Spatial variation of soil δ13C and its relation to carbon input and soil texture in a subtropical lowland woodland

► We quantified soil δ13C in a C3 woodland changed from grassland. ► Spatial patterns of soil δ13C are a function of soil texture and SOC pool sizes. ► Locations of invading mesquite trees did not affect spatial patterns of soil δ13C. ► The woody invasion process in the lowland may be different from the upland. ► Spatial analysis of soil C isotope will enhance our ability to study C cycling.