Population succession and associated plant diversity change
In efforts to elucidate the succession processes of cushion-dominated communities, we randomly selected 90 living and 109 trace individual cushions of the PJ1 population, 98 and 94, respectively, of the PJ2 population, as well as 154 and 149, respectively, of the PJ3 population. As the vegetation cover and number of individual cushion traces decrease and the population density increases with increases in elevation, we considered PJ1 as a ‘climax (relatively stable) community’, PJ2 as a ‘balanced community’ and PJ3 as a ‘primary community’. We counted and recorded all beneficiary species associated with each selected individual, and their abundance (number of individuals). The PJ4 population was ignored in this analysis because beneficiary cover in individual cushions of this population was too low, i.e. , few beneficiaries occupied the cushion surfaces, and no cushion trace was detected. Thus, we could not assess the potential replacement of the species in the PJ4 population.