Potential energy in a falling tree?

Hi,

My first post here, hope it goes well.

I wonder if someone of you skilled persons could help me and my friend calculate the energy in a falling tree.

I´m no good at maths neither good in english but I will try to explain what I´m after.

If you cut down a tree that is 25m heigh and weighs approx 700kg. How much energy does it produce when falling to ground?

Or, if different, if you trying to hold back the energy 1m up on the stem, how much energy must you use to stop it?



Hope someine can help me this, thanks in advance.

Note, it is not homework.