CARBON DIOXIDE FLUXES FROM SUBTROPICAL INTERMITTENTLY DRY AND WET STREAMS IN AUSTRALIA

Intermittent streams, a common feature of coastal floodplains, generally have higher CO₂ emissions than perennial rivers, due to their high flow dynamic. Globally 50% of rivers and streams are intermittently dry. Despite their significance, intermittent stream studies are limited, especially in the southern hemisphere. In this study, we measured CO₂ fluxes in nine intermittent streams over one year in northern New South Wales, Australia. Our study compares seasonal soil-air CO₂ fluxes measured from dry areas, and water-air CO₂ fluxes from when water was present in the nine streams. Mean water-air CO₂ fluxes were higher from flowing streams (9.3 ± 7.4 g CO₂ m^-2 d^-1), compared to dry fluxes from streambed sediments (4.8 ± 7 g CO₂ m^-2 d^-1), and water-air fluxes from stagnant channels (2.5 ± 1 g CO₂ m^-2 d^-1 ) and stagnant pools (2.5 ± 1.7 g CO₂ m^-2 d^-1). These findings highlight the need to account for CO₂ fluxes under varying hydrological conditions in intermittent streams when calculating inland water carbon budgets.

Presentation Preference: Oral

Primary Presenter: Micha Nebel, Southern Cross University, Lismore, NSW, Australia (micha_nebel@web.de)

Authors:

Micha Nebel, Southern Cross University  (m.nebel.10@student.scu.edu.au)

Judith Rosentreter, Southern Cross University  (Judith.Rosentreter@scu.edu.au)

Joanne Oakes, Southern Cross University  (joanne.oakes@scu.edu.au)

Naomi Wells, Lincoln University  (Naomi.Wells@lincoln.ac.nz)

Bradley Eyre, Southern Cross University  (Bradley.Eyre@scu.edu.au)