Non-perennial streams comprise more than half of global stream length, and these streams extend and contract seasonally and during storm events. Recent work indicates that these tributaries can act as biogeochemical hotspots and may have disproportionate influence on biogeochemical fluxes across the terrestrial-aquatic nexus. Despite these advances, our understanding of the complex, often interconnected, mechanisms by which stream chemistry responds to changing hydrologic conditions remains understudied in the southeastern United States. To explore the biogeochemical “fingerprint” across a representative watershed of the Gulf coastal plain, we conducted monthly spatially-intensive sampling to explore the impacts of stream size (as area km2) on nutrient concentrations of [C]arbon, [N]itrogen, and [P]hosphorus in 2024-2025. During each sampling event, we collected surface water samples across twenty sites nested within the South Sandy Watershed (125 km2), which flows within the Talladega National Forest in central AL. We found that C (as dissolved organic carbon, DOC) and ammonium (NH4+) concentrations increased as site area increased, while phosphate (PO43-) and nitrate (NO3-) concentrations generally decreased as site area increased. Our preliminary results suggest that as subcatchment area increases, larger subcatchments act as integrators of upstream processes, being potential sources of DOC and NH4+ and potential sinks of PO43- and NO3- across the South Sandy watershed. Further, our results suggest that frequency, timing, and duration of network expansion and contraction are particularly important for characterizing C, N, and P distributions. Understanding the impact of steam network conditions on nutrient concentration helps us understand the transport and processing of C, N, and P in dynamic headwaters.