Inland waters, particularly headwater streams, cycle and transport substantial amounts of organic carbon (OC) globally. External OC subsidies are transported from headwater streams to fuel in-stream carbon metabolism and food webs downstream. Moreover, headwater streams are hydrologically dynamic systems exhibiting temporal variability in network connectivity and streamflow, which has potential cascading consequences on the transport and fate of OC. While reach-scale linkages have been examined, the linkages between network-scale connectivity and antecedent conditions and OC export are not clear. Therefore, we instrumented three Alabama headwater stream networks, each with distinct physiography, with high-frequency environmental sensors between three years (2021-2024). At each watershed outlet, we developed relationships between time series of absorbance spectra (s::can spectro::lyser V3) and fluorescent dissolved organic matter (YSI EXO2), with site-specific dissolved OC (DOC) concentrations from tri-weekly site visits. We used water presence-absence sensors placed across each stream network to estimate changes in active stream network length and summative network connectivity through time. Preliminary results from a single watershed show that DOC concentration increased during warmer and drier periods of the year (late summer through fall) while DOC export increased with streamflow regardless of season. Daily DOC export generally increased with greater daily average active network length. Despite strong relationships between export and flow, substantial variation in these relationships suggests that antecedent conditions play an important role in controlling DOC export, with daily DOC export ranging from 0.2 to 2.9 kg C on days with <90% of active network flowing (12% of days) and 0.3 to 13.5 kg C on days with 100% of the active network flowing (28% of days). Ongoing work will use additional network connectivity metrics, event-scale assessments of DOC-streamflow relationships, and flow duration analyses to better elucidate how antecedent conditions can alter the links between DOC export, streamflow, and network expansion and contraction across headwater streams.