Destructive harvest data collected from four large tropical rainforest trees in Floresta Nacional de Caxiuanã

Title ----- Destructive harvest data collected from four large tropical rainforest trees in Floresta Nacional de Caxiuanã Authors ------- A. Burt M. Boni Vicari A. C. L. da Costa I. Coughlin P. Meir L. Rowland M. Disney Contact ------- [e-mail] License ------- These data are distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC BY 4.0) - see the LICENSE file for details. Overview -------- We harvested four large tropical rainforest trees (diameter range: 0.6-1.2m, height range: 30-46m) in a natural closed forest stand in Floresta Nacional de Caxiuanã, Pará, Brazil (approx. coordinates in the WGS-84 datum: -1.798, -51.435 degrees), during August/October 2018. The objective was to measure the green mass of each tree in its entirety, and to measure woody tissue green-to-dry mass and volume ratios, and basic/green/dry woody tissue density. A complete description of the four trees, these data, and the companion terrestrial lidar data (collected pre-harvest) can be found in our paper entitled: ‘New insights into large tropical tree mass and structure from direct harvest and terrestrial lidar’. Acquisition ----------- Field measurements: Neighbouring vegetation surrounding each tree was removed, including complete clearing of the felling area. Stem diameter was measured using a circumference/diameter tape at either 1.3m above-ground, or 0.5m above-buttress. Each tree was felled onto tarpaulin using a STIHL MS 650 chainsaw with a 20” bar length and 13/64” chain loop. Tree height (incl. stump) was measured with a surveyor's tape measure, and GPS data were acquired from the centre of the stump using a Garmin GPSMAP 64st. The stem (incl. stump) and crown were cut into manageable sections, and the mass of each section was measured via weighing using two Adam LHS 500 crane scales. Mass measurements commenced immediately post-felling, requiring two, four, four and two days to complete measurement of CAX-H_T1 to CAX-H_T4 respectively. Multiple discs (approx. 50mm thick) were also collected from each tree: at 1.3m and 25%, 50% and 75% the length of the stem, and up to 3x discs were taken from the mid-points of 1st, 2nd and 3rd order branches (totalling a minimum of 11 discs per tree). Foliage/fruit samples were retained to confirm taxonomic identity at the Museu Paraense Emílio Goeldi, Belem, Pará, Brazil. Laboratory measurements: All discs were reduced to a set of subsamples using a consistent approach: for any particular disc, they were cut as guided by parallel chords straddling above and below the major axis, each with approximate dimensions of 150mm x 50mm x 50mm (i.e., each set included periderm, phloem, cambium, xylem and pith tissues). Mass and volume measurements were made on each subsample in a green and dry state. Subsamples were considered in a green state after soaking for 48 hours, and a dry state once a constant mass had been attained whilst drying in an oven at 105 degree Celsius. Mass was measured using an Adam NBL4602i Nimbus Precision balance, and volume measurements were made on the same balance via Archimedes’ principle. Processing ---------- Dry mass was estimated from measured green mass and an estimate of whole-tree woody tissue green-to-dry mass ratio. Whole-tree woody tissue green-to-dry mass ratio was estimated by weighting the mean value from subsamples in each pool (stem and crown), by the green mass in each pool. This mass-weighted approach was also used for estimating whole-tree woody tissue green-to-dry volume ratio and whole-tree basic/green/dry woody tissue density. File and directory naming convention ------------------------------------ The four trees are identified: CAX-H_T1, CAX-H_T2, CAX-H_T3 and CAX-H_T4. The various files and directories are described as follows: ./CAXH-H/ ├───overview/ │ ├───cal_cert/ (Directory: contains balance calibration certificates) │ ├───images/ (Directory: various photographs illustrating the field and laboratory measurements) │ ├───sentinel-2 (Directory: contains RGB and NDVI images from Sentinel-2 data over the harvest site during the campaign dates) │ ├───CAX-H.results.xlsx (File: top-level results) ├───CAX-H_T1/ (Directory: tree-level directories) ├───CAX-H_T2/ ├───CAX-H_T3/ ├───CAX-H_T4/ │ ├───fieldsheets/ │ │ ├───CAX-H_T4.fieldsheets.pdf (File: fieldsheets from the original campaign) │ │ ├───CAX-H_T4.remeasurement.fieldsheets.pdf (File: fieldsheets from the remeasurement campaign) │ ├───gps/ │ │ ├───CAX-H_T4.gps.txt │ ├───media/ (Directory: contains various photographs and videos of the field measurements, and the discs and subsamples) │ ├───CAX-H_T4.results.xlsx (File: tree-level results)标题——在卡克苏阿纳国家森林公园（Floresta Nacional de Caxiuanã）采集的4株大型热带雨林乔木破坏性采伐数据 作者——A. Burt、M. Boni Vicari、A. C. L. da Costa、I. Coughlin、P. Meir、L. Rowland、M. Disney 联系方式——[e-mail] 许可证——本数据集遵循知识共享署名4.0国际公共许可协议（CC BY 4.0）分发，详细条款请参见LICENSE文件。 研究概述——本研究于2018年8月/10月，在巴西帕拉州卡克苏阿纳国家森林公园（Floresta Nacional de Caxiuanã）的天然封闭林分中，对4株大型热带雨林乔木开展破坏性采伐（胸径范围0.6~1.2m，树高范围30~46m），采样点WGS-84坐标系近似坐标为-1.798、-51.435度。本研究的核心目标为：完整测定单株乔木的鲜重，测定木质组织鲜重-干重比与体积比，以及基本/鲜/干木质组织密度。关于4株乔木、本数据集及配套的地面激光雷达（terrestrial lidar）观测数据的完整描述，请参见我们发表的题为《基于直接采伐与地面激光雷达的大型热带乔木生物量与结构新认知》的论文。 数据采集—— 野外测量：移除每株乔木周边的植被，包括采伐区域的全面清场。使用围径/直径卷尺，在地上1.3m处或伐桩以上0.5m处测定茎干直径。使用配备20英寸导板、13/64英寸链环的STIHL MS 650链锯，将每株乔木伐倒至防水布上。使用测绳测定树高（含伐桩），并使用Garmin GPSMAP 64st GPS设备从伐桩中心获取定位数据。将茎干（含伐桩）与树冠切割为便于操作的分段，使用两台Adam LHS 500吊秤对每个分段的重量进行称量。采伐后立即开展重量测定，CAX-H_T1至CAX-H_T4的测定工作分别耗时2天、4天、4天与2天完成。从每株乔木上采集多个厚度约50mm的圆盘试样：分别在茎干1.3m处，以及茎干长度的25%、50%、75%位置；同时从1级、2级、3级侧枝的中点采集最多3个圆盘试样（单株乔木至少采集11个圆盘试样）。留存叶片/果实样本，用于在巴西帕拉州贝伦市的帕拉恩塞埃米利奥戈埃尔迪博物馆（Museu Paraense Emílio Goeldi）进行分类学鉴定。 实验室测量：所有圆盘试样均采用统一方法制备子样本：对于任意圆盘，以横跨其长轴上下的平行弦为参照进行切割，每个子样本的近似尺寸为150mm×50mm×50mm（即每个子样本包含周皮、韧皮部、形成层、木质部与髓组织）。对每个子样本分别在鲜态与干态下进行质量与体积测定。子样本鲜态测定前需浸泡48小时，干态测定则需在105摄氏度烘箱中烘干至恒重。使用Adam NBL4602i Nimbus精密天平测定质量，并通过阿基米德原理在同一天平上完成体积测定。 数据处理——通过实测鲜重与全树木质组织鲜重-干重比的估算值，计算干重。全树木质组织鲜重-干重比的估算方法为：以茎干组与冠组的子样本平均值为基础，按照各组的鲜重进行加权平均。该质量加权方法同样用于估算全树木质组织鲜重-干体积比，以及全树基本/鲜/干木质组织密度。 文件与目录命名规范——4株乔木的标识为：CAX-H_T1、CAX-H_T2、CAX-H_T3与CAX-H_T4。各类文件与目录的说明如下： ./CAXH-H/ ├───overview/ │ ├───cal_cert/ （文件夹：包含天平校准证书） │ ├───images/ （文件夹：展示野外与实验室测量过程的各类照片） │ ├───sentinel-2/ （文件夹：包含本次作业期间采集区域的哨兵二号（Sentinel-2）RGB影像与归一化差异植被指数（NDVI）影像） │ ├───CAX-H.results.xlsx （文件：顶级结果汇总文件） ├───CAX-H_T1/ （单株乔木专属目录） ├───CAX-H_T2/ ├───CAX-H_T3/ ├───CAX-H_T4/ │ ├───fieldsheets/ │ │ ├───CAX-H_T4.fieldsheets.pdf （文件：原始作业野外记录表） │ │ ├───CAX-H_T4.remeasurement.fieldsheets.pdf （文件：复测作业野外记录表） │ ├───gps/ │ │ ├───CAX-H_T4.gps.txt │ ├───media/ （文件夹：包含野外测量、圆盘试样与子样本的各类照片与视频） │ ├───CAX-H_T4.results.xlsx （文件：单株乔木结果文件）