Variation in seed set amongst populations of a redent pollinated geophyte, Colchicum coloratum

Kleizen, C; Midgley, J J; Johnson, S. D.

Variation in seed set amongst populations of a redent pollinated geophyte, Colchicum coloratum

Journal Article

2009

Journal Title

South African Journal of Botany

Link to Journal

http://www.sciencedirect.com/science/article/pii/S0254629909002671

Publisher

University of Cape Town

Department

Botany

Faculty

Faculty of Science

Abstract

Agricultural activities around the rural village of Nieuwoudtville in the Succulent Karoo region of South Africa has lead to the confinement of many plant and animal species to fragmented patches of relatively untransformed habitat. The geophyte Colchicum coloratum subsp. coloratum (Colchicaceae) was studied in five patches of variable size in and around Nieuwoudtville. This species is dependent on rodent visitation for seed production. The influence of variation in population size and plant size on seed set was investigated, as well as whether there is pollen limitation in this species. A pollen-supplementation experiment indicates that there is pollen limitation in C. coloratum, and that much of the natural seed set could be the result of pollinator-mediated selfing. The five populations appeared to have different rodent abundances, however, neither population size nor the abundance of rodents in the area have an effect on seed set. This suggests that the mutualism between C. colchicum and its rodent pollinators is robust, and that habitat fragmentation in Nieuwoudtville has not yet affected the seed production of this geophyte.