Hi John,
colors and silhouette are very nice...........godd seperation in the branches and trees..........a bit more base would help.......but i see you used the 600mm.....so not sure if you could back up.........so if you are so inclined........adding a bit of canvas and black would help ground the image more.
Nice colors and I like the looking up view. Adding/having more fo the base would improve the image. Having the "V" notch of the FG going off the image leads the viewer's eye from the image.