A survey of Cornwall's landscape has revealed that farmland and wildlife habitats are disappearing.
Researchers studied aerial photographs of the county taken between 1995 and 2005 to record the changes.
The photographs showed that farmland and wetlands had been replaced with modern developments.
Dave Lewis from Cornwall Council, which organised the study, said: "It's predicted we might lose 40% of our wildlife species over 50 years."
'Rate of loss'
Mr Lewis added: "It's very difficult to imagine what Cornwall would be like if we lost half our wildlife."
Researchers at Cornwall Wildlife Trust studied the photographs and recorded the data.
Victoria Whitehouse from the trust said: "It came up with some really useful information about the land cover of Cornwall.
"The rate of loss of important wildlife habitats has gone down, so in the years before 1995 we found important areas of wetlands were being destroyed and that's real problem for Cornwall's wildlife.
"In some ways that's good news, but it's still very depressing and we've lost some quite significant areas of wetland habitat, about 60 football pitches across the county."
Enclosed farmland has also decreased with about 4,700 acres lost to developments.
Mary Combe from the Farming and Wildlife Advisory Group said: "The worrying thing about it is it's the edge of farmland people are willing to sell, when that's the most important part for wildlife because of the hedges and scrub."