不同苗龄云南松苗木平茬根系形态特征分析OA北大核心CSTPCD

[Objective]This study aims to analyze root morphological characteristics of Pinus yunnanensis seedlings after stumping at different ages,and to provide evidence for selecting suitable stump-age.[method]Taking P.yunnanensis seedlings aged 6,10,14,18 and 30 months as materials,all seedlings were pruned to a uniform height of 5 cm.The root morphology and biomass were measured at 60,120,180,240,300,360,420,and 480 d after stumping,and the root structure of different seedling ages of P.yunnanensis after stumping was analyzed.[Result]Stumping at different seedling ages significantly affected the root morphological characteristics of P.yunnanensis seedlings(P＜0.05).At 480 days after stumping,the seedlings stumped at 6 months had smaller average root diameter(0.825 mm)and root volume(4.435 cm3)compared with those stumped at 30 months,which had an average root diameter of 1.302 mm and root volume of 16.282 cm3,but the total root length was larger.The specific root length for 6 to 30-month-old stumped seedlings showed a decreasing tendency,and the root specific surface area,root tissue density,and root fineness of the seedlings stumped at 6 months were significantly greater than those of the seedlings stumped at other ages(P＜0.05),showing a decreasing trend with increasing seedling age.There was no significant difference in the growth rate of average root diameter,root volume,and root biomass,while total root length,root surface area,and root biomass showed a trend of decreasing growth rate with increasing seedling age.[Conclusion]Younger seedlings build finer and denser root systems,which is conducive to the absorption and utilization of water and nutrients.The seedlings aged 6 months showed the best effect of stumping.[Ch,2 fig.5 tab.40 ref.]