生态环境学报2018，Vol.27Issue(4)：634-642,9.DOI:10.16258/j.cnki.1674-5906.2018.04.006
沙质草地生长季土壤CO2排放特征及水热因子分析
Characteristics of Soil CO2Emission in Relation to Hydrothermal Factors during the Growing Season in Horqin Sandy Land
摘要
Abstract
CO2emission of grassland soil, as one of the key ecological processes of carbon cycle in terrestrial ecosystems, can be used to quantitatively assess and predict regional CO2emission, and serve the regional carbon management. LI-8150 automatic soil carbon flux measurement system was therefore applied to measure soil CO2flux in the growing season (June to September) in Horqin sandy land, and explore the effective mechanism of hydrothermal factors (precipitation, soil temperature and soil water content) on carbon emission. The results showed that: (1) For all sunny and rainy days, the diurnal dynamic change of soil CO2flux showed unsymmetrical "single peak" curve, and the highest value was in the period of 11:00—16:00, the lowest in 04:00—06:00. (2) In the growing season, the daily averaged soil CO2flux dynamic change showed multi peaks and obvious seasonal changes, higher peak in July and lower peak in September. the minimum value (0.35 μmol·m-2·s-1) on the sunny day of June 8th, and the maximum value (2.68 μmol·m-2·s-1) on a rainy day of July 23rd in 2016.The average discharge flux in the growth season was 1.26 μmol·m-2·s-1. (3) The soil CO2emission rate was different between the sunny day and the rainy day, and it was higher on the rainy day. Precipitation was the key factor to the soil CO2emission. (4) On the day scale, the synergistic effect of soil water content and temperature in sunny and rainy days could explain 95% and 85.5% of soil CO2emission respectively. On the growth season scale, soil water content in sunny days and soil temperature in rainy days could explain 63.6% and 48% of soil CO2emissions variation, respectively; there is a threshold of soil water content and temperature for soil CO2emission, when soil water content was below 4.87% and soil temperature below 25.94 , soil CO℃ 2 emission was increased with the increase of water content and temperature;The synergistic effect of soil water content and temperature in sunny and rainy days could explain 61.6% and 43.7% of soil CO2 emission variation respectively.关键词
沙质草地/生长季/土壤CO2通量/土壤含水量/土壤温度Key words
sandy grassland/growing season/CO2 flux of soil/soil water content/soil temperature分类
农业科技引用本文复制引用
龚相文,李玉强,王旭洋,牛亚毅,连杰,罗永清..沙质草地生长季土壤CO2排放特征及水热因子分析[J].生态环境学报,2018,27(4):634-642,9.基金项目
中国科学院"百人计划"项目(Y551821) （Y551821）
国家重点研发计划项目(2016YFC0500901) （2016YFC0500901）
国家自然科学基金项目(31640012 （）
31560161 （）
31500369) （）
