Refer to figure.
When the angle of attack decreases, the center of pressure moves aft due to changes in the distribution of lift and drag forces acting on the wing. As the angle of attack decreases, the wing presents less surface area to the airflow, resulting in reduced lift generation and typically reduced drag as well.

Consequently, the lift distribution along the wing's span shifts toward the wing's root, concentrating more lift closer to the fuselage. This shift in lift distribution causes the center of pressure to move aft toward the wing's root. The movement of the center of pressure affects the aircraft's stability and control characteristics, necessitating adjustments to control inputs to maintain stable flight conditions.

In summary, a decrease in angle of attack leads to an aft movement of the center of pressure, reflecting changes in aerodynamic forces across the wing's span and impacting the aircraft's stability and control.