Patch Dynamics and Metapopulation Theory: the Case of Successional Species

National Center for Ecological Analysis and Synthesis, University of California, Santa Barbara, 735 State Street, Suite 300, Santa Barbara, CA, 93101-5504, U.S.A.
Journal of Theoretical Biology (Impact Factor: 2.12). 05/2001; 209(3):333-344. DOI: 10.1006/jtbi.2001.2269
Source: PubMed


We present a mathematical framework that combines extinction–colonization dynamics with the dynamics of patch succession. We draw an analogy between the epidemiological categorization of individuals (infected, susceptible, latent and resistant) and the patch structure of a spatially heterogeneous landscape (occupied–suitable, empty–suitable, occupied–unsuitable and empty–unsuitable). This approach allows one to consider life-history attributes that influence persistence in patchy environments (e.g., longevity, colonization ability) in concert with extrinsic processes (e.g., disturbances, succession) that lead to spatial heterogeneity in patch suitability. It also allows the incorporation of seed banks and other dormant life forms, thus broadening patch occupancy dynamics to include sink habitats. We use the model to investigate how equilibrium patch occupancy is influenced by four critical parameters: colonization rate, extinction rate, disturbance frequency and the rate of habitat succession. This analysis leads to general predictions about how the temporal scaling of patch succession and extinction–colonization dynamics influences long-term persistence. We apply the model to herbaceous, early-successional species that inhabit open patches created by periodic disturbances. We predict the minimum disturbance frequency required for viable management of such species in the Florida scrub ecosystem.

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Available from: Hugh P Possingham, Mar 20, 2015
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    • "Successional dynamics are a well-documented consequence of disturbance (Bengtsson et al. 2000;Lake et al. 2007;Leavesley et al. 2010;Banks et al. 2011), with species commonly showing preference for early or late postdisturbance stages, or having habitat suitability mediated by disturbance return intervals. Therefore, disturbance history can have major effects on amount and connectivity of suitable habitat, as well as viability of populations (Amarasekare and Possingham 2001). Introducing simulation approaches that explicitly include habitat dynamics would further improve insights into dynamics of genetic diversity under variation in disturbance regimes. "
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    ABSTRACT: Exploring interactions between ecological disturbance, species’ abundances and community composition provides critical insights for ecological dynamics. While disturbance is also potentially an important driver of landscape genetic patterns, the mechanisms by which these patterns may arise by selective and neutral processes are not well-understood. We used simulation to evaluate the relative importance of disturbance regime components, and their interaction with demographic and dispersal processes, on the distribution of genetic diversity across landscapes. We investigated genetic impacts of variation in key components of disturbance regimes and spatial patterns that are likely to respond to climate change and land management, including disturbance size, frequency, and severity. The influence of disturbance was mediated by dispersal distance and, to a limited extent, by birth rate. Nevertheless, all three disturbance regime components strongly influenced spatial and temporal patterns of genetic diversity within subpopulations, and were associated with changes in genetic structure. Furthermore, disturbance-induced changes in temporal population dynamics and the spatial distribution of populations across the landscape resulted in disrupted isolation by distance patterns among populations. Our results show that forecast changes in disturbance regimes have the potential to cause major changes to the distribution of genetic diversity within and among populations. We highlight likely scenarios under which future changes to disturbance size, severity, or frequency will have the strongest impacts on population genetic patterns. In addition, our results have implications for the inference of biological processes from genetic data, because the effects of dispersal on genetic patterns were strongly mediated by disturbance regimes.
    Preview · Article · Jan 2016 · Ecology and Evolution
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    • "Empirical examples of such systems are agricultural landscapes in which habitable areas are frequently changed by mowing and harvesting, lands in which flood and inundation events are frequent, and early-successional communities in disturbed sites, where the habitat quality declines due to resource depletion and the timing for habitat to become suitable for recolonization depends on disturbance (Stelter et al. 1997; Amarasekare and Possingham 2001; Blaum et al. 2012). In all of these systems dispersal is closely linked to the state of the habitat patch, and longterm survival in such habitat systems depends on the timing of dispersal. "
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    ABSTRACT: Abstract A challenge for conservation management is to understand how population and habitat dynamics interact to affect species persistence. In real landscapes, timing and duration of disturbances can vary, and species' responses to habitat changes will depend on how timing of dispersal and reproduction events relate to the landscape temporal structure. For instance, increasing disturbance frequency may promote extinction of species that are unable to appropriately time their reproduction in an ever-changing habitat and favor species that are able to track habitat changes. We developed a mathematical model to compare the effects of pulsed dispersal, initiated by shifts in habitat quality, with temporally continuous dispersal. We tested the effects of habitat (and population) turnover rates on metapopulation establishment, persistence, and long-term patch occupancy. Pulsed dispersal reduced patch occupancy and metapopulation longevity when habitat patches are relatively permanent. In such cases, demographic extinction was the primary form of local extinction. Conversely, when habitat patches are short-lived and new ones are frequently formed, pulsed dispersal promoted rapid colonization, increased occupancy, and prolonged metapopulation persistence. Our results show that species responsiveness to habitat disturbance is critical to metapopulation persistence, having profound implications for the species likely to persist in landscapes with altered disturbance regimes.
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    • "Keymer et al., 2000; Amarasekare and Possingham, 2001; Wimberly , 2006), mostly focusing on a comparison between dynamical vs static systems. In general, these theoretical studies have shown that metapopulation occupancy of ephemeral habitats is lower than that of permanent habitats (Amarasekare and Possingham, 2001) and that habitat turnover rate is negatively correlated with patch occupancy (Keymer et al., 2000). An intuitive implication of these shifting mosaics is that, at some point, as habitat conditions worsen, individuals using a patch will need to relocate into other patches of suitable habitat. "
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