Soil Organic Carbon Storage in Restored Salt Marshes in Huntington Beach, California

Abstract

There is a growing interest in managing wetland restoration and conservation projects to maximize carbon sequestration. We measured soil organic carbon storage and methane flux from two southern California salt marshes which had been restored for 2 and 22 years. We hypothesized that organic carbon would accumulate following restoration and that methane flux would be negligible in both sites. While methane flux was minimal, soil organic carbon content was generally higher in the more recently restored site. Although there is a potential for carbon sequestration in salt marshes, tracking this process through time may be complicated by initial site conditions.

Coupling between the Changes in CO<sub>2</sub> Concentration and Sediment Biogeochemistry in Mudflat of Salinas de San Pedro, California, USA

“…Two head escape samples were collected in 15 -30 min interval for each chamber from six locations. Samples were transported on the same day of collected gas samples to the School of Earth and Environmental Sciences Lab, Chapman University, Orange, CA for CO 2 and CH 4 analysis using gas chromatograph equipped with a flame ionization detector (SRI Instrument/1-mL sample loop, 100˚C column temperature/using GHG Standard = 1 ppm CH 4 ; 351 ppm CO 2 ). Laboratory blank was analyzed at the end of field gas sampling day along with five laboratory duplicates on June 13th, 2013.…”

“…Therefore, wetland and salt marsh ecosystems have triggered interest due to the fact that they are a source for methane (CH 4 ) and nitrous oxide (NO 2 ) production carrying on a biologically active surface, and operating as greenhouse gas sink through photosynthetic absorbing and incorporating of CO 2 and consequently storage in long-lasting biomass. The salt marsh biota trap sediment (mostly clay and silt) fine particles, organic material, and trace metals, allowing large amount of plant growth.…”

“…The salt marsh biota trap sediment (mostly clay and silt) fine particles, organic material, and trace metals, allowing large amount of plant growth. The accumulation of soil organic carbon is primarily from plant yield and through microbial respiration [1] promoting microbiological reactions causing the elevated atmospheric concentrations of CO 2 . The latter can stimulate sulfate reduction [2,3] along with changes in pore water concentrations of CH 4 and dissolved organic carbon in the grass dominated sys-tem.…”

“…Our objectives were to 1) understand the link between total CO 2 volume on salt marsh surface (including CO 2 emission from fault line and total organic carbon) and heavy metal concentration and speciation in salt marsh sediments and 2) analyze and interpret tidal marsh CO 2 and CH 4 emission in the context of carbon sequestration rate and metal speciation.…”

Soil Organic Carbon and Nitrogen Storage in Two Southern California Salt Marshes: The Role of Pre-Restoration Vegetation

“…We have previously measured soil organic carbon storage in two restored salt marshes in Huntington Beach, California (Keller et al 2012). This work showed that soil organic carbon was generally higher in a marsh that had been restored for two years than in an adjacent marsh that had been restored for 22 years.…”