干旱区生态环境知识资源中心(Arid): Soil organic carbon transfer in aggregates subjected to afforestation in karst region as indicated by 13C natural abundance

Arid

DOI	10.1016/j.foreco.2023.120798
	Soil organic carbon transfer in aggregates subjected to afforestation in karst region as indicated by 13C natural abundance
	Wang, Junxian; Lan, Jiacheng; Long, Qixia; Wang, Shasha; Qi, Xue; Huang, Mingzhi
通讯作者	Lan, JC
来源期刊	FOREST ECOLOGY AND MANAGEMENT
ISSN	0378-1127
EISSN	1872-7042
出版年	2023
卷号	531
英文摘要	The measurement of 13C natural abundance provides valuable information in studying carbon (C) incorporation in soil aggregates. Exploring the pathways of C between aggregates of different size classes are vital to further understand the stabilization of soil organic matter (SOM) and aggregate formation. However, little is known on the mechanism of C stabilization in soil, especially when subjected to afforestation effects in karst rocky desertification area. Soil in the 0-20 cm layer was collected from two afforestation types [natural secondary forest (NF) and artificial Zanthoxylum bungeanum forest (AF)] in the karst rocky desertification area, with cropland (CL) as the reference. Stable isotope fractionation was used to analyze the dynamic changes in organic carbon (OC) in aggregates, and the Delta 13C (difference in delta 13C between the bulk soil and aggregate fractions) was utilized to quantify the C flow in aggregates under different land use types and soil layers. Results showed that afforestation significantly affected the dynamics of soil aggregate OC. Afforestation on cropland increased the number of large macroaggregates (>2 mm, LMA) and decreased the proportions of small macroaggregates (0.25-2 mm, SMA), microaggregates (0.053-0.25 mm, MI), and silt + clay fraction (<0.053 mm, SC). With the increase in aggregate class size, the OC content in aggregates rose under CL and AF, but no obvious regularity was found in NF. The proportion of new SOC was higher in NF (27.0%) than in AF (20.6%) and in 0-10 cm soil layer (27.3%) than in 10-20 cm soil layer (20.3%) under different afforestation measures. No significant differences in particle size were found among aggregates (P > 0.05). The delta 13C in bulk soil and aggregates was significantly decreased by afforestation and increased with the increment in soil depth. Stable isotope analysis results showed that the flow of OC was mainly from larger aggregates to smaller aggregates in CL and AF, which is consistent with the stabilization mechanism of SOM in aggregate hierarchy theory. However, the C flow occurred from smaller aggregates to larger aggregates in NF topsoil due to that newly input OC is first associated with MI and then incorporated into macroaggregates during soil aggregation process. The different human disturbance frequencies and the replenishment levels of plant biomass through litter input, root biomass, and exudates resulted in variation in aggregate turnover (formation and breakdown) among CL, AF and NF. These conclusions can provide sufficient reference for the formation and stabilization of aggregate-associated OC.
英文关键词	Soil organic carbon Afforestation 13 C natural abundance Karst rocky desertification
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000927278500001
WOS关键词	LAND-USE CHANGE ; LONG-TERM FERTILIZATION ; VEGETATION RESTORATION ; ROCKY DESERTIFICATION ; LOESS PLATEAU ; DENSITY FRACTIONS ; NITROGEN MINERALIZATION ; SILTY SOILS ; DYNAMICS ; SEQUESTRATION
WOS类目	Forestry
WOS研究方向	Forestry
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/396383
推荐引用方式 GB/T 7714	Wang, Junxian,Lan, Jiacheng,Long, Qixia,et al. Soil organic carbon transfer in aggregates subjected to afforestation in karst region as indicated by 13C natural abundance[J],2023,531.
APA	Wang, Junxian,Lan, Jiacheng,Long, Qixia,Wang, Shasha,Qi, Xue,&Huang, Mingzhi.(2023).Soil organic carbon transfer in aggregates subjected to afforestation in karst region as indicated by 13C natural abundance.FOREST ECOLOGY AND MANAGEMENT,531.
MLA	Wang, Junxian,et al."Soil organic carbon transfer in aggregates subjected to afforestation in karst region as indicated by 13C natural abundance".FOREST ECOLOGY AND MANAGEMENT 531(2023).