The plans for a Centenary Wood for Northern Ireland were announced during a visit to the Province by the trust's patron Princess Anne.
The 20-hectare site in County Londonderry's Faughan Valley currently consists of a pocket of ancient woodland surrounded by grassland.
Director of the Woodland Trust in Northern Ireland Patrick Cregg said: "Here, we aim to plant up to 40,000 native trees and create carpets of wildflowers, including iconic poppies. And we hope that a special memorial area, possibly by the banks of the stunning River Faughan, will provide a place for quiet reflection.
"This new wood will be a living, lasting tribute to the people from the island of Ireland who fought or supported others during the war."
Members of the public will have a chance to offer ideas and find out more at a public consultation meeting this summer, while schools, youth groups and community groups can take part in the lanting.
The site was purchased with the assistance of Northern Ireland Environment Agency, a number of charitable trusts and foundations, and individual donors. The wood's creation will be in partnership with Sainsbury's.