Chin J Plan Ecolo ›› 2011, Vol. 35 ›› Issue (3): 256-267.DOI: 10.3724/SP.J.1258.2011.00256

• Research Articles • Previous Articles     Next Articles

Effects of simulated precipitation and nitrogen addition on seedling growth and biomass in five tree species in Gutian Mountain, Zhejiang Province, China

WU Qian1,2, DING Jia1,2, YAN Hui1,2, ZHANG Shou-Ren1*, FANG Teng3, MA Ke-Ping1   

  1. 1State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China;

    2Graduate Universityof Chinese Academy of Sciences, Beijing 100049, China;

    3Gutianshan National Nature Reserve Administrative Bureau, Kaihua, Zhejiang 324300,China
  • Received:2010-04-14 Revised:2010-11-18 Online:2011-03-01 Published:2011-03-02
  • Contact: ZHANG Shou-Ren

Abstract:

Aims Precipitation change and nitrogen deposition are two important aspects of global climate change affecting forest ecosystems. Meteorological data from Gutian Mountain, which has typical subtropical evergreen broad-leaved forest, shows a slow downward trend in precipitation, particularly in the last ten years. Our objective was to investigate the effects of precipitation change and nitrogen deposition on physiological and ecological processes of subtropical tree species to better understand change patterns and mechanisms. Methods We set up a controlled-experiment with two factors: nitrogen (control and addition of 10 g·m–2·a–1 NH4NO3) and precipitation (natural precipitation as control and reduction of 30%). We collected seeds of five tree species of Gutian Mountain in the fall of 2006, sowed them in the spring of 2007 and grew the tree seedlings under the treatments. We periodically investigated traits of growth, biomass and allocation for three years. Important findings Nitrogen significantly promoted growth in height, stem basal diameter and biomass of Elaeocarpus glabripetalus, Liquidambar formosana and Schima superba, but only increased branch and leaf biomass of Pinus massoniana and branch biomass of Cyclobalanopsis glauca. After two years of treatment, nitrogen increased leaf weight ratio of E. glabripetalus and S. superba and increased branch weight ratio of L. formosana and C. glauca. With three years, nitrogen increased stem weight ratio of E. glabripetalus, L. formosana and S. superba and branch weight ratio of C. glauca and P. massoniana. The increase of the aboveground weight ratio is at the cost of decreased underground weight ratio. Nitrogen reduced the root weight ratio of E. glabripetalus, L. formosana, S. superba and C. glauca. Reducing precipitation by 30% had no significant effects on growth.