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林业科学 ›› 2010, Vol. 46 ›› Issue (8): 22-32.doi: 10.11707/j.1001-7488.20100804

• 论文 • 上一篇    下一篇

东北天然次生林下木树种生物量的相对生长

李晓娜,国庆喜,王兴昌,郑海富   

  1. 东北林业大学林学院 哈尔滨 150040
  • 收稿日期:2009-05-07 修回日期:2010-06-06 出版日期:2010-08-25 发布日期:2010-08-25
  • 通讯作者: 国庆喜

Allometry of Understory Tree Species in a Natural Secondary Forest in Northeast China

Li Xiaona;Guo Qingxi;Wang Xingchang;Zheng Haifu   

  1. College of Forestry, Northeast Forestry University Harbin 150040
  • Received:2009-05-07 Revised:2010-06-06 Online:2010-08-25 Published:2010-08-25

摘要:

以东北天然次生林下木层主要树种为研究对象,将各树种按照植株形态分为乔木型植物和典型灌木2类,利用不同函数和自变量构建单物种及混合物种2类器官生物量方程,挑选出标准误较小、拟合性较好的方程作为最佳生物量模型,比较基于不同自变量的生物量模型的优劣,分析植物生物量与个体大小的相对生长关系。结果表明:1) 筛选出的各树种器官最佳生物量模型大多显著(P<0.05),且R2值大多超过0.800,方程形式以幂函数为主,少数为二次多项式、线性方程和指数方程,乔木型植物生物量均以离地面10 cm处树干直径(D10)解释较理想,典型灌木的最佳生物量模型多以冠幅(CA)和冠幅乘以高度(CAH)为自变量; 单物种模型与混合物种模型相比,并非所有的单物种模型都优于混合物种模型。2) 引入高度变量H和主干长变量L对各树种器官生物量模型的R2值的贡献相似,但包含主干长变量的生物量模型的R2值增加较小。与单变量生物量模型相比,大多典型灌木生物量模型的R2值增加,多数乔木型植物生物量模型的R2值减小; 与H相比,L并不是一个较好的预测变量。3) 下木树种器官生物量与植物大小的相对生长研究再次表明相对生长关系并不唯一,乔木型植物器官生物量与D10的相对生长关系的变化范围是1.712~2.555,其中多年枝、总枝、地上部分、粗根、地下部分和个体生物量与D10的幂指数接近理论值8/3。典型灌木各器官生物量与CA和CAH的相对生长关系的范围分别是0.688~1.293和0.436~1.017,其中叶、新枝、粗根、地下部分和个体的生物量与CA接近等速生长,多年枝、总枝和地上部分与CAH接近等速生长。

关键词: 林下植物, 生物量方程, 相对生长, 温带森林

Abstract:

Temperate forests in northeastern China play a key role in the national and global carbon budgets. However, relatively few studies were conducted in biomass allometry of these species, although understory tree species (including tree-like plants and typical shrubs) accumulate a substantial amount of nutrients and carbon. In this study, allometric equations for the organ (leaf, branch and root) and total biomass of 16 understory tree species were developed, and allometry of the organ biomass against plant size was analyzed. The result showed that 1) the forms and variables of optimal biomass equation varied with species and organs. The optimal equations for tree-like plants were power functions with diameter at 10 cm height (D10) as the predictor. For typical shrubs, most of these equations were also power functions using crown area (CA) or crown area multiplying height (CAH) as predictors while the left few species fitted the other functions such as linear and quadratic polynomial equations. Generalized models regardless of species could be used to estimate biomass when the species-specific models were unavailable. 2) Models using plant height (H) or stem length (L) as independent variables in the biomass equations only improved the fit for most of the typical shrubs but not for the tree-like plants. Percentage increase in determination coefficients (R2) with adding L in the allometric equations was smaller than that with adding H. 3) The relationship between biomass of the understory with the plant size complied with allometric theory (P<0.05), but the power varied. For tree-like plants, power exponents of biomass components against D10 varied from 1.712 to 2.555, and old branch biomass, branch biomass, large root biomass belowground biomass and total biomass nearly scaled as 8/3 power of D10. For typical shrubs, the ranges of power exponents scaling with CA and CAH were 0.688-1.293 and 0.527-1.017, respectively. In the contrast, foliage biomass, new branch biomass, large root biomass, belowground biomass and total biomass scaling with CA, and old branch biomass, branch biomass and aboveground biomass scaling CAH were both isometry.

Key words: understory tree species, biomass equations, allometry, temperate forest