Pollinators maintain biodiversity in assembling plant communities

Area of Science:

• Ecology
• Conservation Biology
• Pollination Biology

Background:

• Most flowering plants (angiosperms) rely on animal pollination for reproduction and fitness.
• Pollinators play a crucial role in maintaining plant biodiversity and seedling recruitment.
• The impact of pollinators on plant community structure is less understood than other ecological factors.

Purpose of the Study:

• To investigate the impact of pollinator visitation levels on plant diversity in a prairie restoration.
• To determine if reduced pollination affects plant species richness and abundance.
• To assess the potential for a plant-pollinator extinction vortex.

Main Methods:

• Experimental application of three pollinator visitation levels (exclusion, augmented, control) to forb flowers.
• Manipulation of graminoid/forb ratio seed mixes in prairie restoration patches.
• Estimation of plant diversity in the fourth growing season.

Main Results:

• Pollinator exclusion caused a 50% reduction in viable seeds for animal-pollinated species.
• Species richness declined by 27% for animal-pollinated species and 23% overall.
• The positive correlation between forb abundance and plant richness was lost under pollinator exclusion.

Conclusions:

• Pollinator decline can lead to reduced local plant diversity and viable seed production.
• A plant-pollinator extinction vortex may be driven by reduced pollination, leading to cascading effects on plant communities.
• Animal pollinators are critical limiting factors for plant biodiversity at the community level.