Soil water content measurements from a long-term western larch spacing and thinning study in northwestern Montana, 1967-1991

This data publication contains soil water data collected at the western larch spacing study in western Montana. It is a supplement to the core study that was established in 1961 and was conducted on the same four replicate sites as the original study. Percent soil water content was quantified using a neutron probe and access tubes for repeat measurements. Measurements of soil water, taken at 12-inch intervals from 6 to 102 inches, were collected approximately every other week during the growing season in 1967-1969, 1971, 1976, 1981, 1983-1984, 1986, and 1988-1991. Minimum and maximum air temperature as well as precipitation measurements are also provided for the dates soil water data were collected.
This study expands on the original western larch spacing study, which was established to develop spacing guides that could be used in the management of young western larch for any single or combination of desired end-products. The original study focused on thinning western larch stands that were approximately ten years old at the start of the study and was intended to continue for 40 years. This data package is one of multiple supplements to the spacing study. It was designed to assess the effects of tree spacing (i.e., stem density) on stand water usage. Moreover, it was designed to determine the basic process of water use in larch stands, including the amount, rate, and period of soil moisture use by vegetation under various levels of site occupancy.
For information on the core study and associated supplementary studies see Wyman (1998) and Hayes et al. (2021).