东北地区樟子松根系分泌物分泌速率纬度间的差异

Variation in Root Exudation Rate of Pinus sylvestris var.mongolica among Different Latitudes in Northeast China

以东北地区露水河、帽儿山和凉水3个位于不同纬度实验地点的樟子松(Pinus sylvestris var.mongolica)为研究对象,利用根系分泌物原位收集装置收集了根系分泌物,分析3个地点间根系分泌物分泌速率的差异、分泌速率与细根特征和环境因子的关系。结果表明:3个实验地点间的樟子松根系分泌物分泌速率差异显著(P<0.05);在露水河樟子松的根系分泌物分泌速率,显著高于在帽儿山、凉水的樟子松的根系分泌物分泌速率(P<0.05);帽儿山与凉水的樟子松根系分泌物分泌速率,差异不显著(P>0.05)。3个实验地点间,樟子松的根比表面积差异显著(P<0.05)、比根尖数差异显著(P<0.05)、比根长差异不显著(P>0.05)、比根直径差异不显著(P>0.05)。帽儿山的樟子松人工林土壤有机碳和磷质量分数均为最低(P<0.05),凉水的土壤pH显著低于帽儿山和露水河的土壤pH(P<0.05)。樟子松根系分泌物分泌速率与年降水(调整后R 2=0.548,P<0.001)、年均温(调整后R 2=0.437,P=0.002)、比根尖数(调整后R 2=0.456,P=0.001)、土壤pH(调整后R 2=0.357,P=0.005)有显著的线性关系。

With Pinus sylvestris var.Mongolica in three experiment sites(Lushuihe,Maoershan,and Liangshui)at different latitudes in Northeast China,we collected root exudates and used a non-soil system to investigate the changes of root exudation rate among different latitudes and the relationship between root exudation rate and fine root traits and environmental factors.The results showed that there were significant differences in the root exudation rates of P.sylvestris var.mongolica among three experimental sites(P<0.05),the root exudation rate in Lushuihe site was significantly higher than in Maoershan site and Liangshui site(P<0.05),but the root exudation rate in Maoershan site were not significantly different from Liangshui site(P>0.05).Specific surface area(SRA)and specific root tips(SRT)of Pinus sylvestris var.Mongolica were significantly different among three latitudes(P<0.05),but specific root length(SRL)and specific root diameter(SRD)of Pinus sylvestris var.Mongolica have no significant change among latitudes(P>0.05).Soil organic carbon(TOC)and phosphorus(TP)content were lowest in Maoershan site(P<0.05).Soil pH in Liangshui site were significantly lower than in Maoershan site and Lushuihe site(P<0.05).The root exudation rate had a significant linear relationship with mean annual precipitation(MAP)(Adjust R 2=0.548,P<0.001),mean annual temperature(MAT)(Adjust R 2=0.437,P=0.002),specific root tips(Adjust R 2=0.456,P=0.001),and soil pH(Adjust R 2=0.357,P=0.005).