锐齿栎林土壤呼吸对土壤水热变化的响应  

Response of Soil Respiration to Soil Temperature and Moisture Regimes in the Natural Forest of Quercus aliena var. acuteserrata

作　　者：常建国[1] 刘世荣[1] 史作民[1] 康冰[2] 陈宝玉[3] 

机构地区：[1]中国林业科学研究院森林生态环境与保护研究所 [2]西北农林科技大学生命科学学院,杨凌712100 [3]北京师范大学生命科学学院,北京100875

出　　处：《林业科学》2006年第12期21-27,共7页Scientia Silvae Sinicae

基　　金：中国杰出青年基金资助项目(30125036);国家林业局948引进项目(2004-4-36;2004-2007);宝天曼森林生态站资助。

摘　　要：按照5个土壤含水量（0．20、0．25、0．30、0．35、0．40kg·kg^-1）和5个温度（15、20、25、30、35oC）梯度设计试验，对取自北亚热带-暖温带过渡区锐齿栎（Querctts aliena var．acuteserrata）天然林中0～20cm的原状土柱进行恒温培养和呼吸速率测定。结果表明：土壤温度、含水量及二者的交互作用都对土壤呼吸速率产生显著影响（P〈0．01）；土壤呼吸速率与土壤温度呈正相关，随土壤含水量增高的变化规律为单峰曲线，含水量为0．20～0．35kg·kg^-1时土壤呼吸速率随含水量的增加而增加，0．35kg·kg^-1时土壤呼吸速率最高，0．35～0．40kg·kg^-1时随含水量的增加土壤呼吸速率下降，是对土壤呼吸产生抑制的土壤含水量临界点；锐齿栎林土壤呼吸Q10值的变化范围为1．36～3．10，平均为2．13，Q10随土壤温度的升高而下降，随含水量增加的变化趋势与土壤呼吸速率一致；土壤含水量0．35kg·kg^-1和土壤温度35℃结合下的土壤呼吸速率最高；回归关系表明土壤呼吸速率与土壤温度呈显著的指数函数关系（P〈0．01），与土壤含水量呈二次函数关系（P〈0．10），土壤温度与含水量可以分别解释呼吸速率变化的73．26％与21．85％，共同解释能力为86．40％，土壤温度对呼吸速率的影响大于土壤含水量。Many studies have shown multiple confounding factors influencing soil respiration in the field, which often hampers a correct separation and interpretation of effects of soil temperature and soil water content on respiration. Undisturbed soil cores in the 0 - 20 cm upper depth were taken from a natural Quercus aliena var. acuteserrata stand in the transitional area of northern subtropics to warm temperate zone, and incubated under five gradients of soil temperatures（ 15,20,25,30,35 ℃ ）and soil water contents（0.20,0.25,0.30,0.35,0.40 kg·kg^-1）. The soil respiration rates were measured when the soil temperatures and water contents met the experiment requests. Results indicate that there are significant effects of soil temperature, water content and their interaction on soil respiration rate（ P 〈 0.01 ）. The soil respiration rate is positively correlated to soil temperature at 15 - 35 ℃, and the variation pattern of soil respiration rate with soil water content increase is unimodal curve, increasing at 0.20 - 0.35 kg·kg^-1then decreasing at 0.35 - 0.40 kg·kg^-1. The highest soil respiration rate is under the condition of soil temperature at 35 ℃ and soil water content at 0.35 kg·kg^-1. The calculated Q10 value based on soil temperature is 1.36 - 3.10（mean is 2.13）, and decreases with soil temperature increase, the variation pattern of Q10 with soil water content increase is same as soil respiration rate. The regression models indicate that the relationship between soil respiration rate and soil temperature is significant exponential function（ P 〈 0.01 ） and the relationship between soil respiration and water content is quadratic function, soil temperature and soil water content can explain 73.26 and 21.85 percent of variation in soil respiration rate respectively, they can together explain 86.40 percent of variations, the effect of soil temperature on soil respiration rate is greater than soil water content.

关 键 词：锐齿栎林 土壤呼吸速率 土壤温度 土壤水分 

分 类 号：S718.5[农业科学—林学]