Spatial concordance between seed rain and seedling establishment in bird-dispersed trees: does scale matter?
Article first published online: 19 APR 2005
Journal of Ecology
Volume 93, Issue 4, pages 693–704, August 2005
How to Cite
GARCÍA, D., OBESO, J. R. and MARTÍNEZ, I. (2005), Spatial concordance between seed rain and seedling establishment in bird-dispersed trees: does scale matter?. Journal of Ecology, 93: 693–704. doi: 10.1111/j.1365-2745.2005.01004.x
- Issue published online: 19 APR 2005
- Article first published online: 19 APR 2005
- Received 22 November 2004 revision accepted 20 January 2005 Handling Editor: Michael Hutchings
- post-dispersal seed predation;
- seed dispersal;
- spatial heterogeneity
- 1We explored whether seedling recruitment was spatially predicted by seed rain (spatial concordance) at different scales (microsite, microhabitat and site) in the bird-dispersed trees Crataegus monogyna, Ilex aquifolium and Taxus baccata, in temperate secondary forests in north-west Spain.
- 2We propose that both spatial concordance within each scale and consistency of concordance patterns across scales are dependent on differences between seed rain and post-dispersal processes in the partitioning of spatial variance at each scale.
- 3We measured the density of dispersed seeds, the percentage of post-dispersal seed predation by rodents and the density of emerged first-year seedlings at sampling stations distributed throughout five microhabitats (under canopies of parental trees and in open gaps) and four localities over two seasons.
- 4Seed rain density of all tree species varied most at the microhabitat scale, but microsite and site differences accounted for most of the spatial variance in post-dispersal seed predation and, especially, in seedling establishment.
- 5All three species showed concordance between seed rain and seedling establishment at the microhabitat scale, because strong patchiness in avian-generated seed rain overrode the slight uncoupling effects exerted by the more homogeneous post-dispersal processes. Seed rain was also a good predictor of recruitment of Ilex and Crataegus at the microsite scale, but, for Taxus, the rather homogeneous dispersal across microsites contrasted with the heterogeneous post-dispersal losses. At the site scale, only Taxus showed a positive trend of concordance.
- 6Concordance patterns were maintained from microsite to microhabitat in Crataegus and Ilex, and from microhabitat to site in Taxus. Low-variance allocation to the site scale at the seed rain stage precluded complete consistency in Crataegus and Ilex.
- 7Positive responses of recruitment to seed dispersal depended on both species and scale, resulting in a complex template for dispersal-limitation effects on metapopulations and communities.