青藏高原北缘3种高寒草地的CH_4、CO_2和N_2O通量特征的初步研究  

CH_4,CO_2 and N_2O flux among three types of alpine meadow in the north regions of Qinghai-Tibetan Plateau

作　　者：郭小伟[1,2] 杜岩功[1] 林丽[1] 李以康[1] 张法伟[1] 李茜[1] 刘淑丽[1,2] 欧阳经政[1,2] 曹广民[1] 

机构地区：[1]中国科学院高原生物适应与进化重点实验室中国科学院西北高原生物研究所,青海西宁810001 [2]中国科学院大学,北京100039

出　　处：《草业科学》2016年第1期27-37,共11页Pratacultural Science

基　　金：国家自然科学基金重点(41030105);国家自然科学基金(30970520);青海省自然科学基金(31200379;2012-Z-921Q)

摘　　要：高寒草地温室气体排放研究已成为高寒草地与气候变化关系的重要议题之一,但目前的研究多集中于单种类型草地的温室气体通量研究,缺乏多种草地类型间的比较。本研究于2009年以高寒草甸、栽培草地和高寒灌丛为研究对象,利用静态箱法研究3种草地的CH_4、CO_2和N_2O通量特征。结果显示,天然高寒草甸、栽培草地和高寒灌丛是大气CH_4的汇,大气CO_2和N_2O的源,其CH4通量分别为-21.4、-28.1和-41.1μg·m^(-2)·h^(-1);CO_2通量分别为360.6、447.9和475.1 mg·m-2·h-1;N_2O通量分别为34.2、51.6和50.6μg·m^(-2)·h^(-1)。生长季的高寒草地CH_4吸收占全年的42.4%~45.6%,生长季的CO_2和N_2O排放量分别占全年的64.1%~67.8%和37.9%~66.7%。土壤5 cm温度与CH_4、CO_2、N_2O通量分别呈负相关、正相关和正相关关系,除高寒草甸CH_4通量外土壤5 cm与其他草地温室气体通量均达到显著水平(P<0.01);土壤湿度与草地CH_4和CO_2通量呈正相关,与N_2O通量呈负相关,但仅与高寒草地CH_4和CO_2相关性达到显著水平(P<0.01)。土壤呼吸温度敏感性大小(Q10)值显示,CO_2通量较CH_4和N_2O通量对温度更为敏感。将3种草地的CH_4、N_2O通量值换算为等量CO_2后发现草地温室气体通量造成的温室效应表现为高寒灌丛>栽培草地>高寒草甸。Greenhouse gas flux from alpine grassland has been one of hotspots to study the relationship between climate change and alpine grassland. Most of these studies focused on gas flux of one type grassland and differences in gas flux among different alpine meadows receives little attention. A experiment was conducted in three types of grassland,ie. alpine meadow,artificial pasture and shrub meadow to investigate the Greenhouse gas fluxes in three types of grassland by using static chambers and gas chromatography. This study indicated that three types of alpine grassland were the sink of atmospheric CH4,and were the source of atmospheric CO2 and N2O. CH4 flux rates were-21. 4,-28. 1 and-41. 1 μg·m-2·h-1for FC,FCP and GG. CO2 flux rates were 360. 6,447. 9 and 475. 1 mg·m^（-2）·h^（-1） for FC,FCP and GG.N2O flux rates were 34. 2,51. 6 and 50. 6 μg·m^（-2）·h^（-1） for FC,FCP and GG. CH4,CO2 and N2O flux in growing season accounted for 42. 4% ~ 45. 6%,64. 1% ~ 67. 8% and 37. 9% ~ 66. 7% of the whole year,respectively. Soil temperature at 5 cm depth negatively correlated with CH4 flux rate（ P 0. 01） and positively correlated with CO2 and N2O flux rate（ P〈0. 01）. Soil moisture positively correlated with CO2 and CH4flux rate,negatively correlated with N2 O flux rate. Q10 revealed that CO2 flux rate was more sensitive to increase in temperature than CH4 and N2O flux rate. The three grasslands for controlling greenhouse effect were in the following order： GGFCPFC. The CO2 flux rate was much higher than CH4 and N2O flux rate,then contributing an important role to greenhouse effect of grassland.

关 键 词：青藏高原 高寒草地 温室气体通量 生长季 非生长季 

分 类 号：S812[农业科学—草业科学]