Tree planting and felling have been completed at the Valley Ponds in Newhaven after some of the trees were found to be in a dangerous condition.
Newhaven Town Council said a recent tree survey had identified several of the trees, particularly at the western end of the site, were likely to fall due to advanced basal decay and honey fungus.
Replacement trees have now been planted after the felling took place.
The new trees will be around ten to 12 foot high.
A town council spokesperson said: “It is hoped that planting them now will enable them to make a good growth start over the summer period.”
More trees were planted around the Valley Ponds area, which is just off Lewes Road, as part of a new five year management plan to look after and enhance the natural ecology of the site.
Some less urgent tree works and further tree planting will take place as part of this plan in the autumn and winter.
The town council will also be carrying out maintenance works to other new tree planting carried out over the past couple of years by the local community.
All the trees were carefully inspected to ensure there were no nesting birds or bats before the work began.
The works were carried out by contractors employed by East Sussex County Council on behalf of the town council, which owns and manages the Ponds.
A large branch had fallen from one of the diseased trees, which the council said could be dangerous to families walking or playing nearby and unfortunately meant that these trees had to be felled.