Effect of management activities on forest soil properties in the Rocky Mountains: I. Understory vegetation

This data set contains vegetation measurements collected in a study that was designed to determine how mechanical site preparation and prescribed fire affected understory vegetation growth, conifer establishment and growth, and soil physical and chemical properties of some Rocky Mountain national forests. The treatments (listed by treatment code) applied to the sites included the following: 1 = bole removed followed by broadcast burn, 2 = bole removed followed by dozer or grapple pile, 3 = control (undispersed), 4 = whole tree removal (only in 1990 Helena/Deerlodge Forest), and 9 = burned only. Not every treatment was used in each forest. The data in this publication were collected over a five-year period (1989-1993) from 11 national forests located in Montana, Idaho, and Arizona. The data focus on the recovery of understory vegetation after treatment. It consists of information on habitat types (Pfister et al. 1977) at each sample location, estimates of cover for all species present at the sample location, and estimates of height for each species present. The original intent of the study was to summarize the data to an individual stand so returning to each stand for additional sampling in subsequent years was not planned and plot locations were not permanently marked. However, written or diagrammed descriptions of the location of each sample site exist on the sample forms. These descriptions are included with these archived data in case there is a future need to return to the sample areas.
The overall purpose of this study was to determine how management practices, such as burning, machine piling, scarifying, and scalping, change the character of the organic-rich surface soil layer; and how this change affects seed sprouting, seed-growth performance, and mycorrhizal development that maintains vegetation in these Rocky Mountain forests. The specific purpose of the understory vegetation research was to determine if vegetation composition changed depending on whether the site was dozer piled or prescribe burned compared to an adjacent unharvested area and whether soil chemistry changes caused by the treatments may have affected seed germination and seed spread throughout the stand.
There are six separate data publications containing the data collected to examine the effect of management activities on forest soil properties in the Rocky Mountains: I. understory vegetation; II. tree, stump, and downed woody debris data (variable plots and transects); III. soil core data; IV. soil chemistry data; V. burn and soil surface conditions; and VI. microsite data. Data were originally published on 08/04/2021. Minor metadata updates were made on 09/24/2021.