There has been a decline in species such as oak, ash and field maple
Conservationists are planning to buy an 800-acre site to grow the largest continuous native forest in England.
The Woodland Trust will plant more than 600,000 trees on the site near St Albans in Hertfordshire.
The trust says a new native forest of this size and type has never been created in England before, and could take shape within 12 years.
England has lost half its ancient woodland to development, agriculture or conifer woods since the 1930s.
More forest has been created than lost in recent years but this has been mostly non-native conifer trees planted for commercial purposes.
The trust says it is a different story when it comes to native broadleaved woodland of species such as oak, ash and field maple.