Sediment phosphorus data from coastal wetlands in China: effects of Spartina invasion and aquaculture conversion

China's coastal wetlands have experienced sequential transformations over recent decades, driven first by the spread of the exotic cordgrass Spartina alterniflora and subsequently by large-scale conversion to aquaculture ponds. These anthropogenic shifts are expected to profoundly alter sedimentary phosphorus (P) cycling, given that P is often a limiting nutrient in estuarine and coastal ecosystems, and its mobility and bioavailability are tightly coupled to sediment redox conditions, organic matter loading, and microbial activity. Changes in P speciation and regeneration kinetics can, in turn, affect primary productivity and exacerbate downstream eutrophication. To evaluate these impacts, we collected surface sediment samples from three representative habitat types—native mudflats (MFs), S. alterniflora marshes (SAs), and aquaculture ponds (APs)—across a broad latitudinal gradient (21–32°N) along the Chinese coast. We quantified P fractions using a sequential extraction scheme, measured net PO43- regeneration potential via anaerobic incubation, and determined microbial biomass P (MBP) and key enzyme activities. Detailed data on these parameters are provided in the accompanying tables.