Final answer:
Erosion is the forest carbon cycle process that moves carbon from one Geosphere reservoir to another Geosphere reservoir.
Step-by-step explanation:
The forest carbon cycle process that moves carbon from one Geosphere reservoir to another Geosphere reservoir is Erosion. Erosion refers to the movement of sediments, including carbon-rich organic matter, from one location to another. In the case of forests, erosion can occur due to factors such as wind, water, or gravity, which can transport soil and organic matter containing carbon to different areas within the geosphere.