Above and belowground biomass data for a set of beech trees of different age and crown classes sampled in Hesse state forest (NE France) with a view to analyzing the distribution and the allocation of biomass in the tree

A first set (samples 1 and 2 in the data tables) comprising 23 beech (Fagus sylvatica L.) trees of different crown classes (dominant, co-dominant, intermediate, suppressed), aged 30 in average, was selected and felled in 1996-1997 in a compartment of the state forest of Hesse (NE France). The objective of the study was to establish equations relating the biomass and biomass increment of above and below-ground tree parts to easily measured tree parameters (diameter or girth at breast height in particular), and then to use these relations at the stand level to compare the carbon sequestration in trees to carbon fluxes. In two papers co-authored with ecophysiologists, the carbon sequestration in trees – biomass converted to carbon mass – was favorably compared to carbon fluxes (NPP) at tree and stand levels (1, 2). A more specific paper dealing with the distribution of biomass and biomass increment in the root system divided in root categories (coarse, small and fine) was published in 2001 (3). Later on, in the period 2000-2003, an additional set of 38 beech trees (samples 3 to 7 in the data tables), aged 8-172 and of different crown classes, was selected in different compartments of the state forest of Hesse to establish generalized biomass and biomass increment equations and analyze how the distribution and allocation of biomass in trees change with age. A last paper deals with these issues and was published in 2018 (4). More informations concerning the biomass data collected on the sampled beech trees in Hesse forest can be found in the sections “Material and Methods” of the third and fourth referenced papers. Two data tables with corresponding headings tables are provided: - one for the entire tree sample (61 trees) with data on aboveground tree parts (bole, branches, twigs and leaves) and data on the root system considered as a whole for a subsample of 40 trees ("Beech biomass sample.csv", "Beech biomass headings.xlsx") - one devoted to the subsample of 40 trees with more detailed data on the root system divided into root categories (coarse, small and fine) ("Beech root biomass sample.xlsx", "Beech root biomass headings.xlsx")

本数据集第一组样本（对应数据表中的样本1与2），于1996-1997年间在法国东北部黑森州国有林的一处林班内遴选并伐倒，共包含23株欧洲山毛榉（Fagus sylvatica L.），平均树龄为30年，涵盖优势木（dominant）、伴生木（co-dominant）、中庸木（intermediate）与被压木（suppressed）等不同冠层等级。本研究旨在构建林木地上、地下各组分的生物量及其增量与易测林木参数（尤其胸径，即直径或围径）之间的关联方程，进而在林分尺度上利用该关系对比林木碳固存与碳通量。本团队与生态生理学家（ecophysiologists）合作发表的两篇参考文献（1、2）中，将林木碳固存（即生物量转换为碳质量）与林木及林分尺度下的碳通量（净初级生产力，Net Primary Productivity，NPP）进行对比，结果吻合良好。2001年发表的第三篇参考文献（3）则针对根系系统按根径分级（粗根、小根、细根）的生物量及其增量分布展开专门研究。2000-2003年间，研究团队在黑森州国有林不同林班内又遴选了38株欧洲山毛榉（对应数据表中的样本3至7），其树龄跨度为8-172年，同样涵盖不同冠层等级，旨在构建通用的生物量及其增量方程，并分析林木生物量的分布与分配随树龄的变化规律。2018年发表的第四篇参考文献（4）针对上述问题展开相关研究。有关黑森州国有林内采样山毛榉的生物量采集数据详情，可参见第三、第四篇参考文献的“材料与方法（Material and Methods）”章节。本数据集附带两份数据表及对应表头文件：- 一份针对全部61株林木样本，包含地上组分（主干、枝条、小枝与叶片）的相关数据，以及40株子样本的整株根系系统数据，对应文件为"Beech biomass sample.csv"与"Beech biomass headings.xlsx"；- 另一份专门针对该40株子样本，包含按根径分级的根系详细数据，对应文件为"Beech root biomass sample.xlsx"与"Beech root biomass headings.xlsx"