How our forests have changed
By Jan TenBruggencate
If you walked ashore on one of the Hawaiian Islands before the first Polynesian voyagers arrived, what would it look like?
Fossil and pollen evidence suggest that in addition to a complex collection of bird life, you'd find coastal forests unlike anything growing today. And you'd find evidence of species growing together that no longer do so.
Researchers can identify many species of plants from their pollen, even in soil samples that can be dated to long before human arrival in the Islands.
Early pollen work on O'ahu found that parts of the island were made up of dense palm forests not coconuts but the native Pritchardia fan palm, loulu.
Another common plant was the kanaloa, of which only one plant still survives in the wild, on Kaho'olawe.
New work from a coastal limestone sinkhole at Maha'ulepu on Kaua'i, done under the direction of Fordham University biologist David Burney, found that the prehuman botany of South Kaua'i was far different.
Common seeds and pollen came from Pritchardia palms and the shrub whose seeds have wings 'a'ali'i.
There was also plenty of the fragrant-flowered alahe'e, whose hard wood the Hawaiians used for digging sticks.
There were relatives of the 'olapa, the forest species whose leaves flutter in the slightest breeze, and of lama, a relative of the persimmon.
The woods of this region had 'ohi'a, whose colorful, sap-filled flowers are so prized by nectar-eating birds, and the olive relative known as olopua.
There was a soapberry a relative of a'e or manele and something related to one of the plants known as kawa'u.
Additionally, there were traces of pollen from hala, kou and 'iliahi, or sandalwood.
Burney and his co-authors discuss the pollen evidence in their paper, "Fossil Evidence for a Diverse Biota from Kaua'i and Its Transformation since Human Arrival," published in the journal Ecological Monographs.
Their work suggests that with the first human arrivals came dramatic change in the coastal environment.
The work also suggests that many of the plants of the wet, intermediate and dry climates of present-day Hawai'i once coexisted in this one region. That suggests that what scientists now consider to be plants of a specific environment might not be.
"Many plants may be restricted to high elevations and wet sites today simply because these remote locations have, by nature of their difficult topography and climate, resisted most human impacts more effectively than the coastal lowlands," Burney and his associates write.
They concede, however, that it is possible the Maha'ulepu site may have been geologically unique and able to sustain an assembly of plants unlike those elsewhere.
Jan TenBruggencate is The Advertiser's Kaua'i bureau chief and its science and environment writer. Contact him at (808) 245-3074 or e-mail email@example.com.