The ahupua'a — often described as a pie-shaped slice of land that runs from a point in the mountains to a wide area at the sea — is commonly raised in environmental discussions as a model for modern environmental behavior.

The argument holds that the ahupua'a was a self-sufficient microcosm, that early Hawaiians carefully managed and protected this system that provided them with everything they needed: fish from the sea, sunny lowlands for taro fields, uplands for wood products and plants for medicine, canoe hulls and construction materials.

But University of Hawai'i assistant professor Carlos Andrade says that's a simplistic view. Andrade teaches in the university's Center for Hawaiian Studies, including classes on Hawaiian resource management, geography and land use. A subsistence farmer, Hokule'a crewman, fisherman, geographer and canoe builder, Andrade on Friday gave the keynote address to the first Kaua'i Conservation Conference.

"I'm here to explode a few myths," he said. "The ahupua'a has a diversity about it that most people overlook."

For one thing, not all ahupua'a touch the sea, and not all reach the mountains.

"The term 'ahupua'a' has been used by too many people and appropriated to cover whatever their particular agenda is," he said.

Andrade said no ahupua'a contained all the needs of its people; each zone could provide only certain resources. "How do people have mats in ahupua'a that don't have hala trees?" he said. Similarly, how did residents of a landlocked ahupua'a gain access to fish, and how did a dry ahupua'a get poi?

It is inescapable that the people in land divisions depended on their neighbors, and even those in distant land divisions. It happened through islandwide networks supported by the alanui, or main roads, that occur on each major island. "Independence is kind of a contemporary thing. Reciprocity was a highly respected trait" in early days, he said.

Andrade suggested that the exchange system of Hawai'i was different from the Western concept of trade. It was not so much a barter of items of equal value, but an exchange of gifts. When you had plenty, you gave a larger proportion. When your own larder was low but someone else had abundance, you might receive a larger proportion.

Andrade also cited a tradition of avoiding overharvesting. Among the meanings of the term " 'aina momona" is to "let the land be fat; leave it in the land," he said.

If you have a question or concern about the Hawaiian environment, drop a note to Jan TenBruggencate at P.O. Box 524, Lihu'e, HI 96766 or jant@honoluluadvertiser.com. Or call him at (808) 245-3074.