Silvicultural effects on first-rotation ponderosa pine plantation in northern California: Garden of Eden study

This data publication includes tabular tree measurement data of ponderosa pine grown at six installations in northern California under an experiment named the Garden of Eden study. At each installation, 24 plots under a completely randomized plot design were assigned eight factorial treatment combinations of a control, herbicide to control competing vegetation, fertilizer, insecticide. Due to lack of insect outbreaks and visible damage in the plots as well as surround forests, some plots were thinned between the ages of 8 and 12 based on site quality. Each plot consisted of 20 trees, each of which were measured 5-8 times (varies per installation) between 1986 and 2021. Measurements include: tree height, diameter at 20 centimeters above ground-level when trees were small, diameter at breast height (at 1.37 meters) when they were tall enough, crown width, and height to the live crown. In the early years (trees aged 1-8), additional height measurements were taken by measuring whorls at Elkhorn, Feather Falls, and Whitmore in years where standard tree measurements were not taken. Study site locations are also provided as vector point data in multiple spatial formats.The original objectives of the study were to: (1) to determine the growth potential of planted ponderosa pine in California as constrained or enhanced by moisture availability, nutrient availability, insects, and their interactions; (2) to investigate how these factors affect tree physiology, pest resistance, nutrient and water use, plant succession, and other site processes; and (3) to develop a process-based model to estimate the effects of herbicides, fertilizer, and insecticide treatments over a broad array of forest sites.These data have been summarized in various publications since 1984 (see cross-references listed below).

本数据集收录了在加利福尼亚北部六个实验站点种植的 ponderosa pine 的表格化树体测量数据，这些数据源自名为伊甸园研究的实验。在每个站点，按照完全随机区组设计，分配了24个样地，并对其进行了八个因子的处理组合，包括对照组、用于控制竞争植被的除草剂、肥料和杀虫剂。由于部分样地及周围森林未发生虫害且未出现可见损害，基于站点质量，部分样地在8至12年期间进行了疏伐。每个样地包含20棵树，这些树木在1986年至2021年期间被测量了5至8次（具体次数因站点而异）。测量数据包括：树高、树木幼小时离地面20厘米处的直径、树木足够高大时胸高直径（1.37米）、树冠宽度和树冠顶端高度。在早期年份（树木年龄为1至8年），在标准树木测量未进行的情况下，通过测量Elkhorn、Feather Falls和Whitmore的年轮来获取额外的树高测量数据。研究地点也以多个空间格式提供了矢量点数据。该研究的原始目标包括：（1）确定在加利福尼亚种植的 ponderosa pine 的生长潜力，该潜力受水分、养分、昆虫及其相互作用的影响或增强；（2）探究这些因素如何影响树木生理、害虫抗性、养分和水资源利用、植被演替以及其他地点过程；（3）开发基于过程模型的模型，以估计除草剂、肥料和杀虫剂处理对广泛森林地点的影响。自1984年以来，这些数据已在各种出版物中被总结（见下文列出的交叉引用）。