Chin J Plant Ecol ›› 2021, Vol. 45 ›› Issue (8): 903-917.DOI: 10.17521/cjpe.2020.0421

• Research Articles • Previous Articles     Next Articles

Soil infiltration dynamics in early period of a post-fire Pinus tabulaeformis plantation

QIN Qian-Qian1, QIU Cong1, ZHENG Da-Cheng3, LIU Yan-Hong2,*()   

  1. 1School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China
    2Beijing Key Laboratory of Forest Resources and Ecosystem Process, Beijing Forestry University, Beijing 100083, China
    3College of Forestry, Beijing Forestry University, Beijing 100083, China
  • Received:2020-12-17 Revised:2021-04-13 Online:2021-08-20 Published:2021-04-25
  • Contact: LIU Yan-Hong
  • Supported by:
    National Key R&D Program of China(2017YFC0504004)


Aims As a key factor for the redistribution of rainwater or meltwater, soil infiltration has a substantial effect on forest eco-hydrological processes. This study aims to investigate the characteristics of soil infiltration and its structural controlling factors in the early stage of a post-fire Pinus tabulaeformis plantation in Beijing.
Methods After a fire occurred in March of 2019, the 0-20 cm soils in both post-fire and control plots were monthly collected from May to December 2019. Soil structure and infiltration were determined to analyze their response to fire disturbance and explore how they changed with soil depth and time. Path analysis was employed to discuss the effects of fire and soil structural properties on infiltration.
Important findings The results showed that: 1) In general, the surface soil had higher values of structural indexes (except small aggregates) than subsoils, and values of structural indexes recorded from June to August were higher than those recorded in other months. The vertical distribution characteristics and seasonal dynamics of soil structure were changed by fire. The content of soil aggregates >5, 2-5 and 1-2 mm and bulk density increased significantly two months after fire, while other indicators decreased significantly after fire. The effect of fire was weakened as soil layers deepened and time went by. Also, we observed distinct interactions among fire, soil depth and time. 2) Soil infiltration characteristics changed slowly with soil depth, but changed significantly with time. In addition, soil initial infiltration rate, steady infiltration rate, cumulative-infiltration volume and saturated hydraulic conductivity were largest in August (with higher rainwater and heavy rainfall events). After the fire, soil infiltration in 0-5 cm and that from June to September considerably varied. Soil infiltration characteristics generally decreased, and the peak value in post-fire plots occurred one or two months ahead of that in control plots. 3) Fire significantly affected soil structural properties, while soil infiltration was mainly and directly affected by soil structural properties. Excluding the impact of fire disturbance, the infiltrability of soil had a significant positive correlation with soil aggregate, bulk density and water holding capacity, and a negative correlation with porosity. Although organic matter content and initial water content had no significant effect on infiltrability, organic matter content could indirectly affect infiltrability by affecting porosity or water holding capacity. However, only initial water content had a significant and direct effect on infiltrability at the early stage of a post-fire forest, and the higher the initial moisture content was, the slower the soil infiltration was. Taken together, fire could change or decouple the way soil structure affected soil infiltration and its internal part, and indirectly affected soil infiltration in the early period of post-fire.

Key words: fire disturbance, infiltration process, soil depth, soil structure, time variation