Yeah do as catlin said. Choose the eroding cliff material then go into the DTE like in post 3 then select add. Now select the graveyard material and ctrl-click the channel C marker next to diffuse. Then as shown in post 2 for channel B select the technorock 4 that you added and for C forest (which is in bump). Now for an explantion of what is happening since the author of the tut doesn't know. With and ABC blend (markers in 3 channels for the same thing, in this case diffusion(color)) A and B are blended together based on the alpha channel in texture C and how that blending is done is based on the filter chosen for those textures (ie an altitude filter will blend them vertically). If you dont have "Real World Bryce" I highly suggest getting it because it goes into great detail of the material lab and all the formulas.