Chin J Plant Ecol ›› 2009, Vol. 33 ›› Issue (2): 331-337.DOI: 10.3773/j.issn.1005-264x.2009.02.010

• Research Articles • Previous Articles     Next Articles

NESTED REGRESSION FOR ESTABLISHING TREE BIOMASS EQUATIONS

LIU Qi-Jing()   

  1. Department of Forest Science, Beijing Forestry University, Beijing 100083, China
  • Received:2008-06-06 Accepted:2008-10-09 Online:2009-06-06 Published:2009-03-31

Abstract:

Aims The objective was to introduce a simplified method called nested regression for quick establishment of allometric models for tree biomass.

Methods Main branches at all orders were used as basic sample units. The biomass of a branch was obtained by summing that of its sub-branches or sub-main branches, either observed or estimated. Thus the span of branch diameter for the equation was extended. The branch was dissected into main braches, and a main branch is the axis of a branch at any order. Biomass equations were established for main branches, branches and individual trees, progressively. By summing the values of main braches, the biomass of a branch in a higher order was obtained.

Important findings Because of data nesting, i.e., small branches were encompassed in their upper-order branches, the measured sample was reduced to a minimum, making the method time- and cost-effective. Satisfactory accuracy of predicted values was shown by testing with observed data.

Key words: biomass, branch, allometric equation, nested sampling