【摘要】 采用标准株收获法对西北半干旱半湿润地区的沙棘(Hippophae rhamoides L.)灌木生物量进行了测定,结果表明由于不同地区气候和土壤条件的差异导致了沙棘生物量亦存在较大的差异:生物量中树干所占的比率随树龄的增长先增大后减小,枝条所占比率相对保持稳定,叶子所占的比率则随树龄增大而减小;生物量的茎根比随树龄的增长而增大,且与各地区降水量呈正相关;根系的分布一般较浅,大约有65.66%-79.95%的根系生物量分布在0-15 cm的土壤表层,而且在径级为Φ>4 cm和Φ=1-2 cm根系上的分配比例占到总量的1/2以上;根系长度在径级Φ<0.5 cm的毛细根上的分配占到根系总长的64.894%-80.09%;根瘤的数量在6-10龄沙棘上分布最多,且主要分布于0-15 cm土层和径级Φ<1.0 cm的细根上。此外,沙棘地上部分生物量可用生长因子或立地因子两种模型进行预估,而且在各立地因子中,区域气候和土壤条件对其生物量的影响最为显著,其次为坡向和坡位,坡度的影响最小。更多还原

【Abstract】 Biomasses of Hippophae rhamoides L.in semi-arid and semi-humid area of northwest China had been widely measured with the method of harvesting of standard trees in sample plots.The results show that the biomass varied greatly between different areas due to the differences of climatic and soil conditions.Within the biomass of total tree,the allocation in trunk increases firstly and then decreases,and it in branches conserves relative stable,while it in leaves decreases with the age of trees.The ratio of stem/root of biomass increases with the age of trees and is positively related to the precipitation of different zones. The distribution of roots in soil is generally shallow and there is about 65.66%～79.95%of roots concentrated in top soil of 0～15cm and the biomass allocations in roots of >4cm and =1～2cm take about a half of the total roots.The allocation of root length in thin roots of <0.5cm is about 64.894%～80.09% of total.The root nodules grow mostly on trees of 6～10 year old and are mostly distributed on roots of <1.0cm and in top soil of 0～15cm.In addition,the above-ground biomass of H.rhamoides can be estimated with both growth-factor model and site-factor model.Among the influencing factors of biomass,the zonal climatic and soil factors affect strongly and then is aspect and location of slope,except the factor of gradient of slope.更多还原