Recovery time of soil carbon pools of conversional Chinese fir plantations from broadleaved forests in subtropical regions, China

Long-Chi Chen; Hua Wang; Xin Yu; Wei-Dong Zhang; Xiao-Tao Lü; Si-Long Wang

doi:10.1016/j.scitotenv.2017.02.140

Recovery time of soil carbon pools of conversional Chinese fir plantations from broadleaved forests in subtropical regions, China

Sci Total Environ. 2017 Jun 1:587-588:296-304. doi: 10.1016/j.scitotenv.2017.02.140. Epub 2017 Feb 27.

Authors

Long-Chi Chen¹, Hua Wang², Xin Yu³, Wei-Dong Zhang⁴, Xiao-Tao Lü⁵, Si-Long Wang⁶

Affiliations

¹ Huitong Experimental Station of Forest Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; Huitong National Research Station of Forest Ecosystem, Huitong 418307, China. Electronic address: lcchen@iae.ac.cn.
² College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China. Electronic address: wangchina926@163.com.
³ Huitong Experimental Station of Forest Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; University of Chinese Academy of Sciences, Beijing 100049, China.
⁴ Huitong Experimental Station of Forest Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; Huitong National Research Station of Forest Ecosystem, Huitong 418307, China.
⁵ Huitong Experimental Station of Forest Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
⁶ Huitong Experimental Station of Forest Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; Huitong National Research Station of Forest Ecosystem, Huitong 418307, China. Electronic address: slwang@iae.ac.cn.

PMID: 28249750
DOI: 10.1016/j.scitotenv.2017.02.140

Abstract

The conversion from natural forest to plantation has been widely applied, with consequences on ecosystem carbon pool. The experimental results of changes of soil carbon stocks after forest conversion are often contradictory. Moreover, the recovery time of soil carbon stocks after forest conversion varies among different sites. To examine the changes of soil carbon stocks following the forest conversions in the long-term and to estimate the recovery time, we selected 116 subtropical forests, including 29 pair-wise replicates for evergreen broadleaved forests (EBF, 40-100-year-old), young Chinese fir plantations (Cunninghamia lanceolata) (YCP, 4-8-year-old), middle-aged Chinese fir plantations (MACP, 13-20-year-old), and mature Chinese fir plantations (MCP, 23-32-year-old), and estimated soil carbon stocks. Soil carbon stocks of YCP and MACP decreased in average 12.5 and 28.7Mgha^-1 compared with EBF, and showed no variation between MCP and EBF. Soil carbon stocks were positively correlated to soil total nitrogen stocks and C:N ratio. Our results showed that the forest conversions didn't cause a variation of soil carbon stocks in the long-term, although there was a short-term decline after conversion. The recovery time of soil carbon stock is 27years. These results indicate that the conversion from evergreen broadleaved forests to Chinese fir plantations in subtropical region of China causes soil carbon release in early stage, but has no effect on soil carbon stocks in the long-term. Prolonging the rotation period (>27years) would offset the adverse effects of the forest conversion on soil carbon stocks, and be critical in alleviating global climate change.

Keywords: Chinese fir plantation; Evergreen broadleaved forest; Forest conversion; Soil carbon stock; Soil total nitrogen stock.