TEMPERATURE EFFECTS ON THE CARBON CONTENT OF MARSH CORE SUBSAMPLES THROUGH TIME

Within the last decade, many studies have begun looking at blue carbon, which is carbon stored in coastal environments, specifically salt marshes, mangrove forests, and seagrass beds. However, the methodology for carbon analysis in marsh cores has not been standardized. Carbon stored in marsh sediments is subject to microbial and recalcitrant degradation through time. In this paper, we focus on salt marsh core storage temperature and how it affects the carbon content. We used a marsh core from Onslow Beach area, and separated two 10 cm sections from the upper and lower part of the core. Homogenized sections of the upper and lower core were placed in 3 different temperature locations: freezer, refrigerator, and room temperature. We subsampled each section 9 times over 128 days and used CHN analysis to determine the percent carbon in the sample. We then compared CHN analysis to carbon loss on ignition. Our results show that variation in storage temperature does not steadily change the carbon content of a sample in one direction. However, it does appear that subsampling the sections introduces the most uncertainty in the measurements. We conclude that marsh core storage temperature does not largely affect carbon content measurements, and multiple subsamples of each section in a core should be processed for the most accurate analysis of carbon content.