Abstract : Rodent-mediated seed dispersal largely affects the
regeneration and colonization of the forest vegetation. However, due to
the steep topography, complex terrains and the heavy anthropogenic
logging from 1970s to 1990s, the secondary succession process of the
forest is greatly inhibited where temperate deciduous broadleaf forests
were the zonal vegetation. Previous studies have ignored the seed
dispersal limitation mechanism among different slope positions in
montane forests. We established 90 sample plots in
Taihang Mountains among different
slope positions (i.e., ridge, midslope and valley), and investigated the
characteristics of seed removal rate, seed fate and seed dispersal
distance of Quercus wutaishanica forest according to three slope
positions. The results showed
that only one from each of the three rodent species was captured at the
ridge, while 52.1% and 43.8% of the small rodents were found in valley
and midslope, respectively.
Compared to the ridge whose
almost all released seeds were intact in site, the seed removal rates
were significantly higher in midslope and valley, and the proportions of
scatter hoarded in ridge and midslope were significantly different,
while both has no significant difference with that in
valley. The average seed
dispersal distance in midslope was 4.78 m, significantly greater than
that in valley, while that of the ridge was only 2.09 m.
Therefore, the midslope had the
best seed dispersal, but the seed dispersal of ridge was severely
restricted, providing the first empirical evidence for the Mid-domain
Effect model and the Resource Availability Hypothesis. These results
provide a better understanding of the dispersal limitation mechanism of
the oak forest and the plant-animal interactions system in mountainous
areas.
Keywords :
slope
position; rodent; dispersal limitation; seed dispersal; seed predation;
Taihang Mountains