Final answer:
The area of the forest after 6 years will be approximately 1,299.97 km².
Step-by-step explanation:
To find the area of the forest after 6 years, we need to calculate the area after each year and then subtract 3.75% from the previous year's area.
The formula to calculate the new area is: New Area = Previous Area - (Previous Area * 0.0375).
Starting with an initial area of 1600 km², the area after 6 years will be approximately 1299.9682 km².