Title

Propagule pressure: A null model for biological invasions.

Date of Award

2003

Degree Type

Thesis

Degree Name

M.Sc.

Department

Biological Sciences

First Advisor

MacIsaac, Hugh J.,

Keywords

Biology, Ecology.

Rights

CC BY-NC-ND 4.0

Abstract

I begin with a review of recent attempts to identify characteristics of species 'invasiveness' (i.e., the ability to invade) and habitat 'invasibility' (i.e., the susceptibility to invasion), and find little support for an emerging consensus on species- or habitat-specific characteristics. Moreover, I find that few studies consider hypotheses based on the concept of 'propagule pressure' (i.e., introduction effort), despite its potential as a confounding factor. Another barrier to generalizations may be the divergent use of operationally important terms like 'invasive', 'naturalized', or 'nuisance'. I therefore introduce a framework that conceptualizes biological invasions as a series of obligatory stages. This stage-based framework can aid in identifying characteristics that are confounded by 'propagule biases' (i.e., non-random variation in introduction effort), and can serve as common ground for an operational lexicon. I use this framework to investigate the enemy release hypothesis (ERH), which relates invasion success of a host species with the number of co-occurring enemies. (Abstract shortened by UMI.)Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2003 .C655. Source: Masters Abstracts International, Volume: 42-05, page: 1610. Advisers: Hugh J. MacIsaac; Daniel D. Heath. Thesis (M.Sc.)--University of Windsor (Canada), 2003.