Chin J Plant Ecol ›› 2021, Vol. 45 ›› Issue (4): 383-393.DOI: 10.17521/cjpe.2021.0001

• Research Articles • Previous Articles     Next Articles

Lifespan and morphological traits of absorptive fine roots across six typical tree species in subtropical China

WANG Yi-Dan1,2, LI Liang2,3, LIU Qi-Jing1,*(), MA Ze-Qing2,3,*()   

  1. 1College of Forestry, Beijing Forestry University, Beijing 100083, China
    2Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Science and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
    3Qianyanzhou Ecological Research Station, Chinese Academy of Sciences, Ji’an, Jiangxi 343700, China
  • Received:2021-01-04 Accepted:2021-03-08 Online:2021-04-20 Published:2021-04-23
  • Contact: LIU Qi-Jing,MA Ze-Qing
  • Supported by:
    National Natural Science Foundation of China(31822010);National Natural Science Foundation of China(31971633);“0-1” Original Innovation Project of the Chinese Academy of Sciences(ZDBS-LY-DQC023)

Abstract:

Aims Root turnover is a primary driver of belowground ecological processes, and root functional traits can indicate species ecological strategies, hence root lifespan and morphological traits are essential for understanding ecosystem carbon and nitrogen cycling as well as community diversity. Yet, data on root ecological processes in subtropical evergreen forest is very rare.

Methods We observed root dynamics of six tree species across root orders for two years in an experimental forest farm in Zhangshu, Jiangxi Province. Based on 28 000 minirhizotron photos, we analyzed interannual and seasonal changes of absorptive fine roots in relation to both lifespan and morphology.

Important findings 1) The variation of root lifespan among the six species in subtropical forest was as high as 4.6-fold, the variation of coefficient was 73%, with median lifespan in the sequence of: Taxus wallichiana(426 d) > Koelreuteria bipinnata (155 d) > Nageia nagi(145 d) > Cinnamomum camphora (126 d) > Cerasus yedoensis (93 d) > Michelia maudiae (92 d); 2) Absorptive fine root lifespan appeared remarkable in both seasonal and interannual variations, a pattern seemingly related to the monsoon climate which is characterized by summer-to- autumn drought and the supplies of soil water resources; 3) The lifespan of absorptive roots was positively associated with diameter, but negatively correlated with specific root length, suggesting that the root construction cost is a key predictor of lifespan. These results provide parameters for modeling belowground carbon and nitrogen cycling processes in subtropical evergreen broadleaf forest, and pave the way for exploring species coexistence mechanisms from belowground.

Key words: fine root, absorptive root, root turnover, root productivity, root mortality, belowground ecological process, morphological trait, net primary productivity, soil organic carbon