Tidal freshwater marshes are critical buffers that exist at the interf
ace between watersheds and estuaries. Little is known about the physic
al dynamics of tidal freshwater marsh evolution. Over a 21-mo period,
July 1995 to March 1997, measurements were made of biweekly sediment d
eposition at 23 locations in a 3.8-ha tidal freshwater marsh in the Bu
sh River subestuary of the upper Chesapeake Bay. Biweekly accumulation
showed high spatial and temporal variability, ranging from -0.28 g cm
(-2) to 1.15 g cm(-2). Spatial variability is accounted for by habitat
differences including plant associations, elevation, and hydrology. T
emporal variability is accounted for by interannual climate variabilit
y, the growth cycles of marsh plants, stream marsh interactions, fores
t-marsh interactions, and animal activity.