University of East Anglia researchers Toby Pillatt, Gerry Barnes and Tom Williamson said lessons from their review of arboreal history, Rural tree populations in England: historic character and future planting policy, are that ash, elm and oak have been the most important trees (85-100 per cent in the four counties studied - Yorkshire, Northamptonshire, Hertfordshire and Norfolk) planted in the countryside "with consequences that are now frightening - elm has effectively gone, ash is threatened and there are serious concerns about oak".
In a report for British Wildlife, they said "we are obliged" to plant different trees now, and not just for economic and practical reasons as in the past. They advised planting trees that "have long been characteristic of different localities" using "selective diversity".
They recommended sycamore for Yorkshire, as well as field maple beech and alder. In Hertfordshire, aspen, wild cherry, beech and apple for the hedgerows of the east and black poplar, hornbeam and field maple for the clay of the east. Northamptonshire would be good for willows.
The researchers also recognised suggestions for planting trees such as downy oak in preparation for climate change and planting small-leaved lime for historical reasons. Rigorous management of trees may produce healthier populations, with felling of mature trees and regular pollarding creating resilience, they suggested.
After the "catastrophic decline in the numbers of farmland trees" over the past 150 years, they said: "We need to plant very large numbers of trees and we need to plant them now. But we need to think carefully about what we should plant and where. Here, the history of the landscape, while it should by no means be our only guide, ought to be one influence on our thinking."