Fenced and Fragmented: Conservation Value of Managed Metapopulations.

Susan M Miller,Paulette Bloomer,Jennifer Hofmeyr,Cindy K Harper,Paul J Funston,Alfred L Roca

doi:10.1371/journal.pone.0144605

Abstract

Population fragmentation is threatening biodiversity worldwide. Species that once roamed vast areas are increasingly being conserved in small, isolated areas. Modern management approaches must adapt to ensure the continued survival and conservation value of these populations. In South Africa, a managed metapopulation approach has been adopted for several large carnivore species, all protected in isolated, relatively small, reserves that are fenced. As far as possible these approaches are based on natural metapopulation structures. In this network, over the past 25 years, African lions (Panthera leo) were reintroduced into 44 fenced reserves with little attention given to maintaining genetic diversity. To examine the situation, we investigated the current genetic provenance and diversity of these lions. We found that overall genetic diversity was similar to that in a large national park, and included a mixture of four different southern African evolutionarily significant units (ESUs). This mixing of ESUs, while not ideal, provides a unique opportunity to study the impact of mixing ESUs over the long term. We propose a strategic managed metapopulation plan to ensure the maintenance of genetic diversity and improve the long-term conservation value of these lions. This managed metapopulation approach could be applied to other species under similar ecological constraints around the globe.

Highlights

IntroductionOne of the major threats to biodiversity is habitat loss and resulting population fragmentation
We propose that a key requirement for conservation success would be for lions from these reserves to be managed in a way such that a) they are genetically similar to the populations that had been extirpated from the region as recommended by the IUCN/SSC Re-introduction Specialist Group [19] b) there are enough prides and adult individuals to form a viable population, and they are managed in such a way that c) simulates natural social mechanisms and d) mimics the genetic diversity and gene flow of a natural metapopulation situation
The analysis was performed without the Pilanesberg National Park (NP) samples and three further clusters were identified by the ΔK Evanno statistic (Fig 3C)

Summary

Introduction

One of the major threats to biodiversity is habitat loss and resulting population fragmentation. Population fragmentation is not always as problematic for a population as it may seem, since some species naturally occur as metapopulations (e.g. Melitaeini butterflies [1]). The term metapopulation was first used in by Levins in 1970 in referring to a “population of populations” [2]. Hanski & Gilipin [3] refined the concept in 1991, defining a metapopulation as a “set of local populations which interact via individuals moving among populations”. Harrison [4] realised that classic metapopulations are rare and PLOS ONE | DOI:10.1371/journal.pone.0144605. Harrison [4] realised that classic metapopulations are rare and PLOS ONE | DOI:10.1371/journal.pone.0144605 December 23, 2015

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Conclusion