Selection for niche differentiation in plant communities increases biodiversity effects

Area of Science:

• Ecology
• Evolutionary Biology
• Plant Science

Background:

• Biodiversity enhances ecosystem functioning, often attributed to resource complementarity and plant-soil feedbacks.
• The strengthening of biodiversity effects over time in experimental communities is a key ecological observation.

Purpose of the Study:

• To investigate if selection for niche differentiation drives the increasing biodiversity effect over time.
• To determine the role of character displacement in enhancing ecosystem functioning.

Main Methods:

• Growing 12 grassland species in monocultures and mixtures for 8 years.
• Analyzing character displacement (differences in height and specific leaf area) between species selected in monocultures versus mixtures.
• Quantifying biodiversity and complementarity effects in mixtures of these selected types.

Main Results:

• Species selected in mixtures exhibited greater character displacement (increased differences in height and specific leaf area) compared to those selected in monocultures.
• Mixtures of species selected in mixtures showed greater net biodiversity and complementarity effects than mixtures of species selected in monocultures.
• This indicates selection for niche differentiation enhances biodiversity effects.

Conclusions:

• Selection for niche differentiation through character displacement is a novel mechanism driving increased biodiversity effects over time.
• Selection in diverse mixtures can enhance species coexistence and ecosystem functioning, with implications for agriculture and forestry.
• Loss of biodiversity and prolonged monoculture selection may negatively impact this adaptive potential.