Tree-ring δ18O identifies similarity in timing but differences in depth of soil water uptake by trees in mesic and arid climates

•Tree-ring δ18O as an indicator of soil moisture content was suggested.•The water-use seasonality of trees under contrasting climates is similar.•The water uptake depth of trees under contrasting climates is different.•Tree-ring δ18O can be a reliable proxy to extend soil moisture content record.