Overstory tree measurements from a long-term western larch spacing and thinning study in northwestern Montana, 1961-2015

This data publication contains data for four replicates of a western larch spacing study in northwestern Montana. The core study was established in 1961 and remeasured every five years until 2001, with the exception of 1996. Data were collected again in 2015. The core study measured growth metrics of individual trees based on different thinning treatments and stocking levels. These quantative and qualitative metrics included species, diameter at breast height, tree height, crown dimensions (width, length, base, and height), vigor, crown class, crown density, qualitative damage assessment, and diameter at one bole height.
The spacing study was established to develop spacing guides for the management of young western larch for any single or combination of desired end-products. It also sought to determine what effect stocking level, thinning intervals, and shrub competition have on a variety of aspects of western larch growth and health. The study was focused on western larch stands that were approximately ten years old at the start of the study and intended to run for 40 years. The study was measured once more after this initial 40-year tenure in 2015 and is now planned to be maintained for at least 100-years.
This core study is referred to as study 496 internally. The study sites are known colloquially as Coram 1, Coram 2, Cottonwood, and Pinkham. This is reflected in many of the data and supplemental materials provided in this data packet. There were several other studies supplementing the core study, see cross-references for more information. This data publication was original published on 09/21/2021. On 10/28/21 the metadata was updated to include reference to another related data publication that is now available.