High plant diversity is needed to maintain ecosystem services.

Area of Science:

• Ecology
• Environmental Science
• Biodiversity Research

Background:

• Global biodiversity decline threatens ecosystem functioning and services.
• The exact number of species required to sustain ecosystem services remains uncertain.
• Previous research has not simultaneously assessed species' roles across multiple times, places, functions, and environmental changes.

Purpose of the Study:

• To investigate the role of a large number of grassland plant species in promoting ecosystem functioning.
• To determine if species' contributions to ecosystem functioning vary across different years, locations, functions, and environmental change scenarios.
• To assess the necessity of numerous species for maintaining ecosystem services under dynamic conditions.

Main Methods:

• Studied 147 grassland plant species across 17 biodiversity experiments.
• Evaluated species' contributions to ecosystem functioning under various temporal, spatial, functional, and environmental change conditions.
• Compared species requirements for single vs. multiple functions and across different time scales.

Main Results:

• 84% of studied grassland plant species promoted ecosystem functioning at least once.
• Different species were essential for ecosystem functioning in different years, locations, for different functions, and under different environmental changes.
• Species supporting one function over multiple years differed from those supporting multiple functions within a single year.

Conclusions:

• A high proportion of species contribute to ecosystem functioning under specific circumstances.
• Maintaining ecosystem functioning and services likely requires a greater number of species than previously estimated.
• Functional redundancy may be limited when considering multiple ecosystem functions, times, places, and environmental changes.