Title: Patterns and influencing factors of spatio-temporal variability of soil organic carbon in karst catchment

Authors: Zhenming Zhang; Yunchao Zhou; Shijie Wang; Xianfei Huang

Addresses: Institute for Forest Resources and Environment of Guizhou, Guizhou University, Guiyang, 550025, China; Guizhou Institute of Biology, Guiyang, 550001, China; College of Forestry, Guizhou University, Guiyang, 550001, China ' Institute for Forest Resources and Environment of Guizhou; College of Forestry, Guizhou University, Guiyang, 550001, China; Puding Karst Ecosystem Research Station of Guizhou Province, Anshun, 561000, China ' State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Science, Guiyang, 550002, China; Puding Karst Ecosystem Research Station of Guizhou Province, Anshun, 561000, China ' Institute for Forest Resources and Environment of Guizhou; College of Forestry, Guizhou University, Guiyang, 550025, China; Guizhou Provincial Key Laboratory for Environment, Guizhou Normal University, Guiyang, 550001, China

Abstract: The patterns of spatio-temporal variability of the soil organic carbon (SOC) stored in karst catchment were investigated, to provide a scientific basis for estimating SOC storage in karst regions and selecting technical measures for soil carbon sequestration. In this paper, field sampling, laboratory measurement, geostatistics, and geographic information system (GIS) were combined, to investigate the patterns and influencing factors of SOC's spatio-temporal variability in Houzhai catchment from 1980 to 2015. The results showed that according to the soil samples of the entire catchment, the SOC content averaged 21.98 g/kg in 1980 and 25.07 g/kg in 2015, with an increase of 3.09 g.kg⁻¹ (14.58%). Over the three and a half decades, SOC in this region showed weakened spatial structure, reduced correlation, and broken spatial distribution. Moreover, SOC in both periods presented a pattern of high values in the east and low values in the west, high in the periphery and low in the centre, and high in the south and low in the north. However, some local values were highly variable in embedded or block distribution. The key factors that could affect spatio-temporal variability of SOC in Houzhai catchment included the soil types, land utilisation, and major environmental factors.

Keywords: soil organic carbon; SOC; temporal and spatial distribution; influencing factors; small watershed; karst.

DOI: 10.1504/IJGW.2019.096764

International Journal of Global Warming, 2019 Vol.17 No.1, pp.89 - 107

Received: 02 Sep 2017
Accepted: 10 Jun 2018
Published online: 10 Dec 2018 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article