This data set contains decomposition rates for litter of Salicornia pacifica, Distichlis spicata, and Deschampsia cespitosa buried at 7 tidal marsh sites in 2015. Sediment organic matter values were collected at a subset of sites. These data support the following in-press publication: Janousek, C.N., Buffington, K.J., Guntenspergen, G.R., Thorne, K.M., Dugger, B.D., and Takekawa, J.Y., 2017. Inundation, vegetation, and sediment effects on litter decomposition in Pacific coast tidal marshes. Ecosystems.

Decomposition of plant matter is one of the key processes affecting carbon cycling and storage in tidal wetlands. In this study, we evaluated the effects of factors related to climate change (temperature, inundation) and vegetation composition on rates of litter decay in seven tidal marsh sites along the Pacific coast. In 2014 we conducted manipulative experiments to test inundation effects on litter decay at Siletz Bay, OR and Petaluma marsh, CA. In 2015 we studied decay of litter in high and low elevation marshes at seven Pacific coast sites. These data support the following publication: Janousek, C.N., Buffington, K.J., Guntenspergen, G.R. et al. Ecosystems (2017). doi:10.1007/s10021-017-0111-6. http://link.springer.com/article/10.1007/s10021-017-0111-6

This data table contains mean decomposition rates and mean carbon:nitrogen ratios for different litter types buried in 7 marshes during 2015. Note that C:N data are repeated for low and high marsh areas at each site in the table. These data support the following in-press publication: Janousek, C.N., Buffington, K.J., Guntenspergen, G.R., Thorne, K.M., Dugger, B.D., and Takekawa, J.Y., 2017. Inundation, vegetation, and sediment effects on litter decomposition in Pacific coast tidal marshes. Ecosystems.

This data table contains summary data for temperature time series in near-surface sediments in high and low tidal marsh at 7 sites during 2015. These data support the following in-press publication: Janousek, C.N., Buffington, K.J., Guntenspergen, G.R., Thorne, K.M., Dugger, B.D., and Takekawa, J.Y., 2017. Inundation, vegetation, and sediment effects on litter decomposition in Pacific coast tidal marshes. Ecosystems.

This table contains data on dry mass remaining in a subset of Salicornia pacifica and Deschampsia cespitosa litter bags removed over a series of time points spanning 6 months. These data support the following publication: Janousek, C.N., Buffington, K.J., Guntenspergen, G.R. et al. Ecosystems (2017). doi:10.1007/s10021-017-0111-6. http://link.springer.com/article/10.1007/s10021-017-0111-6

The Mississippi River Deltaic Plain has extensive marsh habitats (fresh, intermediate, brackish, and saline) where soil cores were collected to a depth of 100 cm at 24 sites to assess long-term carbon accumulation rates and coast-wide burial rates. Each core was sectioned into 2-cm depth intervals, and select intervals were analyzed for percent moisture, bulk density, total carbon, and radionuclide (137Cs and 210Pb).

As part of the San Francisco Bay Marsh Sediment Experiments and hydrodynamic investigations in San Pablo Bay and China Camp Marsh, California, vegetation sampling measurements were taken over several periods at numerous locations. This portion of the data release presents physical characteristics and percent cover data from vegetation plots sampled in China Camp State Park salt marsh (northern San Francisco Bay) in 2015, 2016, and 2017. One-meter quadrats (1m x 1m) were analyzed for percent cover of each vegetation species present, average canopy height, and maximum canopy height. The percent cover was done by visual inspection. A quarter-meter quadrat (0.25m x 0.25m) was then used for stem count and stem diameter measurements. Stem counts were only done for S. foliosa. These quadrats ran along the instruments used to collect sediment and hydrodynamic data, which is described elsewhere in this data release. This survey was conducted on January 23, 2015 (winter conditions) and again on June 6, 2016 (summer conditions). A separate survey was conducted on September 29, 2016 and May 3, 2017, to measure the length, width, and spacing of S. foliosa leaves. Data collected are provided as a comma-delimited spreadsheet (.csv).

Vegetation delineations based on photo interpretation and formal vegetation classification plus change detection.

This data table contains results for the 2014 mesocosm tests of inundation effects on decomposition. These data support the following publication: Janousek, C.N., Buffington, K.J., Guntenspergen, G.R. et al. Ecosystems (2017). doi:10.1007/s10021-017-0111-6. http://link.springer.com/article/10.1007/s10021-017-0111-6