Methane Emissions from Subtropical and Tropical Mangrove Ecosystems in Taiwan

Abstract

Mangroves are one of the blue carbon ecosystems. However, greenhouse gas emissions from mangrove soils may reduce the capacity of carbon storage in these systems. In this study, methane (CH4) fluxes and soil properties of the top 10 cm layer were determined in subtropical (Kandelia obovata) and tropical (Avicennia marina) mangrove ecosystems of Taiwan for a complete seasonal cycle. Our results demonstrate that CH4 emissions in mangroves cannot be neglected when constructing the carbon budgets and estimating the carbon storage capacity. CH4 fluxes were significantly higher in summer than in winter in the Avicennia mangroves. However, no seasonal variation in CH4 flux was observed in the Kandelia mangroves. CH4 fluxes were significantly higher in the mangrove soils of Avicennia than in the adjoining mudflats; this trend, however, was not necessarily recapitulated at Kandelia. The results of multiple regression analyses show that soil water and organic matter content were the main factors regulating the CH4 fluxes in the Kandelia mangroves. However, none of the soil parameters assessed show a significant influence on the CH4 fluxes in the Avicennia mangroves. Since pneumatophores can transport CH4 from anaerobic deep soils, this study suggests that the pneumatophores of Avicennia marina played a more important role than soil properties in affecting soil CH4 fluxes. Our results show that different mangrove tree species and related root structures may affect greenhouse gas emissions from the soils.

Biophysical Controls of Ecosystem‐Scale Methane Fluxes From a Subtropical Estuarine Mangrove: Multiscale, Nonlinearity, Asynchrony and Causality

“…Indeed, K . obovata has been identified as a direct CH 4 emitter in recent studies (Gao et al., 2021; Lin et al., 2020).…”

“…LE is likely to be a control of F CH4 because dissolved CH 4 from soil pore water can be transported via the transpiration stream and subsequently emitted from the mangrove stems (Covey & Megonigal, 2019;Jeffrey et al, 2019). Indeed, K. obovata has been identified as a direct CH 4 emitter in recent studies (Gao et al, 2021;Lin et al, 2020).…”

Dynamics of Methane in Mangrove Forest: Will It Worsen with Decreasing Mangrove Forests?

“…The above-mentioned studies have mainly focused on CH 4 emissions from water and sediment in mangrove forests, and CH 4 emission through stems, leaves, and pneumatophores from mangroves is poorly understood [41]. A positive correlation between the density of pneumatophores and CH4 flux is often found in various mangrove forest sediment [39,49,51,100]. However, some specific mangrove forest tree species such as Sonneratia apetala decrease CH 4 flux [41].…”

The influence of physicochemical environment on the distribution and abundance of mangrove gastropods in Ngurah Rai Forest Park Bali, Indonesia

“…In aerobic conditions, DO concentration oxidizes organic matter and inorganic materials which can fertilize the waters. Meanwhile, in anaerobic conditions DO concentration reduces chemical compounds in the form of nutrients and gases (Barreto et al 2018;Shantelle et al 2018;Lin et al 2020). This oxidation and reduction process is very important in the effort to reduce the debit of pollution from anthropogenic waste.…”