Chin J Plant Ecol ›› 2011, Vol. 35 ›› Issue (8): 801-807.DOI: 10.3724/SP.J.1258.2011.00801

Special Issue: 生态化学计量

• Original article • Previous Articles     Next Articles

Effects of N addition on nutrient resorption efficiency and C:N:P stoichiometric characteristics in Stipa bungeana of steppe grasslands in the Loess Plateau, China

AN Zhuo, NIU De-Cao, WEN Hai-Yan, YANG Yi, ZHANG Hong-Rong, FU Hua*()   

  1. Key Laboratory of Grassland Agro-ecosystem Ministry of Agriculture, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, China
  • Received:2011-03-24 Accepted:2011-06-03 Online:2011-03-24 Published:2011-07-28
  • Contact: FU Hua

Abstract:

Aims Our purpose was to study the effects of deposition of nitrogen (N) on plant carbon (C), N, phosphorus (P), N and P nutrient resorption efficiencies, C : N : P stoichiometry and their internal relations on Stipa bungeanaof Loess Plateau natural grassland.

Methods Deposition of N was simulated by N fertilization at four levels. Changes of C, N and P contents were detected, and C : N : P and the N and P nutrient resorption efficiencies were estimated for S. bungeana.

Important findings The C and N contents of leaves and N and P contents of standing litter increased significantly with N addition. However, the P content of leaves and C content of standing litter did not response to N addition. The N and P resorption efficiencies of S.bungeana decreased significantly with N addition. When there was no N addition, N and P resorption efficiencies were highest (60.35% and 71.75%, respectively). Meanwhile, the P resorption efficiency was greater than that of N in same treatment. The C : N ofS. bungeana decreased gradually with N addition, but the N : P and C : P increased with N addition. Values of the N : P were 18.25-29.01. The results showed the Loess Plateau natural grassland was mainly limited by P, and the strength of P limitation was enhanced with N deposition. Higher N and P resorption efficiencies were an important strategy for S. bungeana to survive soil infertility.

Key words: Key words ecological stoichiometry, Loess Plateau, nitrogen addition, nutrient limitation, nutrient resorption efficiency