bmac,
I was thinking about your trails and forgot to mention a few things.
Winter time is ALLOT better for clearing than any other time. No leaves or bugs. The bugs might be more important if you hit a hive or get stung. The back of my neck is usually tore up by bugs eating on me. For some reason that's were I get bit the most. Every tractor has a bottle of DEET in it that I use religously. When I hit a hive, I back off and start spraying myself all over to just create a cloud. So far it's worked. /forums/images/graemlins/grin.gif
With the leaves down, you can see where your going. It's also easier to burn just branches without the leaves. Not that leaves don't burn, but they float off and start other fires.
The other advantage to winter clearing is the ground is usually saturated from the rains. When it's dry out, the ground acts like cement holding trees in. After a rain, even though it's dry enough to drive on, it's still wet just below the surface. This makes a HUGE difference in the size and ease of what you can take out.
Pines are the toughest for me to get out on my place. In winter, the size of tree is several inches wider that I can push over with my dozer. Trees I wouldn't even try in summer just pop right out in winter. I also don't break off as many in winter. Sometimes small trees just snap off at the base in my situation. But that's very rare when the ground is wet.
Hope this helps,
Eddie