ABSTRACT Rainfall is a major dimension of species climate niches. It has been proposed that groundwater can change species responses to rainfall by creating ‘hydrological refugia’ under a drier climate. However, the available evidence is conflicting and biased towards plants. This study tested whether shallow water tables (< 5 m deep) provide hydrological refugia to the Amazonian mound‐building termite, Amitermes excellens . This termite builds mounds up to 4 m tall in the Lavrado , the largest continuous savanna in northern Amazonia. Google Street View was used to remotely survey A. excellens mounds in 131 sites along a road network covering the study region (~795 km). For each site, published products on environmental and land use variables were also obtained. Mound abundance was modelled as a function of an interaction between mean water table depth and mean annual rainfall, while accounting for other factors. The analysis showed that mound abundance was higher on sandier soils and inside Indigenous lands but decreased with fire frequency and the Normalized Difference Vegetation Index. After accounting for these effects, a climate–groundwater interaction was found: Mound abundance increased with annual rainfall over deeper water tables but was consistently low over shallow water tables regardless of rainfall. Thus, groundwater can drastically change the realized climate niche of both plants and animals. However, shallow groundwater need not provide hydrological refugia under drier climates. Given that termites concentrate much of the terrestrial animal biomass and are major detritivores in the tropics, climate–groundwater interactions may have neglected impacts on global biogeochemical cycles.
Pedro Aurélio Costa Lima Pequeno (Thu,) studied this question.