Effects of soil erosion and reforestation on soil respiration, organic carbon and nitrogen stocks in an eroded area of Southern China

Xiong Yao; Kunyong Yu; Guangyu Wang; Yangbo Deng; Zhuangjie Lai; Yan Chen; Yusen Jiang; Jian Liu

doi:10.1016/j.scitotenv.2019.05.221

Effects of soil erosion and reforestation on soil respiration, organic carbon and nitrogen stocks in an eroded area of Southern China

Sci Total Environ. 2019 Sep 15:683:98-108. doi: 10.1016/j.scitotenv.2019.05.221. Epub 2019 May 20.

Authors

Xiong Yao¹, Kunyong Yu¹, Guangyu Wang², Yangbo Deng³, Zhuangjie Lai³, Yan Chen³, Yusen Jiang³, Jian Liu⁴

Affiliations

¹ College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China; University Key Lab for Geomatics Technology and Optimize Resources Utilization in Fujian Province, Fuzhou, Fujian 350002, China.
² Faculty of Forestry, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
³ College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China.
⁴ College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China; University Key Lab for Geomatics Technology and Optimize Resources Utilization in Fujian Province, Fuzhou, Fujian 350002, China. Electronic address: fjliujian@fafu.edu.cn.

PMID: 31129335
DOI: 10.1016/j.scitotenv.2019.05.221

Abstract

Soil erosion and reforestation greatly affects the functionality of many terrestrial ecosystems. However, the effects of soil erosion and reforestation on soil respiration (SR), and soil organic carbon (SOC) and total nitrogen (TN) stocks remain unclear. Therefore, we investigated the changes in SR, and SOC and TN stocks at four different soil erosion levels (severely, moderately, lightly, and non-eroded) and two different aged Pinus massoniana plantations (8- and 36-year-old) in the hilly red soil regions of Southern China. Our results showed that soil erosion level and reforestation significantly influenced SR, and SOC and TN stocks. Meanwhile, the mean SR, and SOC and TN stocks all significantly decreased with erosion level but increased significantly with times since reforestation. Soil temperature (ST) could explain 70-92% of SR seasonal variation based on exponential models, whereas no significant relationship between SR and soil water content were found. Furthermore, the structural equation modeling indicated that SOC stocks at 0-20 cm had a much stronger effect on SR than ST. Meanwhile, the SOC stocks for 0-20 cm increased by 177% and 558% in the 8- and 36-year-old Pinus massoniana plantations in comparison with the severely eroded forestland, respectively. This study highlights that reforestation could be an effective strategy for restoring the carbon and nitrogen storage in eroded regions of Southern China and emphasizes the need to consider the effects of soil erosion and reforestation when assessing regional carbon budgets under different climate scenarios.

Keywords: C storage; N storage; Pinus massoniana; Soil CO(2) efflux; Soil temperature; Water erosion.