First coined by Gilpin & Soulé in 1986, the extinction vortex is the term used to describe the process that declining populations undergo when” a mutual reinforcement occurs among biotic and abiotic processes that drives population size downward to extinction ” (Brook, Sodhi & Bradshaw 2008).
What drives extinction vortex?
These events can include rapid loss of population size due to disease, natural disasters, and climate change. Habitat loss and/or habitat degradation can also kick start an extinction vortex. Other factors include events that occur more gradually, such over-harvesting (hunting, fishing, etc.), or excessive predation.
What is meant by extinction vortex?
Abstract. An extinction vortex is one of the greatest threats to endangered species; when demographic, environmental, and genetic stochasticity interact with each other and with deterministic factors, such as habitat quality, to reinforce the demise of a small population.
What are the drivers of extinction?
The major ''systematic drivers'' of modern species loss are changes in land use (habitat loss degradation and fragmentation), overexploitation, invasive species, disease, climate change (global warming) connected to increasing concentration of atmospheric carbon di oxide, and increases in nitrogen deposition.
What population conditions make an extinction vortex likely to occur?
What population conditions make an extinction vortex likely to occur? little genetic variability. A population with little genetic variability is at risk for a reduction in fitness, which can lead to high mortality and low reproduction.
What are the main causes of extinction?
In general terms, species become extinct for the following reasons:Demographic and genetic phenomena.Destruction of wild habitats.Introduction of invasive species.Climate change.Hunting and illegal trafficking.
What defines background extinction?
Background extinction rate, or normal extinction rate, refers to the number of species that would be expected to go extinct over a period of time, based on non-anthropogenic (non-human) factors. The background extinction rate is often measured for a specific classification and over a particular period of time.
What are the types of extinction?
The three types of extinction are mass extinction, background extinction, and human-led extinction.
What are the effects of extinction?
As species go extinct, they are taken out of the food chain. Animals that ate the newly-extinct species have to find new food sources or starve. This can damage the populations of other plants or animals. Furthermore, if a predator goes extinct, its prey's population can proliferate, unbalancing local ecosystems.
What is the main cause of extinction in plant and animal species?
The main cause of the extinctions is the destruction of natural habitats by human activities, such as cutting down forests and converting land into fields for farming. Due to human activities, populations of many species have become small and isolated.
Why are small populations more vulnerable to extinction vortex?
The extinction vortex As populations decline in size, they become increasingly vulnerable to the combined impacts from the loss of genetic diversity, inbreeding depression, Allee effects, environmental stochasticity, and demographic stochasticity.
Which of the following factors typically increases the risk of extinction for a species?
Species become endangered for two main reasons: loss of habitat and loss of genetic variation. A loss of habitat can happen naturally. Dinosaurs, for instance, lost their habitat about 65 million years ago.
Why are small populations more prone to extinction?
Small populations tend to lose genetic diversity more quickly than large populations due to stochastic sampling error (i.e., genetic drift). This is because some versions of a gene can be lost due to random chance, and this is more likely to occur when populations are small.
What do you mean by metapopulation?
metapopulation, in ecology, a regional group of connected populations of a species.
What is stochasticity in ecology?
Environmental stochasticity refers to unpredictable spatiotemporal fluctuation in environmental conditions. The term is often used in the literature on ecology and evolution. Unpredictability is defined as an inability to predict the future state precisely such that only its distribution can be known.
What is meant by habitat fragmentation?
Fragmentation happens when parts of a habitat are destroyed, leaving behind smaller unconnected areas. This can occur naturally, as a result of fire or volcanic eruptions, but is normally due to human activity. A simple example is the construction of a road through a woodland.
What is an area's extinction debt?
Technically, extinction debt generally refers to the number of species in an area likely to become extinct, rather than the prospects of any one species, but colloquially it refers to any occurrence of delayed extinction.