Waiting for Timber to chime in here. Giles Run in Lorton VA was covered with this stuff if I recall.
Giles Run is mostly Blackberries which have been declared a non-invasive natural habitat buffer.
Seneca Creek was Multiflora rose. The previously mentioned, rake and saw method works well with two people. A third person to drag the debris away can make the work go really quick.
Much of what I cleared at Seneca was done solo with my truck, a mattock and a rope lasso. A 3/8" metal cable, with a loop on both ends, and a chainsaw, would have made the job much easier.:doh:
Back the truck up to the patch of thorns, circle the patch with the rope about two feet above the ground surface. Place the end of the rope through the lasso, pull with the truck until well cinched. Set parking brake, get out and cut as much base as possible. Pull again to cinch tighter, cut remainder of base. The entire mass comes out as a huge 8'x8'x8' ball of nastiness which can be pulled with the truck to your disposal site. Loosening and removing the lasso is a pain but disposal is the hardest part of the process.
We were lucky that a controlled burn, by the fire department, was allowed. A 50' x 100' x 8' pile was compacted in a clearing near the original 10th fairway. It burned in about 90 seconds and melted the snow for 100 yards in all directions.
The solo truck method caused five flat tires in 18 months, two of which were unrepairable sidewall punctures.
In some areas,we wanted to keep small trees which were surrounded by multiflora rose. These areas required walking backwards into the thorns to expose the base so an awkward cut could be completed.
ALWAYS drag the debris 3 x farther from the area than you think you need to. Moving a half dried debris pile is a pain, especially if you have to do it repeatedly. Extracting a disc from a debris pile is really frustrating for players.
Eye Protection, sharp tools, long welders gloves, good boots and cold weather (thick clothes) makes the work much easier and safer. A quilted Dickies full body suit is well worth the investment to keep most (not all) of the thorns out of your nether regions...