Skip to main content

Main menu

  • Home
  • Articles
    • Current
    • Special Feature Articles - Most Recent
    • Special Features
    • Colloquia
    • Collected Articles
    • PNAS Classics
    • List of Issues
  • Front Matter
    • Front Matter Portal
    • Journal Club
  • News
    • For the Press
    • This Week In PNAS
    • PNAS in the News
  • Podcasts
  • Authors
    • Information for Authors
    • Editorial and Journal Policies
    • Submission Procedures
    • Fees and Licenses
  • Submit
  • Submit
  • About
    • Editorial Board
    • PNAS Staff
    • FAQ
    • Accessibility Statement
    • Rights and Permissions
    • Site Map
  • Contact
  • Journal Club
  • Subscribe
    • Subscription Rates
    • Subscriptions FAQ
    • Open Access
    • Recommend PNAS to Your Librarian

User menu

  • Log in
  • My Cart

Search

  • Advanced search
Home
Home
  • Log in
  • My Cart

Advanced Search

  • Home
  • Articles
    • Current
    • Special Feature Articles - Most Recent
    • Special Features
    • Colloquia
    • Collected Articles
    • PNAS Classics
    • List of Issues
  • Front Matter
    • Front Matter Portal
    • Journal Club
  • News
    • For the Press
    • This Week In PNAS
    • PNAS in the News
  • Podcasts
  • Authors
    • Information for Authors
    • Editorial and Journal Policies
    • Submission Procedures
    • Fees and Licenses
  • Submit
Letter

Further wet-taro evidence from Polynesia’s southernmost Neolithic production margins

View ORCID ProfileIan G. Barber
  1. aArchaeology Programme, School of Social Sciences, University of Otago, Dunedin, Otago 9054, New Zealand

See allHide authors and affiliations

PNAS January 21, 2020 117 (3) 1257-1258; first published January 14, 2020; https://doi.org/10.1073/pnas.1918374117
Ian G. Barber
aArchaeology Programme, School of Social Sciences, University of Otago, Dunedin, Otago 9054, New Zealand
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • ORCID record for Ian G. Barber
  • For correspondence: ian.barber@otago.ac.nz
  • Article
  • Figures & SI
  • Info & Metrics
  • PDF
Loading

For Prebble et al. (1), the cultivation of introduced semiaquatic tropical taro (Colocasia esculenta) on cooler southern Pacific islands during the Polynesian “initial colonization period” (ICP) (1200 to 1500 CE) represents a “striking” Neolithic example of nonoptimal, marginal crop production. In that respect, ICP taro pollen from Ahuahu, a warm-temperate, northern New Zealand (NZ) offshore island, is especially notable (1). However, the suggestion that NZ wet-taro cultivation “may have been confined” to such offshore islands (ref. 1, p. 8828) overlooks important mainland archaeological evidence (Fig. 1).

Fig. 1.
  • Download figure
  • Open in new tab
  • Download powerpoint
Fig. 1.

(Upper) Map of Aupouri Peninsula and lands at the tombolo base (“Aupouri region” in text), northern North Island, New Zealand, showing archaeological ditch systems that once extended wet production for tens of hectares. The relative location of Ahuahu (1) is shown in Inset map. (Lower) Radiocarbon (14C) calibration ranges (95% probability) by laboratory number for atmospheric plant detritus from the western area of ditch system site N3/639, Motutangi. Calibrations are by SHCal13 in OxCal v.4.3.2 (7) on conventional 14C ages (in citations in ref. 2, p. 107). Base data are sourced from ref. 2 which is licensed under CC BY 4.0.

Prebble et al. (1) cite the report of microscopic C. esculenta starch granules from a Māori ditch system of northern North Island’s Aupouri Peninsula (a tombolo) with records of “tentatively identified” ICP crops (ref. 1, p. 8824). Yet this taro evidence from former interdune swamp site N3/638, Motutangi, is far more substantive in context. Although reserve C. esculenta starch granules that are generally <8μm can be difficult to characterize alone, taro corm granules are “most easily” identified in the size range <1 to 3 μm when aggregated in masses (refs. 2, p. 113, and 3⇓–5). From N3/638, multiple ditch-base and interdrain peaty samples present just such discrete, dense taro-like aggregations of hundreds of small reserve starch granules, mostly <4 μm, along with native NZ pollens and spores only as one would expect in pre-19th century “Neolithic” contexts (2, 3). Reserve starch granules of other Polynesian and native NZ plants, including widespread semiaquatic Typha orientalis, are always predominantly >3 μm in any concentration (2⇓⇓–5).

Ditch networks provide further archaeological evidence. Contiguous Motutangi ditch systems integrated irrigation, reticulation, and drainage functions to create >50 ha of bordered, raised, and possibly flooded fields (ref. 2, pp. 106–107), comparable to Polynesian production systems of record for wet taro (1, 6). This engineering feat is mirrored in ditch networks that extended wet cultivation over lacustrine and floodplain lands at the Aupouri Peninsula base (Fig.1), where soils from site O4/237 also incorporate taro-like starch granule aggregations (3). In Māori oral history, these extensive systems predate the 19th century (ref. 2, p. 106).

Radiocarbon dates by SHCal13 (7) on plant detritus from peaty samples of an uncomplicated Motutangi system (western N3/639) include terminus ante quem age NZ5626 on basal ditch fill at cal AD 1460 to 1670 (95% probability). Age NZ6358 from the native anthropic section of a soil profile 50 m away is identical at 94% probability, while lower NZ6388 around the palynological marker of wetland management beginnings is cal AD 1320 to 1480 (95% probability) (Fig. 1).

Collectively these data identify the Aupouri region as Neolithic NZ’s wet-field production hub. The identification of perennial wet taro from pre-1500 Ahuahu (1) is important nevertheless and may elucidate abandonment of ancient Polynesia’s southernmost wet fields. Marginal wet agronomy disappeared from the Aupouri region and Ahuahu by or during the Little Ice Age (LIA) NZ duration, ∼1450 to 1850 CE (8). Cooler LIA temperatures might have influenced the later northern Māori production shift to more resilient dryland taro varieties and sweet potato/kūmara Ipomoea batatas (1).

Acknowledgments

I acknowledge Royal Society of New Zealand Marsden Award UOO1415. Les O’Neill completed Fig. 1.

Footnotes

  • ↵1Email: ian.barber{at}otago.ac.nz.
  • Author contributions: I.G.B. designed research, analyzed data, and wrote the paper.

  • The author declares no competing interest.

Published under the PNAS license.

References

  1. ↵
    1. M. Prebble et al
    ., Early tropical crop production in marginal subtropical and temperate Polynesia. Proc. Natl. Acad. Sci. U.S.A. 116, 8824–8833 (2019).
    OpenUrlAbstract/FREE Full Text
  2. ↵
    1. M. Horrocks,
    2. I. Barber
    , Microfossils of introduced starch cultigens from an early wetland ditch in New Zealand. Arch. Oceania 40, 106–114 (2005).
    OpenUrl
  3. ↵
    1. M. Horrocks,
    2. S. L. Nichol,
    3. P. C. Augustinus,
    4. I. G. Barber
    , Late Quaternary environments, vegetation and agriculture in northern New Zealand. J. Quat. Sci. 22, 267–279 (2007).
    OpenUrl
  4. ↵
    1. R. Fullagar,
    2. J. Field,
    3. T. Denham,
    4. C. Lentfer
    , Early and mid Holocene tool-use and processing of taro (Colocasia esculenta), yam (Dioscorea sp.) and other plants at Kuk swamp in the highlands of Papua New Guinea. J. Archaeol. Sci. 33, 595–614 (2006).
    OpenUrlCrossRef
  5. ↵
    1. J. J. Maxwell,
    2. M. Tromp
    , Corynocarpus laevigatus: Where art thou? Finding evidence of this elusive tree crop. Rev. Palaeobot. Palynol. 234, 198–210 (2016).
    OpenUrl
  6. ↵
    1. P. V. Kirch
    , The Wet and the Dry: Irrigation and Agricultural Intensification in Polynesia (University of Chicago Press, Chicago, IL, 1994).
  7. ↵
    1. A. G. Hogg et al
    ., SHCal13 Southern Hemisphere calibration, 0–50,000 years cal BP. Radiocarbon 55, 1889–1903 (2013).
    OpenUrlCrossRef
  8. ↵
    1. A. Lorrey et al
    ., The Little Ice Age climate of New Zealand reconstructed from Southern Alps cirque glaciers: A synoptic type approach. Clim. Dyn. 42, 2039–2060 (2014).
    OpenUrl
PreviousNext
Back to top
Article Alerts
Email Article

Thank you for your interest in spreading the word on PNAS.

NOTE: We only request your email address so that the person you are recommending the page to knows that you wanted them to see it, and that it is not junk mail. We do not capture any email address.

Enter multiple addresses on separate lines or separate them with commas.
Further wet-taro evidence from Polynesia’s southernmost Neolithic production margins
(Your Name) has sent you a message from PNAS
(Your Name) thought you would like to see the PNAS web site.
CAPTCHA
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.
Citation Tools
Further wet-taro evidence from Polynesia’s southernmost Neolithic production margins
Ian G. Barber
Proceedings of the National Academy of Sciences Jan 2020, 117 (3) 1257-1258; DOI: 10.1073/pnas.1918374117

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero
Request Permissions
Share
Further wet-taro evidence from Polynesia’s southernmost Neolithic production margins
Ian G. Barber
Proceedings of the National Academy of Sciences Jan 2020, 117 (3) 1257-1258; DOI: 10.1073/pnas.1918374117
del.icio.us logo Digg logo Reddit logo Twitter logo CiteULike logo Facebook logo Google logo Mendeley logo
  • Tweet Widget
  • Facebook Like
  • Mendeley logo Mendeley

Article Classifications

  • Social Sciences
  • Anthropology
  • Biological Sciences
  • Ecology

This Letter has a Reply and related content. Please see:

  • Relationship between Letter and Reply - January 14, 2020
  • Early tropical crop production in marginal subtropical and temperate Polynesia - April 08, 2019
Proceedings of the National Academy of Sciences: 117 (3)
Table of Contents

Submit

Sign up for Article Alerts

Jump to section

  • Article
    • Acknowledgments
    • Footnotes
    • References
  • Figures & SI
  • Info & Metrics
  • PDF

You May Also be Interested in

Water from a faucet fills a glass.
News Feature: How “forever chemicals” might impair the immune system
Researchers are exploring whether these ubiquitous fluorinated molecules might worsen infections or hamper vaccine effectiveness.
Image credit: Shutterstock/Dmitry Naumov.
Reflection of clouds in the still waters of Mono Lake in California.
Inner Workings: Making headway with the mysteries of life’s origins
Recent experiments and simulations are starting to answer some fundamental questions about how life came to be.
Image credit: Shutterstock/Radoslaw Lecyk.
Cave in coastal Kenya with tree growing in the middle.
Journal Club: Small, sharp blades mark shift from Middle to Later Stone Age in coastal Kenya
Archaeologists have long tried to define the transition between the two time periods.
Image credit: Ceri Shipton.
Illustration of groups of people chatting
Exploring the length of human conversations
Adam Mastroianni and Daniel Gilbert explore why conversations almost never end when people want them to.
Listen
Past PodcastsSubscribe
Panda bear hanging in a tree
How horse manure helps giant pandas tolerate cold
A study finds that giant pandas roll in horse manure to increase their cold tolerance.
Image credit: Fuwen Wei.

Similar Articles

Site Logo
Powered by HighWire
  • Submit Manuscript
  • Twitter
  • Facebook
  • RSS Feeds
  • Email Alerts

Articles

  • Current Issue
  • Special Feature Articles – Most Recent
  • List of Issues

PNAS Portals

  • Anthropology
  • Chemistry
  • Classics
  • Front Matter
  • Physics
  • Sustainability Science
  • Teaching Resources

Information

  • Authors
  • Editorial Board
  • Reviewers
  • Subscribers
  • Librarians
  • Press
  • Cozzarelli Prize
  • Site Map
  • PNAS Updates
  • FAQs
  • Accessibility Statement
  • Rights & Permissions
  • About
  • Contact

Feedback    Privacy/Legal

Copyright © 2021 National Academy of Sciences. Online ISSN 1091-6490