Arthur Ross began to finance the establishment of the Arthur Ross Pinetum in 1971 with Cornelius O'Shea, Central Park's chief forester. The pinetum, located to the northwest of Central Park's Great Lawn, covers of Central Park. The Arthur Ross Pinetum is currently home to a collection of 25 species of conifers, from both the United States and other countries. Ross stayed actively involved in the pinetum, despite some instances of early vandalism. Ross added approximately 35 pine trees a year to the Arthur Ross Pinetum. His collection grew to include trees from the Himalayas, Macedonia and Japan. The pinetum became a popular recreational area for New Yorkers. Wendy Wasserstein, a New York City based playwright, called the Arthur Ross Pinetum a little bit of Maine in Manhattan.