By Wednesday more than half the area was cleared to ground level from having been covered in dense scrub, eight to ten feet high.
They said the 2.5 acre site was the subject of hotly contested planning applications between 2007 and 2011.
It was placed outside the Lewes Local Plan boundary with no applications allowed. One said: “This small urban wilderness is known locally for wildlife and large flocks of birds.
“A large adjacent pond is home to waterfowl and a heron can be seen fishing. Birds of prey also hover as they hunt. Sadly, toads and other protected species are less abundant since it was last flattened in the same way by the owner in 2007.
“It appears, despite assurances that only a narrow firebreak was being created, the whole site is stripped to bare earth as happened in 2007 causing public outcry. Residents are horrified to see the destruction, many voicing their concerns of ‘not again!’ The trees being destroyed have been the day time perch and night time roost for thousands of birds.”
A spokesperson for Lewes District Council, said: “Soon after being contacted about the clearance work, we sent planning enforcement officers and our ecologist to the area to investigate.
“The land is in private ownership and as such the landowner is entitled to manage the area.
“However, if a landowner wilfully destroys habitat inhabited by protected species, the police will need to consider whether a wildlife crime has been committed under the Wildlife and Countryside Act 1981.
“We will provide Sussex Police with any support they ask for in regard to this matter.”