This picture is made with several parts, some took from web and some with my camera. It is a long job because of the various selections to do, but I've had a lot of fun creating it.
Import the tree, make a selection of a branch and enlarge it. Set it close to the bottom. Duplicate it, desaturate the copy by pressing ctrl-shift-U and blend it to soft light. Next duplicate the not-desaturate branch and apply: filter-high pass filter and set it to 3.5. Then set it to overlay.
Import the tree, make a selection of a branch and enlarge it. Set it close to the bottom. Duplicate it, desaturate the copy by pressing ctrl-shift-U and blend it to soft light. Next duplicate the not-desaturate branch and apply: filter-high pass filter and set it to 3.5. Then set it to overlay.