Shrub effects on seeding establishment, 2019 - 2020.

Plant communities in mountain ecosystems are particularly vulnerable
due to amplified rates of warming (Pepin and Lundquist, 2008; Pepin
et al., 2015) and declines in snowpack (Fyfe et al., 2017). As a
result of these global change drivers, there is a widespread pattern
of biotic shifts in the alpine (Bueno de Mesquita et al., 2018).
However, it is unclear how important these biotic shifts will be in
mediating the response of other species to global change. For
example, the uphill movement and expansion of structure-forming
species (e.g. trees, shrubs, cushion plants), can create small-scale
variations in the conditions experienced by species (microclimates)
through their effects on snow, wind, solar radiation, and soil
properties (Holtmeier and Broll, 1992; Seastedt and Adams, 2001;
Pistón et al., 2018; Chen et al., 2019). One such expanding
structure-forming group of species are shrubs—the expansion and
densification of shrubs is occurring in arctic and alpine zones
across the globe (Myers-Smith et al., 2011; Formica et al., 2014;
Elmendorf et al., 2012b, 2012a).Shrub microclimatic effects can
alter fine-scale variability across the landscape, which may have
important consequences for plant communities through increased
heterogeneity and modified exposure. For instance, the microclimatic
effects shrubs in the alpine may facilitate the establishment of
subalpine species that need to migrate uphill to track their
climatic niche (Akhalkatsi et al., 2006; Martínez, 2012; Cranston
and Hermanutz, 2013). References Akhalkatsi, M., Abdaladze, O., Nakhutsrishvili, G., and Smith, W.
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