Aboveground and belowground biodiversity have complementary effects on ecosystem functions across global grasslands

Area of Science:

• Ecology
• Environmental Science
• Biodiversity Research

Background:

• Grasslands are vital for biodiversity and ecosystem services but face climate change threats.
• Plant and soil microbial diversity interactions underpin ecosystem multifunctionality.
• The distinct and shared roles of plant and microbial diversity in grassland multifunctionality remain unclear.

Purpose of the Study:

• To determine the individual and interactive contributions of plant and soil microbial diversity to grassland multifunctionality.
• To assess these contributions under varying aridity and experimental drought conditions.
• To understand how climate context influences the relationship between biodiversity and multifunctionality.

Main Methods:

• Combined a global survey of 101 grasslands with a controlled microcosm study.
• Manipulated plant and soil microbial diversity to isolate their effects.
• Assessed impacts on above- and belowground ecosystem functioning and multifunctionality.

Main Results:

• Plant and soil microbial diversity uniquely and independently predicted variation in ecosystem functioning.
• Interactions between plant and soil microbial diversity positively influenced multifunctionality, including primary production and nutrient storage.
• Climate context mattered: soil fungal diversity linked to multifunctionality in less arid areas, while plant diversity was key in more arid regions.

Conclusions:

• Conserving both above- and belowground biodiversity is essential for maintaining grassland multifunctionality.
• Climate change may alter the relative importance of plant versus soil microbial diversity for ecosystem functions.
• Future grassland management must consider the interplay between biodiversity and climate change.