Negative correlation between soil salinity and soil organic carbon variability

Author:

Hassani Amirhossein1ORCID,Smith Pete2ORCID,Shokri Nima3ORCID

Affiliation:

1. The Climate and Environmental Research Institute NILU, Kjeller 2027, Norway

2. Institute of Biological and Environmental Sciences, School of Biological Sciences, University of Aberdeen, Aberdeen AB24 3UU, United Kingdom

3. Institute of Geo-Hydroinformatics, Hamburg University of Technology, 21073 Hamburg, Germany

Abstract

Soil organic carbon (SOC) is vital for terrestrial ecosystems, affecting biogeochemical processes, and soil health. It is known that soil salinity impacts SOC content, yet the specific direction and magnitude of SOC variability in relation to soil salinity remain poorly understood. Analyzing 43,459 mineral soil samples (SOC < 150 g kg −1 ) collected across different land covers since 1992, we approximate a soil salinity increase from 1 to 5 dS m −1 in croplands would be associated with a decline in mineral soils SOC from 0.14 g kg −1 above the mean predicted SOC ( SOC ¯ c = 18.47 g kg −1 ) to 0.46 g kg −1 below SOC ¯ c (~−430%), while for noncroplands, such decline is sharper, from 0.96 above SOC ¯ nc = 35.96 g kg −1 to 4.99 below SOC ¯ nc (~−620%). Although salinity’s significance in explaining SOC variability is minor (<6%), we estimate a one SD increase in salinity of topsoil samples (0 to 7 cm) correlates with respective SOC ¯ declines of ~4.4% and ~9.26%, relative to SOC ¯ c and SOC ¯ nc . The SOC ¯ decline in croplands is greatest in vegetation/cropland mosaics while lands covered with evergreen needle-leaved trees are estimated with the highest SOC ¯ decline in noncroplands. We identify soil nitrogen, land cover, and precipitation Seasonality Index as the most significant parameters in explaining the SOC’s variability. The findings provide insights into SOC dynamics under increased soil salinity, improving understanding of SOC stock responses to land degradation and climate warming.

Funder

EC | ERC | HORIZON EUROPE European Research Council

NILU SIS-EO

NILU

Publisher

Proceedings of the National Academy of Sciences

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3