CAJ | 학술논문

土壤碳通量是陆地生态系统中碳循环的重要组成部分.为了揭示放牧对荒漠草原土壤呼吸速率的影响,我们采取完全随机区组设计比较研究了不同载畜率下草地土壤的呼吸速率.试验包括4个处理,3次重复.4个处理分别是对照(CK)、轻度放牧(LG)、中度放牧(MG)和重度放牧(HG),相应的载畜率分别为0,0.91,1.82 和2.71只羊*hm-2*半年-1.在2004年和2006年8月,采用LI-6400-09土壤呼吸室与LI-6400连接对每个样地的土壤呼吸速率进行了测定,在测定过程中,同时获取了土壤温度及土壤呼吸室中的相对湿度等相关指标.通过对测定数据的分析表明,内蒙古荒漠草原土壤呼吸速率介于0.80 μmol·m-2·s-1与5.00 μmol·m-2·s-1之间.随着载畜率的增加,土壤呼吸速率明显增加(P<0.05).另外,土壤呼吸速率也随着土壤呼吸室中相对湿度的增加而增大,但是二者的相关关系不太明显(P>0.05).经过2年放牧后,重度放牧条件下的土壤呼吸速率明显低于对照区和轻度放牧区,不同载畜率下土壤呼吸速率随时间的变化并没有明显的差异.高载畜率下土壤呼吸速率明显降低可能与该条件下土壤水分和草地生物量的明显降低有关,土壤水分对土壤和大气之间CO2的交换起着非常重要的作用.
토양탄통량시륙지생태계통중탄순배적중요조성부분.위료게시방목대황막초원토양호흡속솔적영향,아문채취완전수궤구조설계비교연구료불동재축솔하초지토양적호흡속솔.시험포괄4개처리,3차중복.4개처리분별시대조(CK)、경도방목(LG)、중도방목(MG)화중도방목(HG),상응적재축솔분별위0,0.91,1.82 화2.71지양*hm-2*반년-1.재2004년화2006년8월,채용LI-6400-09토양호흡실여LI-6400련접대매개양지적토양호흡속솔진행료측정,재측정과정중,동시획취료토양온도급토양호흡실중적상대습도등상관지표.통과대측정수거적분석표명,내몽고황막초원토양호흡속솔개우0.80 μmol·m-2·s-1여5.00 μmol·m-2·s-1지간.수착재축솔적증가,토양호흡속솔명현증가(P<0.05).령외,토양호흡속솔야수착토양호흡실중상대습도적증가이증대,단시이자적상관관계불태명현(P>0.05).경과2년방목후,중도방목조건하적토양호흡속솔명현저우대조구화경도방목구,불동재축솔하토양호흡속솔수시간적변화병몰유명현적차이.고재축솔하토양호흡속솔명현강저가능여해조건하토양수분화초지생물량적명현강저유관,토양수분대토양화대기지간CO2적교환기착비상중요적작용.
Soil surface carbon dioxide flux is a very important component of carbon cycle of terrestrial ecosystems.In order to determine grazing impact on soil respiration rates under different stocking rates,a comparative study of soil respiration was conducted in a Desert Steppe in Inner Mongolia,P.R.China.A randomized complete block design was used with three replications and four grazing treatments:Control (CK),lightly grazed (LG), moderately grazed (MG) and heavily grazed (HG).The stocking rates were 0,0.91,1.82 and 2.71 sheep\5hm-2·half-year-1,for control,LG,MG and HG treatments, respectively.Soil respiration rate,soil temperature,and soil moisture were obtained in each plot by enclosed chamber method in 2004 and 2006.The results showed that soil respiration rate fluctuated from 0.80 μmol·m-2·s-1 to 5.00 μmol·m-2·s-1.Soil respiration rate was sharply decreased with increase of stocking rate (P<0.05).Meanwhile,soil respiration rate increased with increase of relative humidity in an enclosed chamber,but the regression relationship was not significant (P>0.05).Soil respiration rate has a significant decrease in HG treatment compared to CK and LG treatments through two years' treatment.There is no significant effect of time change on soil respiration in different stocking rates.Soil respiration rate was decreased significantly in a high stocking rate,which might be related to low soil moisture and biomass in these sites.Soil moisture plays an important role in CO2 exchange between soil and atmosphere.