Nitrogen addition reduced carbon mineralization of aggregates in forest soils but enhanced in paddy soils in South China  

作　　者：Ruirui Cao Longchi Chen Xincun Hou Xiaotao Lü Haimei Li 

机构地区：[1]College of Landscape Architecture and Forestry,Qingdao Agricultural University,Qingdao 266109,China. [2]Huitong Experimental Station of Forest Ecology,CAS Key Laboratory of Forest Ecology and Management,Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China. [3]Hunan Key Laboratory for Structure and Ecosystem Service of Subtropical Forest,Huitong National Research Station of Forest Ecosystem,Huitong 418307,China. [4]Research and Development Center for Grasses and Environment,Beijing Academy of Agriculture and Forestry Sciences,Beijing 100097,China.

出　　处：《Ecological Processes》2021年第1期597-607,共11页生态过程（英文）

基　　金：The National Natural Science Foundation of China(41630755 and 31971718).

摘　　要：Background:Despite the crucial role of nitrogen(N)availability in carbon(C)cycling in terrestrial ecosystems,soil organic C(SOC)mineralization in different sizes of soil aggregates under various land use types and their responses to N addition is not well understood.To investigate the responses of soil C mineralization in different sized aggregates and land use types to N addition,an incubation experiment was conducted with three aggregate-size classes(2000,250,and 53μm)and two land use types(a Chinese fir plantation and a paddy land).Results:Cumulative C mineralization of the<53-μm fractions was the highest and that of microaggregates was the lowest in both forest and paddy soils,indicating that soil aggregates enhanced soil C stability and reduced the loss of soil C.Cumulative C mineralization in all sizes of aggregates treated with N addition decreased in forest soils,but that in microaggregates and the<53-μm fraction increased in paddy soils treated with 100μgNg−1.Moreover,the effect sizes of N addition on C mineralization of forest soils were below zero,but those of paddy soils were above zero.These data indicated that N addition decreased SOC mineralization of forest soils but increased that of paddy soils.Conclusions:Soil aggregates play an important role in soil C sequestration,and decrease soil C loss through the increase of soil C stability,regardless of land use types.N addition has different effects on soil C mineralization in different land use types.These results highlight the importance of soil aggregates and land use types in the effects of N deposition on the global terrestrial ecosystem C cycle.

关 键 词：ULTISOL Land use type MICROAGGREGATES Soil organic carbon 

分 类 号：S15[农业科学—土壤学]