Microbially mediated climate feedbacks from wetland ecosystems

Abstract

Wetlands are crucial nodes in the carbon cycle, emitting approximately 20% of global CH4 while also sequestering 20%–30% of all soil carbon. Both greenhouse gas fluxes and carbon storage are driven by microbial communities in wetland soils. However, these key players are often overlooked or overly simplified in current global climate models. Here, we first integrate microbial metabolisms with biological, chemical, and physical processes occurring at scales from individual microbial cells to ecosystems. This conceptual scale‐bridging framework guides the development of feedback loops describing how wetland‐specific climate impacts (i.e., sea level rise in estuarine wetlands, droughts and floods in inland wetlands) will affect future climate trajectories. These feedback loops highlight knowledge gaps that need to be addressed to develop predictive models of future climates capturing microbial contributions. We propose a roadmap connecting environmental scientific disciplines to address these knowledge gaps and improve the representation of microbial processes in climate models. Together, this paves the way to understand how microbially mediated climate feedbacks from wetlands will impact future climate change.

Investigating Salinity Effect on Temperate Coastal Wetland Soil Microbes and Greenhouse Gas Emissions.

“…The study underscores the critical role of characterizing microbial communities in coastal wetlands to unravel their significance in the intricate biogeochemical processes driving carbon cycling. While acknowledging the study's limited scope and the complex nature of wetland systems, it emphasizes a potential trade-off between reduced CH4 emissions and increased CO2 emissions with rising salinity levels, as supported by current research (Candry et al, 2023). Although CO2 is a less potent greenhouse gas than CH4, higher CO2 emissions could counterbalance wetlands' carbon sequestration capacity, potentially shifting them from carbon sinks to carbon sources.…”

“…Anaerohalosphaera (7.73±3.79%) is an obligately anaerobic bacteria, moderately halophilic and mesophilic, and can assimilate sulfate (Pradel et al, 2020). Sulfur-cycling process seems also to enhance C mineralization, potentially both reducing CH4 emissions and enhancing C storage (Candry et al, 2023). Desulfatiglans is, ad an example, the most prevalent genus in all samples from PIR, and this is probably linked to its role in sulfur metabolism (Kevorkian et al, 2020).…”

“…Saltwater may promote the growth of bacteria that reduce sulfate, which further complicates the biogeochemical processes that take place in wetlands (Jørgensen et al, 2019). The balance between rates of sea level rise, sulfate intrusion, and wetland accretion will have strong impacts on the capacity to store and sequestering carbon (Yousefi Lalimi et al, 2018;Candry et al, 2023). By the end of the 21 st century, ecosystems like eutrophic, shallow, and microtidal estuaries in temperate and high latitudes will be at moderate to high risk of submergence and erosion under future emission scenarios (IPCC , 2022;Yang et al, 2023).…”

Integration of Wetland Technology for Sustainable Urban Development

“…This aligns with the positive relationship found between WTI and ECI. Wetland ecosystems contribute to biodiversity, carbon sequestration, and resilience to climate change (Candry et al, 2023). The positive relationship between WTI and ENI suggests that integrating wetland technology enhances environmental sustainability.…”