Most of the trees in a patch of woodland near Newhaven are to be felled after they succumbed to ash dieback.
About nine in ten trees in Bollen’s Bush Nature Reserve, next to Peacehaven Golf Course, will be chopped down next month.
Lewes District Council says the work will start in early December and take ten days.
Councillor Emily O’Brien, Cabinet Member for Climate, Nature and Food Systems, said: “It’s devastating to see local woodlands, like trees in so many parts of the UK, being decimated by ash dieback.
“This is an airborne fungus that leaves diseased trees weak, with branches or the tree itself at risk of falling. Currently there is no preventative treatment available.
“We have been monitoring the spread of ash dieback in Lewes district and have identified the need to remove diseased trees at Bollen’s Bush to keep people safe.
“We are absolutely committed to only removing trees when necessary and making sure that we do this in the most ecologically friendly way possible.”
Ash dieback, which is forecast to kill 80% of the UK’s ash trees. Diseased trees pose a risk through falling branches, and public footpaths run through Bollen’s Bush.
The Forestry Commission has issued a felling licence and the council has put up signs in the area and has been communicating with local stakeholders to make them aware.
Councillor O’Brien said: “By managing these trees in this responsible way, we will be creating new opportunities for plant and wildlife regeneration.
“As a result, the density of bramble cover will be reduced and light levels capable of reaching the woodland floor increased, allowing for a wider variety of plant and tree species to become established.
“Retaining some dead wood will also boost biodiversity by creating vital habitats for a great many species, alongside providing soil nutrients.”
