Flower counts in the black sand extended growing season experiment, 2023.

As a result of climate change, the Rocky Mountain Front Range is
experiencing warmer summers and earlier snowmelt. Due to the
importance of snow for regulating soil temperature, growing season
length, and available moisture in alpine ecosystems, even small
shifts in the snow-free period could have large impacts. The focus
of the Black Sand Extended Growing Season Length Experiment is to
examine how terrain-related differences in climate exposure
influence the way alpine habitats respond to climate change via
earlier snowmelt. To simulate how climate exposure may affect plant
communities, NWT LTER researchers established 5 experimental sites
each containing a pair 10 x 40m rectangular plots. These sites
include north and south facing aspects, subalpine and alpine tundra
meadows in a range of hydrological conditions (e.g. dry meadows,
moist meadows, wet meadows). We accelerated snowmelt in one plot of
each block by adding chemically inert black sand, while keeping the
second plot as an unmanipulated control; black sand was added to
these plots after snow had naturally melted. This dataset includes
~biweekly flower counts from late June – late August 2023, which can
be used to estimate onset, peak, and end of flowering and how these
might change under a longer growing season due to black sand
application.