糖心视频

New University of Otago鈥斉宼膩kou Whakaihu Waka research has uncovered the unlikely location of one of the earliest securely dated sites of sweet potato (k奴mara) cultivation in Polynesia.

The study, in Antiquity, found evidence of microscopic k奴mara starch granules alongside Asia-Pacific taro and Pacific yam (uwhi) at Triangle Flat in Golden Bay (Mohua) that were cultivated as early as AD 1290鈥�1385.

These early dates correspond with the period during which settlement of Aotearoa New Zealand began and provide the first pre-1400 evidence for k奴mara cultivation in Te Waipounamu鈥攁s early as anywhere else in Polynesia鈥攁nd for the southernmost world attempt to grow uwhi.

The site is on a conservation estate under the customary jurisdiction of Manawhenua ki Mohua.

Lead author Professor Ian Barber, from Otago's Archaeology Program, says the site incorporates evidence of the longest duration of m膩ra (garden) conservation from a single place anywhere in Polynesia.

"The earliest m膩ra pits incorporating k奴mara-like starch at Triangle Flat date to the beginning of the fourteenth century when Polynesians first settled the motu."

Despite its importance to Polynesian life both in the past and today, little is known about the timing and circumstances of the sweet potato's initial spread across Oceania.

Some botanists propose it drifted naturally into Polynesia thousands of years ago, but many anthropologists infer undated human mediation instead, especially since the M膩ori name k奴mara is a variation on pre-Columbian American sweet potato names.

Given these uncertainties and intriguing possibilities, scholars have debated exactly when, and even if, sweet potato became important in early Polynesian colonization, Professor Barber says.

Existing views have assumed the first settlers turned instead to forage for the flightless moa, other birds and marine animals, with k奴mara only becoming important later, especially in warmer areas central to northern Aotearoa New Zealand where p膩 earthworks proliferated.

"The Otago research now challenges standard archaeological assumptions that the first Polynesian settlers of Aotearoa, and Te Waipounamu especially, abandoned tropical horticulture largely if not entirely.

"The new Triangle Flat evidence points to the early adaptation of tropical crops, especially k奴mara, from the outset of Polynesian settlement, even in unlikely places.

"In short, k奴mara was not a colonization after-thought in Aotearoa."

The early chronology supports those M膩ori traditions that speak of k奴mara as a crop established in the central Polynesian homeland, Hawaiki, when the first voyagers ventured south for Aotearoa.

Co-author Rebecca Waikuini Benham (Ng膩ti Kahungunu ki Wairarapa, Ng膩ti Porou, Ng膩ti Awa), from Heritage New Zealand Pouhere Taonga, was responsible for preparing the microscopic starch granule samples.

This important microbotanical science has been used to identify ancient crops throughout Polynesia, including Aotearoa, that may leave no other traces.

She says Aotearoa offers a unique case study when compared to the other Polynesian Islands.

"There are significantly fewer starch producing crops that were cultivated here than compared to the more tropical islands.

"I am hopeful that the identification of granules, along with the possible raphides, may be able to be applied to other early sites across the motu to investigate the cultivation of taro and uwhi alongside k奴mara from an archaeological perspective, of course in collaboration with local k艒rero."

The study also demonstrates that the first Aotearoa gardeners developed sophisticated planting pit and shell mulch technologies in local environments and soils, which helped secure k奴mara horticulture in a marginal climate.

Currently, sweet potato is the world's fifth most important edible crop but is under threat from climate and other environmental changes in many parts of the world, Professor Barber says.

"New knowledge from the past as well as the present may yet support food security science targeting sweet potato production.

"Archaeological knowledge of these ancient technologies might yet inform modern efforts to improve natural hardiness and nutrition in sweet potato."