Chin J Plant Ecol ›› 2017, Vol. 41 ›› Issue (10): 1041-1050.DOI: 10.17521/cjpe.2016.0317

• Research Articles • Previous Articles     Next Articles

Effects of short-term nitrogen addition on fine root biomass, lifespan and morphology of Castanopsis platyacantha in a subtropical secondary evergreen broad-leaved forest

Guan-Tao CHEN1, Yong PENG1, Jun ZHENG2, Shun LI1, Tian-Chi PENG1, Xi-Rong QIU1, Li-Hua TU1,*()   

  1. 1College of Forest, Sichuan Agricultural University, Chengdu 611130, China

    2Suining Forestry Bureau, Suining, Sichuan 629000, China
  • Online:2017-10-10 Published:2017-12-24
  • Contact: Li-Hua TU


Aims Fine roots are the principal parts for plant nutrients acquisition and play an important role in the underground ecosystem. Increased nitrogen (N) deposition has changed the soil environment and thus has a potential influence on fine roots. The purpose of this study is to reveal the effect of N deposition on biomass, lifespan and morphology of fine root.Methods A field N addition experiment was conducted in a secondary broad-leaved forest in subtropical China from May 2013 to September 2015. Three levels of N treatments: CK (no N added), LN (5 g·m-2·a-1), and HN (15 g·m-2·a-1) were applied monthly. Responses of fine root biomass, lifespan, and morphology of Castanopsis platyacantha to N addition were analyzed by using a minirhizotron image system from April 2014 to September 2015. Surface soil sample (0-10 cm) was collected in November 2014 and soil pH value, and concentrations of NH4+-N and NO3--N were measured.Important findings The biomass and average lifespan of the fine roots of C. platyacantha were 128.30 g·m-3 and 113-186 days, respectively, in 0-45 cm soil layer. Nitrogen addition had no significant effect on either fine root biomass or lifespan in 0-45 cm soil layer. However, LN treatment significantly decreased C. platyacantha root superficial area in 0-15 cm soil layer. HN treatment significantly decreased soil pH value. Our study indicated that short-term N addition influences soil inorganic N concentration and thus decreased pH value in surface soil, and thereafter affect fine root morphology. Short-term N addition, however, did not affect the fine root biomass, lifespan and morphology in subsoil.

Key words: nitrogen deposition, fine root biomass, fine root lifespan, fine root morphology, minirhizotron