Spatiotemporal patterns of greenhouse gas fluxes in the subtropical wetland ecosystem of Indian Himalayan foothill.

The study characterized the temporal and spatial variability in greenhouse gas (GHG) fluxes (CO ₂ , CH ₄ , and N ₂ O) between December 2020 and November 2021 and their regulating drivers in the subtropical wetland of the Indian Himalayan foothill. Five distinct habitats (M1-sloppy surface at swamp forest, M2-plain surface at swamp forest, M3-swamp surface with small grasses, M4-marshy land with dense macrophytes, and M5-marshy land with sparse macrophytes) were studied. We conducted in situ measurements of GHG fluxes, microclimate (AT, ST, and SMC _(v/v) ), and soil properties (pH, EC, N, P, K, and SOC) in triplicates in all the habitat types. Across the habitats, CO ₂ , CH ₄ , and N ₂ O fluxes ranged from 125 to 536 mg m ^-2  h ^-1 , 0.32 to 28.4 mg m ^-2  h ^-1 , and 0.16 to 3.14 mg m ^-2  h ^-1 , respectively. The habitats (M3 and M5) exhibited higher GHG fluxes than the others. The CH ₄ flux followed the summer > autumn > spring > winter hierarchy. However, CO ₂ and N ₂ O fluxes followed the summer > spring > autumn > winter. CO ₂ fluxes were primarily governed by ST and SOC. However, CH ₄ and N ₂ O fluxes were mainly regulated by ST and SMC _(v/v) across the habitats. In the case of N ₂ O fluxes, soil P and EC also played a crucial role across the habitats. AT was a universal driver controlling all GHG fluxes across the habitats. The results emphasize that long-term GHG flux monitoring in sub-tropical Himalayan Wetlands has become imperative to accurately predict the near-future GHG fluxes and their changing nature with the ongoing climate change.
(© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)