A unique initiative partly fueled by charitable contributions has helped return a half-million native trees to deforested Hawaii ranch lands over the last decade.

The nonprofit Hawaiian Legacy Reforestation Initiative said it recently reached its 500,000th tree planting, a milestone that includes contributions from an affiliated for-profit company, Hawaiian Legacy Hardwoods LLC.

The trees — koa, ohia, mamane, naio, milo and sandalwood — have been planted mainly on two ranches on Hawaii island and one on Oahu where cattle pastures replaced former native forests.

Under the nonprofit, which was established in 2014, donors pay to have tree seedlings planted.

Hawaiian Legacy Reforestation offers a “legacy tree” for a $90 fee that includes directing $30 to a charity selected by the donor. These seedlings are tagged with a transmitter that allows a donor to see where their tree was planted and to track its growth.

Project officials were not available Friday to say how many of the 500,000 trees were established through the nonprofit. Some of the 500,000 trees were established by Hawaiian Legacy Hardwoods, which began planting koa trees in 2010 under a model through which investors help the company plant and manage trees in return for potential long-term financial returns from harvesting wood.

Francis Wong, board chairman of the nonprofit, said all the trees are benefiting the environment by supporting ecosystems that include shrubs, grasses and birds returning to the areas.

“It’s wonderful to witness the birth of a forest, but there is much more going on here,” he said in a statement. “It’s remarkable how fast these changes are happening.”

Other benefits of planting trees include creating jobs, reducing effects of climate change and restoring watersheds, the organization said.

Most of the trees have been planted on about 1,200 acres of former pastureland at Kukaiau Ranch on Hawaii island. Other sites include the 700-acre Kahua Ranch on Hawaii island and 500 acres at Gunstock Ranch on Oahu.

Hawaiian Legacy Reforestation expressed gratitude to partners that have helped the nonprofit attract donors, including resorts that have promoted the opportunity sometimes in conjunction with tours of reforestation sites where donors can take part in the planting. Another for-profit affiliate, Hawaiian Legacy Tours, operates such tours for additional costs.

Jeff Dunster, who heads the companies and the nonprofit, said the partnerships with resorts and other entities have been key to the nonprofit’s success.

“Through these partnerships, tens of thousands of individuals have participated in the Legacy Tree program,” he said in a statement. “The simple act of sponsoring a tree by countless individuals has transformed these lands.”