If the reed canary grass is standing tall and you try to burn it, the heat from the fire will boil the sap under the bark of the willow and kill them... And obviously the willow is the better habitat compared to the RCG... What I did with some of my willow/rcg thickts along my river is I took a hand saw and made a slit in the willow about head height (5'6"). Then i bent the willow over just like a hinge cut on a tree. I did this to almost every single willow in thicket. If you look through a willow/rcg thicket before you do anything to it, and you can do just that, "look through it". Or at least a long ways into it. However, after I hingecut the willows, I couldnt see but 10ft into the thicket! All of the fallen down tops of the willows, I made sure rested on the other tops and you pretty much have a 5' tall room under all that mess! Bukket is right, willow thickets are pretty good, but hinge them so the deer cant see out and feel safe, and they go from good to great in 2.5 hrs of work!