干旱
土壤水分
有机质
环境科学
土壤科学
地球科学
地质学
水文学(农业)
生态学
岩土工程
古生物学
生物
作者
Xiaojuan Li,Ting Hui Yang,Lettice C. Hicks,Bin Hu,Xin Liu,Dan-Dan Wei,Zilong Wang,Weikai Bao
出处
期刊:Catena
[Elsevier]
日期:2022-08-01
卷期号:215: 106293-106293
被引量:2
标识
DOI:10.1016/j.catena.2022.106293
摘要
• Light fraction organic matter increased exponentially with increasing latitude. • Heavy fraction organic matter increased linearly with increasing latitude. • Latitudinal patterns of light fraction organic matter were controlled by climate. • Heavy fraction organic matter was driven by soil physicochemical factors. Semi-arid and arid ecosystems are important for the global C cycle. Despite this, it remains unclear how organic matter fractions vary across latitudinal gradients, and what drives this variation, in dry ecosystems. In this study, we sampled soils from 100 sites across a latitudinal gradient in the dry valleys of southwestern China to explore the latitudinal patterns of light fraction organic matter (LFOM) and heavy fraction organic matter (HFOM) at two soil depths (0–10 cm and 10–20 cm). Across the studied gradient, HFOM accounted for a larger fraction of soil organic matter than LFOM. LFOM increased exponentially with increasing latitude at both 0–10 cm and 10–20 cm depths. Heavy fraction organic C increased linearly with increasing latitude at both depths, while heavy fraction organic N only increased with latitude in soils from 10 to 20 cm depth. Latitudinal patterns of LFOM were mainly explained by climate, with the most important driver being mean annual temperature, followed by mean annual precipitation. Soil physicochemical factors – in particular cation exchange capacity and silt content – explained the most variation in HFOM. Total microbial biomass was also important in explaining variation in HFOM, especially in the 10–20 cm soil layer. Overall, our results shed light on the spatial distribution of organic matter fractions in arid and semi-arid regions. We also identify candidate drivers of the variation in LFOM and HFOM in arid and semi-arid regions, finding that climate primarily explains variation in LFOM while soil physiochemistry primarily explains variation in HFOM.
科研通智能强力驱动
Strongly Powered by AbleSci AI