Soil chemistry, temperature and bacterial community composition drive brGDGT distributions along a subarctic elevation gradient

•Measured brGDGTs and bacterial communities along Scandinavian altitudinal gradients.•Soil chemistry is the main driver of brGDGT concentration and MBTʹ5ME ratio values.•Changes in CI values are coeval with an increase in Acidobacteria subgroup 1 and 3.•Bacterial community reflects soil pH, partially agrees with change in brGDGT signal.•Soil pH needs to be taken into account when determining MBTʹ5ME temperature response.