Population dynamics
Confirming the first prediction, the landscape metrics indicate that the
cushion individual distributions in low-elevation communities
(i.e. , experiencing warmer conditions) are more fragmented than
that in high-elevation communities (i.e. , experiencing colder
conditions; Figure 2). Specifically, we found that four key metrics areca. 40–90% lower in warmer communities than in colder
communities (Table S1). Two are the total cushion patch area (CA) and
the mean cushion patch area (Area_Mn), the other two are the percentage
of core area of the landscape containing cushions (CPLAND) and
percentage of like adjacencies of patch types (PLADJ). However, the
number of cushion patches (NP) and edge density (ED) in warmer
communities are ca. 30% - 1000% higher than these parameters in
colder communities (Table S1). Additionally, a large proportion of the
area of the warmest (i.e. , lowest elevation) community was
previously occupied by individual cushions (now traces of dead
cushions), but this proportion decreases with decreases in temperature
(i.e. , elevation) and no cushion traces were detected in the
coldest (i.e. , highest elevation) community (Figure 1). All above
results suggest that a large number of individual cushions will be
excluded due to ongoing climate warming (Figure 1), resulting in more
rapid population turnover.