Influence of Land Cover on Woody Plant Encroachment in the Northern Rocky Mountains: A Geospatial Analysis
Abstract/Contents
- Abstract
- Over the last 100 to 160 years, shrubs and trees have been proliferating across grasslands in the American West as part of a global phenomenon called woody plant encroachment (WPE). WPE has resulted from changing climatic conditions and the removal of natural processes that have historically inhibited the spread of woody plants and leads to decreased forage availability for livestock, uncertain or negative changes to ecosystem services, and worsening wildfires. In this study, LANDFIRE Existing Vegetation Type data and tree-rangeland classifications from the 1950’s and 2019 were used to calculate the amount of conifer cover change that occurred in a variety of vegetation types and elevation zones over approximately 60 years across a portion of the High Divide region in Idaho. This was done in an effort to determine if and to what degree WPE is influenced by biophysical conditions and existing vegetation type. This data was also used to investigate whether conifer cover growth tends to densify existing forest stands or spread to previously unforested areas and how strong this preference is over relatively long time scales. Existing vegetation type, and specifically the amount of pre-existing forest cover, was found to be strongly related to conifer cover change. Varying amounts of pre-existing forest cover across elevation zone classes created a confounding effect that prevented determination of the impact of elevation on WPE without additional analysis. Finally, the analysis indicated that conifer cover increase was more likely to densify existing forest stands than to result in colonization of unforested areas which has substantial implications for increased wildfire severity risk across U.S. rangelands.
Description
| Type of resource | text |
|---|---|
| Publication date | March 28, 2023 |
Creators/Contributors
| Author | Cochrane, Sheila |
|---|---|
| Thesis advisor | Lambin, Eric |
Subjects
| Subject | Woody plant encroachment |
|---|---|
| Subject | Conifer expansion |
| Subject | forest densification |
| Subject | High Divide |
| Subject | Northern Rocky Mountains |
| Genre | Text |
| Genre | Thesis |
Bibliographic information
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- This work is licensed under a Creative Commons Attribution Non Commercial 4.0 International license (CC BY-NC).
Preferred citation
- Preferred citation
- Cochrane, S. (2023). Influence of Land Cover on Woody Plant Encroachment in the Northern Rocky Mountains: A Geospatial Analysis. Stanford Digital Repository. Available at https://purl.stanford.edu/rn554ft7660. https://doi.org/10.25740/rn554ft7660.
Collection
Master's Theses, Doerr School of Sustainability
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- smvc@alumni.stanford.edu
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