Figure 4. Proportion of species whose distributions are shaped
by limited (‘dispersal limitation’, dark red data), sufficient (‘species
sorting’, gray data), or excess (‘sink populations’, light blue data)
dispersal across the productivity gradient, as communities are connected
by dispersal to form a larger metacommunity. Data shown separately for
the (A) ‘with neighbors’ and (B) ‘without neighbors’
treatments, respectively. Dispersal outcomes of species are categorized
as follows: ‘dispersal limitation’ occurs when species can persist but
are absent from a location, ‘species sorting’ is when a species is
present where it can persist or is absent where it cannot persist, and
‘sink populations’ are when species cannot persist at the current
population size, but are present. Productivity is represented by a
green-red vegetation index, where less productive sites are towards the
left. Proportions are based on a maximum number of four species (the
number of focal species used in our experiment). Points are the raw data
jittered for interpretability, lines and 95% confidence bands are
fitted from our models.