No abstract

Variability of CO 2 concentrations within the Earth system occurs over a wide range of time and spatial scales. Resolving this variability and its drivers in terrestrial and aquatic environments ultimately requires high-resolution spatial and temporal monitoring; however, relatively high-cost gas analyzers and data loggers can present barriers in terms of cost and functionality. To overcome these barriers, we developed a low-cost Arduino monitoring platform (CO2-LAMP) for recording CO 2 variability in electronically harsh conditions: humid air, soil, and aquatic environments. A relatively inexpensive CO 2 gas analyzer was waterproofed using a semi-permeable, expanded polytetrafluoroethylene membrane. Using first principles, we derived a formulation of the theoretical operation and measurement of PCO 2(aq) by infrared gas analyzers submerged in aquatic environments. This analysis revealed that an IRGA should be able to measure PCO 2(aq) independent of corrections for hydrostatic pressure. CO2-LAMP theoretical operation and measurement were also verified by accompanying laboratory assessment measuring PCO 2(aq) at multiple water depths. The monitoring platform was also deployed at two sites within the Springfield Plateau province in northwest Arkansas, USA: Blowing Springs Cave and the Savoy Experimental Watershed. At Blowing Springs Cave, the CO2-LAMP operated alongside a relatively greater-cost CO 2 monitoring platform. Over the monitoring period, measured values between the two systems covaried linearly (r 2 = 0.97 and 0.99 for cave air and cave stream dissolved CO 2 , respectively). At the Savoy Experimental Watershed, measured soil CO 2 variability capturing sub-daily variation was consistent with previously documented studies in humid, temperate soils. Daily median values varied linearly with soil moisture content (r 2 = 0.84). Overall, the CO2-LAMP captured sub-daily variability of CO 2 in humid air, soil, and aquatic environments that, while out of the scope of the study, highlight both cyclical and complex CO 2 behavior. At present, long-term assessment of platform design is ongoing. Considering cost-savings, CO2-LAMP presents a working base design for continuous, accurate, low-power, and low-cost CO 2 monitoring for remote locations.

No abstract

No abstract

Measuring carbon (C) loss through different pathways is essential for understanding the net ecosystem exchange of carbon dioxide (CO2) in tidal wetlands, especially in a reality where wetland mitigation and protecting coastlines from rapid sea-level rise is a growing priority. Tracking C loss can help reveal where an ecosystem is storing the most C, but it can also help scientists understand near- and long-term impacts of wetland restoration on climate. A recently developed dissolved CO2 (pCO2) platform was tested in a subtropical salt marsh with an apparatus that raised and lowered sensor housing with the tide. Additional low-cost water quality sensors were installed nearby for measuring turbidity and salinity. Here, we evaluated how well this floating sensor platform along with twenty-eight days of biogeochemical data from a tidal salt marsh could detect C import and export from tidal effects. This work provides a pathway to low-cost, routine in-situ C exchange measurements which serve the needs of environmental managers, researchers, and others interested in better estimating wetland C storage and transport.

No abstract

No abstract

No abstract