Determinants of gemmae output in the liverwort Lophozia ventricosa

Algar, Natalie

Determinants of gemmae output in the liverwort Lophozia ventricosa

Bachelor Thesis

2004

Publisher

University of Cape Town

Department

Department of Biological Sciences

Faculty

Faculty of Science

Abstract

The spacial variation and population parameters affecting gemmae output of a boreal and arctic liverwort species, Lophozia ventricosa, were studied in Trnndelag, a boreal region of central Norway and in the arctic tundra on Svalbard. The population parameters investigated included colony size, colony shoot density, number of gemmae per shoot, proportion of gemmiferous shoots and gemmiferous shoot density. The gemmae output in a colony was calculated as the product of the number of gemmae per shoot, colony size and gemmifeorus shoot density. A Nested Analysis of Variance was used to partition population parameters spacially and a Pearsons Product-Moment Correlation was used to evaluate which of these population parameters affect gemmae output in a colony. The number of gemmae per shoot differed significantly between areas, populations and colonies, and was significantly varied between populations and colonies on Svalbard. No significant variation in the number of gemmae per shoot was found in Trnndelag. Population influences on shoot density, gemmiferous shoot density and gemmae output were significant in Trnndelag. This was expected, as more shoots in a colony is thought to influence gemmiferous shoot density and gemmae output. In Trnndelag, the only significant relation that can explain gemmae output is colony size whereas on Svalbard, gemmae output in a colony is affected by colony size, shoot density and number of gemmae per shoot. The results indicate that most of the variation in gemmae output occurs at the population level and that gemmae output differs between the arctic and boreal regions.

Keywords

Botany

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