中文摘要：

刨花楠、山樱花、福建柏3个树种1年生幼苗为材料,对根、茎、叶生物量及不同根序细根的平均直径（D）、比根长（SRL）、根表面积（SSA）和根组织密度（RTD）等形态指标进行测定、比较、分析其不同根系细根形态特征差异,并对其根序形态特征与生物量分配关系进行分析。结果显示：（1）同一等级细根的SRL、SSA和RTD等形态指标在同一树种间变动较大;同一根序细根在不同树种之间及同一树种在不同根级之间的细根D、SRL、SSA及RTD等形态指标也存在差异。（2）不同树种幼苗的不同根序细根的D、SRL、SSA和RTD等形态指标与幼苗生物量分配关系表现不同。刨花楠与福建柏幼苗生物量分配与其2、3级细根关系密切,而福建山樱花幼苗生物量分配则主要与其1、3级细根关系紧密。研究结果表明,不同树种幼苗不同根系细根的D、SRL、SSA及RTD等形态指标存在差异,其对生物量分配的影响也各有不同。

英文摘要：

The biomass of the root, stem, leaf and the root morphological indexes of fine root orders 1-3,such as average diameter （D）, specific root length （SRL） , specific surface area （SSA） and root tissue density （RTD） were measured and analysed, with one-year tree seedlings of three life forms （ Machilus pauhoi, Prunus campanulata and Fokienia hodginsii ） in the same nursery garden, to compare fine root morphological characteristics among mot orders of tree seedlings of different life forms and its relation with the biomass allocation. The results show that： （1） The fine root SRL, SSA and RTD of the same fine mot branch order （FRBO） differed enormously among the individuals of the same tree species, The D, SRL, SSA and RTD have significant differences in the same FRI30 between the different tree species, or in the same tree species between the different FRBO. （2） The morphological characteristics of D, SRL, SSA and RTD in the different FRBO of the tree seedlings ,which one the different life forms, show different relationships with the seedling＇s biomass allocation. The seedling＇s biomass allocation is mainly close relations with its fine root order 2 and order 3 in M. pauhoi and F. hodginsii, and with its fine root order 1 and order 3 in P. campanulata instead. The research results illustrated that the biomass allocation of the different life-forms＇ tree seedlings was different influenced on the its D, SRL, SSA and RTD of the different FRBO, that also reflects the resource utilization strategy differences between different life-form species.