Testing a common allometric equation for predicting the above-ground weight of trees and estimation of net ecosystem production

在先前的研究中(Komiyama等人)。2005年；J.Trop.Eco.21：471-477)，在植物形态静态模型生物学理论的基础上，建立了预测红树植物地上部分重量的通用异速生长方程。在目前的研究中，我检验了这个方程是否适用于生长在东亚的各种树种，包括红树林。从印度尼西亚、泰国和日本的热带到温带森林中收集了387棵树的数据，包括71个物种。以树干木材密度为变量，地上部分重量与树干直径之间的一般异速生长方程对这些树种具有显着的适用性。该方程的实测值与估算值的相对误差为19.5%，在110年生次生林中，地上部分净第一性生产量为9.96吨/公顷/年。地下净初级生产力=0.97吨/公顷/年。因此，在110年生的次生林中，净初级生产力=10.93吨/公顷/年。另一方面，净生态系统生产量(NEP)是用NPP减去异养呼吸(HR)来计算的。HR假设土壤呼吸的一半，碳含量也假设树木和/或凋落物的一半。因此，在该林分中，NEP=NPP-HR=4.98-3.71=1.27吨碳/公顷/年。

In the previous study (Komiyama et al. 2005 ; J.Trop.Ecol. 21:471-477), a common allometric equation for predicting the above-ground weight was developed for mangrove tree species based on a biological theory of statical model of plant form. In the present study, I examine whether this equation is applicable to a wide variety of tree species growing in East-Asia, including mangroves. The 387 tree data consisted of over 71 species were collected from tropical to temperate forests located in Indonesia, Thailand, and Japan. A common allometric equation between the above-ground tree weight and trunk diameter held significantly for these trees adding the wood density of trunk as a variable. The relative error between actual and estimated above-ground weight was 19.5% for this equation.In 110-year-old secondary forest, Net primary production (NPP) of aboveground=9.96 ton/ha/year. NPP of underground=0.97 ton/ha/year. Thus, in 110-year-old secondary forest, NPP=10.93 ton/ha/year. On the other hand, net ecosystem production (NEP) is calculated by subtraction of heterotrophic respiration (HR) from NPP. HR assumes half of soil respiration and carbon content also assumes half of tree and/or litter. Thus, NEP=NPP-HR=4.98-3.71=1.27 ton carbon /ha/year, in this stand.