Dataset of woody plant biomass models for subtropical mixed evergreen and deciduous broad-leaved forest

Evergreen deciduous broad-leaved mixed forest is a zonal vegetation in the climate transition zone between North and South China. It has extremely rich biodiversity and plays an irreplaceable role in biodiversity protection, nutrient maintenance and circulation, climate regulation and so on. Biomass model is the most commonly used method to estimate the biomass of trees and forests on various temporal and spatial scales. It has the characteristics of less damage, high efficiency and high relative accuracy. It is an important basic data for the study of forest ecosystem productivity and carbon sink. This data set searches and collects the biomass model of evergreen deciduous broad-leaved forest based on the plant directory obtained from the investigation of 28.9ha evergreen deciduous broad-leaved mixed forest sample plot (1.9hm2 in Xingdoushan reserve, 15hm2 in qisishan reserve, 6hm2 in Mulinzi reserve and 6hm2 in Jinshan state-owned forest farm). A total of 167 groups of 665 biomass models were obtained. Each model mainly includes species name, life form, estimated plant components, variables, regression model, correlation coefficient（R） or determination coefficient (R2), measurement unit and range of independent variables, sample number and source, etc. Among them, 642 models in 161 groups are at the species level, and 23 models in 6 groups are at the ecosystem level, involving plants in 49 families and 98 genera; The model involves 19 forms of independent variables (diameter at breast height D, base diameter BD, root diameter RCD, tree height H, crown width C, tree age t and their combinations, such as D2H and BD2H) and 5 types of equation forms (388 power function equations, 121 linear equations, 73 polynomial equations, 68 logarithmic equations and 15 exponential equations); 568 models (85.4%) marked the value range of independent variables; 596 models (89.6%) were marked with the number of modeling standard wood; 559 models (84.1%) listed R / R2, ranging from 0.17 to 0.99, with an average of 0.9166. Compared with the existing biomass model data set in China, this data set is established for the subtropical evergreen deciduous broad-leaved mixed forest, which has stronger directivity and richer plant species, fills the research gap, and provides a solid data basis for the estimation of forest biomass and carbon storage in the subtropical region. However, there are still limitations in the data set, and the biomass models of some species and components are still missing. Efforts to improve and improve the database will still be the focus of the next research. 

常绿落叶阔叶混交林，位于南北气候过渡带，乃一区域性植被景观。该区域生物多样性极为丰富，其在生物多样性保护、养分维持与循环、气候调节等方面发挥着不可替代的作用。生物量模型为估算不同时空尺度上的树木与森林生物量最为常用的方法，具有损伤小、效率高、相对精度高的特点，是研究森林生态系统生产力与碳汇的重要基础数据。本数据集基于对28.9公顷常绿落叶阔叶混交林样地（包括星斗山保护区1.9hm2、七里山保护区15hm2、木林子保护区6hm2及金山国有林场6hm2）的植物目录调查，搜寻与收集了常绿落叶阔叶林生物量模型。总计获得665个生物量模型，分为167组。每个模型主要包含物种名称、生活型、估计的植物成分、变量、回归模型、相关系数（R）或确定系数（R²）、测量单位及自变量范围、样本数量及来源等。其中，161组中的642个模型处于物种水平，6组中的23个模型处于生态系统水平，涉及49个科、98个属的植物；模型涉及19种自变量形式（如胸径D、基径BD、根径RCD、树高H、冠幅C、树龄t及其组合，如D²H和BD²H）和5种方程形式（包括388个幂函数方程、121个线性方程、73个多项式方程、68个对数方程和15个指数方程）；568个模型（85.4%）标明了自变量的值域；596个模型（89.6%）标注了建模标准木的数量；559个模型（84.1%）列出了R/R²，其值介于0.17至0.99之间，平均值为0.9166。与我国现有的生物量模型数据集相比，本数据集针对亚热带常绿落叶阔叶混交林建立，具有较强的针对性和更丰富的植物种类，填补了研究空白，为亚热带地区森林生物量及碳储量的估算提供了坚实的数据基础。然而，数据集仍存在局限性，部分物种和成分的生物量模型尚不完整。未来研究将继续致力于数据库的完善与提升。