Stieha, Christopher , Crowley, Philip , McLetchie, Nicholas .
The Effects of Spatial Structure on Sex Ratio Dynamics in Marchantia inflexa.
THE loss of one sex can lead to extinction of the population, but single sex populations exist in many plants. In the case of the liverwort Marchantia inflexa, populations can be either two sex or single sex. A metapopulation model linking spatially isolated groups of interacting individuals (patches) by sexual and asexual propagules found that both sexes are maintained within the metapopulation although individual patches may be single sex. By extending this model we test whether patch structure (distance between patches, patch size) influence whether a metapopulation will contain both sexes or only a single sex. We use the model coupled with structure data from natural populations of M. inflexa in Trinidad to look at the effect of patch structure on sex ratios and compare these effects to actual sex ratios. We found that at large distances between patches, the metapopulation losses one sex, while the natural population shows extreme bias in the sex ratio. Populations with closely interacting patches contain both sexes in both the model and natural populations. These patterns may arise when single sex metapopulations are either single large patches or many patches spaced far apart to impede colonization by sexual propagules, allowing competition to drive one sex extinct. Metapopulations containing both sexes consist of patches close together thereby allowing colonization by sexual propagules.
Log in to add this item to your schedule
1 - University of Kentucky, Department of Biological Sciences, 101 Morgan Bld, Lexington, Kentucky, 40506-0225, USA
Presentation Type: Oral Paper:Papers for Topics
Location: 134/Performing Arts Center
Date: Wednesday, August 2nd, 2006
Time: 11:30 AM