If you are useing Bryce5...Go into the Tree editor and Pick Douglas Fir and then go into the Tree editor by clicking on the E in your working window...Then go over to Trunk Material it is Down at the Bottom on the Left hand side and then you are Brought into the Material Editor...Go and Find the Trunk Texture you want(For Winter scene's I like to use the Mountain Texture Mud and Snow)and I apply it as the Trunk Texture and I make sure that the Mapping mode is set at WORLD SPACE...now I go into the Leaf Material Editor and change the Leaf Texture to the same thing...Then click ok and render your tree and make adjustments as Needed....