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选择四川省阿坝藏族羌族自治州壤塘林业局二林场3 500-3 700 m皆伐迹地上的云杉未成林造林地,逐一调查前期栽培的26株云杉幼树(年龄≤25年;树高≤4 m)生长状况(高度、生物量及其分配、基部直径、冠幅)及其共存(距离小于1 m)的5个主要灌丛的构型特征参数,评估幼树生长动态及其受灌木荫蔽的影响程度.结果表明:1)高海拔地区迹地上的云杉幼树生长十分缓慢,15-22年生时平均高仅2.23 m,平均地径仅6.23 cm,其生长过程可划分成3个不同期,即前10年生长缓慢,而后经过一个阶段的波动期,15年左右进入生长加速阶段;2)同一云杉幼树不同区分段组合的11个处理中在树高50 cm以下采用10 cm区分段而其上采用20或30 cm区分段开展幼树树干解析分析效果最佳,与实际幼树生长过程最接近,可较准确地揭示幼树高生长过程并减少分析工作量;3)高海拔地区云杉幼树生长受灌木的抑制性影响主要发生在栽培5年后,其径向生长受到灌木的抑制大于高生长,早材所受影响也大于晚材;在5类(柳、蔷薇、绣线菊、忍冬、茶藨子)灌丛中,云杉幼树长势在绣线菊灌丛下最好,而在柳灌丛下长势最差.综合分析表明,灌丛类型差异显著影响了迹地栽培的目的树种幼树后期的生长,因此栽培5-8年进行必要的割灌抚育处理是加速高海拔迹地上云杉幼树生长的重要措施.
Thirty-six spruce saplings (age≤25 years) and tree height (height) were planted one by one on the deforestation sites of 3-5 500-3 700 m in No.2 Forest Farm, Erhtang Forestry Bureau of Erbaizang and Qiang Autonomous Prefecture, ≤4 m) were used to evaluate the growth dynamics of young saplings and their effects on the growth of young saplings (height, biomass and their distribution, base diameter, crown width) and their coexistence (distance less than 1 m) The results showed that: 1) The spruce saplings on the top of the high altitude area grew very slowly with an average height of 2.23 m and an average diameter of only 6.23 cm at 15-22 years old. The growth process can be divided into 3 A period of different periods, that is, slow growth in the first 10 years, and then after a period of fluctuation period, about 15 years into the accelerated growth stage; 2) the same spruce saplings of different sections of the combination of 11 treatments at the tree height of 50 cm below 10 cm section and 20 or 30 cm section on sapling analysis of the best results, and the actual saplings closest to the growth process, can more accurately reveal the sapling growth process and reduce the workload of analysis; 3 The growth of spruce seedlings in high altitude area is affected by shrubs Mainly occurred after 5 years of cultivation, its radial growth was inhibited by shrubs more than high growth, early wood affected more than late wood; in 5 categories (willow, rose, meadowsweet, honeysuckle, tea cake shrub) , The spruce seedlings grew best under the spirea but not under the willow shrubs.A comprehensive analysis showed that the shrub type significantly affected the growth of the seedlings of the purpose tree species in the cultivated region Cultivated 5-8 years to carry out the necessary cutting and tending is an important measure to accelerate the growth of young spruce trees on high altitude land.