<正>在云南元谋县的干热河谷引种了9个木麻黄种和1个无性系，并比较它们的生长情况。结果表明：短枝木麻黄、细枝木麻黄和肥木木麻黄的树高生长最好，粗枝木麻黄的树高生长最差。造林1年和2年后都以短枝木麻黄的保存率最高，轮生木麻黄的保存率最低。综合树高及保存率两个生长指标，短枝木麻黄可作为云南干热河谷造林树种进行进一步推广试验。木麻黄接种Frankia菌后造林的试验结果表明，接种Frankia固氮菌后对木麻黄树高生长有极显著影响。

Platycladus orientalis and Pinus tabulaeformis are the most important tree species in limestone mountains region. The method used here is to choose the single-species wood to build the math model to measure the biomass per hectare. By using Area Proportion Method to measure the biomass of shrub and herbaceous plant under the tree, the biomass of arbor layer and shrub herbaceous layer from the interblending trees and single-species wood was calculated and analyzed respectively. It showed that the biomass of arbor layer and shrubt; erbaceous layer from the interblending trees was lower than single-spedes wood respective ly. The total biomass, however, of the interblending trees was far higher than single-species wood, which suggested that the policy makers take the interblending trees as the way to afforest in calcareous mountains.