Daily variation characteristics of CO_(2) emission fluxes and contributions of environmental factors in semiarid grassland of Inner Mongolia, China  

作　　者：QI Yuchun DONG Yunshe LIU Jiyuan GENG Yuanbo LI Mingfeng YANG Xiaohong LIU Lixin 

机构地区：[1]Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China

出　　处：《Science China Earth Sciences》2005年第7期1052-1064,共13页中国科学(地球科学英文版)

基　　金：the Statc Key Basic Research Development and Planning Project(Grant No.2002CB412503);the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No.KZCX1-sw-01-04);the Knowl-edge Innovation Project of the Institute of Geographic Sciences and Natural Resources Research,CAS(Grant No.CXIOG-E01-03-01).

摘　　要：Fixed field experimental studies are carried out on daily variations of the undis-turbed community and soil respiration fluxes in different phenological phases of 2001―2002 in semiarid Aneurolepidium chinense steppe of Inner Mongolia,China using static black chamber method.Corresponding statistical analysis of the contributions of the water-heat factors(air temperature,ground temperature,surface soil water content)and ecological factors(above-ground biomass,underground biomass,litter biomass)to daily variation law of the undisturbed community and soil respiration fluxes as well as differences in daily respiration are also con-ducted.The results indicate that undisturbed community and soil respiration have apparent daily variation laws,daily variation patterns of respiration fluxes during different phenological phases are basically the same,and the variations of environmental factors only exert effect on CO_(2)emission intensities,while the effect on daily variation pattern of grassland CO_(2)emission fluxes is relatively small.The daily total respiration of the undisturbed community in different phenological phases ranges from 1.34―10.13 g·m^(-2);soil daily total respiration ranges from 0.98―5.17 g·m^(-2);both daily variations of undisturbed community and soil respiration fluxes are significantly corre-lated(p<0.05)or extremely significantly correlated(p<0.01)with air temperatures and ground surface temperatures,but the correlativity with the soil temperature at 5 and 10 cm depths is relatively weak;multiple regression analysis indicates that about 80%of the difference in daily respiration of the undisturbed community among different phenological phases is induced by the variation of the aboveground biomass,while the variations of the remaining factors can jointly explain around 20%of the daily respiration variations of the whole grassland ecosystem;about 83%of the soil daily respiration variation of the different phenological phases is caused by 0―20 cm underground biomass.Besides,surface soil water co

关 键 词：Inner Mongolia Aneurolepidium chinense steppe CO_(2)emission flux daily variation environmental factors. 

分 类 号：N[自然科学总论]