Reproductive biology of gorse, Ulex europaeus (Fabaceae) in the mount lofty ranges of South Australia and Sri Lanka.
The present study aims at understanding how certain traits of gorse (Ulex europaeus L.) contribute to its reproductive success in two climatically distinct regions in its invasive range, South Australia and Sri Lanka. We examined three different traits, namely seed production per pod, pod predation and the density of seeds in the soil seed bank. Our results suggest that gorse populations in Sri Lanka had higher seed numbers per pod compared with gorse populations in South Australia. We found that predation of pods was negligible in our study sites in both countries during the period of study; although the literature shows that predation in gorse strongly depends on the time period. We observed significant differences in the density of gorse seeds in the top 5 cm layer of the seed bank between 3 m away from shrubs and under gorse shrubs. The estimated density of gorse seeds under shrubs in Sri Lanka was 2141/m2 which was 1.5 times higher than that of South Australia. This information can be useful to design strategies (i.e., biocontrol measures) for the control and management of gorse in countries in its invasive range.