After several years of financial neglect the Harold L. Lyon Arboretum, the only university arboretum in the United States that is in a tropical rainforest, is fighting back to full operation.

The facility has completed a series of environmental and managerial program assessments and public hearings, and the state Board of Land and Natural Resources has approved a Conservation District Use Permit that will allow the arboretum to move ahead with much needed improvements, the University of Hawai'i announced yesterday.

"Now we can start making progress," said Cliff Morden, a UH-Manoa botanist who was appointed interim director of the arboretum earlier this year. "We can develop specific plans, put the jobs out for bid and get the contractors in here to do the work."

Lyon Arboretum was closed to the public in August 2004 after employees brought attention to extensive safety and health problems at the 194-acre site in upper Manoa, including structural instability in some of the cottages, dangerous electrical wiring and safety problems along the trails.

It was reopened in early 2005, but most of the arboretum's commercial activities, including a gift shop and educational programs for schoolchildren as well as adults, have not yet been resumed.

"We're all waiting for the time when things get back to the way they used to be," said Gwen Ihrig, a volunteer who has been with the arboretum for 15 years. "But the spirit here is good, and now that we have the permits we can get our classes and guided tours going and repair the buildings."

The state Legislature appropriated $3 million in January toward structural improvements, which can be started now that the permit has been obtained.

Morden said that a half-million dollars has been appropriated to increase staffing, providing more stable funding for four current staff members and bringing in four part-time employees and six new full-time people.

One new employee, he said, will be a weed specialist who will help to predict which plants are likely to become invasive species.

The gift shop will reopen, he said, and educational programs will be expanded.

Weekend hours of operation could be scheduled again by next summer, he said.

"Work on the grounds is most exciting," he said. "We're planning out new displays and preparing new sections that were previously dormant. We're excited to see things happening and looking forward to watching things take off and grow."

Reach Karen Blakeman at kblakeman@honoluluadvertiser.com.