The way to make a picture of a forest with PS is to take it out and copy it. The specific method is:

1. Open the original image, as shown in the following figure:

2. Select-Color Range-Select Green-Adjust Tolerance, as shown in the following figure:

3. Copy and paste and delete the unnecessary parts, as shown in the figure below:

4. Copy the layer-adjust the position, and you can copy as many as you need, as shown in the following figure: