Photophysiology data from smooth cordgrass (Sporobolus alterniflorus) measured in a North American saltmarsh using pulse amplitude modulated (PAM) fluorescence

Coastal saltmarshes play an important role as an interface between terrestrial and marine environments. Sporobolus alterniflorus (smooth cordgrass) occurs naturally along the east coast of North America, from Texas to Quebec, where it often forms extensive monospecific stands. Sporobolus alterniflorus is highly productive and is often the dominant plant in terms of biomass. This data set presents variable chlorophyll fluorescence measurements made in situ from the leaves of Sporobolus alterniflorus growing in a tidal saltmarsh ecosystem (North Inlet, South Carolina, United states). Measurements were made using pulse amplitude modulated (PAM) fluorescence. The data include raw measurements of variable fluorescence (F_t) and maximum fluorescence (F’_m) made at 12 different actinic photosynthetic photon flux densities (PPFD). These data were used to calculate the quantum yield of photosystem II (Φ_PSII) and estimate electron transport rates (ETRs). Rapid light curves (RLCs) were fitted to the ETRs to parametrize the relationship between ETR and PPFD in S. alterniflorus under different environmental conditions. Measurements were made from S. alterniflorus culms growing at different positions on the shore and at different times of the day. These data provide a resource for researchers interested in the photophysiology and photosynthesis of Sporobolus alterniflorus, and saltmarsh ecology and management.