Abstract Water stored in weathered bedrock plays a crucial role in the terrestrial water cycle by influencing vegetation, streamflow, and groundwater recharge. Past studies on the impact of aspect‐driven differences in insolation quantify moisture in shallow soils but largely ignore moisture dynamics in deeper weathered bedrock. Here, we measure moisture dynamics via geophysical surveys and borehole measurements in two opposing hillslopes with similar properties in the seasonally dry central California Coast Range. Despite greater insolation, the grassy equator‐facing slope experienced less and shallower moisture withdrawal during the dry season relative to the pole‐facing slope with oak trees, which experienced greater and deeper moisture withdrawal. Consequently, following the dry season, water content on the grassy equator‐facing slope was higher, which may contribute to aspect‐dependent differences in runoff generation, landslide susceptibility, and drought resilience.
Observations from the Little Bunker
Last updated: October 16, 2025 02:57 AM
Atmospheric CO₂
424.4 ppm
+18.2
ppm/year
Atmospheric CH₄
1933.54 ppb
+12.29
ppb/year
Global Temperature
+1.48 °C
Peak: +1.73°C
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8.1 billion
+67
million/year