Spatial-Temporal Variability of Caragana korshinskii Vegetation Growth in the Loess Plateau | 黄土高原柠条锦鸡儿灌木林生长的时空变异特征

Chinese. 利用宁夏回族自治区固原水平阶整地和荒坡不整地种植23年生柠条锦鸡儿灌木林的连续定位监测资料,分析不同坡位柠条灌木林幼龄期（1～7年生）、中龄期（8～15年生）和老龄期（16～23年生）生长的时空变异特征。结果表明：柠条灌木林株高生长受坡位和整地方式的影响,柠条株高生长量在幼龄期表现为下坡〉中坡〉上坡,中龄期表现为上坡〉中坡〉下坡,水平阶与荒坡株高相比,从幼龄期到中龄期提高幅度为23.48%～45.33%,老龄期差异不显著;水平阶柠条锦鸡儿单株分枝数、地径、地上生物量和地下生物量比荒坡分别提高了26.79%～78.82%,37.50%～50.00%,3.50%～91.97%和19.59%～50.17%;柠条锦鸡儿灌木林生长过程均符合Logistic生长模型;对柠条锦鸡儿各生长指标的综合分析表明,中龄期是平茬利用的最佳时期。

English. The spatial-temporal variations of Caragana korshinskii vegetation growth were investigated based on the 23 a monitoring data on fixing plots of Caragana korshinskii plantations on terrace and non-terrace barren land in Guyuan, Ningxia Hui Atonomous Region. The investigation was carried out in different slope positions and with different ages of the plantations, including young-age period （1 -7 a）, middle-age period （8- 15 a） and old-age period （16-23 a）. The results showed ： The plant height of C. korshinskii was affected by the slope position and the soil preparation methods. The change tendencies of average heights showed that lower slope 〉 middle slope 〉 upper slope in juvenile period, and upper slope 〉 middle slope 〉 lower slope in middle period. Compared with the non-terrace barren land, the plant height of leveled terrace were improved by 23.48% ~ 45.33% in both young-age period and middle-age period, while there were no significant differences in the heights in the old-age period. With the slope position increased, the individual branches number, ground diameter and biomass decreased. Compared with the non-terrace barren land, the branches number, ground diameter, aboveground biomass and underground biomass of level terrace were improved by 26.79% - 78.82% , 37.50% - 50.00% , 3.50% - 91.97% , and 19.59% - 50. 17% , respectively. The growth of C. korshinskii fit the logistic curve model. It is concluded that the best time for utilizing C. korshinskii is the middle period according to the obtained results.