Clearing new fenceline

A map showing the planned fence addition area with a red and blue dotted line.  The red portion indicates planned fence line area which has been mostly cleared of trees and brush and the blue indicates area ready for fence installation.  For reference, the white line is the property boundary line, the white circles are the posts of our temporary electric fence, and the closely spaced yellow circles are permanent fence.  
Aside from clearing trees for more pasture my other primary task has been continuing the fencing of our ranch.  Last year new fencing enabled us to give the bison access to 10 more acres of land and this year we hope to add an additional 27.8 acres of land.  Today I managed to completely finish preparing a 640 foot long section represented in the above map by the blue dotted line at the bottom of the image. Below are some photographs of this section. 
This is the first section of future fence line measuring 675 feet long.  To clear this I first used a brush cutter and chainsaws to cut the trees and brush and then finally used the tractor front end loader to carefully push the debris out of the way. 
The same section prior to clearing with the tractor.
The heavy rain this past week made some of the ground very soft so I had to lay logs down to keep the tractor from sinking down. 
The second area of soft ground.  Some sections were more prone to becoming soft than others.  I soon learned that the best way to reduce the risk of making mud was to keep the tractor wheels from spinning in place by keeping resistance on the front end loader very low. 
Another 170 feet of area where I had stacked the brush and logs by hand.  I prefer the method that involves the tractor better.
A sample or what still needs to be cleared.
As you may have noticed from the map, much of the new area still needs to be cleared of trees.  I haven't completely eliminated the option of renting a bulldozer, but, given how damp and uneven a lot of this ground is, I'm hesitant to do so.  Bulldozing very uneven land without compromising the topsoil seems like it would be difficult and the last thing I'd want to do would be to get a rented bulldozer sunk halfway down in mud.  Also, even if I were able to bulldoze the trees without encountering these problems I'd have quite a challenge stabilizing the soil before it all washed away.

Another option for tree removal would be to cut the area over with a chainsaw, and either burn everything when it dries or allow it to rot in place.  Most of the area is covered with loblolly pine, so it would burn or rot quickly.  Once the trees were cut and most of the find material either burned or rotted away, I would simply plant grass seed around the stumps which would eventually rot away.  I'm testing this method with a 5 acres section of trees within the fenced bison area.  Right now the trees are cut and mostly dried out and I will probably try burning it in the fall.  The results of this experiment will probably help me decide which method to use for the rest of the property.