#4 is the best for me. I like what you were trying to do i.e. show the fungi in its environment. The composition is spot on as is the perspective. The fungi is a little over flashed, however, and some of the highlights are blown. Try a minus value on your flash exp compensation.
#1 is over exposed and the duck competes with the bright background. It looks like it might have been heavily cropped.
#2 seems fine, a different perspective. The trunk on the left might benefit form a little brightening.
#3 The background is distracting.
Having said all that if I had produced images like this when I was starting out I would have been over the moon! Keep it up.