Allee effects within small populations of Aconitum napellus ssp. lusitanicum, a protected subspecies in northern France
Article first published online: 28 JUN 2008
© The Authors (2008). Journal compilation © New Phytologist (2008)
Volume 179, Issue 4, pages 1171–1182, September 2008
How to Cite
Le Cadre, S., Tully, T., Mazer, S. J., Ferdy, J.-B., Moret, J. and Machon, N. (2008), Allee effects within small populations of Aconitum napellus ssp. lusitanicum, a protected subspecies in northern France. New Phytologist, 179: 1171–1182. doi: 10.1111/j.1469-8137.2008.02529.x
- Issue published online: 6 AUG 2008
- Article first published online: 28 JUN 2008
- Received: 13 February 2008Accepted: 28 April 2008
- flower density;
- germination rate;
- isolation distance;
- local density;
- pollen limitation;
- pollen supplementation;
- seed production;
- seed quality
- • Plants growing at low density can suffer from Allee effects as a result of pollen limitation. Previous studies of Allee effects have focused on the effects of variation among populations in size or density on reproduction. Here, the effects of plant distribution within populations on fitness components are explored in a rare plant, Aconitum napellus ssp. lusitanicum, and ecological and genetic mechanisms underlying these effects are identified.
- • To detect pollen limitation, seed production was compared under natural versus hand-supplemented pollinations on inflorescences of different sizes in natural patches differing both in flower density and in isolation from other patches. Germination rate and juvenile survival of seeds produced in low- and high-density patches were also compared.
- • Pollen-supplemented flowers always produced more seeds than open-pollinated flowers, especially among small plants and plants growing at low density. Offspring produced in low-density patches exhibited lower fitness that those produced in high-density patches. This could have been caused by post-fertilization mechanisms, including inbreeding depression or differential maternal resource allocation.
- • These results show that Allee effects on fitness components (ecological and genetic Allee effects) occur within A. napellus populations at different spatial scales. The spatial distribution of plants seems to be a crucial factor affecting reproductive output and fitness.