The impacts of olivine-based enhanced weathering on the growth of the salt marsh grass Spartina alterniflora

Enhanced weathering is a promising carbon dioxide removal strategy aimed at mitigating the effects of anthropogenic CO₂ emissions on Earth's climate. Olivine, a naturally occurring mineral, is frequently utilized in this process due to its capacity to capture CO₂ during weathering. Salt marshes, recognized as vital blue carbon ecosystems, play a significant role in carbon sequestration and storage within their soils. This study investigates the effects of olivine-based weathering on the growth of the keystone marsh grass species, Spartina alterniflora. Experimental treatments involved amending potting soil with either quartz play sand or olivine, each comprising one-third of the mixture, with and without the incorporation of natural marsh soil. Seedlings of S. alterniflora were planted in each treatment and monitored over a 12-week period. Results indicated that soil pH was significantly elevated in the olivine treatments compared to non-olivine treatments. However, metrics of plant success—including aboveground and belowground biomass, average growth rate, and plant height—were lower in the olivine treatments. Notably, a positive correlation was observed between soil pH and total biomass in the non-olivine treatments, suggesting that factors beyond soil pH may inhibit plant growth in olivine-amended soils. Further analysis of potentially toxic heavy metal concentrations in plant tissues is currently underway. While the limited performance of S. alterniflora seedlings in this controlled setting may not accurately reflect outcomes in natural salt marsh environments, this study highlights potential negative impacts of enhanced weathering on salt marsh vegetation and underscores the need for further research in this area.

Presentation Preference: Oral

Primary Presenter: Tyler Cyronak, Georgia Southern University (tcyronak@georgiasouthern.edu)

Authors:

Tyler Cyronak, Georgia Southern University  (tcyronak@georgiasouthern.edu)

Tyler Cyronak, Georgia Southern University  (tcyronak@georgiasouthern.edu)

Tyler Cyronak, Georgia Southern University  (tcyronak@georgiasouthern.edu)

Tyler Cyronak, Georgia Southern Unversity  (tcyronak@georgiasouthern.edu)