Evolution of facilitation requires diverse communities.

Area of Science:

• Ecology
• Evolutionary Biology
• Plant Science

Background:

• Diverse plant communities exhibit higher productivity than monocultures.
• Biodiversity effects are thought to increase over time due to evolutionary selection for complementarity.

Purpose of the Study:

• To investigate the evolutionary mechanisms driving changes in plant interactions within diverse communities.
• To determine if evolutionary selection favors facilitation or reduced competition in mixtures versus monocultures.

Main Methods:

• Experimental plant communities were established and monitored over time.
• Evolutionary selection pressures were analyzed based on community composition (monoculture vs. mixture) and history.

Main Results:

• Evolutionary selection for enhanced net facilitative plant interactions was observed exclusively in mixtures.
• Evolutionary selection for reduced net competition occurred in mixtures with prior mixture coexistence and in monocultures with prior monoculture coexistence.
• These findings indicate distinct evolutionary trajectories based on community history and diversity.

Conclusions:

• Biodiversity loss could impede the evolution of facilitative interactions, which are vital for ecosystem functioning.
• Understanding these evolutionary dynamics is critical for effective nature conservation and sustainable agricultural development.