Was collapse inevitable on Easter Island (Rapa Nui)?

Reconstructing a civilisation's failure.

In his book "Collapse", Jared Diamond highlights the spectacular and mysterious collapse of civilisation on Easter Island. Diamond outlines a number of factors leading to success or failure of civilisations. We have identified that one of these factors - fragile soils - allows us to hypothesise that Easter Islanders could have overshot the carrying capacity of their landscape, reaching maximum population as soil nutrient depletion caused declining crop yields.

We are using isotope, biomarker and DNA approaches to reconstruct the biogeochemistry of collapse and thereby testing whether the timing of nutrient depletion can answer the question: "Why did they cut down the last tree?"

Within dormant volcanic craters where settlement occurred, we have obtained carefully located cores to precisely resolve the timing of changes in plant, animal and human populations, as well as soil fertility. We are examining plant microfossils (e.g. pollen, starch grains), nitrogen isotopes, the DNA of native and introduced species, and steroid biomarkers derived from humans, animals (faeces) and plants.

Collectively, these analyses will enable biogeochemical modelling to identify the factors that make societies around the world vulnerable to collapse by stressing the carrying capacity of their soils. The approach encourages us to ask if we can learn whether our global civilisation could be more unstable than we think.

Principal Investigator: Troy Baisden

Co-Principal Investigator:

  • Dr Mark Horrocks, Microfossil Research, Auckland

Associate Investigators:

  • Prof. John Flenley, Massey University
  • Dr Anthony Aufdenkampe, Stroud Water Research Centre, USA