Even for schoolchildren who live and play in O'ahu's lushly landscaped areas, the enormous burst of rainforest chlorophyll that greets visitors to Lyon Arboretum is momentarily stunning.

"We get that every time the bus doors open and the kids get off," said Jill Laughlin, Lyon's education programs manager.

They throw their heads back to look at the trees — some topping out at 40 meters above the ground — jaws drop and, "There's an escape of 'Wow!' " in the air, Laughlin said.

James Krolikowski, an education programs assistant, added that when the grounds are damp, some young visitors will also be "holding their noses and saying 'It stinks!' So, we talk about why."

Laughlin continued, "That's the earth you're smelling, the living earth."

At the University of Hawai'i's arboretum tucked into leafy Mänoa Valley, all education programs stress appreciation and conservation of the sometimes pungent terra firma and its flora and fauna in a hands-on learning environment.

Last year, an estimated 7,000 children took part in school field trips, intersession and seasonal programs, with activities such as hiking trails, harvesting fruits and garden vegetables for cooking projects, writing haiku and producing recyclable art.

Through one activity geared for fourth-graders, "Ka Wai Ola: Manoa Watershed," students conduct an aquatic survey at Mänoa Stream. Then, at a table split down the middle by an illustration of a flowing stream, they draw their own dream buildings — everything from palaces and shopping malls to water-slide parks, said Richard Sears, an education specialist.

"That's fun for them," Sears said, noting, however, that extravagant sketches are sometimes reworked with renewable energy in mind after educators clutter the canvas with bits representing generated waste and pollutants headed downstream.

"We ask them to think about the positive and negative impacts" of their imaginary neighborhood, Sears said.

Laughlin added, "We're trying to empower these kids to be able to see the problems and come up with some solutions."

An arboretum staffer for 17 years, Laughlin said while many environmental problems that surfaced several decades ago — both locally and globally — linger on, messages directed at children are changing.

"In the past, it was more often a doom-and-gloom type teaching" in which "we were the victims of industrial waste," Laughlin said. "Now it's: 'Hey, it's us doing this (harming the environment) and there's something we can do about it."

At the arboretum's new children's center, kids are learning reduce-reuse-recycle lessons even at lunchtime, when leftovers are fed to worms in a compost bin.

"We want (children) to be aware of their surroundings." Krolikowski said.

Before explaining the benefits of compost, she said she might ask, " 'Who has plants for lunch?' And the kid with a mouthful of musubi is saying: 'Not me.' "

Situated in the only easily accessible tropical rainforest on O'ahu, the arboretum serves as a sensory-intensive setting for environmental education, Laughlin said.

"It's low-tech but very hands-on," she said.

For some, mild physical exertion in the setting — far from a boxed-in schoolhouse — improves their ability to focus and fosters openness to learning, Sears said. "You get them out hiking and just breathing, and anxiousness and other energies dissipate."

When children learn about green living using sight, sound, taste, smell and touch, Sears said, "those are memories that can be embedded — they can stay with you for life." Acknowledging that traditional books-and-blackboards classroom learning is also crucial to a well-rounded education, Sears added, "I just feel grateful that we can offer a balance to these kids."