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).