To answer a few questions (pms) ...
I am not absolutely sure but, I think most wood will be OK.
Anyhow this log is pine, I found it a couple of years back, I stored it my shed & intended to use it as a decoration at Christmas time!
There are a few points to remember though, wet wood will swell up & increase in size so be careful if it is a tight fit in your tank.
I coated this log with three coats of epoxy, the wood needs to be very dry for the epoxy to cure properly.
I also soaked the wood after it was coated in a water butt for 3 weeks before it went in my tank.
I weighed the wood before soaking & after just to see if it had absorbed any water & increased in weight - it had not.
I tried a few methods to hold the log in position, in the end I found that by coating the ends with 5mm of silicone, the log holds in place nicely.
I can see lots of different configurations for scaping with a log & it would be great to see someone else have a go?
I can see a plain sand bottom with HC cascading down & growing into the sand? (I am probably better at making things than designing plantscapes)
If i can help anyone who could take this idea further then I would be happy to do so, I could possibly make another log for someone but, I fear the postage to the UK would be high!