Like said in post #7..
We have a couple pastures that are reclaimed bush and heavy timer. This was about 20 years ago and they were left to revert to bush with only some sparse grazing to keep them clear.
It was slowly creeping back to bush with a lot of Fire Weed, Thimble Berry and other stuff that makes good jam. Jam is wonderful but nothing will eat those plants.
In the last 3 years I have done like post #7. Reseed with annual rye over winter and such. Using the rye as ground cover and green fertilizer of sorts.
This process started with brush hog every thing down to about 15 cm high. Some of it was as much as 1.5 meter tall. Brush hog small patches again down to 5 cm, level out the rough spots as described in post #7, then seed and cover seed for good contact. We finished with planting several short shelter belts of sorts in spots that will retain snow for the best benefit of the pasture. About 2/3 of each shelter belt is native berry bushes. In this area all the trees and bushes require moose proof cages to keep them from being browsed off right away.
Once an area starts to re establish its self, you need to brush hog to keep thistle and other unwanted things at bay. The pasture/hay plants will take mowing in stride.
This can be done reasonably economically, but you can't skimp on the seat time and effort to make it good. It surely is not a one pass and done effort.
My 5 cents of experience and opinion for this area of the world.
Your needs may vary.
