Direct and indirect effects of dominant plants on ecosystem multifunctionality

Area of Science:

• Ecology
• Plant Ecology
• Ecosystem Science

Background:

• Biodiversity underpins ecosystem multifunctionality (EMF), the ability of ecosystems to provide multiple functions simultaneously.
• The specific role of dominant plant species in influencing EMF remains largely unexplored.
• Understanding these impacts is crucial for predicting ecosystem responses to environmental changes.

Purpose of the Study:

• To investigate how dominant plant species influence EMF in alpine meadows.
• To disentangle the direct and indirect pathways (abiotic and biotic) through which dominant species affect EMF.
• To compare the effects of two dominant species with contrasting ecological traits.

Main Methods:

• Field study in alpine meadows assessing the impacts of two dominant species: *Dasiphora fruticosa* and *Ligularia virgaurea*.
• Measured changes in soil abiotic factors (water content, pH) and biotic communities (plant and nematode richness, biomass, abundance).
• Quantified the effects of dominant species on EMF.

Main Results:

• Both dominant plant species enhanced EMF, with *L. virgaurea* showing a stronger positive effect than *D. fruticosa*.
• Dominant species influenced EMF indirectly through alterations in soil water content and pH.
• No significant indirect effects on EMF were observed via changes in surrounding plant or nematode biodiversity.

Conclusions:

• Dominant plant species play a significant role in promoting EMF in alpine meadows.
• The mass-ratio hypothesis, typically applied to single functions, may extend to multifunctionality.
• Dominant species could be key in mitigating negative impacts of vegetation shifts on EMF.