Dataset: Accretion rates of low intertidal salt marshes in the Pacific Northwest
datasetposted on 13.11.2019 by Ronald M. Thom
Datasets usually provide raw data for analysis. This raw data often comes in spreadsheet form, but can be any collection of data, on which analysis can be performed.
Salt-marsh accretion rate was investigated at sites that spanned a gradient in relative rate of sea-level rise in Washington and Oregon. Mean accretion rate over all sites was 3.6 mm yr-1 (95% CI = 2.4 to 4.8 mm yr-1), which exceeded present mean sea-level-rise rate (1.3 mm yr-1; sd = 0.6). However, a mean rise rate of 5.5 mm yr-1 (sd = 1.9) predicted by a moderate sea-level-change scenario to occur by the year 2050 exceeds mean accretion rate. Marshes with adequate sediment input seemed to have the capacity to keep pace with an increased sea-level-rise rate. Lowest accretion rates were recorded at sites with the least sediment supply. Accretion rate showed a weak negative correlation with sediment organic matter (measured as volatile solids) and marsh standing stock. The data suggest that moderate and high rise-rate scenarios would threaten the existence of salt marshes in the region in the absence of increased sediment supply. A better understanding is required of marsh accretion and predicted rate of sea-level rise to refine predictions of the effects of sea-level rise on Pacific Northwest salt marshes.