Document Type

Thesis - Open Access

Award Date

2026

Degree Name

Master of Science (MS)

Department / School

Natural Resource Management

First Advisor

A. Joshua Leffler

Abstract

Coastal high-latitude ecosystems are increasingly flooded from storm surges associated with climate change, exposing soils that were historically infrequently inundated to higher-salinity waters for longer durations. Sub-Arctic wetlands and tundra store large amounts of carbon, yet how flooding characteristics, particularly flood duration, influence microbial mineralization and, consequently, greenhouse gas (GHG) production in these soils remains poorly understood. We conducted a full-factorial microcosm incubation experiment in which coastal wetland and tundra soils were subjected to simulated flooding with three durations (1, 3, and 10 days) and four salinity treatments (unflooded, freshwater, 3 ppt, and 12 ppt) and measured carbon dioxide (CO2) and methane (CH4) fluxes over 80 days following the simulated flooding events. We found salinity to be more influential on GHG dynamics than flood duration. While freshwater flooding reduced CO2 production and enhanced CH4 production, saline floods inhibited the production of both gases. The inhibitory effects of flooding on CO2 production were stronger in tundra soils than in wetland soils, but the effects of flooding on CH4 production were more variable in tundra soils. Although flood duration had limited overall effects, longer floods increased CH4 production in tundra soils. As coastal flooding increases, salinity may constrain GHG production in these high-latitude ecosystems, but longer floods could enhance CH4 production in areas of the landscape that were not historically exposed to inundation.

Publisher

South Dakota State University

Download

Share

COinS
 

Rights Statement

In Copyright