Bartlett Experimental Forest permanent cruise plot data: 2nd edition

This data publication contains overstory tree measurements collected between 1931 and 2017 at the Bartlett Experimental Forest in Bartlett, New Hampshire. These cruise plots measure all trees greater than 1.5 inches in diameter at breast height, across a 0.25 acre plot. Plots were installed and first inventoried in 1931-1932, with follow-up in 1939-1940. Since then, there were partial remeasurements in the 1950s and 1960s of compartments scheduled for harvesting treatment followed by complete remeasurements in 1991-1992, 2001-2003 and 2015-2017. Data are available in several data sets. 1) Overstory measurements from 1931-1992 including species codes, diameter class (1 inch classes), and count; 2) Overstory measurements from 2001-2003 including species codes, diameter class (1 inch classes), and count; 3) Overstory measurements from 2015-2017 including species codes, diameter class (1 inch classes), live/dead, and count; 4) Seedling data from 2015-2017 including species codes, live/dead, and count; 5) Sapling data from 2015-2017 including species codes diameter class (1 inch classes), live/dead, and count; 6) Height data from 2015-2017 including species codes, diameter at breast height (to the nearest 0.1 inch), location, and height; 7) compartment spatial data; and 8) compartment history. Additionally, approximately 3% of the over 56,000 tree records from 2001-2003 include height, crown and diameter at breast height (to the nearest 0.1 inch) measurements.
The primary objective of the cruise plots at the Bartlett Experimental Forest (BEF) is to establish a uniform study area to study the silviculture of northern hardwoods with a strong focus on impacts and interactions with birds and mammals. The BEF is divided into Compartments, which are delineated based on size distribution, stand condition, species composition, and topography. This publication includes all plots from the original footprint of the Bartlett Experimental Forest, as well as those within the expansion compartments added in 2005. Numerous studies have been conducted within the 48 original Compartments. For a complete list of Compartment-level silvicultural treatments, cruise plot numbers and Compartment assignments as well as a list of major studies see the Supplements folder in the full data publication download.
We strongly encourage that users read the accompanying documentation provided with the full data publication download before proceeding with data summary or analysis. Contact Olivia Fraser ([e-mail]) if you have questions or if interested in collaboration.

This data publication is a second edition, which spans 1931-2017. This newer edition includes all data from the first edition (https://doi.org/10.2737/RDS-2017-0036) which only included data from 1931-2003, but also adds 2015-2017 seedling, sapling, and tree height measurements. A few additional supplemental files have been included, along with an update to the field manual.

本数据集发布内容包含1931年至2017年间，在新罕布什尔州巴特利特的巴特利特实验森林（Bartlett Experimental Forest, BEF）采集的上层林木测量数据。这些清查样地覆盖0.25英亩的区域，测量所有胸径（diameter at breast height）超过1.5英寸的林木。样地于1931-1932年设立并完成首次清查，后续于1939-1940年开展复查。此后，研究人员于1950至1960年代对计划实施采伐处理的林分分区开展部分复测，并分别于1991-1992年、2001-2003年及2015-2017年开展全面复测。
数据集以8个分册形式提供：1）1931-1992年上层林木清查数据，包含物种代码、径级（以1英寸为一档）及株数；2）2001-2003年上层林木清查数据，包含物种代码、径级（以1英寸为一档）及株数；3）2015-2017年上层林木清查数据，包含物种代码、径级（以1英寸为一档）、存活/死亡状态及株数；4）2015-2017年幼苗数据，包含物种代码、存活/死亡状态及株数；5）2015-2017年幼树数据，包含物种代码、径级（以1英寸为一档）、存活/死亡状态及株数；6）2015-2017年树高测量数据，包含物种代码、胸径（精确至0.1英寸）、位置信息及树高；7）林分分区空间数据；8）林分分区历史记录。
此外，2001-2003年的56000余条林木记录中，约3%附带了树高、冠幅及胸径（精确至0.1英寸）的测量数据。
巴特利特实验森林（Bartlett Experimental Forest, BEF）的清查样地核心目标为建立标准化研究区域，以开展北方硬阔林营林研究，重点关注其与鸟类、哺乳类的影响及种间互作关系。该实验森林按林分大小分布、林分状况、物种组成及地形划分为多个林分分区（Compartments）。本数据集涵盖巴特利特实验森林原始范围内的全部清查样地，以及2005年新增扩建林分分区内的样地。48个原始林分分区内已开展多项研究工作。如需获取林分分区营林处理详情、清查样地编号、林分分区分配表及主要研究清单，请查阅完整数据集下载包中的“补充材料”文件夹。
我们强烈建议用户在开展数据汇总或分析前，先阅读完整数据集下载包中附带的官方说明文档。如有疑问或合作意向，请联系Olivia Fraser（邮箱：[e-mail]）。
本数据集为第二版，收录周期覆盖1931-2017年。新版数据集包含仅收录1931-2003年数据的第一版（https://doi.org/10.2737/RDS-2017-0036）的全部数据，同时新增了2015-2017年的幼苗、幼树及树高测量数据。此外，本版还新增了部分补充文件，并更新了野外操作手册。