Chin J Plant Ecol ›› 2014, Vol. 38 ›› Issue (6): 626-634.DOI: 10.3724/SP.J.1258.2014.00058

• Research Articles • Previous Articles     Next Articles

Early responses of vegetation and soil organic carbon to waterlogging and winter wildfire on abandoned red paddy soils

TIAN Wen-Wen1,2,3,WANG Wei1,3,CHEN An-Lei1,3,LI Yu-Yuan1,LI Yan-Yong1,2,3,XIE Xiao-Li1,3,*()   

  1. 1Key Laboratory of Agro-Ecological Process in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China
    2University of Chinese Academy of Sciences, Beijing, 100049, China
    3Taoyuan Station of Agro-Ecology Research, Chinese Academy of Sciences, Taoyuan, Hunan 415700, China
  • Received:2013-12-31 Accepted:2014-03-03 Online:2014-12-31 Published:2014-06-10
  • Contact: XIE Xiao-Li

Abstract:

Aims Large tracts of land have been abandoned since last century and the trend continues. Our objectives were to seek an effective solution for facilitating plant diversity on abandoned red paddy soils at an early stage, and to investigate the dynamics of soil organic carbon in relation to changes in vegetation.
Methods The experiment consisted of four treatments, including control (no disturbance from human activities), waterlogging, winter wildfire, and a combination of waterlogging and winter wildfire. Measurements were made in each treatment within quadrate sampling method. In each quadrate, the maximum plant height, density, coverage, and composition were surveyed and recorded by species. The above and belowground biomass and soil organic carbon content were determined with the methods of harvesting, soil coring, and K2Cr2O7 calefaction, respectively.
Important findings The results showed that waterlogging and winter wildfire significantly altered the vegetation richness, evenness, diversity, and species composition on the abandoned red paddy soils at the early stage. Paspalum paspaloides and Murdannia triquetra were the dominant plant species when the abandoned paddies had suffered waterlogging for the first few years, and Microstegium vimineum was the dominant species on sites experienced winter wildfire. Bidens frondosa was a co-dominant species in all the treatments. Compared with the control, the belowground biomass at the depth of 0-20 cm was increased by 49.84%, 73.34%, and 28.94%, respectively, in the waterlogging treatment in the year 2011, 2012 and 2013, and the aboveground biomass was increased by 25.74%, 64.30%, and 50.24%, respectively, in the winter wildfire treatment. The roots collected from the upper 5 cm soil layer accounted for 66.50%-80.34% of the total from the 0-20 cm layer. Winter wildfire resulted in greater values in the Shannon-Wiener diversity index of the vegetation. Different from the uptrend before abandonment, the soil organic carbon in the treatments of control, waterlogging, winter wildfire, and a combination of waterlogging and winter wildfire was reduced by 11.16%, 18.99%, 9.17%, and 19.12%, respectively, after six years of abandonment, and it was significantly lower in the waterlogging treatment (p < 0.05). Plant species richness, evenness, diversity, composition, biomass, and soil organic carbon all had strong relationships with waterlogging and winter wildfire on abandoned red paddy soils (p < 0.05).

Key words: abandonment, biomass, dominant species, red paddy soil, soil organic carbon