Oak trees are the dominant tree type at our study catchments in Blue Oak Ranch Reserve, however they are not uniformly spread across the landscape. Oak trees are only established on  north facing slopes, while grasses are dominant the  south facing slopes. Generally, north facing  (or pole-facing) slopes are expected to be both wetter and cooler than south facing (or equator-facing) slopes. Work led by Nerissa Barling showed that at BORR, subsurface moisture was actually higher on the south facing slopes, which we believe is due to oak trees on north facing slopes needing water all summer long, while grasses on south facing slopes are only active during spring. Importantly, these differneces in subsurface moisture may contribute to aspect-dependent (north vs south facing) differences in streamflow, landslide susceptibility, and drought resilience (Read more about it here!). ​