Science Center Objects

Black John marsh is located along the Petaluma River and covers 25 hectares. We surveyed 217 elevation points and 110 vegetation plots to determine baseline conditions of the marsh. Water level loggers deployed in 2010 were used to characterize the tidal inundation patterns throughout the year. Sediment accretion rates from soil cores at Petaluma marsh were extrapolated to Black John Ecological Reserve marsh and used as input for the WARMER sea-level rise response model. WARMER projects that by 2060 Black John marsh will be dominated by low marsh vegetation and will transition into mudflat habitat by 2080. 

Black John marsh is located along the Petaluma River and covers 25 hectares. We surveyed 217 elevation points and 110 vegetation plots to determine baseline conditions of the marsh. Water level loggers deployed in 2010 were used to characterize the tidal inundation patterns throughout the year. Sediment accretion rates from soil cores at Petaluma marsh were extrapolated to Black John Ecological Reserve marsh and used as input for the WARMER sea-level rise response model. WARMER projects that by 2060 Black John marsh will be dominated by low marsh vegetation and will transition into mudflat habitat by 2080. 

BLACK JOHN MARSH

WERC Black John Marsh study area
(Public domain.)
WERC Black John Marsh figures
The elevation histogram for Black John Marsh shows the marsh platform is above MHW on average (Fig. 1). Data from the vegetation surveys indicate moderate species richness (Fig. 2). Results from WARMER response model indicate that Black John will lose relative elevation as sea levels rise (Fig. 3). The marsh platform at Black John Marsh is projected to transition to low marsh habitat by 2060 and be below mean sea level by 2080 (Fig. 4). The percent of time Black John Marsh is inundated varies throughout the year by season, with the most inundation during the winter (Fig. 5).(Public domain.)
WERC Black John WARMER results
(Public domain.)

To download the Black John PDF Summary Report (Black John appendix from USGS Open-File Report Final report for sea-level rise response modeling for San Francisco Bay estuary tidal marshes):