I nearly missed the tree hugger - saw your title and wondered what the fun was - the passer by? - the station? - ohh, there. Perhaps a variation in cropping to bring the subject (based on your title) into play more, however the color of the clothing on the 'little one' (compared to the tree) isn't allowing much contrast with this tone - but maybe with a tighter crop, who knows.
I wonder... if there were any possible way to somehow get closer to the child hugging the tree, without loosing the impression that the tree is enormous... If we could see the child's face closer, maybe it would give the image a more dramatic, emotive atmosphere. Just a thought. In any case, the wonderful tones and contrasts bring out the texture of the bark very nicely. Good work!