Natural Resources Wales says it will spend £500,000 immediately to try to stop the Phytophthora ramorum tree disease from spreading further.
An extra £2 million will be provided for carrying out future work.
This is the most serious and devastating action we’ve had to take on our estate because of tree disease and it again highlights both the need to tackle tree disease and the importance of restoring as much of our damaged ancient woodland as possible to make it more resilient in decades to come.
Following the felling the Trust believes that the best approach is to immediately replant the wood with native broadleaf trees such as oak and cherry in the hope of preserving woodland specialist plants that only thrive when sheltered by tree canopy.
More top news
Swansea's defeat was their joint-heaviest of the season and they remain bottom of the Premier League with 12 points from 17 games.
Winds will ease through the day, with patchy ice where lying snow still remains.
Windy overnight, with sleet and rain moving quickly east through the evening, with snow falling over the hills.