Invaders do not require high resource levels to maintain physiological advantages in a temperate deciduous forest

Area of Science:

• Ecology
• Plant Biology
• Invasive Species Research

Background:

• Non-native invasive plants often require high resources, but shade-tolerant species invade Eastern US forests despite light and nutrient limitations.
• This invasion contradicts typical plant invasion theories dependent on resource availability or disturbance.

Purpose of the Study:

• To test if invasive woody species in Eastern US deciduous forests have superior metabolic performance and biomass production compared to native species.
• To determine if these differences are influenced by varying light and soil nitrogen availability.

Main Methods:

• Established a factorial experiment manipulating light and soil nitrogen in a deciduous forest.
• Used hierarchical Bayesian models of photosynthesis, incorporating leaf traits, to analyze species responses.
• Compared metabolic performance and biomass production of three invasive and six native woody species.

Main Results:

• Invasive species exhibited higher rates of carbon gain and greater responsiveness to increased light compared to native species.
• Neither invasive nor native species showed direct growth responses to soil nitrogen additions.
• Invasive species displayed increased photosynthetic nitrogen use efficiency under lower nitrogen conditions, unlike natives.

Conclusions:

• Invasive woody plants in this ecosystem possess physiological advantages over native species, particularly in higher resource conditions.
• These invaders can maintain advantages irrespective of resource availability, suggesting complex invasion dynamics beyond simple resource competition.