Apart from built heritage like protected monuments, Delhi will also have natural heritage.
The Delhi forest department has identified five tree species - Pilkhan, Peepal, Burgad, Neem and Jamun - for heritage tag. One tree each from these species will be given the status of heritage tree.
Department head GN Sinha said, "The five heritage trees will have a signboard each to explain their importance. They will get absolute protection for lifetime."
The department has also announced another category of trees - reserve - to arrest the slide in green cover. Their number may run into thousands. "These are the trees which are equally old and majestic. We're looking at all trees of two or three species as reserve trees, but this will be subject to government's approval," said Sinha.
Reserve tress will be felled only in exceptional cases. But for each reserve tree felled, the department will also ensure plantation of 20 saplings and their maintenance for five years. Currently 10 saplings are planted for each tree felled.
"For both categories, we will first decide the criteria, do field surveys and finally identify trees. We hope to complete the task in three months," Sinha said.
For heritage trees, the department is essentially looking for old age, rarity, big size and aesthetics, besides botanical, ecological and historical values. These trees have to be irreplaceable. Heritage tag would ensure protection from removal of the five specific trees and not the whole species.
Many dynasties ruled Delhi and each ruling class had their own choices of trees to stop sand dunes from moving into Delhi from Rajasthan. From the Tughlaq dynasty, the Mughal rule to the British period, the rulers planted a large number of trees both for ecology and aesthetics.
"Some of these trees are now quite old (between 100 and 200 years of age), big and majestic. These trees are mainly located in south Delhi, Civil Lines, Old Delhi and Tughlaqabad," said AK Shukla, another senior forest official.
Heritage trees will get treatment similar to that accorded to protected monuments.
"Old trees have many complications. We may need to fill cavities with bamboos, we need to prolong the lifespan of such trees and keep caring for them till they die a natural death," said Shukla.