DOI: 10.5061/dryad.vt4b8gtvk
title: Species-level termite methane production rates

description: Termites consume substantial amounts of plant material across tropical and
 subtropical ecosystems. During the process of lignocellulose digestion,
 the symbiotic methanogenesis within termites’ guts produces the potent
 greenhouse gas methane (CH4). Termites contribute an estimated 1-5% of
 global CH4 emissions, with these estimates derived from the product of
 termite biomass and termite CH4 production rate per unit of termite
 biomass. However, termite CH4 production rates vary significantly across
 species, genus, family, and feeding group, yet our understanding of this
 variation remains poor. Here, we reviewed papers published from 1975 to
 2021 to create a single consistently derived list of species-level termite
 CH4 production rates. We searched Google Scholar using two key words:
 termite AND methane. We only included studies that had measured termite
 CH4 production rates using the incubation method. For each eligible study,
 we extracted and tabulated termite CH4 production rates and other relevant
 variables (e.g., feeding groups). We used μg CH4 g-1(termite) h-1 as the
 standardized unit, and if other units were presented, we converted them
 into this standardized unit. Overall, These data include 134 termite
 species from 65 genera and 5 families. Termite CH4 production rates ranged
 from 0 to 25.26 μg CH4 g-1(termite) h-1, with an average rate of 3.74
 (standard deviation = 4.08, n = 251). Reported CH4 production rates were
 largely concentrated in the family Termitidae. Across feeding groups, soil
 feeders tended to have higher CH4 production rates than wood feeders.
 However, published data represent fewer than 5% of described termite
 species, and therefore we hope that our study will initiate a
 community-wide effort to fill data gaps and advance our understanding of
 the role of termites in critical biogeochemical cycles and other ecosystem
 processes.
description: We collected termite CH4 production rates from the literature,
 including both peer-reviewed articles and book chapters. Data gathering
 was conducted in October 2020 and updated in February 2022. We searched
 Google Scholar using two key words: termite AND methane. All 7,699 search
 results were screened for eligibility. We only included studies that had
 measured termite CH4 production rates using the incubation method, which
 involves sealing a known number of termites in serum or glass vials and
 incubating in the dark at a fixed temperature (generally between 25 to
 30°C) for a fixed time period (generally ranging from 1 to 3 hours) (see
 the scheme presented in Bignell et al., 1997). The CH4 produced during the
 incubation was then measured using a gas chromatograph for all studies.
 Although incubation conditions, including vial volume, incubation time,
 and incubation temperature, varied slightly across studies, the reported
 termite CH4 production rates were generally comparable across species. For
 studies that incubated termites with air and N2 (or H2) (e.g., Pester
 & Brune, 2007), we only included termite CH4 production rates
 measured from the incubation with air. For each eligible study, we
 extracted and tabulated termite CH4 production rates and other relevant
 variables (see the following section). We used μg CH4 g-1(termite) h-1 as
 the standardized unit, and if other units (e.g., μmol CH4 g-1(termite)
 h-1) were presented, we converted them into this standardized unit. In a
 few instances, we extracted data presented in figures using
 WebPlotDigitizer 4.5. Note: On May 5, 2024, we made
 some corrections regarding the subfamily classification of termite
 species.