Diversity and productivity in a long-term grassland experiment

Area of Science:

• Ecology
• Ecosystem Science
• Plant Biology

Background:

• Biodiversity is crucial for ecosystem functioning, but the magnitude and mechanisms of these effects are debated.
• The role of niche complementarity in driving diversity-ecosystem functioning relationships requires further investigation.
• Long-term studies are needed to understand the temporal dynamics of biodiversity effects.

Purpose of the Study:

• To quantify the long-term effects of plant diversity on ecosystem functioning, specifically biomass production.
• To determine if diversity effects are transient or persistent over a 7-year experimental period.
• To assess the contribution of niche complementarity to observed diversity-ecosystem functioning relationships.

Main Methods:

• A 7-year field experiment manipulating plant species diversity in plots.
• Comparison of biomass production in monocultures versus diverse plots (up to 16 species).
• Analysis of niche complementarity as a driver of ecosystem functioning.

Main Results:

• Plant diversity effects on ecosystem functioning strengthened progressively over the 7-year experiment.
• 16-species plots achieved 2.7 times greater biomass than monocultures.
• Higher-diversity plots consistently outperformed the best monoculture, refuting transient or few-species dominance explanations.

Conclusions:

• Niche complementarity and plant diversity have increasingly significant impacts on ecosystem functioning over time.
• Biodiversity effects are robust and not solely attributable to a few dominant species.
• Even optimized monocultures cannot match the productivity and carbon storage of diverse ecosystems.