Disturbance-mediated colonization-extinction dynamics in experimental protist metacommunities

Area of Science:

• Ecology
• Metacommunity Dynamics
• Community Ecology

Background:

• Colonization-extinction dynamics and species sorting shape metacommunity structure.
• Disturbances are theorized to decrease species sorting and increase spatial and stochastic influences, but experimental evidence is limited.

Purpose of the Study:

• To experimentally investigate how varying extinction rates impact metacommunity regulation.
• To determine the effects of extinctions on environmental, spatial, and stochastic factors influencing community composition.

Main Methods:

• Utilized a simplified protist metacommunity with two species and two habitats.
• Imposed four distinct levels of random extinctions across local patches.
• Monitored metacommunity changes over nine colonization-extinction cycles.

Main Results:

• Metacommunity variability patterns reached a near-steady state rapidly.
• Higher extinction rates diminished the role of environmental factors.
• Increased spatial and stochastic effects were observed with elevated extinction rates.

Conclusions:

• Experimental extinctions alter metacommunity regulation by reducing environmental control.
• Findings support the theory that disturbances enhance spatial and stochastic effects in metacommunities.
• Provides a potential explanation for observed patterns in natural metacommunities.