Chin J Plan Ecolo ›› 2016, Vol. 40 ›› Issue (6): 543-553.DOI: 10.17521/cjpe.2015.0420

• Research Articles • Previous Articles     Next Articles

Effects of night warming on the uptake of inorganic nitrogen by two dominant species in subalpine coniferous forests

Bo TANG1,2, Huan YANG1,2, Chun-Ying YIN1,*(), Yu-Yu SUN1,2, Dong-Hui ZHENG1,2, Qing LIU1   

  1. 1Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China

    2University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2015-11-22 Accepted:2016-03-26 Online:2016-06-30 Published:2016-06-15
  • Contact: Chun-Ying YIN

Abstract:

Aims Plant roots play a critical role in the uptake of nutrients, and nitrogen (N) absorption is considered as the first step and a pivotal process in N metabolism of plants. Our objective was to better understand the absorption of two major inorganic N forms (NH4+ and NO3-) in subalpine coniferous forests under global warming Methods Experimental warming using infrared heater was applied to two dominant species in subalpine coniferous forests of Sichuan, China, Picea asperata and Abies fargesiivar. faxoniana. The non-invasive micromeasurement technology was used to investigate the effects of warming on the uptake rates of NH4+ and NO3- and the potential interactions between these two ions.Important findings Results showed that the maximal net root uptake of NH4+ and NO3-occurred at a distance of 17-18 mm and 17 mm from root tips, respectively for P. asperata. and at a distance of 11 mm and 11.5 mm from root tips respectively for A. fargesiivar. faxoniana. Experimental warming elevated the uptake rates of NH4+ and NO3- in both species, but the interactions between NH4+ and NO3- differed between the two species. While NO3- uptake was inhibited in the presence of NH4+ for both P. asperataand A. fargesiivar. faxoniana, net NH4+ uptake was promoted by NO3- supply only in P. asperata roots under experimental warming.

Key words: night warming, N absorption, conifer tree, subalpine forest