cubeba forest. The authors recommend vigorously developing L. cubeba forest in the mountainous area of Guizhou Province, and providing scientific and technological support to the forest tenure reform.

目的 探究云南松林结构调整对林木生长和土壤性状的影响，为云南松林保护和利用提供科学依据。 方法 按照森林抚育规程对林分进行结构调整，采用典型取样法对比分析林分结构调整前后土壤性质和林木生长状况的差异。 结果 云南松林结构调整后，（1）结构调整样地单株蓄积量比对照样地提高了近60%，树高和胸径提高幅度均在15%以上，林下天然更新植株数量是对照样地的3.1倍；（2）结构调整后林内植物种类增加，林下灌木层和草本层盖度分别提高了63.3%和22.7%，灌木层和草本层平均高度分别提高了24.7%和17.9%；（3）结构调整样地现存凋落物量显著下降，与对照相比下降了20.4%，土壤表层温度、有机质含量、基础呼吸和土壤微生物生物量显著提高，土壤其他性质参数变幅相对较小。 结论 林分结构调整可显著提高云南松生长量，有利于云南松较大径级林木的培育；促进了云南松林下更新和林下植被发育，有利于林分群落结构的形成；提高了土壤微生物数量和活性，加速了土壤有机质转化，研究揭示林分结构调整促进了云南松林土壤-植物系统正反馈作用。

滇榄仁为金沙江干热河谷特有的一级标志种，常与乡土草本植物扭黄茅形成“稀树草丛”景观。长期以来，滇榄仁幼苗极少能在自然群落中成功建植。为了探讨扭黄茅竞争对滇榄仁幼苗早期生长和存活的影响，通过室内盆栽实验人为控制滇榄仁幼苗与扭黄茅之间的竞争强度，研究了扭黄茅竞争对滇榄仁幼苗形态、生物量积累与分配以及叶片数量与大小等特征的影响。结果表明，扭黄茅竞争严重限制了滇榄仁幼苗的早期生长。当存在扭黄茅竞争时，滇榄仁幼苗的生物量分配格局发生了较大变化，根冠比变化范围为0.42~0.62之间。无论滇榄仁幼苗延后定居、同时定居或提前定居，其根系长度以及生物量干质量均会因为受到限制而缩短或减少。然而，定居时间在滇榄仁幼苗存活与生长状况中扮演了一个极为重要的角色。提前定居时，滇榄仁幼苗根冠比远高于同时定居和延后定居时，且其根冠比不受扭黄茅竞争强度的显著影响，表现出了较强的竞争力。