Woody plants modify environmental conditions, increase heterogeneity, and affect the spatial distribution of other species. These changes can include differences between under-canopy and exposed areas, microheterogeneity under the canopy, and temporal variability. Data on the mechanisms explaining microenvironmental heterogeneity remains scarce in drylands, while their understanding is crucial for planning conservation, management, and restoration programs. In the Monte Desert (Argentina), Neltuma flexuosa alters the spatial distribution of shrubs and herbs, as well as soil properties. In this work, we analysed the changes in irradiance, edaphic, and water conditions produced by N. flexuosa at two different scales in the Ñacuñán Reserve (Mendoza, Argentina). We randomly selected 12 trees, installed a set of pluviometers and evaporimeters, and monthly registered soil water content, temperature, and photonic photosynthetic flux in two mesohabitats (under the canopy and exposed areas) and two microhabitats (under the northern or southern canopy of N. flexuosa). Our results showed the significant role of N. flexuosa in generating diverse microhabitats. At the mesohabitat scale, it intercepted rainfall and reduced evaporation, resulting in a lower hydric deficit. In addition, it moderated extreme temperatures and reduced solar radiation. This effect was stronger in the southern microhabitat than in the northern one, and in the summer season. These modifications were not homogeneous but promoted microheterogeneity under their canopy, resulting in distinct microenvironments. This heterogeneity aligns with species distribution patterns found in previous studies. The varying requirements of the species to these factors likely determine the capacity of each species to occupy these different microhabitats.