色季拉山急尖长苞冷杉林不同层次土壤CO_(2)浓度及温湿度响应  

Response of soil CO_(2)concentration at different depths of Abies georgei var.smithii forest to soil temperature and water content on Sejila Mountain,Tibet of southwestern China

作　　者：曹丽花 刘合满[1] 杨红 连玉珍 Cao Lihua;Liu Heman;Yang Hong;Lian Yuzhen(Department of Forestry,Xinyang Agriculture and Forestry University,Xinyang 464000,Henan,China;Tibet Agriculture and Animal Husbandry University,Linzhi 860000,Tibet,China;Station of Soil and Fertilizer,Zhoukou City Agriculture and Rural Bureau,Zhoukou 466099,Henan,China)

机构地区：[1]信阳农林学院林学院,河南信阳464000 [2]西藏农牧学院,西藏林芝860000 [3]周口市农业农村局土壤肥料工作站,河南周口466099

出　　处：《北京林业大学学报》2023年第2期1-10,共10页Journal of Beijing Forestry University

基　　金：国家自然科学基金项目(41561052、41461055);河南省科技攻关项目(202102310030、212102310981)。

摘　　要：【目的】揭示西藏高原森林生态系统不同层次土壤CO_(2)浓度变化特征及主要影响因素,为土壤呼吸CO_(2)排放变异性机制提供科学依据。【方法】以西藏东南部典型森林生态区色季拉山(鲁朗段)为研究区,以急尖长苞冷杉林土壤为研究对象,原位监测不同层次(5、10、20、40和60 cm)土壤CO_(2)浓度,分析不同层次土壤CO_(2)浓度分布特征及对温度和含水量的响应。【结果】(1)各层次土壤CO_(2)浓度日均值表现为40 cm>60 cm>20 cm>10 cm>5 cm,平均值分别为5094、4965、4613、4119和3925μmol/mol,且各层次之间均极显著正相关(P<0.01)。(2)在日变化尺度上,5和10 cm层次土壤CO_(2)浓度具有相反的变化特征,分别呈现“V”字型和“单峰型”特征,5 cm土壤CO_(2)浓度最高值和最低值分别出现在22:00-23:00和12:00-13:00之间,10 cm层次分别出现在16:00-17:00和00:00-01:00之间,其他各层CO_(2)浓度日变化特征不明显。(3)不同层次土壤CO_(2)浓度对温度的响应存在一定的延迟效应,而表现出不同的响应曲线,其中表层5和10 cm呈现近似“椭圆”的响应曲线;(4)表层(5和10 cm)土壤CO_(2)浓度主要受含水量的显著影响,而下层(40和60 cm)主要受土壤温度的影响。【结论】温度和含水量对不同层次土壤CO_(2)浓度具有不同的影响效应,并最终影响土体CO_(2)的传输和动态。[Objective]This paper aims to elucidate the variation characteristics and main influencing factors of soil CO_(2)concentration at different depths of the Tibetan Plateau forest ecosystem,so as to provide a scientific basis for variation mechanism of soil respiration CO_(2)emission.[Method]We selected Sejila Mountain(Lulang Section)in Tibet of southwestern China as a model area and a typical forest ecological area.Soil temperature(St)and water content(Sw)at different depths(5,10,20,40 and 60 cm)were measured in situ for analyzing the distribution characteristics of soil CO_(2)concentration at different levels and its response to Stand Swin the Abies georgei var.smithii forest.[Result](1)The daily mean value of soil CO_(2)concentration at all levels was 40 cm>60 cm>20 cm>10 cm>5 cm,the mean values were5094,4965,4613,4119 and 3925μmol/mol,respectively,and there was a significantly positive correlation among different depths.(2)On the diurnal variation scale,soil CO_(2)concentrations at 5 cm and 10 cm layers had opposite variation characteristics,showing a“V”-shaped and a“single peak”curve,respectively.The peak value and valley value of soil CO_(2)concentration at 5 cm layer appeared at 22:00-23:00 and 12:00-13:00,respectively,and the 10 cm appeared at 16:00-17:00 and 00:00-01:00,respectively,but no obviously diurnal variation in other layers.(3)The diurnal variations in the soil CO_(2)concentration were not completely synchronized with the St,and showed a lagged behind changes,showing an approximate ellipse shaped curve in 5 cm and 10 cm layers.(4)The soil CO_(2)concentration in the surface layer(5 and 10 cm)is mainly affected by water content,while the deeper layer(40 and 60 cm)soil is mainly affected by soil temperature.[Conclusion]Stand Swhave different effects on soil CO_(2)concentration at different depths,and ultimately affect soil CO_(2)transport and dynamics.

关 键 词：色季拉山 森林土壤 土壤CO_(2)浓度 土壤温度 土壤含水量 

分 类 号：S791.14[农业科学—林木遗传育种] S154.6[农业科学—林学]