Not exactly known for environmentalism, Staten Island will become a showcase of mass timber construction — if city officials can persuade a developer to try it. The city issued an RFP Thursday for someone to build 500 apartments using wood. Two 50-foot-tall buildings would go on city-owned land along the Stapleton waterfront on the North Shore, about a mile from the Staten Island ferry terminal. “This is the biggest opportunity to use mass timber at scale in the city,” said Melissa Román Burch, chief operating officer of the city’s Economic Development Corporation, which put out the request for proposals. Up for grabs are 99-year ground leases on two parcels just south of the Urby, a 571-unit residential project developed by Ironstate at 7 Navy Pier Court, where tenants can watch boats come and go from the Homeport pier that juts into the New York Bight.