科尔沁沙地主要造林树种细根生物量垂直分布特征

Fine Root Biomass Vertical Distribution Character of Main Afforestation Tree Species in Horqin Sandy Land

以科尔沁沙地主要造林树种杨树、榆树、油松和樟子松细根为对象,分析各树种细根生物量的垂直分布特征,探讨其与土壤水分和有机质的关系。结果表明,科尔沁沙地主要造林树种细根生物量分布消弱系数为0.968~0.979,32 a生樟子松总细根生物量显著高于其它年龄樟子松（P〈0.05）,而同龄级树种细根总生物量差异不显著（P〉0.05）。各树种细根生物量垂直分布与土壤水分的相关性大于土壤有机质（22 a生樟子松除外）;10、22、42 a生樟子松及44 a生油松和35 a生榆树细根生物量与土壤水分呈显著正相关（P〈0.05）,而32 a生樟子松和13 a生杨树细根生物量与土壤水分呈显著负相关（P〈0.05）。以上结果表明,科尔沁沙地主要造林树种细根生物量垂直分布较深,其与土壤水分显著相关。

We studied the fine root vertical distribution characters of Populus simonii,Ulmus pumila,Pinus tabulaeformis and Pinus sylvestris var.mongolica in Horqin sandy land,and discussed the relationships with soil water and organic matter.The distribution extinction coefficient of fine root was 0.968- 0.979 for main afforestation tree species in Horqin sandy land.There was no significant difference in the total fine root biomass between the same age class tree species（P 〉0.05）,while the value of P.sylvestris var.mongolica was significantly higher at 32 years old than that at the other age（P 〈0.05）.The correlation of the fine root biomass was higher with soil water content than with soil organic matter content except 22-year old P.sylvestris var.mongolica.There were significant positive linear correlations between the fine root biomass and soil water content for 10-,22- and 42-year P.sylvestris var.mongolica,44-year P.tabulaeformis,and 42-year U.pumila（P〈 0.05）,but the relationships were significant negatively correlated for 32 years old P.sylvestris var.mongolica and 13 years old P.simonii（P〈 0.05）.The fine root biomass vertical distribution was deeper for main afforestation tree species in Horqin sandy land with significant dependence on the soil water content.