The patterns of change in bioclimatic conditions determine the vegetation cover and soil properties along the altitudinal gradient. Together, these factors control the spatial variability of soil respiration (RS) in mountainous areas. The underlying mechanisms, which are poorly understood, shape the resulting surface CO2flux in these ecosystems. We aimed to investigate the spatial variability of RSand its drivers on the northeastern slope of the Northwest Caucasus Mountains, Russia (1,260–2,480 m a.s.l.), in mixed, fir, and deciduous forests, as well as subalpine and alpine meadows.RSwas measured simultaneously in each ecosystem at 12 randomly distributed points using the closed static chamber technique. After the measurements, topsoil samples (0–10 cm) were collected under each chamber (n= 60). Several soil physicochemical, microbial, and vegetation indices were assessed as potential drivers ofRS. We tested two hypotheses: (i) the spatial variability ofRSis higher in forests than in grasslands; and (ii) the spatial variability ofRSin forests is mainly due to soil microbial activity, whereas in grasslands, it is mainly due to vegetation characteristics. Unexpectedly,RSvariability was lower in forests than in grasslands, ranging from 1.3–6.5 versus 3.4–12.7 μmol CO2m−1s−1, respectively. Spatial variability ofRSin forests was related to microbial functioning through chitinase activity (50% explained variance), whereas in grasslands it was related to vegetation structure, namely graminoid abundance (27% explained variance). Apparently, the chitinase dependence ofRSvariability in forests may be related to soil N limitation. This was confirmed by low N content and high C:N ratio compared to grassland soils. The greater sensitivity of grasslandRSto vegetation structure may be related to the essential root C allocation for some grasses. Thus, the first hypothesis concerning the higher spatial variability ofRSin forests than in grasslands was not confirmed, whereas the second hypothesis concerning the crucial role of soil microorganisms in forests and vegetation in grasslands as drivers ofRSspatial variability was confirmed.