Artist's Bracket

This fungi is growing on a large oak tree which is at the end of the lane running down the side of our house. 
A quick Google search reveals it to be Artist's Bracket Fungus or Ganoderma Applanatum.
It looks as though it has recently released brown spores. Evidently it can release up to 4.65 billion spores in 24 hours from a piece measuring 10cm x 10cm. This one measures about 30 cm across and it probably averages 10cm depth. Therefore it could have released getting on for 14 billion spores!! No wonder the area below and all round is brown.