New research blows Rapa Nui collapse theory

Transcript

Newly-published research into ancient land use on Rapa Nui or Easter Island shows the collapse of pre-European society there wasn't as dramatic as first thought.

The multi-national team has come up with the first empirical evidence of changes in land use on the island which reveals how the slowly changing environment influenced people's living and farming patterns.

One of the researchers, New Zealand-based archaeologist Thegn Ladefoged, told Sally Round they used new obsydian hydration technology to date hundreds of artifacts found lying around Rapa Nui.

THEGN LADEFOGED:  The orthodox archaeological story about Rapa Nui is that people arrive on the island and due to population growth they start using more and more of the island and clearing more of the island for slash and burn agriculture.  By clearing the island for slash and burn agriculture, they deforest the whole island and that deforestation results in loosening up the soils and the soils get blown into the ocean and you get really massive environmental degradation which then lowers the productivity of the island, causes populations to collapse and essentially societal collapse.  Our findings show that there are changes in land use prior to European contact so certain regions of the island were abandoned.  The dry side of the island was occupied around 1200 or so AD and then by around 1650, it starts to be abandoned and starts tailing off.  The uplands, the wet, less productive part of the island starts to be abandoned around 1700.  Our research does suggest that there's change going on but it doesn't support the notion that there was a huge environmental collapse, rather it's a much slower change, more of a continuum in terms of change rather than a punctuated collapse.  So in this sense it adds support to the quote 'collapse hypothesis' but I think a better way to look at it is not in terms of this massive degradation and collapse but rather in terms of environmental constraints and that people were using certain areas of the island and then changing to other more optimal areas.

SALLY ROUND:  Is this the first time that such research has been conducted?

TL:  The study is really the first empirical evidence of changes in land use on the island.  By first empirical evidence, I mean first large data sets that we can look at how people were living in an area and then through time abandoned that area.  A lot of the 'collapse hypothesis' is based on very very limited data, very limited radio carbon dating of a number, a handful of residential features or a handful of gardens.  What we've been able to do is use those large numbers of obsydian hydration dates to actually look at much larger areas and look at how people changed their land use patterns over time.

SR:  How do you hope this research, these findings, how do you hope they will be used?

TL:  The research hopefully will reframe the way that people approach archaeology on the island and instead of thinking in terms of this dichotomy of whether societal collapse occurred before European contact or societal collapse occurred after European contact with the introduction of diseases and slave raiding and those sorts of things.  We can look at it in a more nuanced way and we can look at changes in land use which probably correlate to changes in population and agricultural productivity, in a more nuanced way and start thinking about environmental constraints on the island and how that would have affected people's behaviours.

SR:  How did the local Rapa Nui, what did they think of what you were doing and were they interested in those findings?

TL:  Rapa Nui people on the island are very interested in archaeology.  Very interested in what our research can tell them about the past.  Usually the story that's been told is that story about collapse and societal anarchy and resulting cannibalism and to a certain extent friends on the island really do not appreciate or like that story whatsoever.  They see themselves as having a long history on the island, as there not being environmental devastation on the island and as living on the island perfectly fine until Europeans came there.  I mean there is certainly evidence the island was deforested over time.  When Rapa Nui Polynesians first got to the island they certainly had an affect on the environment.  I don't think that's really debatable.  Some people think that the rats or the kiore that came with the Polynesians had more of an influence on that deforestation process than Polynesians themselves.  But there's certainly been environmental changes on the island over time.  The question is whether those environmental changes really were so major that it led to societal collapse.  I think that some people on the island most certainly don't feel their ancestors had that great an impact on the island and that those significant societal changes only occurred after European contact.