High Monoterpenoid Emissions from Scots Pine Litter Controlled by Moisture

Area of Science:

• Atmospheric Chemistry
• Forest Ecology
• Biogeochemistry

Background:

• Biogenic volatile organic compounds (VOCs) are crucial in atmospheric chemistry.
• Forest litter decomposition is an understudied VOC source, impacting atmospheric processes.
• Scots pine litter is terpene-rich, potentially a significant VOC source.

Purpose of the Study:

• Quantify VOC and CO2 fluxes from decomposing Scots pine needle litter.
• Investigate the influence of temperature and moisture on VOC emissions.
• Explore the relationship between VOCs and CO2 fluxes.

Main Methods:

• Incubation of fresh Scots pine needle litter under controlled conditions.
• Measurement of VOC and CO2 fluxes.
• Analysis of emission patterns in response to varying temperature and moisture levels.

Main Results:

• Monoterpenoids dominated VOC emissions (91%), with camphor and 2,5-bornanedione being most abundant.
• Increased moisture significantly enhanced monoterpenoid fluxes (5- to 7-fold).
• A strong correlation was observed between monoterpenoid and CO2 fluxes, suggesting shared microbial drivers.

Conclusions:

• Moisture is a key factor controlling VOC release from decomposing pine litter.
• Microbial activity likely plays a significant role in VOC emissions.
• CO2 flux data may help estimate monoterpenoid emissions from pine forest floors.