Disturbance, interspecific interaction and diversity in metapopulations

Abstract

Metapopulation diversity patterns depend on the relations among the timescales of local biological interactions (predation, competition), the rates of dispersal among local populations and the patterns of disturbance. We investigatc these relationships using a family of simple non-linear Markov chain models. We consider three models for interspecific competition; if the species are identified with early and late successional spccies, the models describe the facilitation, inhibition and tolerance modcls of ecological succession. By adding a third competing species we also compare transitive competitive hierarchies and intransitive competitive networks. Finally, we examine the effects of predation in mediating coexistence among competing prey species. In each model we find circumstances in which biotic or abiotic disturbance ran increase both local and regional diversity, but those circumstances depend on the various timescales in the model in ways that arc neither obvious nor trivial.KEY WORDS: mediated coexistence ~ patch occupancy models -Markov chains.

Understanding ecological community succession: Causal models and theories, a review

“…Farrell (1991) has provided a useful model for explaining and predicting the effects of grazers on successional rates, based on the Connell and Slatyer classification. Caswell and Cohen (1991) used a formalized version of Connell and Slatyer's (1977) classification to examine species diversity and coexistence.…”

“…These problems are partly an inevitable result of ambiguity inherent in any verbal or conceptual model that is not formalized or quantitative (but see Caswell & Cohen 1991). Ecological theory may progress by increasing formalization and modification in response to critical theoretical or empirical testing (Loehle 1988(Loehle , 1990Shrader-Frechette & McCoy 1990).…”

Impacts of tree species diversity on litter decomposition in northern temperate forests of Wisconsin, USA: a multi-site experiment along a latitudinal gradient

“…Indeed, the bulk of experimental manipulations of diversity have been performed in small plots or micro/mesocosms that have been intentionally homogenized in space and time to minimize experimental 'noise' (Cardinale et al 2000(Cardinale et al , 2004Loreau et al 2001;Schmid et al 2001;Symstad and Tilman 2001;Symstad et al 2003;Hooper et al 2005). Yet, it is the inherent heterogeneity of ecosystems in both space and time that is typically invoked to explain why biodiversity exists in the first place (Hanski 1989;Caswell and Cohen 1991;Hastings 1991;Kolasa and Pickett 1991;Tilman and Kareiva 1997;Chesson 2000;Amarasekare 2003). Not surprisingly, a growing body of theory suggests that loss of diversity can have variable impacts on ecosystem processes from one location to the next (Cardinale et al 2000(Cardinale et al , 2004Mouquet et al 2002;Loreau et al 2003), and identifying why these impacts change across spatially heterogeneous landscapes has become one of the major challenges in this field.…”

How does stochasticity in colonization accelerate the speed of invasion in a cellular automaton model?

“…These CA models have been used to describe cell colony growth (Eden 1961;Richardson 1973), plant populations with multiple modes of reproduction (Harada and Iwasa 1994;Harada et al 1995), forest gap expansion (Kubo et al 1996;Satake et al 2004), competition (Caswell and Cohen 1991;Etter 1992, 1999;Etter and Caswell 1994;Tilman et al 1997;Durrett and Levin 1998;Buttel et al 2002;Cannas et al 2003), predation (Hassell et al 1991), epidemics (Mollison and Kuulasmaa 1985;Tainaka 1988;Sato et al 1994;Filipe and Maule 2004), and game-theoretical interactions (Nowak et al 1995;Nakamaru et al 1996;Nakamaru and Levin 2004). A series of works by Levin and Durrett have provided comprehensive guides to ecological applications of stochastic CA models (Levin 1992;Durrett andLevin 1994a, 1994b;Levin and Durrett 1997;Chave et al 2002).…”