• 前沿与重点: 森林碳汇专题 •

### 南亚热带常绿阔叶林4个常见树种的生物量分配特征与异速生长模型

1. 中国林业科学研究院热带林业研究所 南岭北江源森林生态系统国家定位观测研究站 广州 510520
• 收稿日期:2020-12-04 出版日期:2022-02-25 发布日期:2022-04-26
• 通讯作者: 周光益
• 基金资助:
中央级公益性科研院所基本科研业务费专项资金项目(CAFYBB2019SZ003);国家自然科学基金面上项目(31770664)

### Biomass Allocation and Allometric Growth Models of Four Common Tree Species in Southern Subtropical Evergreen Broad-Leaved Forest

Houben Zhao,Guangyi Zhou*,Zhaojia Li,Zhijun Qiu,Zhongmin Wu,Xu Wang

1. Research Institute of Tropical Forestry, CAF Beijiangyuan National Forest Ecosystem Research Station, Nanling Guangzhou 510520
• Received:2020-12-04 Online:2022-02-25 Published:2022-04-26
• Contact: Guangyi Zhou

Abstract:

Objective: In order to improve the accuracy of biomass estimation of southern subtropical evergreen broad-leaved forest, the biomass distribution among different organs of 4 common tree species were investigated, and the models of single plant and different biomass components(aboveground and underground) were constructed for each of the 4 species. Method: Based on the historical data of forest survey of the southern subtropical evergreen broad-leaved forest in Guangzhou and its actual species composition, 4 common tree species, Castanopsis fissa, C. chinensis, Aleurites montana and Machilus chinensis were selected to measure the biomass of single plant and different components of each tree species using the harvest method, and further to construct the biomass models of each tree species. The influences of adding tree height (H) and wood density (ρ) as second independent variables in the models on the accuracy of the models were discussed. Result: The proportion of leaf biomass of the four 4 tree species accounted for 5.34%-7.28%, and the proportion was significantly lower of M. chinensis than of C. fissa (P < 0.05). The proportion of branch biomass accounted for 16.82%-24.20%, and significantly lower of M. chinensis than of C. chinensis and C. fissa (P < 0.05). The proportion of trunk biomass accounted for 47.22%-58.05%, and significantly lower of C. chinensis than of the other three species (P < 0.05). The proportion of root biomass accounted for 14.25%-22.25%, and significantly lower of C. fissa and A. montana than of C. chinensis and M. chinensis (P < 0.05). The proportion of leaf biomass of A. montana and M. chinensis decreased significantly (P < 0.01) with the increase of DBH. With the increase of DBH, the proportion of branch biomass increased, while the proportion of trunk biomass decreased of the four species. There was no significant correlation between the proportion of root biomass and DBH. The biomass model with DBH as a single independent variable had good fitting accuracy (average R2=0.947). Adding H compounded with D as one variable (D2H) in the models decreases the model fitness of aboveground and total biomass, and slightly improves the fitness of underground biomass. Including H as an independent second variable in the models increases the multiple col-linearity of the model. Adding ρ compounded with D as one variable (D2ρ) in the models decreases the model fitness of single plant and all components, but including ρ as an independent second variable in the models slightly improves the model fitness. Conclusion: The sunlight-loving tree species, A. montana, allocated more biomass to the trunk, while the shade tolerant tree species, C. chinensis, allocated more biomass to the crowns. The shade tolerant tree species have more developed roots. We suggest that the model of D as a single independent variable be used to estimate the biomass of the four species, and H is not recommended to be included in the model as the second variable. Adding ρ as the second independent variable slightly improves the fitting ability of the model. It is suggested to make a trade-off between accuracy and difficulty according to the investigation purpose in practical applications.