Matrix models for a changeable world: the importance of transient dynamics in population management

Abstract

Summary1. Matrix population models are tools for elucidating the association between demographic processes and population dynamics. A large amount of useful theory pivots on the assumption of equilibrium dynamics. The preceding transient is, however, of genuine conservation concern as it encompasses the short-term impact of natural or anthropogenic disturbance on the population. 2. We review recent theoretical advances in deterministic transient analysis of matrix projection models, considering how disturbance can alter population dynamics by provoking a new population trajectory. 3. We illustrate these impacts using plant and vertebrate systems across contiguous and fragmented landscapes. 4. Short-term responses are of fundamental relevance for applied ecology, because the time-scale of transient effects is often similar to the length of many conservation projects. Investigation of the immediate, post-disturbance phase is vital for understanding how population processes respond to widespread disturbance in the short-and into the long term. 5. Synthesis and applications. Transient analysis is critical for understanding and predicting the consequences of management activities. By considering short-term population responses to perturbations, especially in long-lived species, managers can develop more informed strategies for species harvesting or controlling of invasive species.

Revisiting reproduction and population structure and dynamics ofProcambarus clarkiieight years after its introduction into Lake Trasimeno (Central Italy)

“…This initial explosion may drive researchers to erroneous conclusions regarding the alien population status, since colonizing new habitats may facilitate the expression of emergent population properties (Strayer et al, 2006;Strayer, 2010). These emerging features can gradually shift, after a certain period after introduction (Ezard et al, 2010), generating difficulties in predicting the spread and population dynamics of alien species in freshwater ecosystems. To date, several aspects of the life history of alien crayfish have been collected (see SoutyGrosset et al, 2006;DAISIE, 2009), since they act as keystone species of littoral food webs (Nyström, 1999(Nyström, , 2002, dominating a variety of freshwater communities (Usio and Townsend, 2004), being among the longest-lived invertebrates in temperate areas (Scalici et al, 2008a,c), general polytrophic omnivorous consumers (Momot, 1995;Whitledge and Rabeni, 1997;Scuderi et al, 2006;Scalici and Gibertini, 2007), prey for different species (Slater and Rayner, 1993;Blake, 1995;Rodríguez et al, 2005), and supporting recreational and commercial activities worldwide (Hobbs et al, 1989;Holdich, 2002) including Central Italy (Dörr et al, 2001;Chiesa et al, 2006;Nonnis Marzano et al, 2009;Scalici et al, 2009a,c).…”

Population Responses to Perturbations: The Importance of Trait-Based Analysis Illustrated through a Microcosm Experiment

“…Thus, an understanding of the dynamics of populations in variable environments consequently requires an understanding of the transient dynamics (Hastings 2001(Hastings , 2004. This is true both in the short term, when predicting how a population may respond numerically to a particular perturbation, and in the long term, as the perturbations may alter the selection pressures on the life history, leading to evolutionary change (Coale 1972;Benton and Grant 1999b;Fox and Gurevitch 2000;Koons et al 2006;Caswell 2007;Tuljapurkar et al 2009;Ezard et al 2010).…”

The role of transient dynamics in stochastic population growth for nine perennial plants

“…How frequently this assumption is adequately met is unclear (Bierzychudek 1999, Williams et al 2011, as are the implications of deviances from SSD in model applications (Ezard et al 2010, Johnson et al 2010. Consequently, there has been an increasing focus on analyzing the short-term, transient dynamics that result when populations are not at SSD (e.g., Fox and Gurevitch 2000, Caswell 2007, Stott et al 2011.…”