Effects of population density on the fruit set of Litsea cubeba.

Abstract

Fruit set of Litsea cubeba, a range-expanding dioecious small tree species, was measured for females with different population densities in Tottori prefecture. The ratio of mature fruits to flowers of females in low density site was significantly lower than in high density site. Distance to the nearest male tree was significantly longer for females in low density site than in high density site, while stem diameter, growth rate of stem diameter and relative growth rate of stem diameter were not significantly different between females in low and high density sites. These results suggested the density-dependent fruit set and pollen limitation in a lower density population of Litsea cubeba.