Another ground anchor 'retrieve-from-tree' method...
I hope I'm not covering something that's already been posted, but I don't recall seeing it anywhere and I tried this yesterday and it worked really well and I videoed it so here it is.
This is for an SRT ground anchor entry to a tree. The concept is simple, tie two shorter ropes together and locate the bend near the TIP. This method is particularly well suited for climbing with a shorter rope in the tree.
Climb up to the TIP or bend, and with the free end of the rope, set up another TIP, in the video, I use a DdRT setting. Slack the SRT line and untie the bend; the rope anchored at the ground can be dropped and you now have access to both ends of the other rope.
It's really pretty simple and worked well. Here's the video and in the video I set a DdRT setting and tie in with a lanyard too, but you wouldn't have to do both if you were comfortable and confident in your DdRT setting.
You do realize untying a life support line at height is potentially dangerous - right? http://www.youtube.com/watch?v=LYRJqbeqcPY