Plant-mediated nitrous oxide emissions from beech (Fagus sylvatica) leaves

Area of Science:

• Environmental Science
• Forest Ecology
• Biogeochemistry

Background:

• Current nitrous oxide (N2O) emission estimates from forest ecosystems rely on soil enclosure methods.
• These methods may underestimate total N2O emissions by excluding plant-mediated pathways.

Purpose of the Study:

• To investigate plant-mediated nitrous oxide (N2O) emissions from beech (Fagus sylvatica) leaves.
• To determine if fertilization and elevated root-zone N2O concentrations influence foliar N2O emissions.

Main Methods:

• Measured N2O emissions from beech seedling leaves after soil fertilization with 15N-labelled ammonium nitrate.
• Measured N2O emissions from beech leaves after exposing roots to elevated N2O concentrations.

Main Results:

• Ammonium nitrate fertilization led to N2O emissions from beech leaves.
• Exposure of beech roots to elevated N2O concentrations also resulted in foliar N2O emissions.
• Average emissions were 0.4 µg N m⁻² leaf area h⁻¹ (fertilization) and 2.0 µg N m⁻² leaf area h⁻¹ (root exposure).

Conclusions:

• Forest trees, specifically beech, can emit nitrous oxide (N2O) through their foliage.
• A previously unrecognized pathway for N2O release from forest ecosystems via plants exists.
• Further research is needed to quantify canopy N2O emissions at larger scales.