An evaluation of alternative dispersal functions for trees
Article first published online: 16 SEP 2004
Journal of Ecology
Volume 92, Issue 5, pages 758–766, October 2004
How to Cite
GREENE, D. F., CANHAM, C. D., COATES, K. D. and LEPAGE, P. T. (2004), An evaluation of alternative dispersal functions for trees. Journal of Ecology, 92: 758–766. doi: 10.1111/j.0022-0477.2004.00921.x
- Issue published online: 16 SEP 2004
- Article first published online: 16 SEP 2004
- Received 26 January 2004 revision accepted 15 June 2004; Handling Editor: Mark Williamson
- inverse modelling;
- seed dispersal;
- tree regeneration
- 1We compared three commonly used empirical seed/seedling dispersal functions for trees (lognormal, 2Dt, and two-parameter Weibull) by analysis of published studies where the location of the source is known, as well as by inverse modelling within an old growth hardwood forest in southern Quebec. Almost all the species were wind-dispersed.
- 2For the discrete source studies, the lognormal was clearly superior, while for the inverse modelling the performance of the three dispersal functions was somewhat more even. We speculate that collisions with boles spuriously enhanced the likelihood of the 2Dt and the Weibull with inverse modelling, as both these functions assume that the greatest seed/seedling density will occur at the base of the maternal parent bole.
- 3We conclude that the lognormal function is to be preferred because, as well as providing a framework for mechanistic interpretation, it tends to provide a closer approximation to observed dispersal curves.
- 4We also argue that mean distances travelled by seed crops are far more extensive than indicated by previous studies that used the Weibull function.