Research of soil respiration in a less fertile soil suggests a lot of questions, which are not generated in more productive ecosystems. The influence of soil productivity, soil moisture and other factors play bigger role in the intensity of soil carbon efflux in soils where the value of these factors are more extreme. On the base of my six years of soil respiration researches in the Hungarian sand forest steppe I would make comparisons in the factors influencing soil respiration in Doñana Biological Reserve. I also would investigate and compare methodology in measurement technics between our Hungarian site and Doñana Biological Reserve.