干旱区生态环境知识资源中心(Arid): Salinity decreases the contribution of microbial necromass to soil organic carbon pool in arid regions

Arid

DOI	10.1016/j.scitotenv.2024.172786
	Salinity decreases the contribution of microbial necromass to soil organic carbon pool in arid regions
	Jia, Bin; Mao, Han; Liang, Yanmei; Chen, Jie; Jia, Li; Zhang, Meilan; Li, Xiao Gang
通讯作者	Li, XG
来源期刊	SCIENCE OF THE TOTAL ENVIRONMENT
ISSN	0048-9697
EISSN	1879-1026
出版年	2024
卷号	930
英文摘要	Saline soils are widely distributed in arid areas but there is a lack of mechanistic understanding on the effect of salinity on the formation and biochemical composition of soil organic carbon (SOC). We investigated the effects of salinity on the accumulation of microbial necromass under natural vegetation and in cropland in salt-affected arid areas stretching over a 1200-km transect in northwest China. Under both natural vegetation and cropland, microbial physiological activity (indicated by microbial biomass carbon normalized enzymatic activity) decreased sharply where the electrical conductivity approached 4 ds m(-1) (a threshold to distinguish between saline and non-saline soils), but microbial biomass was only slightly affected by salinity. These indicated that a larger proportion of microbes could be inactive or dormant in saline soils. The contribution of fungal necromass C to SOC decreased but the contribution of bacterial necromass C to the SOC increased with increasing soil salinity. Adding fungal and bacterial necromass C together, the contribution of microbial necromass C to SOC in saline soils was 32-39 % smaller compared with non-saline soils. Fungal necromass C took up 85-86 % of microbial necromass C in non-saline soils but this proportion dropped to 60-66 % in saline soils. We suggested that the activity, growth, and turnover rate of microbes slowed by salinity was responsible for the decreased accumulation of fungal necromass in saline compared with non-saline soils, while the increased accumulation of bacterial residue in saline soils could be induced mainly by its slower decomposition. Soil microbial biomass was a poor predictor for the accumulation of microbial necromass in saline soils. We demonstrated a reduced contribution of microbial necromass to SOC and a shift in its composition towards the increase in bacterial origin in saline relative to non-saline soils. We concluded that salinity profoundly changes the biochemistry of SOC in arid regions.
英文关键词	Arid areas Microbial necromass carbon Salt-affected soils Soil organic matter biochemistry
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:001237299100001
WOS关键词	COMMUNITY ; BIOMASS ; WATER ; MICROORGANISMS ; SEQUESTRATION ; STOICHIOMETRY ; DECOMPOSITION ; CONVERSION ; DYNAMICS ; GRADIENT
WOS类目	Environmental Sciences
WOS研究方向	Environmental Sciences & Ecology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/405494
推荐引用方式 GB/T 7714	Jia, Bin,Mao, Han,Liang, Yanmei,et al. Salinity decreases the contribution of microbial necromass to soil organic carbon pool in arid regions[J],2024,930.
APA	Jia, Bin.,Mao, Han.,Liang, Yanmei.,Chen, Jie.,Jia, Li.,...&Li, Xiao Gang.(2024).Salinity decreases the contribution of microbial necromass to soil organic carbon pool in arid regions.SCIENCE OF THE TOTAL ENVIRONMENT,930.
MLA	Jia, Bin,et al."Salinity decreases the contribution of microbial necromass to soil organic carbon pool in arid regions".SCIENCE OF THE TOTAL ENVIRONMENT 930(2024).