GURGAON, December 25: Prompted by the afforestation done by the Haryana forest department in the Aravalli ranges, the Delhi government has urged the Haryana government to extend expertise and knowhow for preparing a management plan to increase the green cover in the Delhi Ridge Forest area.The Ridge area comprising of about 18,000 acre has over the years seen massive degradation. It was only after the Supreme Court directed the Delhi government to preserve the Ridge forest that the government had launched a campaign to remove encroachments and oust illegal occupants. The govt had also directed the DDA, MCD, NDMC, PWD and the CPWD to strictly man these areas for preserving green cover. The Ridge forest considered the lungs of the national capital is geographically an extension of the Aravalli ranges.