ZANCHI, Fabrício B. et al. Soil CO2 efflux in central Amazonia: environmental and methodological effects. Acta Amaz. [online]. 2012, vol.42, n.2, pp. 173-184. ISSN 0044-5967. http://dx.doi.org/10.1590/S0044-59672012000200001.
Soil temperature, environmental and methodological effects determine Soil CO2 efflux in Central Amazonia
A group of researchers from the Universidade Federal do Amazonas-UFAM, Free University-VU, Wageningen University-WUR, Instituto Nacional de Pesquisas da Amazonia-INPA and Max Planck institute-MPI, measured the soil CO2 respiration in the Central Amazon forest to understand the environmental and methodological effects on the soil CO2 emission.
The authors found that the main factor influencing the soil respiration was soil temperature, because the soil respiration followed the same pattern, while rainfall only caused a brief disturbance in soil respiration. Rainfall seems to contribute by creating favorable conditions for a quick decrease in temperature and consequently respiration followed the physical effect of soil water percolation. The methodology of automatic soil respiration used in this paper showed a better estimative of total CO2 emission in the Central Amazonian ecosystem. The authors also noticed that it was difficult to account for the rainfall effects in the simple model estimation.
According to the authors, for a better estimative of soil CO2 emissions, or to model a region and vegetation type, it is necessary to find the main influencing factors to decrease the uncertainties about the final carbon release measurements. The automated soil respiration datasets and the right procedure are a good tool to improve the technique and increase the reliability of measurements to allow a better understanding of all possible factors driven by soil respiration processes.
The study was carried out in the Cuieiras and Campina reserves near to Manaus city, during 2006 to 2008 at seven different rainforest types, four at different forests in the Cuieira reserve (plateau, slope, campinarana and valley forest) and another tree at different forests in the Campina reserve (bare soil, stunted and tall heath forest). The researchers used an automatic soil respiration system.. The authors investigated the effects of the method of ring insertion in the soil as well as of rainfall and spatial distribution on CO2 emission.
The article is published in the Acta Amazonica Journal (Vol. 42, n.2).