I've never tried it with a track loader, but have my doubts it's the best tool for the job. Trees are all about the roots, once you get them free, the tree falls over pretty easily where you push it. If you snap a tree off and leave the root ball in the ground, it's ten times as much work getting it out because you don't have the leverage of the tree helping you.
I use a full sized, 80 hp, backhoe to take out trees. I've taken out thousands of them this way, and my 80 year old dad has take out a lot more them I have this was also. For small trees, you just push them over and then drag over the root ball with the teeth and pull them out. Fast, easy and clean. You don't disturb the ground very much and you don't have a lot of dirt left on the roots to deal with in your burn pile.
For bigger trees, you first dig the side you want it to fall, then the opposite side. Then change positions to where you want to push it over from and then dig out the other two sides of the root ball. Then reach up with the hoe stick and push it over. If it doesn't go, take out more dirt and try again. With a little practice, you'll learn how deep to dig depending on the size and type of tree.
I have a grapple that I can put on my loader instead of my bucket. I use that to pick up the trees and take them to the burn pile. For bigger trees, I wrap a chain around them and drag them to the pile. Having a grapple makes it easier to clean up the mess. That is where all the work is. Taking down the trees is easy, getting the area cleaned up is where you will be working the hardest and stressing the most.
I've done some clearing with my Case 1550 dozer, which is equal to a Cat D6 in size and power. 180 hp and 40,000 pounds. I cut the roots with the blade and dig down some, then get the blade up as high as I can and push them over. If the ground is still a little wet, they go over easy enough. If the ground is dry, it's a battle. Sometimes I snap them off and have to use the backhoe to dig out the stump. If they are smaller trees, I can clear a lot of land quite a bit faster then using the backhoe, but the mess created by all the down trees tangled up in each other, and the damaged done to the ground digging them up is massive. The clean up takes forever!!!!! Having the two options, I don't even consider the dozer for clearing trees anymore.
If I had more money, I would buy an excavator with a thumb to take out trees, and a 4x4 tractor with a grapple to haul them to the burn pile. The backhoe does it all, but I think the excavator would be more maneuverable and powerful. Same thing with a tractor with more traction.
Good luck,
Eddie