Collaborative Research: Termite Methane Emissions Across Tropical Savannas and Forests

Termites are highly abundant and impactful social insects found across more than half of the Earth’s land surface, mainly in tropical and subtropical regions. They play a major role in decomposing up to 60% of plant litter and fallen wood in these areas. During this process, termites rely on a partnership with microorganisms in their guts to help break down organic matter.

In the process, some termites can also produce substantial amounts of methane that can be released into the atmosphere. There is still much uncertainty about how much methane termites release worldwide due to a lack of understanding of the processes that determine termite methane production and emission. The goals of this project are to understand the differences in methane production rate across termite species and how that relates to the microorganisms in their guts, and to estimate total methane emissions from termites across large areas using field measurements and remote sensing data.

The fieldwork focuses on termites in the tropical savannas and forests of Odzala-Kokoua National Park, home to an exceptionally wide variety of termite species. The results from this project could greatly improve understanding of how much methane termites produce and how it happens, from individual species to whole colonies and larger areas, helping to fill important gaps in knowledge of termites' role in contributing to atmospheric methane.

The project will train early-career scientists and engage K-12 students and the public through field, education, and museum programs in the United States and beyond, enhancing public understanding of insect ecology and their impact on the environment.

Researchers will conduct field surveys to assess termite populations across tropical savannas and forests in Odzala-Kokoua National Park. An incubation method will measure methane production rates across termite species, considering variations in castes, nesting behaviors, and feeding groups, followed by DNA isolation and sequencing to characterize the methanogen community in termite symbiotic systems.

A mass balance approach will determine the oxidation rates of termite-produced methane across different colonies, while laboratory incubations and metagenomic analyses will assess methanotrophic activities and communities within the colonies. Field measurements of colony-level methane emissions will be integrated with high-resolution, drone-based, LiDAR remote sensing to develop algorithms for upscaling termite methane emissions to landscape scales.

The data collected will be used to address: 1) How do methane production rates vary across termite species, and what are the underlying mechanisms for these variations? 2) What are the oxidation rates of termite-produced methane within colonies and surrounding soils, and what are the mechanisms driving these processes? 3) How much methane is emitted by termites across tropical savanna and forest landscapes? This project has the potential to transform knowledge of the rates and underlying processes of termite methane production and emissions, from individual species to colonies to landscapes, filling crucial knowledge gaps and advancing understanding of this overlooked yet important contribution of termites to global atmospheric methane cycling.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.