J Plant Ecol ›› 2024, Vol. 17 ›› Issue (2): rtae005.DOI: 10.1093/jpe/rtae005

• Research Articles •    

Parameterization of height-diameter and crown radius-diameter relationships across the globe

Xiang Song1,*, Jinxu Li2, Xiaodong Zeng1,3   

  1. 1International Center for Climate and Environment Sciences, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China;
    2School of Mathematics and Statistics, North China University of Water Resources and Electric Power, Zhengzhou 450046, China;
    3College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2023-10-04 Revised:2023-12-02 Accepted:2024-01-13 Online:2024-02-01 Published:2024-02-22
  • Contact: E-mail: songxiang@mail.iap.ac.cn

全球尺度上树高-胸径和树冠半径-胸径关系的参数化方案

Abstract: The tree height-diameter at breast height (H-DBH) and crown radius-DBH (CR-DBH) relationships are key for forest carbon/biomass estimation, parameterization in vegetation models and vegetation-atmosphere interactions. Although the H-DBH relationship has been widely investigated on site or regional scales, and a few of studies have involved CR-DBH relationships based on plot-level data, few studies have quantitatively verified the universality of these two relationships on a global scale. This study evaluated the ability of 29 functions to fit the H-DBH and CR-DBH relationships for six different plant functional types (PFTs) on a global scale, based on a global plant trait database. Results showed that most functions were able to capture the H-DBH relationship for tropical PFTs and boreal needleleaf trees relatively accurately, but slightly less for temperate PFTs and boreal broadleaf trees (BB). For boreal PFTs, the S-shaped Logistic function fitted the H-DBH relationship best, while for temperate PFTs the Chapman-Richards function performed well. For tropical needleleaf trees, the fractional function of DBH satisfactorily captured the H-DBH relationship, while for tropical broadleaf trees, the Weibull function and a composite function of fractions were the best choices. For CR-DBH, the fitting capabilities of all the functions were comparable for all PFTs except BB. The Logistic function performed best for two boreal PFTs and temperate broadleaf trees, but for temperate needleleaf trees and two tropical PFTs, some exponential functions demonstrated higher skill. This work provides valuable information for parameterization improvements in vegetation models and forest field investigations.

Key words: tree height, diameter at breast height, crown radius, fitting function, parameterization, vegetation model

摘要:
全球尺度上树高-胸径和树冠半径-胸径关系的参数化方案树高-胸径(H-DBH)、树冠半径-胸径(CR-DBH)函数关系不仅是森林碳库/植被生物量估算的关键,同时也是植被模式参数化方案的重要组成部分,对陆-气相互作用的模拟起着至关重要的作用。目前,已有大量工作研究了站点或区域尺度的H-DBH函数关系,也有少量工作基于站点观测数据探讨了CR-DBH函数关系,但鲜有研究在全球尺度上定量研究这些函数关系的普适性。因此,本文基于全球植物性状数据库,率先在全球尺度上评估了29种函数对6种不同植物功能型 (Plant Functional Types, PFTs)的H-DBH和CR-DBH关系的拟合能力。研究结果显示,大多数函数能够较准确地刻画热带PFTs和寒带针叶林的H-DBH关系,但对温带PFTs和寒带阔叶林的拟合稍差。Logistic函数最适合拟合寒带PFTs的H-DBH关系,而对于温带PFTs而言,Chapman-Richards函数表现较好。分数函数能够较好地刻画热带针叶林H-DBH关系,而Weibull函数和一些复合函数则是热带阔叶林的最佳选择。对于大多数PFTs(寒带阔叶林除外)而言,所有函数对CR-DBH关系的拟合能力相当,其中,Logistic函数对两种寒带PFTs和温带阔叶林的CR-DBH关系拟合最佳,而一些指数函数对温带针叶林和两种热带PFTs的拟合效果更好。本研究为植被模式参数化方案的改进和森林实地调查研究提供了宝贵的信息。

关键词: 树高, 胸径, 树冠半径, 拟合函数, 参数化方案, 植被模式