Tumultuous Treeline: Creating a Better Alpine Map

Broadly defined, the alpine zone is the area above treeline and below permanent snow. However, the alpine in practice is more difficult to pin down. While temperature is understood to be the leading factor in the transition to treelessness, the alpine paradoxically resists traditional mapping efforts, with many classification attempts excluding smaller alpine areas, such as the peaks of mountains. However, some of these “barely-alpine” regions are home to rare and endemic alpine plants, so it is imperative that they are included in our alpine analysis. Over the last several years, creating a more exact and comprehensive map of the alpine regions of North America has been a high priority of the North American Botanic Garden Strategy for Alpine Plant Conservation (the Alpine Strategy). The Alpine Strategy, published in 2020 by Betty Ford Alpine Gardens and Denver Botanic Gardens, is a blueprint for the protection of high-elevation flora and habitats with a focus on the role of botanic gardens. Building on existing models, we used data from a variety of sources, including multispectral imagery, temperature data, land cover classification, and historical records of known alpine plants to create a new map of the alpine landscape, with many iterations proving unsatisfactory until now. The Alpine Map is fundamental to our conservation efforts and we look forward to the use of this new tool for all of our Alpine Strategy partners and beyond.