J Plant Ecol ›› 2016, Vol. 9 ›› Issue (1): 1-9.DOI: 10.1093/jpe/rtv036

• Research Articles •     Next Articles

Impacts of fire severity and post-fire reforestation on carbon pools in boreal larch forests in Northeast China

Xueyang Hu1,?, Jianxiao Zhu1,?, Chuankuan Wang2, Tianli Zheng1, Qiqian Wu2, Hui Yao1 and Jingyun Fang1,*   

  1. 1 Department of Ecology, College of Urban and Environmental Science, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing 100871, China; 2 Center for Ecological Research, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China
  • Received:2015-01-25 Accepted:2015-03-31 Published:2016-01-27
  • Contact: Fang, Jingyun

Abstract: Aims Boreal larch (Larix gmelinii) forests in Northeast China have been widely disturbed since the 1987 conflagration; however, its long-term effects on the forest carbon (C) cycling have not been explored. The objective of this study thus was to quantify the effects of fire severity and post-fire reforestation on C pools and the changes of these forests.
Methods Sixteen permanent plots have been set in two types of larch stands (L. gmelinii -grass, LG; and L. gmelinii-Rhododendron dahurica, LR) with three levels of fire severity (unburned, low-severity and high-severity but replanted), at 1987 burned sites in Daxing'anling, northeastern China, to repeatedly measure ecosystem C pools in 1998 and 2014. C components were partitioned into vegetation (foliage, branch, stem and roots), soil and detritus (standing and fallen woody debris and litter). The fire effects on post-fire C dynamics were examined by comparing the differences of C pools and changes between the two field investigations caused by fire severity.
Important findings During the study period, unburned mature stands were C sinks (105g C m ?2 year-1 for LG, and 190g C m ?2 year-1 for LR), whereas the low-severity stands were C-neutral (?4 and 15g C m ?2 year-1 for LG and LR, respectively). The high-severity burned but reforested stands were C sinks, among which, however, magnitudes (88 and 16g C m ?2 year-1 for LG and LR, respectively) were smaller than those of the two unburned stands. Detritus C pools decreased significantly (with a loss ranging from 26 to 38g C m ?2 year-1) in the burned stands during recent restoration. Soil organic C pools increased slightly in the unmanaged stands (unburned and low-severity, with accumulation rates ranging from 4 to 35g C m ?2 year-1), but decreased for the high-severity replanted stands (loss rates of 28 and 36g C m ?2 year-1 for LG and LR, respectively). These results indicate that fire severity has a dynamic post-fire effect on both C pools and distributions of the boreal larch forests, and that effective reforestation practice accelerates forest C sequestration.

Key words: carbon budget, wildfire, fire severity, Larix gmelinii, reforestation

摘要:
Aims Boreal larch (Larix gmelinii) forests in Northeast China have been widely disturbed since the 1987 conflagration; however, its long-term effects on the forest carbon (C) cycling have not been explored. The objective of this study thus was to quantify the effects of fire severity and post-fire reforestation on C pools and the changes of these forests.
Methods Sixteen permanent plots have been set in two types of larch stands (L. gmelinii -grass, LG; and L. gmelinii-Rhododendron dahurica, LR) with three levels of fire severity (unburned, low-severity and high-severity but replanted), at 1987 burned sites in Daxing'anling, northeastern China, to repeatedly measure ecosystem C pools in 1998 and 2014. C components were partitioned into vegetation (foliage, branch, stem and roots), soil and detritus (standing and fallen woody debris and litter). The fire effects on post-fire C dynamics were examined by comparing the differences of C pools and changes between the two field investigations caused by fire severity.
Important findings During the study period, unburned mature stands were C sinks (105g C m ?2 year-1 for LG, and 190g C m ?2 year-1 for LR), whereas the low-severity stands were C-neutral (?4 and 15g C m ?2 year-1 for LG and LR, respectively). The high-severity burned but reforested stands were C sinks, among which, however, magnitudes (88 and 16g C m ?2 year-1 for LG and LR, respectively) were smaller than those of the two unburned stands. Detritus C pools decreased significantly (with a loss ranging from 26 to 38g C m ?2 year-1) in the burned stands during recent restoration. Soil organic C pools increased slightly in the unmanaged stands (unburned and low-severity, with accumulation rates ranging from 4 to 35g C m ?2 year-1), but decreased for the high-severity replanted stands (loss rates of 28 and 36g C m ?2 year-1 for LG and LR, respectively). These results indicate that fire severity has a dynamic post-fire effect on both C pools and distributions of the boreal larch forests, and that effective reforestation practice accelerates forest C sequestration.