新疆西天山峡谷不同坡向野核桃幼苗种群动态及生长分析

Population dynamics and growth of Juglans cathayensis seedlings of different slope aspects in the west Tianshan valley in Xinjiang,China

在非破坏性判定幼苗年龄及大样方逐苗调查的基础上,编制了新疆西天山峡谷不同坡向野核桃幼苗种群静态生命表,分析了幼苗株高的数量特征和生长规律。结果表明：不同坡向野核桃幼苗的期望寿命均以1龄最大,阳坡为2.018,阴坡为1.766,1～6龄普遍为阳坡大于阴坡。不同坡向幼苗种群均以1龄个体数量所占比率最大,阳坡为39.7%,阴坡为44.2%;3龄幼苗死亡率均最高,阳坡为82.0%,阴坡为78.3%;均为增长型年龄结构;存活曲线均趋于Deevey-Ⅱ型。1龄幼苗在阳坡和阴坡分别仅有3.3%和1.1%可以存活到7龄。不同坡向幼苗株高随着年龄的增加均为指数函数异速生长,其模型的生长速度（b值）也大体相同。

On the basis of the non-destructive determination of seedling age and survey one by one in plots, the static life table of Juglans cathayensis of different slope aspects in the west Tian- shah valley in Xinjiang was established, and the quantitative characteristics of seedling height and the growth patterns were analyzed. Results showed that the seedling life expectancy of different slope aspects was longest in the 1st age class, being 2. 018 on the sunny slope and I. 766 on the shady slope. The seedling life expectancy was generally higher on the sunny slope than on the shady slope in the 1st to 6th age classes. The proportions of the seedling population number of different slope aspects were largest in the 1st age class, being 39.7% on the sunny slope and 44.2% on the shady slope. The mortality rates of the seedlings were highest in the 3rd age class, with 82.0% on the sunny slope and 78.3% on the shady slope. The age structure of the seedling population was of an expanding type, and the survival curve tended to be of Deevey-Ⅱ type re- gardless of slope aspects. The seedlings could survive only 3.3% on the sunny slope and 1.1% on the shady slope from 1 st to 7th age class. The seedling heights followed an allometry of the exponent function with the age classes, and the growth rate （ b value） of the model was substantial- ly the same regardless of slope aspects.