Drought refuge

A drought refuge is a site that provides permanent fresh water or moist conditions for plants and animals, acting as a refuge habitat when surrounding areas are affected by drought and allowing ecosystems and core species populations to survive until the drought breaks. Drought refuges are important for conserving ecosystems in places where the effects of climatic variability are exacerbated by human activities.

Reliable drought refuges are characterised by the ability to retain sufficient water throughout the drought, having water quality good enough to maintain the life of the ecosystem that are not subject to physical disturbance and that have access to surrounding habitat, so that refugees can recolonise the main habitat when the drought ends.

For fish and aquatic invertebrates a drought refuge may be an isolated permanent pool in a stream that ceases to flow and mostly dries up during a period of drought. Permanent wetlands may serve as non-breeding drought refuges for a range of waterbirds that nest at ephemeral lakes when these are inundated.

“Drought refuge is a secure place persisting through a disturbance with the critical criterion being that after the disturbance the refuge provides colonist to allow populations to recover.”

For some species the refuge is their only water source and is necessary for survival. For birds and invertebrate taxa, the drought refuge is not only necessary for survival but contribute to their reproductive success. Some organisms that are able to adapt to the environment when there is a drought but adapting traits that will be beneficial for survival in a prolong drought is extremely difficult to accomplish.

The term refugium (plural: refugia) was originally used by evolutionary biologists for refuges that protected entire species from disturbance events of large temporal and spatial scales, such as glaciation or the long-term effects of climate change. A disturbance involves a temporary removal of biomass resulting in change in physical environment. Smaller-scale ecologists now use this term synonymously with the simpler term refuge, to define places that protect populations of plants or animals from smaller-scale disturbances, such as fire, flood, storm, or human impacts.Refugia are the habitats or environmental factors that give spatial and temporal resistance and resilience to biotic communities impacted by disturbance. Here negative effects of disturbance are lower than surrounding areas or times. Refugia buffer species long-term, where as, a refuge buffers species short-term.

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Wikipedia