文献类型：期刊文献

英文题名：Nitrogen-fixing tree species modulate species richness effects on soil aggregate-associated organic carbon fractions

作者：Ye, Yuqian[1] Wang, Hui[1] Luan, Junwei[2] Ma, Jinhao[1,2] Ming, Angang[3,4] Niu, Baoliang[1] Liu, Cuiju[1] Freedman, Zac[5] Wang, Jingxin[6] Liu, Shirong[1]

第一作者：Ye, Yuqian

通信作者：Liu, SR[1]

机构：[1]Chinese Acad Forestry, Natl Forestry & Grassland Adm, Ecol & Nat Conservat Inst, Key Lab Forest Ecol & Environm, Beijing 100091, Peoples R China;[2]Int Ctr Bamboo & Rattan, Beijing Bamboo & Rattan Sci & Technol, Inst Resources & Environm, Key Lab Natl Forestry & Grassland Adm, Beijing 100102, Peoples R China;[3]Chinese Acad Forestry, Expt Ctr Trop Forestry, Pingxiang 532600, Peoples R China;[4]Guangxi Youyiguan Forest Ecosyst Res Stn, Pingxiang 532600, Peoples R China;[5]Univ Wisconsin Madison, Dept Soil Sci, Madison, WI 53706 USA;[6]West Virginia Univ, Div Forestry & Nat Resources, Morgantown, WV 26506 USA

年份：2023

卷号：546

外文期刊名：FOREST ECOLOGY AND MANAGEMENT

收录：;EI(收录号：20233314535755);Scopus(收录号：2-s2.0-85167437041);WOS:【SCI-EXPANDED(收录号:WOS:001063017700001)】；

基金：This work was jointly funded by the National Natural Science Foundation of China (31930078), the Ministry of Science and Technology of China (2021YFD2200402, 2021YFD2200405), and the Fundamental Research Funds of Chinese Academy of Forestry (CAFYBB2021ZW001).

语种：英文

外文关键词：Tree species richness; N-fixing tree species; Aggregate-associated organic carbon; Soil carbon fraction

摘要：Soil aggregation is an important mechanism shaping soil organic carbon (SOC) fractions, but the effects of tree species richness on soil aggregate-associated organic carbon fractions are poorly understood. In this study, a manipulative experiment was conducted to examine whether and how tree species richness (1, 2, 4 and 6) together with or without the presence of nitrogen (N)-fixing tree species affect soil aggregate-associated organic carbon. Soil aggregates were classified into four fractions: large macroaggregates (>2 mm), small macroaggregates (0.25-2 mm), microaggregates (0.053-0.25 mm), and silt and clay (<0.053 mm). And then large and small macroaggregates were further separated into coarse (c-iPOC), fine intra-aggregate particulate organic carbon (fiPOC) and mineral associated organic carbon (MAOC), and microaggregates were divided into f-iPOC and MAOC. We observed that the effects of tree species richness on soil aggregate-associated organic carbon fractions were depended on the presence or absence of N-fixing tree species. In the presence of N-fixing tree species, organic carbon contents of small macroaggregate, microaggregate and silt and clay fractions were increased across the gradient of tree species richness (+10.4%, +31.3% and + 26.7% from monocultures to 6-species mixture), and the similar responses occurred for c-iPOC within small macroaggregates (+42.9%) and f-iPOC within microaggregates (+50.0%). In the absence of N-fixing tree species, however, only f-iPOC within large macroaggregates (+60.0%) had a positive linear relationship with tree species richness. Structural equation modeling was then used to dissect the mechanism underlying the positive effects of tree species richness on the aggregate-associated organic carbon fractions, indicating either direct or indirect effects by increasing root length density. Our study highlights the important roles of N-fixing tree species in shaping tree species richness effects on soil aggregateassociated organic carbon fractions, and therefore, N-fixing tree species should be preferentially considered in mixed-species plantations to enhance long-term SOC stabilization.