以内蒙古大兴安岭根河林区白桦根系为研究对象,利用解析木法与全部挖掘法测定不同树龄白桦根系生物量,研究白桦根系生物量的分配规律,结果表明:白桦根茎比在(0.1449 ±0.0439)～(0.0930±0.0090)之间变动,且随树龄增大呈减小的趋势;各龄组白桦根系小根生物量占比均较少,占比为2%～5%、中根占比为16%～26%、大根与粗根占比合计为60%～80%,证明大根与粗根是根系生物量的主要贡献者;随树龄增大,大根生物量占比不断减小,而粗根生物量占比不断提高,这可能是根系平周生长的结果。基于20株解析木数据,建立了白桦根系生物量回归模型、白桦根系生物量累计生长模型、白桦根系生物量连年生长模型,各模型均具有较高精度,在内蒙古大兴安岭林区具有可用性。

The root system of birch in the Genhe area of the Greater Hinggan Mountains region of Inner Mongolia was taken as the research object.The analytical method of wood and all mining method were used to measure different old birch root biomass to study the distribution features of white birch root biomass.The results show that ratio of root and stem of birch changes between 0.1449 ±0.0439 and 0.0930±0.0090,and has a tendency to decrease with increasing age.For each age group of birch root system small roots account for small proporation,about 2% to 5%,medium roots occupied 12% to 26%,large roots and coarse roots were main contribution part of the biomass,making up 60% to 80%.With the increase of tree age,the big root biomass proportion decreases continuously,and coarse root biomass proportion enhances unceasingly,this might be the result of roots system periclinal growth.Based on the data of 20 parse trees,birch root biomass regression model,birch root biomass accumulated growth model,birch root biomass current annual growth model was established,each model has a high precision,which can be used in the Greater Hinggan Mountains Region of Inner Mongolia.