There isn't much of the swamp left.
Joining as Shrek. First action: confront the invaders. Use dialogue option "WHAT ARE YOU DOING IN MY SWAMP?"
Fire sweeps across the swamps in a massive blast wave.
go here and burn trees. try and kill all remaining people
There is a small oasis there that will sustain you.
The tree are located in the water. It will be diffiult. Also this place is rather close to the light territory perhaps you should move to the desert?
Only three of your people have survived the war.