Testing the causal mechanism of the peninsular effect in passerine birds
from South Korea
Abstract
The peninsular effect is a geographical phenomenon that explains
patterns of species richness. Hypotheses regarding the peninsular effect
in bird taxa should be more focused on testing not only recent
deterministic processes but also migrant inflow associated with recent
environmental variations. We aimed to identify the latitudinal patterns
of passerine species richness and test hypotheses regarding recent
deterministic processes (climate, primary productivity, habitat
diversity, forest area, and anthropogenic disturbances) and migration
influence (ratio of migrant species richness) in the Korean peninsula.
We used the distribution data of 147 passerine species from 2006 to
2012. Single regression between passerine species richness and latitude
supported the existence of the peninsular effect. Mean temperature
induced by latitude gradient negatively affected LAI and forest area,
and positively habitat diversity. However, passerine species richness
was only influenced by LAI and forest area. Ratio of migrant species
richness increased as decreasing habitat diversity and was not
influenced by LAI and forest area. And we found that ratio of migrant
species richness increased with increasing latitude, and contributed to
the increasing in passerine species richness. No. of patches did not
influenced passerine species richness. These results support the
existence of the peninsular effect in the distribution of passerine
birds induced by recent deterministic processes such as primary
productivity and habitat area, and migrant species inflow caused by
competition.