I played around with the filters and made them similar to ones in tutorial.. it had multiple steps and most of very low and then steps up steply. Maybe I am doing the image map distribution wrong on the materials. One thing I did notice if I load the distribution map as texture map, it not fit the terrain correctly like when I orginally added it to terrain. I had more than one line on it - but this was only after change it to mix materials and then changing the ecosystem.