Volatilome of Aleppo Pine litter over decomposition process

Area of Science:

• Environmental Science
• Atmospheric Chemistry
• Ecology

Background:

• Biogenic Volatile Organic Compounds (BVOC) play key roles in atmospheric chemistry and ecosystem functions.
• Forest canopies are known BVOC sources, but emissions from decomposing plant litter remain understudied.
• Understanding litter BVOC emissions is crucial for accurate ecosystem modeling.

Purpose of the Study:

• To quantitatively and qualitatively characterize BVOC emissions from Pinus halepensis litter over 15 months.
• To investigate the temporal dynamics of BVOC profiles during litter decomposition.
• To identify major BVOC compounds and their contribution to total emissions.

Main Methods:

• In situ decomposition of Pinus halepensis needles in litterbags over 15 months.
• In vitro analysis of BVOC emissions from collected litter samples every 3 months.
• Utilized online PTR-ToF-MS and offline GC-MS for comprehensive BVOC detection and quantification.

Main Results:

• Detected a diverse range of 58 BVOC compounds with significant temporal variation.
• Peak total BVOC emissions (9.18 µg gDM⁻¹hr⁻¹) observed at 3 months, primarily terpenes (e.g., α-pinene).
• Key non-terpenic volatiles included methanol, acetone, and acetic acid, especially early in decomposition.

Conclusions:

• Pinus halepensis litter is a dynamic source of diverse BVOCs throughout decomposition.
• Early decomposition stages exhibit the highest BVOC emission rates, influenced by terpenes and oxygenated compounds.
• This research enhances understanding of BVOC dynamics and sources in Mediterranean pine forest ecosystems.