桂西南石漠化区蚬木林土壤呼吸空间变异研究

Spatial variation of soil respiration in Excentrodendron hsienmu forest in karst area in southwestern Guangxi,China

通过对石漠化区蚬木林土壤呼吸及其影响因子的测定和分析,研究蚬木林土壤呼吸的空间变异性。结果表明:随取样面积增大,土壤呼吸速率变异系数从25.64%增至48.48%;土壤呼吸空间变异幅度为46.84%,高于其他环境因子,土壤温度和pH变异幅度最小。土壤呼吸仅与土壤温度间存在显著相关关系,与其他因子无显著相关性。在95%置信水平、85%估计精度下,蚬木林土壤呼吸测定取样需大于37个,而土壤温度、土壤pH仅需1个取样即可,样本容量计算可明显降低取样工作量。

Soil respiration has obvious spatial variation in different scale.The soil respiration and its control factors were measured to detect the soil spatial variation in an Excentrodendron hsienmu forest in karst area.The results show that soil respiration rate has the largest variable coefficients than the other environment factors;pH and temperature of soil have the smallest variable coefficients.Soil respiration has the significant relationship with soil temperature,and no significant relationship with the other factors.To satisfying a95%confidence level and85%sampling precision,there are37samples needed to be measured for soil respiration at least,and only1samples for soil temperature and pH respectively.The calculation of sample capacity can reduce the sampling work in future.