Metapopulation

Concept and Definition

A metapopulation is a group of spatially separated populations of the same species which interact at some level. The term metapopulation was coined by Richard Levins in 1969 to describe a model of population structure in which a species is composed of a network of distinct populations, each occupying a separate habitat patch. The concept assumes that most populations found in fragmented landscapes will not persist indefinitely. Instead, they will go extinct and the resulting vacant patches can be recolonized by individuals from other patches. This model is characterized by the balance between colonization and extinction. Population ecology and conservation biology are two fields where metapopulation models are often applied.

Characteristics of Metapopulations

The concept of metapopulation emphasizes the importance of migration, the exchange of individuals among local populations, in the dynamics of populations distributed in space. The metapopulation model assumes that patches of suitable habitat are typically occupied by relatively small populations and that all patches are subject to occasional extinction. In this model, a region may be occupied by a metapopulation, even though each individual patch may only be occupied for a fraction of the time. This is because the regional population is maintained by a balance between extinction and colonization.

The Metapopulation Model

The metapopulation model is a mathematical model that describes the dynamics of species populations divided into discrete patches, each capable of hosting a local population. The model considers both the local population dynamics and the dynamics of the metapopulation, which are the result of the interactions among local populations. The model is based on the principles of population dynamics, and incorporates the effects of habitat fragmentation, population dispersal, and local adaptation.

A series of small, separated habitats each containing a local population of a species.

Metapopulation Dynamics

Metapopulation dynamics refer to the changes in the size, structure, and distribution of metapopulations over time. These dynamics are influenced by the balance between local extinctions and recolonizations, the size and isolation of each local population, and the dispersal of individuals among local populations. Metapopulation dynamics are a key aspect of spatial ecology, which studies the spatial distributions of species and populations.

Applications in Conservation Biology

In conservation biology, the concept of metapopulation is used to guide strategies for the preservation of species in fragmented habitats. The goal is to maintain a balance between extinction and recolonization by preserving a network of habitat patches that allows for the movement of individuals. This approach recognizes that conservation efforts must extend beyond individual habitat patches to include the landscape as a whole.