植物生态学报 ›› 2011, Vol. 35 ›› Issue (3): 256-267.DOI: 10.3724/SP.J.1258.2011.00256

• 研究论文 • 上一篇    下一篇

模拟降水变化和土壤施氮对浙江古田山5个树种幼苗生长和生物量的影响

吴茜1,2, 丁佳1,2, 闫慧1,2, 张守仁1,*(), 方腾3, 马克平1   

  1. 1中国科学院植物研究所植被与环境变化国家重点实验室, 北京 100093
    2中国科学院研究生院, 北京 100049
    3古田山国家级自然保护区管理局, 浙江开化 324300
  • 收稿日期:2010-04-14 接受日期:2010-09-20 出版日期:2011-04-14 发布日期:2011-03-02
  • 通讯作者: 张守仁
  • 作者简介:*E-mail: zsr@ibcas.ac.cn

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 University of Chinese Academy of Sciences, Beijing 100049, China
    3Gutianshan National Nature Reserve Administrative Bureau, Kaihua, Zhejiang 324300, China
  • Received:2010-04-14 Accepted:2010-09-20 Online:2011-04-14 Published:2011-03-02
  • Contact: ZHANG Shou-Ren

摘要:

为了探讨古田山地区5个树种—秃瓣杜英(Elaeocarpus glabripetalus)、枫香(Liquidambar formosana)、木荷(Schima superba)、青冈(Cyclobalanopsis glauca)和马尾松(Pinus massoniana)幼苗的生长和生物量及其分配对添加氮肥和减少降水的响应, 在野外设置了双因素氮肥(对照和施氮)和降水(自然降水(对照)和减少降水)控制试验, 氮肥的施入量为10 g·m-2·a-1 NH4NO3, 分别于每年5月初和7月初各施5 g·m-2·a-1, 减少降水处理是减少自然降水的30%。经过3个生长季的处理发现: 1)施氮显著促进了秃瓣杜英、枫香和木荷的苗高和基径的生长, 并且对秃瓣杜英和枫香的促进作用经过1个生长季的处理就表现出来, 而木荷在经过2个生长季后才表现出来; 2)施氮显著促进了秃瓣杜英、枫香和木荷的全株生物量以及各部分生物量的增长, 而只增加了马尾松的侧枝和叶片生物量以及青冈的侧枝生物量; 3) 2个生长季的施氮处理提高了秃瓣杜英和木荷的叶重比以及枫香和青冈的枝重比, 3个生长季的施氮处理促进了秃瓣杜英、枫香和木荷的茎重比以及青冈和马尾松的枝重比, 地上干物质分配比例的增加以地下干物质分配比例减小为代价, 施氮后显著降低了秃瓣杜英、枫香、木荷和青冈的根重比和根冠比; 4) 降水减少30%对各树种的生长均无显著影响。

关键词: 生物量, 生物量分配, 古田山, 生长, 施氮, 降水

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.

Key words: biomass, biomass allocation, growth, Gutian Mountain, nitrogen, precipitation