Zsolt, Your timing was impeccable in this shot; Capturing the old tree in silhouette via a low sun angle; looks like you might have filled it in with a bit of flash to bring out the bark features, yet retain the soft colors. There is green of the grass, and shimmering gold aplenty. What struck me though was the contrast of the clouds and the deep sky blue within the upper-right corner.
The imagery evokes a sense of fantasy or even a magical dreamlike state, an image strengthened by the mist in the background.
About the only thing I'd do different is how it's cropped. I'd probably crop a little bit of the sky, plus some of the foreground grass, to change the aspect ratio into one that is slightly more panoramic, This will lead the viewer into the central character of the photo, which is that wonderful tree, and increase it's stature within the frame.
Good Lord in Heaven, what a beauty! I love everything about this, from the subject, to the lighting, to the timing of the shot! This is fantastic! I have to agree with ws6transam's critique. This really does evoke a sense of fantasy. Makes me think of Peter Jackson's The Hobbit trilogy specifically for some reason. Must be the sheer beauty of it all. Great job!