长期封育对不同类型草地碳贮量及其固持速率的影响  

Carbon and nitrogen sequestration rate in long-term fenced grasslands in Inner Mongolia,China

作　　者：何念鹏[1,2] 韩兴国[2] 于贵瑞[1] 

机构地区：[1]中国科学院地理科学与资源研究所,生态系统网络观测与模拟重点实验室,北京100101 [2]中国科学院植物研究所,植被与环境变化国家重点实验室,北京100093

出　　处：《生态学报》2011年第15期4270-4276,共7页Acta Ecologica Sinica

基　　金：国家基础研究发展计划项目(2010CB833504);国家自然科学基金资助项目(31070431,40803024)

摘　　要：基于4个长期封育草地,采用成对取样方法(封育-自由放牧草地)分析了长期封育和自由放牧草地地上生物量、地表凋落物、0—100 cm根系和土壤的碳氮贮量,探讨了长期封育草地的碳固持速率。实验结果表明:长期封育显著提高了草地碳氮贮量;经30a围封处理后,草地碳固持量为1401—2858 gCm-2,平均2126 gCm-2;草地碳固持速率为46.7—129.2 gCm-2 a-1,平均84.2 gCm-2 a-1。长期封育草地氮固持速率为2.8—14.7 g N m-2 a-1,平均7.3 g Nm-2 a-1。封育草地碳和氮固持速率表现为:针茅草地<羊草草地<退化羊草草地<补播黄花苜蓿+羊草草地。长期封育草地0—40 cm土壤碳固持速率相对较高,但下层土壤对草地碳固持的贡献也比较大,因此,未来的相关研究应给予下层土壤更大关注。内蒙古典型草地具有巨大的碳固持潜力,长期封育(或禁牧)是实现其碳固持效应最经济、最有效的途径之一。Land-use change is considered to have a significant impact on the global C balance by profoundly altering biota,land cover,and biogeochemical cycles.Therefore,the impact of land-use change on the storage or sequestration of carbon（C） and nitrogen（N） is one of the most important domains to global change research.As a dominant form of landscape and an integral component of the Eurasian landmass,grasslands of northern China,which account for 40% of the land area in China,play important roles in servicing the ecological environment and in the socio-economy of the region.Furthermore,an increase in the soil C and N storage in the grasslands of northern China is anticipated with the implementation of measures aimed at encouraging grassland protection.However,there is little information regarding the potential of C and N storage（or C sequestration rate） due to the absence of long-term grazing exclusion plots in multiple sites. In this present research,using pair-sampling methods,we investigated the C and N storage in aboveground biomass,litter,roots and soil organic matter in the 0-100 cm soil layer in the fenced grasslands and free-grazing grasslands in 4 sites.The main objectives of this study was to assess the effect of long-term grazing exclusion on the storage of C and N in temperate grasslands of northern China,and further determined the sequestration rates of C and N in fenced grasslands by comparing with the data of free grazing grasslands. The results showed that,compared with free-grazing grasslands,there were significant increases in the C and N storage in the fenced grasslands.It was estimated that,after 3-decades grazing exclusion,the quantity of C sequestration ranged from 1401 to 2858 g C m–2 in the 4 sites,averaging 2126 g C m^-2;and the rates of C sequestration in fenced grasslands ranged from 46.7 to 129.2 g C m^-2 a^-1,averaging 84.2 g C m^-2 a^-1.The rates of N sequestration in fenced grasslands varied from 2.8 to 14.7 g N m^-2 a^-1,averaging 7.3 g N m^-2 a^-1.From the view of C and N se

关 键 词：草地 碳固持 氮贮存 固持速率 土地利用变化 围封 

分 类 号：S812[农业科学—草业科学]