Biodiversity, photosynthetic mode, and ecosystem services differ between native and novel ecosystems

Area of Science:

• Ecology
• Botany
• Environmental Science

Background:

• Non-native plant species can alter ecosystems, but their impact on multiple community and ecosystem aspects is debated.
• Understanding these impacts is crucial for predicting responses to global change.

Purpose of the Study:

• To investigate differences between native and exotic grasslands in species diversity, ecosystem services, and functional diversity (C3:C4 proportions).
• To assess the role of species composition versus environmental factors in observed patterns.

Main Methods:

• Sampling 42 sites across a latitudinal gradient to compare native and exotic grasslands.
• Conducting a controlled experiment to examine C3:C4 proportions and temporal niche partitioning.

Main Results:

• Exotic-dominated grasslands exhibited significantly lower plant diversity and higher tissue nitrogen concentrations and forage quality.
• Latitudinal patterns showed exotic sites dominated by C4 species in the south and C3 species in the north, with a distinct transition zone.
• Native sites maintained C3:C4 mixtures across latitudes, unlike exotic sites.

Conclusions:

• The replacement of native by exotic grasslands presents a management tradeoff between biodiversity and specific ecosystem services.
• Species-specific traits contribute to observed C3:C4 proportion differences, influencing latitudinal patterns.
• Global change models need to incorporate the effects of exotic species on C3/C4 distribution and ecosystem functioning.