Tree establishment in subalpine meadows is a multistep process, from cone production through adult survival, and a potential indicator of ecological effects of climate change.
While most studies have focused on one or a few steps, this study follows a cohort of individually marked subalpine fir saplings for 27 years in two south-facing, tall-sedge meadows in Olympic National Park. Mortality was high for the first few years, but the number of saplings stabilized after the first decade, persisting mainly in lichen and huckleberry communities. Seedling mortality during germination and establishment was directly related to high temperatures and drought, while mortality of established saplings was indirectly related to weather through effects on growth. Growth was enhanced by a longer growing season and warmer minimum temperatures. While microsite factors such as snow depth are important in determining sapling success, the landscape or meadow orientation - such as north vs. south aspect - exerts control over whether a subalpine meadow is likely to disappear with warming climate.
Woodward, A., Soll, J.A., 2021, Establishment and Survival of Subalpine Fir (Abies lasiocarpa) in Meadows of Olympic National Park, Washington: Northwest Science, v. 94, no. 3-4, p. 256-270, https://doi.org/10.3955/046.094.0304.