Role of trait combinations, habitat matrix, and network topology in metapopulation recovery from regional extinction

Luis Giménez,Stuart R Jenkins,Peter Robins

doi:10.1002/lno.11347

Abstract

AbstractWe studied the role of oceanographic conditions and life history strategies on recovery after extinction in a metapopulation of marine organisms dispersing as pelagic larvae. We combined an age‐structured model with scenarios defined by realistic oceanographic conditions and species distribution along the Irish Sea coast (North Europe). Species life history strategies were modeled combining the dispersal behaviors with two levels of fecundity. Recovery times were quantified after simulating extinction in four regions. Two alternative strategies (high fecundity or larval tidal transport) led to short recovery times, irrespective of the effects of other drivers. Other strategies and low larval survival exacerbated the effects of oceanographic conditions on recovery times: longer times were associated with for example the presence of frontal zones isolating regions of extinction. Recovery times were well explained by the connectivity of each focal population with those located outside the area of extinction (which was higher in the so‐called small world topologies), but not by subsidies (direct connections with populations located nearby). Our work highlights the complexities involved in population recovery: specific trait combinations may blur the effects of the habitat matrix on recovery times; K‐strategists (i.e., with low fecundities) may achieve quick recovery if they possess the appropriate dispersal traits. High larval mortality can exacerbate the effect of oceanographic conditions and lead to heterogeneity in recovery times. Overall, processes driving whole network topologies rather than conditions surrounding local populations are the key to understand patterns of recovery.

Highlights

Disturbance is a fundamentally important process in all ecological systems, modifying resource availability and causing disruption to population, community or ecosystem structure (White and Pickett 1985)
Recovery times were well explained by the connectivity of each 30 focal population with those located outside the area of extinction, but not by subsidies
The model predicted that increased fecundity and larval survival mitigates the effects of larval strategies and time of release on recovery times

Summary

Introduction

Disturbance is a fundamentally important process in all ecological systems, modifying resource availability and causing disruption to population, community or ecosystem structure (White and Pickett 1985). In the marine environment regional scale disturbances covering areas of the order of 10-103 km may be produced by a range of drivers including summer anoxia at the sea bed (Bishop et al 2006, Dias and Rosenberg 2008), storms (Woodley et al 1981), heat waves, extreme temperatures (Glynn 1993, Coma et al 2009) and pathogens (Miller and Colodey 1983, Lessios 2016). For example, suggest that extreme weather events, including heat waves and storms are likely to increase in frequency and magnitude (e.g. Burrows et al 2014, Di Lorenzo and Mantua 2016) leading to regional scale levels of mass mortality. Current coral bleaching as the consequence of the recent El Nino is an example of the spread and importance of regional scale events (Tollefson 2016)

Methods

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Conclusion