Seasonal Sensitivity of Reco from Aquatic Ecosystem to Meteorological and Physicochemical Water Parameters

Ecosystem respiration (Reco) is the main contributor to carbon emissions from different types of aquatic ecosystems. For a better understanding of CO2 emissions from the water-atmosphere interface of rivers and to evaluate the influence of meteorological factors and water quality parameters on Reco, in-situ measurements were carried out in Damboviţa River in the winter season when temperatures were up to freezing point as well as in the summer period, which is the most dynamic in terms of CO2 exchange. Reco during the monitoring period ranged from 4.56 to 40.5 gm-2h-1. The statistical analysis of the data set showed that among the meteorological parameters, temperatures explain most temporal variability of CO2 fluxes. By scaling the importance of the water quality parameters, the precision of the permutations indicated the pH as the most influential parameter in the analysis of the dependent factors. The analysed data indicates that aquatic ecosystems are highly sensitive to changes in the current context of climate change, which implies that these ecosystems can easily turn into important sources of carbon in the atmosphere