Deep Invasion Ecology and the Assembly of Communities in Historical Time
A critical component of — and a limitation on — interpreting community structure is a detailed understanding of the ecological and evolutionary history of the assemblage of species in question. There are thus compelling reasons to under stand, and seek to
- PDF / 270,458 Bytes
- 44 Pages / 439.37 x 666.142 pts Page_size
- 55 Downloads / 135 Views
Deep Invasion Ecology and the Assembly of Communities in Historical Time James T. Carlton
“With dim light and tangled circumstance …” – George Elliott, Middlemarch: A Study of Provincial Life (1871)
2.1
Introduction
A critical component of – and a limitation on – interpreting community structure is a detailed understanding of the ecological and evolutionary history of the assemblage of species in question. There are thus compelling reasons to understand, and seek to measure, how communities have changed over both evolutionary (geological) and ecological (historical) time. Vast waves of change have swept across the Earth in the past one to two millennia as waves of humans invaded across the planet in sequential episodes of exploration, colonization, and urbanization. As an expected and inexorable result of human activity, alterations in biodiversity have impacted terrestrial, freshwater, and marine communities. These alterations include the addition of species (invasions), the deletion of species (extinctions), and altered population dynamics (such as decreasing or increasing the abundance of a species, or altering genetic structure). In even seemingly “pristine” areas – such as wave-exposed high-energy rocky intertidal shores – it is no longer tenable to assume that communities and ecosystems have remained unaltered, in part because of supply-side impacts – impacts that are the indirect cascades of human activity originating outside of the area in question (e.g., Butman et al. 1995; Chap. 7, Johnston et al.). Three (among a number of) reasons drive the interest to understand the first of these alterations – the role of invasions in historical time: 1. An academic desire to understand whether community-level processes, such as predation, competition, and disturbance (Chap. 14, Byers; Chap. 16, Crooks; Chap. 17, Grosholz and Ruiz; Chap. 15, Rilov) derive in part from species interactions on an evolutionary-time scale, or from interactions on an ecological-historical time G. Rilov, J.A. Crooks (eds.) Biological Invasions in Marine Ecosystems. Ecological Studies 204, © Springer-Verlag Berlin Heidelberg 2009
13
14
J.T. Carlton
scale, such as might be due to the presence of recently-arrived species (Mooney and Cleland, 2001; Grosholz 2002, 2005; Sax et al. 2005; Strauss et al. 2006; Freeman and Byers 2006; Cadotte et al. 2006). 2. A desire that merges academic interests with management concerns to predict what phenomena and processes characterize invaders and invasible habitats (Ricciardi and Rasmussen 1998; Bax et al. 2001; Kolar and Lodge 2001; Chap. 7, Johnston et al.; Chap. 8, Miller and Ruiz; Chap. 10, Smith; Chap. 11, Torchin and Lafferty; Chap. 12, Olyarnik et al.) 3. An interest in establishing the scale of community alteration, in order to undertake environmental management if not actual restoration (Byers et al. 2002; Lotze et al. 2006; Chap. 21, Hacker and Dethier). The foundation of all three rationales relies not only on the ability to recognize which species are introduced (Chapman and Carlton 1991
Data Loading...
