不同演化阶段白刺灌丛沙堆土壤生态化学计量特征

Characterization of the Soil Ecological Stoichiometry of Nitraria tangutorun Nebkhas During Different Succession Stages

为了阐明灌丛沙堆发育对土壤碳(C)、氮(N)、磷(P)生态化学计量特征的影响,以吉兰泰荒漠区不同演化阶段白刺(Nitraria tangutorun)灌丛沙堆为研究对象,研究0—100 cm土层土壤C∶N∶P化学计量特征在不同演化阶段的变化规律和垂直分布规律。结果表明:(1)白刺灌丛沙堆土壤有机碳(SOC)、全氮(TN)和全磷(TP)随演化阶段(雏形阶段→发育阶段→稳定阶段→衰亡阶段)的变化呈先增后减的变化趋势。演化阶段对白刺灌丛沙堆SOC影响显著(P<0.05),对TN、TP无显著影响(P>0.05),其SOC、TN、TP均值含量在0—100 cm土层分别为0.42~0.58,0.04~0.07,0.22~0.25 g/kg,远小于全国土壤平均水平(11.12,1.06,0.65 g/kg)。(2)白刺灌丛沙堆SOC、TN、TP含量及其生态化学计量比随土层深度增加无明显规律性。(3)土壤SOC、TN、TP含量及其生态化学计量比均属于中等变异,且变异系数随白刺灌丛沙堆演化不断减小。(4)土壤容重、毛管孔隙度、非毛管孔隙度对白刺灌丛沙堆土壤TN、C∶N、N∶P影响显著,而土壤含水量、pH对白刺灌丛沙堆SOC、TN、TP含量及其生态化学计量比无显著影响。各演化阶段白刺灌丛沙堆SOC、TN是调控白刺灌丛沙堆土壤生态化学计量比的主要因素。因此,该研究结果明晰了白刺灌丛沙堆土壤C∶N∶P生态化学计量特征对不同演化阶段的响应,为该区域白刺群落的保护、利用和植被恢复与重建提供科学依据。

To investigate the effect of development stage on soil C∶N∶P stoichiometry characteristics of Nitraria tangutorun nebkhas.Taking Nitraria tangutorun nebkhas at different development stages(for rudimental stage,developinGstage,stabilizinGstage and degradinGstage)in desert area of Jilantai as research object,and measure vertical distribution of soil C∶N∶P stoichiometry from 0 cm to 100 cm in depth under Nitraria tangutorun nebkhas.The results showed that:(1)Soil organic carbon(SOC),total nitrogen(TN)and total phosphorus(TP)showed first increased and then decreased with the succession of N.tangutorum nebkhas(rudimental stage→developingstage→stabilizingstage→degradinGstage).The effect of succession stage on SOC was significant(P<0.05),but not on TN and TP(P>0.05).The contents of SOC,TN and TP in the four stages of evolution were 0.42~0.58 g/kg,0.04~0.07 g/kg and 0.22~0.25 g/kg in 0—100 cm soil depth,respectively,and the contents was far less than national average levels(11.12,1.06,0.65 g/kg).(2)There was no obvious change rule for the contents of SOC,TN,TP and soil C∶N∶P stoichiometry in the four succession stages of Nitraria tangutorun nebkhas decreased with the increase of soil depth.(3)The content and stoichiometry of SOC,TN and TP belonged medium variability,and which decreased with the increase of soil depth.(4)Soil bulk density,soil capillary porosity and non-capillary porosity had significant effect on TN,C∶N,N∶P,and soil water content and pH had no significant effect on the contents of SOC,TN,TP and soil C∶N∶P stoichiometry.Confirm the importance of SOC and TN in regulating the soil C∶N∶P stoichiometry of Nitraria tangutorun nebkhas.Therefore,the presenTresults clarify the response of C∶N∶P stoichiometry of Nitraria tangutorum to different succession stages.It provides scientific basis for the protection,utilization and vegetation restoration and reconstruction of Nitraria tangutorum community in this area.