石漠化地区先锋树种茶条木伐桩的萌蘖特性

The stump sprouting characteristics of the pioneer tree Delavaya toxocarpa in rocky desertification region

为探讨石漠化地区先锋树种茶条木伐桩的萌蘖特性,以砍伐强度和伐桩高度为因子,研究了茶条木在不同砍伐强度(全伐和择伐)和伐桩高度(20、40和60 cm)处理下的伐桩存活情况,以及萌条的数量和生长量等特征。结果表明:砍伐近1年后茶条木伐桩的萌蘖率和存活率分别为99.24%和88.55%,其中伐桩存活率显示择伐大于全伐、高桩大于低桩并与伐桩基径大小呈一定程度的正相关。茶条木伐桩萌蘖具有较强的季节性,萌条死亡率较高,单个伐桩的萌条总数和萌条存活率分别为7.3个和54.9%,两者在砍伐强度相同时随伐桩高度增加而增大。主萌条的平均株高和平均基径分别为168.7 cm和12.38 mm,伐桩萌条平均生长率为40.8%,三者均表现出全伐时随伐桩高度增加而增大、择伐时随伐桩高度增加而下降的特点。根据试验观察结果并结合石漠化区植被恢复的需要,择伐和留桩20 cm是茶条木比较理想的砍伐利用方式。

In order to explore the stump sprouting characteristics of a pioneer tree, Delavaya toxocarpa, in rocky deserti.fication region, the present study investigated the survival percentage of the stumps, sprout number and sprout growth in.crement under different cutting intensity （ clear cutting and selective cutting） and stump height treatments （ 20, 40 and 60 cm） . The results showed that the sprouting rate and survival percentage after one.year cutting were 99. 24% and 88.55%, respectively. The survival percentage of stumps indicated the trends that selective cutting was greater than clear cutting, the higher stump was greater than lower stump, and there was a positive relationship between base diameter and the stump survival percentage.The number of sprouts produced by stump changed with seasons, and the mortality rate of sprouts was high. The average number of sprouts produced by per stump and the survival percentage were 7. 3 and 54.9%, respectively. Both of them increased with the increasing of stump height under the same cutting intensity. The mean plant height, base diameter and growth rate of the biggest sprout were 168.7 cm, 12.38 mm and 40.8%, respec.tively. All of them increased by clear cutting with the increasing of stump height, and decreased by selective cutting with the increasing of stump height. According to the experimental results and the needs of vegetation restoration in rocky de-sertification region, the method of selective cutting with stump height 20 cm maight be an ideal way for logging utilization of Delavaya toxocarpa.