青海湟水河流域退耕还林地沙棘林生物量研究

Study on the Biomass of Hippophae rhamnoides L.-Forest on Converted Land in Huangshui River at Qinghai Province

基于标准株全收获法和平均生物量法,对青海湟水河流域退耕还地沙棘林生物量研究表明:生物量变幅在1895.94～17219.54kg/hm2,地上部分占56.20%～79.25%、地下部分占20.75%～43.80%。各器官生物量分布比例也不同,其顺序是根>枝>干>叶。生物量与树高、地径、冠幅具有协同现象。生物量随树龄的增长符合Logistic生长模型,8a沙棘生长最快、经济系数最大,应适时间种或平茬等措施抚育林分。不同立地条件生物量亦存在较大差异,平坡>陡坡>斜坡>缓坡,半阴坡>阴坡>半阳坡>阳坡,下坡>脊部>中坡>上坡,黑钙土>棕钙土>栗钙土,盖度密>中>疏。降雨量、土壤水分含量与生物量变化一致,水分有效性高的种群,地上生物量所占比例大,单轴型个体多,觅养生长格局倾向于聚集型;水分有效性低的种群,地下生物量所占比例大,合轴型个体多,觅养生长格局倾向于游击型。

Based on the harvesting of standard trees in sample plots,biomasses of HippophaerhamnoidesL.forest on converted land was studied in Huangshui river at Qinghai province.The results showed that its biomass ranged from 1 895.94kg/hm2 to 17 219.54kg/hm2.The ration of the biomass of above ground parts is 56.20%～79.25%,and the others is 20.75%～43.80%.The biomass distributing sequence of different organs is roottrunkbranchesleaves.There is a synergistic phenomenon between its biomass and its height,diameter and crown width.The law of biomass increased with the age is consistent with the Logistic growth model,in which 8ais the fastest growth,the biggest economic factor,and the best period for stand tending.The biomass changes under different site conditions are quite different.Rainfall,soil moisture content and biomass changes were consistent.The single genotype,the ration of the biomass of above ground parts and the index of clonal growth form of the population at high level of soil moisture supply were higher than that of the population at low level of soil moisture supply.