Concluding Thoughts

I’ll be the first to admit that when I started investigating Easter Island, I came across Jared Diamond’s Collapse and thought, wow, how could the Easter Islanders do this to their own island, ‘what were they thinking?’. But as I researched Easter more, I came across numerous other theories, and evidence, behind Easter’s collapse, and I realised that the Easter Island mystery was much more complex than I first thought. I’ve made a table with the summary, evidence and sources of each of the theories (see this previous post).

I started looking at climate variability and its effect on marine biomass, agriculture and other resources. I then looked at deforestation due to rats, which is an alternative theory behind deforestation as proposed by Terry Hunt and Carl Lipo. Deforestation, soil erosion, population expansion, resource depletion and warfare and cannibalism were then investigated in turn, which formed the ecocide theory that as Polynesians arrived onto the island around A.D. 800, population began to expand, as did culture and religion. Both population, and the construction of the moai statues expanded beyond the island’s limits and caused resource depletion and deforestation, which then caused soil erosion and agricultural failure. The population began to decline, and in turn caused warfare and cannibalism as the hierarchal society structure of chiefs and priests were replaced with the ‘birdman’ cult. Lastly, the impact of the European’s arrival, whalers, other colonists, slave-raids and the introduction of foreign diseases on Easter’s population were investigated.

I have tried to be as unbiased as possible when reviewing each of the theories, and looking at how Easter is a parable for today, yet I have found this quite difficult due to the considerable scientific and public support for the ‘ecocide’ theory, and the way in which those who oppose Diamond have argued their case. For example, Benny Peiser (2005) and Mark Lynas (2011) believe that the ecocide theory is just as much a myth as what actually happened on Easter Island. However, their argument seems to be based on a vendetta against Diamond, where they pick parts of his theory that they do not agree with, but don’t provide scientific evidence for doing so, and do not provide an alternative theory based on scientific evidence. I think that scholars investigating Easter Island have slightly lost their way when it comes to evidence and science, where they either seem caught up in the lessons we can learn from Easter or disagreeing with Diamond rather than providing alternative theories based on evidence. They, in my opinion, need to look at the work of Bahn and Flenley, who used archaeological and palaeological evidence from numerous lines of evidence to inform their theories that deforestation was probably the cause behind Easter’s collapse. Improved estimates of settlement dates, peak population, timings of population collapse and reasons behind the collapse are constantly emerging, and I think its this that we need to concentrate on if we are to understand the Easter Island mystery.

I personally think that deforestation did occur on Easter by looking at the pollen evidence, and this in turn triggered soil erosion, which can be seen in the soil profile on Poike Peninsula (see previous post on Soil Erosion). However, I do think that the evidence surrounding resource depletion, such as a reduction in porpoise bones, needs much more work before we can completely prove that population expansion beyond the island’s limits caused resource depletion, particularly deforestation, reduced soil erosion causing agricultural failure, a collapse in Easter’s culture, warfare and cannibalism and the corresponding population collapse. I think that deforestation and soil erosion did occur on the island, and that resource depletion did to some extent cause a population decline. However, I think that it was the European’s arrival, bringing foreign diseases, and slave-raids, which essentially caused the final population collapse. New estimates of population peaks on Easter propose number more like 3000-4000 people. The combination of slave-raids, which took 1500 people, and bringing diseases the natives were non-immune to, in my opinion, could have easily reduced the population from 3000-4000 to its estimated post-collapse numbers of 100 people.

So, what’s the point in this blog?

Despite my opinion, many scholars think that Easter collapsed due to this ecocide theory. My last few posts investigated the lessons that we can, and have learnt from Easter Island, and demonstrates the reason why so many of us argue over the reasons behind its collapse. Easter can be brought into the 21^st Century as a lesson that we can learn from, in terms of societal collapse due to population expansion, resource depletion and deforestation. Today’s society faces many environmental problems; water problems, deforestation, end of tropical rainforests, overfishing, soil erosion and salinisation, global climate change, full utilisation of the world’s fresh water supplies, exhaustion of cheap energy resources, accumulation of toxic chemicals in water, food and soil, increase in human population and increase in the per capita impact of our population. I investigated the lessons that we can learn from Easter’s collapse, particularly resource depletion, population expansion and deforestation. Essentially, Easter as a parallel to Earth boils down to politics and decision-making, but our decision-making can be different because we can use the lessons learnt from past societal collapses such as Easter Island to inform current decisions on our environmental problems.

Easter Island is tale of wonder, where one of the most socially and technologically advanced societies for its time managed to inhabit and flourish on one of the most isolated and inhabitable places on Earth. Yet, it can also be a tale of warning for today’s society, where the same reasons behind Easter’s collapse could be applied to today’s society.

And so, I reach the conclusion for this blog. Thank you all for reading my blog, I really have found it fascinating researching Easter Island and I hope I’ve been able to translate a fraction of this fascination into my blog for you to read! While my blog stops here, the mystery of Easter Island will carry on and with this in mind, I’ll leave you with one more quote:

“Of all the vanished civilisations, no other has evoked as much bafflement, incredulity and conjecture as the Pacific island of Rapa Nui (Easter Island).”

The Moai Statues' Opinion on Easter's Collapse

I found this cartoon online on the moai statues and what they think 'happened to Easter Island'. I thought that one of the little quotes on there was quite interesting/amusing and relevant to the past few posts I have made over the lessons that today's society can learn from Easter Island's society:


"Lunacy is repeating the same actions, yet expecting different results"


Is today's society lunatic for repeating the same actions that past civilisations such as Easter Island have made, expecting that we won't meet the same fate as them? Are we lunatics for thinking that we can deplete our resources or expand our population beyond its limits, and not expect to collapse in the same way Easter did?


"Can we frighten ourselves back from oblivion?"


 I'll leave that one for you to decide....

Easter Island: A Tale of Wonder

Through deforestation, resource depletion and population explosion, it is easy to see how Easter Island is a tale of warning, as investigated by the previous few posts. However, many tend to overlook the fact that Easter Island is also a tale of wonder. Against great odds (the most inhabitable and isolated place on Earth, with few resources), the islanders had painstakingly constructed over several centuries, one of the most advanced societies of its type in the world. From the time of settlement to its peak population, they sustained a way of life that not only allowed them to survive, but also to flourish. The moai statues are an incredible example of this, and demonstrated the islander’s triumph of human ingenuity and an apparent victory over a difficult environment.

Meith and Bork’s (2005) study of soil profile on the Poike Peninsula suggested that the Islander’s were practising sustainable agriculture from their time of settlement until A.D. 1300. Even after A.D. 1300 when agriculture became unsustainable due to population growth and soil erosion, there were still example of some settlements using planting pits, which were the most effective and sustainable method of farming.

The Islanders were responsible for the carving, transport and erection of 800 moai statues, suggesting a socially and technologically advanced society. Both the moai construction and the survival of the islanders depended on the resources scattered round the island. A highly complex society would have been required to organise these resources in a way that its society could flourish and create the moai statues. 

If you support the view that the European’s introduction of foreign diseases and slave-trading were the cause behind Easter’s collapse, then Easter would seem even more a tale of wonder, rather than warning. Easter’s society were not the reason behind its collapse, rather it was another society, one that was more socially and technologically advanced than Easter’s, that caused its demise. Benny Peiser (2005) quotes that:

“Yet in spite of exceptionally challenging conditions, the indigenous population chose to survive – and they did…What they could not endure, however, and what most of them did not survive, was something altogether different: the systematic destruction of their society, their people and their culture.”

So if Easter is a parable for today’s society, then maybe we should be flattered that we are being compared to such a socially and technologically advanced society for its time, one that flourished on one of the most inhabitable places and isolated places on Earth, and one that held devoted cultural and religious beliefs. I think this is perfectly summed up in this quote by Mark Lynas (2011):

“Resilience and sustainability are just as likely outcomes, even over the longer term. This, I think, is the true lesson of Easter Island.”

Earth and Easter: The Lessons We Can Learn From Rapa Nui [2]

So, we know the parallels between our society and Easter Island’s. So what? Its easy enough to state the similarities, but what we need to do now is take the lessons we’ve learnt from Easter and put them into practice for today’s society.

Diamond summarises this point with his likening of history to experiments:

‘History consists of lots of natural experiments, some of which ended badly and some of which ended well. Today we are running a big natural experiment, but it’s a worldwide natural experiment’

So how can we use Easter’s experiment to make ours work? Well it essentially boils down to politics and decision-making. We had the technology to make the damage, therefore we must have the technology to undo it…but it’s about whether or not we want to. Diamond outlines a decision-making process for solving a problem, and Easter provides us with the perfect example of an unfortunate society who, from the decision-making process, made bad decisions:

1. Whether a society anticipates a problem or not: The Easter Islanders were not able to anticipate the problems of dry, low, high-latitude islands because they came from wet, high equatorial islands.
2. Failure to perceive a problem when the problem has arrived: Population growth couple with deforestation would have been slow during early settlement, thus the islanders may not have realised the extent of their problem until it was too late. This teaches us that we must think through our actions and anticipate the consequences as fully as possible, however it seems we have ignored Easter Island in this respect in light of the majority of the environmental problems we are facing today.
3. When a group has perceived a problem, whether or not they try to solve the problem based on rational behaviour of the group. It is proposed that Easter’s chiefs were acting their own self-interest, by building bigger statues to stake their claim as the best chief, which would have caused further soil erosion and deforestation (if you believe that the moai statues were rolled on tree trunks, and this could have majorly contributed to the deforestation. Again its plain to see a parable with today’s society here, as conflicting interests surrounding climate change with China and the rest of the developing work conflicting against the EU and those who are working to curb global warming.
4. A society may fail to solve a problem because some problems are just too difficult to solve given the available technology. With the European’s bringing diseases the natives were immune to, and slave trading, the society were simply incapable of solving their problem with the medicine and weapons they had.

So, have we learnt from Easter Island?

Deforestation rates in the Brazilian Amazon have dropped by 70% over the past 5 years, due to a change in attitude in the Government, famers and cattle owners (see a really interesting podcast by Justin Rowlatt of the BBC, who investigates this deforestation rate drop by talking to farmers, politicians and environmental organisations in associated with this scheme in Brazil - http://www.bbc.co.uk/iplayer/episode/p00mmnqv/Business_Daily_Saving_the_Brazilian_Amazon/). As deforestation continued on Easter Island, instead of seeking to improve the complex political system that allowed the settlement of 7000 people on one of the most inhabitable places on Earth, the islanders overthrew the political system. The ‘birdman’ cult was then created, and was (according to legends) fuelled by competition and warfare between tribes, rather than being a peaceful complex political system.

New sustainable businesses (funnily enough, one of the biggest new sustainable business from the Amazon in Brazil is the production of Rainforest friendly condoms, which kills two birds in one stone as it also reduces population expansion!), changing attitudes of farmers, better monitoring through satellites, and pressure and campaigns by pressure groups were all part of saving the Brazilian Rainforest. Could Easter have survived deforestation if they had similar policies and thinking to Brazil’s? I’ll let you decide that one!

The sustainable businesses from the Brazilian Amazon highlights the success of sustainable development, and this has not stopped in just Brazil. There are plenty of successful sustainable development stories and schemes around the world. Lastly there are numerous population growth policies, some successful and others not - China’s one child policy is a well-known example of a country trying to curb its population expansion.

So to conclude this post, yes, we do have many lessons to learn from Easter Island, and it all boils down to policies and decision-making. Even if you do not believe that the ‘ecocide’ theory is correct, and that deforestation, resource depletion and population expansion caused Easter’s demise, what is the harm in believing that we can learn from Easter Island? There is no doubt we are facing many environmental problems today, so if Easter is used a ‘scare tactic’ to kick out society into gear, so what if you believe in the ecocide theory? At the end of the day, if it helps us to face, and make decisions on how to improve some our environmental problems, then we should let it.  

Attenborough's Warning from Easter Island

David Attenborough presents this short 4 minute video which explains the warning that Easter's history provides today's society, and it pretty much sums up the ecocide theory and how this relates to today. It ends with a plea from Attenborough himself to listen to the lesson Easter provides and to conserve our planet for future generations. Now i don't know about you, but if there is anyone i'm going to listen to who's telling me to save the planet, its going to be David Attenborough!

http://www.bbc.co.uk/learningzone/clips/8982.flv

Earth and Easter: The Lessons We Can Learn From Rapa Nui [1]

In his chapter on Easter Island in the infamous book Collapse, Diamond finishes with this quote:

‘The parallels between Easter Island and the modern world are chillingly obvious. Thanks to globalisation, international trade, jet planes and internet, all countries on Earth today share resources and affect each other, just as did Easter’s dozen clans…those are the reasons why people see the collapse of Easter Island society as a metaphor, a worst-case scenario, for what may lie ahead of us in out future’

Today’s society are facing an overwhelming amount of environmental problems, including; water problems, deforestation, end of tropical rainforests, overfishing, soil erosion and salinisation, global climate change, full utilisation of the world’s fresh water supplies, exhaustion of cheap energy resources, accumulation of toxic chemicals in water, food and soil, increase in human population and increase in the per capita impact of our population. Many past civilisations and societies collapsed due to one or more of these problems, for example the Mayan civilisation collapse due to a combination of environmental degradation, deforestation, a series of severe droughts, economic stress and socio-political upheaval (see Meera’s blog ‘The Lost Chronicles of Mesoamericans’ for more information on the causes behind the Mayan collapse). It is plain to see numerous parallels between the causes of collapse of the Mayans and the environmental problems we are facing today.

The similarities between Easter and today’s society are clear if you support the ‘ecocide’ theory suggested by Diamond and many others, however if you disagree with this theory and think that Easter collapsed due to either rats or the European’s arrival, other colonists, whalers and slave-traders then Easter as an analogy to Earth might not quite be so clear.

So, what parallels exist between Easter and today?

Population Expansion

The global population is growing exponentially, and is projected to carry on expanding if we do nothing, as shown by the diagram below. 

Over the past hundred years population growth has expanded from 0.9 billion in 1750 to today’s 6.9 billion. From Easter’s settlement to its peak population, a population rate growth of 3% per year has been estimated (Hunt and Lipo 2007) in comparison to our current world population growth rate of 1.14%. However, we cannot compare the two in this sense due to the vastly differing scales of the entire Earth and a 64 mile² island. Population growth rates mainly range from 0.1% to 3%, so its plain to see that both Easter’s society, and ours are alike when it comes to rapid population expansion.

Deforestation

The 2005 United Nations Food and Agricultural Organization (FAO) report estimated that the Earth’s total forest area decreases by around 13 million hectares a year, due to a number of factors including clearing for grazing cattle, colonization (human settlement), infrastructure improvements, commercial agriculture and logging. This is plainly comparable to Easter’s deforestation as suggested by Diamond (2005), Meith and Bork (2010) and Anderson (1994) who suggested that the islander’s deforestation their island to the point of no trees to make space for settlement and farming, as well as for resources.

Soil Erosion

Soil erosion, or more generally landscape degradation, is a major problem facing the world today. Caused by land clearance (deforestation), overgrazing, depletion of soil nutrients through poor agricultural practices, poor irrigation, pollution, quarrying and urban sprawl, landscape degradation also had detrimental impacts to Easter. My previous post investigating a study by Meith and Bork (2005) highlights that soil erosion on Easter caused the abandonment of agriculture and human settlement on the Poike peninsula, and the breakdown of the ‘stone culture’. Today, soil erosion and landscape degradation is having similar effects, with an estimated 40% of the world’s agricultural land to be already degraded (Sample 2007), causing further resource depletion.

Resource Exploitation

Resource exploitation and depletion today, is arguably, one of the most serious environmental problems facing the world today, including the depletion of freshwater supplies, the exhaustion of energy and fossil fuel resources, overfishing and food and water scarcity. Common causes of resource depletion are overpopulation, slash and burn agricultural practises, erosion, forestry, overconsumption/excessive use of resources, pollution and irrigation. The majority of these causes (except pollution) contributed to resource depletion on Easter and most certainly contribute to our current society’s resource depletion. It is, again, evident that there are parallels between Easter and Earth, as Easter depleted its marine resources, food (indicated by the extinction of land birds), forests and agricultural land due to overpopulation, slash and burn, erosion and excessive use of resources (rolling the moai statues on tree trunks?).

I have to make it clear here, that looking at the parables between Earth and Easter means that we are supporting the ‘ecocide’ theory, and although it did most certainly have an impact on Easter, we must not forget the devastation caused by slave-raids and foreign diseases caused by the European’s arrival on Easter.

So what can, and have we learnt from Easter Island? Well you’ll just have to wait until the next post to find that out!

An Easy Guide to the Theories of Easter's Collapse

So now we have looked at all of proposed theories of collapse on Easter Island. I have created a table which summarises all of the causes of collapse, how they could have caused Easter’s collapse, the lines of archaeological and palaeological evidence that support each theory and the sources and articles I have used in my posts to investigate their impact on Easter Island….hopefully it will make things a little bit clearer for everyone.

So from looking at all these causes, what can today’s society learn from Easter Island? The next few posts will investigate some of the ways that our society today can look at the mystery of Easter Island and learn something from them, no matter whether they collapsed due to murder or suicide.

Europeans and Easter

“This story of self-induced eco-disaster and consequent self-destruction of a Polynesian island society continues to provide the easy and uncomplicated shorthand for explaining the so-called cultural devolution of Rapa Nui society”

(Rainbird, 2002)

The ‘ecocide’ theory is not the only solution to the Easter Island mystery. Numerous other scholars advocate that the arrival of Europeans and slave traders were the reason behind Easter’s collapse. Benny Peiser (2005) in his paper ‘From Genocide to Ecocide: The Rape of Rapa Nui’ claims that Rapa’s culture and environment were destroyed to all intents and purposes by European slave-traders, whalers and colonists, and not by themselves.

Between the first European contact in 1722 and the beginning of Peruvian slave raids in 1862, it is estimated that 53 European vessels called at Easter Island (Peiser 2005). During this time, the Europeans brought foreign diseases to Easter, particularly smallpox and other Old World diseases. As well as diseases, Benny Peiser paints a gruesome picture of violent assaults, murder, rape and mass deportation of the native people by early European visitors, whalers and slave-raids. Slave-raids first started on Easter Island as early as 1805, however from October 1862 to March 1863 an estimated 1000-1400 people were captured and deported by Peruvian and Spanish slave-raiders. Peiser claims that almost 90% died in the following weeks due to disease and malnutrition (yet provides no evidence to support this claim).

With the deportation and deaths of many within the native population, including tribal and community leaders, the social and religious system disintegrated, leading to internal strife and tribal fighting. It is this fighting, combined with the deaths and deportation of 1000-1400 people that Peiser argues was the cause of societal collapse and starvation. He maintains that there is no reason to believe that Easter’s civilization could not have adapted and survived to an environment devoid of large timber, however what they could not have adapted and survived was the ‘systematic destruction of their society, their people and their culture’. Essentially, it wasn’t suicide by the native people themselves, but rather genocide by whalers, colonists and slave-raiders.  He concludes with a quote from Rainbird (2002):

‘Whatever may have happened in the past on Easter Island, whatever they did to their island themselves, it totally pales in insignificance compared to the impact that was going to come through Western contact’

However, there are a couple points on Peiser’s article that I would like to draw attention to:

1. He spends the majority of his article picking apart Diamond’s ‘ecocide’ theory, claiming that it is not the real cause behind Easter’s collapse. His main line of argument to support this is that Diamond has very little archaeological and palaeological evidence, with statements like ‘Diamond’s methodological approach suffers from a manifest lack of scientific scrutiny. Instead of weighing up and critically assessing the quality, authenticity and reliability of the data he employs to support his arguments, he consistently selects only data and interpretations that seem to confirm his conviction that Easter Island self-destructed.’ This claim is not new (many scholars have questioned Diamond’s lack of evidence), however Peiser seems to do exactly the same as Diamond later on in his article as he uses no scientific evidence to prove his assertion that Western contact was the cause of Easter’s collapse, and makes statements such as ‘It is believed (but by no means certain) that almost 90% died in the following weeks and months of diseases and malnutrition’. Essentially (in my opinion), he seems determined to pick apart Diamond’s theory, before collecting solid scientific evidence to prove his theory.
2. He states that Easter’s population collapse occurred in 1864, however Roggeveen’s observations from 1722 suggested that Easter’s collapse had already happened by the time he arrived, and this is supported by numerous lines of scientific evidence (Flenley and Bahn 2003)

However, Hunt and Lipo (2007, 2009) provide a more solid argument backed by evidence for Western contact as the cause of collapse. They argue that demographic collapse likely began as a consequence of Old World diseases, rather than the murder, rape and mass deportation that Peiser maintains (however, these did still have some impact on Easter’s population). The first wave of epidemics occurred with the arrival of the Dutch in 1722, then with the Spanish in 1770 and the English in 1774. Slave trading, more epidemics and other devastating blows from colonialism then hit the population. However, they contest the arguments made by Flenley and Bahn, and Diamond that Easter’s population collapsed pre-European arrival, simply stating that there is no existing evidence for a pre-European contact population collapse, and that a per-contact demographic collapse remains untested and undemonstrated archaeologically. Rather, the impact of historic slave trading, epidemic diseases, intensive sheep ranching and tragic population collapse has been recognized for a long time.

It is clear from this to see two very opposing sides to the Easter Island mystery with respect to Western contact. While one side argues that there is much evidence for pre-contact population collapse (Diamond, Flenley and Bahn), the other side argues there is no evidence for pre-contact collapse (Rainbird, Peiser, Hunt and Lipo), the quality of archaeological and palaeological evidence on Easter Island is not of good enough quality to prove either argument. European arrival on Easter Island had a clear impact on the population of Easter, however the argument is whether the population was already in decline as a result of population expansion, deforestation and resource exploitation. 

Cannibalism and Civil War

According to Diamond’s theory, as deforestation, resource exploitation and population expansion began to ‘destroy’ Rapa Nui, the Islanders descended into warfare and cannibalism. This has captured the attention of the public, as can been seen in the movie ‘Rapa Nui’ (see previous post), which bases its story around civil war on Easter Island.

BBC’s horizon created a documentary on Easter Island (again, see my previous post), but can be summarised in this article (http://www.bbc.co.uk/science/horizon/2003/easterisland.shtml). Evidence of civil war can be summed up into these points:

• Archaeological evidence include wooden carvings of emaciated people and the appearance of weapons, such as spear tips
• Skeletons have been found with severe wounds (Flenley and Bahn 2007)
• Changes in diet coincide with civil war. Resources were scattered around the island, yet friendly trade on the island allowed all tribes to survive – once they were at war with each other, friendly trade disappeared
• Legends talk of a time of hardship, terror and cannibalism

Diamond claims that three-quarters of the human population died out due to cannibalism, starvation and civil war, and that one of the world’s most remarkable civilisations self-destructed. The last point encapsulates the theory that Easter Island descended into warfare and cannibalism…it is simply a legend and myth. It is plain to see from these points that very little evidence exists to support warfare and cannibalism on Easter Island. The texts from the Dutch expedition in 1722 report fields of yam, and healthy, fit people, which contradicts a violent cannibalistic society suggested by Diamond (1995):

‘They also turned to the largest remaining meat source available: humans, whose bones became common in late Easter Island garbage heaps. Oral traditions of the islanders are rife with cannibalism; the most inflammatory taunt that could be snarled at an enemy was “The flesh of your mother sticks between my teeth.” ‘

Most scholars researching Easter concur that this theory is no more than a hoax designed to capture the imagination of the public, and has very little archaeological evidence to support it:

• Hunt and Lipo (2007) analysed spear heads that were supposedly used for weapons, and concluded that very few of the hundreds they inspected possessed the traits that would make them good weapons
• Based on a study of 2618 bones, Owsley (1994) deduced that 2.5% of them showed signs of traumatic injuries
• NO evidence has actually been found for cannibalism

To conclude, Bahn (1997) claims this theory as:

‘One of the most ridiculous yarns ever spun about the island’

References

Owsley, D. W., Gill, G. and Ousley, S.D. (1994) ‘Biological effects of European contact on Easter Island’ In. Larsen, C.S. and Milner, G.R. (eds) The Wake of Contact: Biological Responses to Conquest 161-1 77. New York: Wiley-Liss, Inc.

Bahn, P.G. (1997) ‘Easter Island or (Man-) Eaters Island?’ Rapa Nui Journal 11(3): 123-125.

Resources on Rapa

Resource exploitation is clearly a potential cause for the collapse of Easter Island, and it is supported by Diamond’s “ecocide” theory and those who follow a similar view to him. Resource overexploitation started with the Jubaea chilensis palm deforestation, which then triggered the overexploitation of a whole host of resources. Meith and Bork (2005) analyse the soil profile on Poike peninsula to prove that soil erosion was a contributing factor to Easter’s collapse, whereby poor soil fertility (caused by deforestation) halted agriculture, thus depleting resources produced from farming. 

Easter Island’s isolation combined with the population expansion suggested by Bologna and Flores (2008) triggered resource exploitation, exceeding Easter Island’s capacity. Population and deforestation of the Jubaea chilensis palm caused the overexploitation of the resources provided by the palm, for example firewood, building materials for houses, roof thatching, food from the palm nuts, hunting material and canoes for fishing offshore. Diamond (2005) suggests that although Roggeveen found no animals bigger that insects when he arrived on the island, however Diamond (2005) claims that Easter once had the richest seabird-breeding site in Polynesia, once being home to porpoises, turtles, fish, shellfish, rats, seals and large lizards. This clearly advocates resource exploitation, however Diamond provides no evidence to support this point.

Croix and Dottori (2008) implement a model that reconstructs the population, economy and resources on Easter Island. It pretty much summarises resource exploitation as a cause of Easter Island collapse, showing the decrease of forest resources from the reconstruction of forest pollen and corresponding increase in soil erosion (from % Loss on Ignition), which triggered a decrease in agricultural resources. It also illustrates evidence from charcoal particles that were used to reconstruct population increases, which is a trigger for resource overexploitation. The figure below represents the model results from this study.

However, Rainbird (2002) has challenged the view that resource degradation was the principle cause of the collapse of the Easter Island economy and society. Although Rainbird acknowledges that extensive environmental degradation may have occurred on other resource-poor and relatively small Pacific Islands, instead he maintains that contact with the “material culture” and “diseases” brought by Europeans was the more likely source of the demise of Easter Island. Hunt and Lipo (2007) also challenge this view, suggesting alternative theories (some already covered in this blog) such as rats causing deforestation, the capture of Islanders for slave trade and the arrival of Europeans brought diseases that the Islanders were not immune to. The impact of the arrival of the Europeans and their disease will be analysed in the next post.

References

Diamond, J. (2005) Collapse: How Societies Choose to Fail or Survive London: Allen Lane

Kevin Costner and Easter Island?!

The Easter Island mystery is so intriguing, that a film has been made about it. Produced by Kevin Costner, the film ‘Rapa Nui’ tells the story of civil war between the ‘short eared’ and ‘long eared’ tribes on Rapa Nui (Easter Island), and the fight between two opposing leaders of these tribes for the love and affection of one girl. In terms of geography and anthropology, you do have to take this film with a pinch of salt, as factually it is most certainly not perfect! I may be in danger here of turning into a movie critic, but by investigating the parts of this film that are factually inaccurate, we can actually highlight and learn some things about Easter Island.

For example, this film is set 300 years ago (around AD 1700), and tells how there is civil war between tribes on the Island. The tribes are still erecting statues, however, it is impossible for these tribes to be erecting the moai when they are at war. As has been highlighted in a previous post, resources were scattered around the island, with stones for the moai in the, quarries for the red stones that formed hats for the moai, fishing in the, agriculture in the, and forests in the. This suggests not only a complex and highly organised society on Easter Island, it also suggests that friendly trade between tribes that congregated round the resources must have been in place for the statues to have been built. Thus statue building and civil war could not have coincided. Basically the film seems to have mixed two eras into one!

Secondly, the film assumes that the islanders cut down the palm trees for space for the moai. Although this could have been possible, it is much more likely that the trees were cut down, if they were cut down at all, to provide resources and to make space for agriculture rather than the statues.

The film advocates the popularised view shared by Jared Diamond that Easter Island collapsed due to the ‘ecocide’ theory. The influence of both the film and Diamond’s books are dangerous for Easter Island as causes people to form a preconceived view on why Easter collapsed, without looking at the different theories of collapse. 

Easter Island Apocalypse: Population Expansion?

So, what has happened to the point I made in my very first post about Easter Island being a parable to today’s society? Well today’s post will look into just this. Already we can see the potential impacts deforestation had on Easter Island (depending on whether you support Jared Diamond’s theory, or Hunt and Lipo’s theories), yet the underlying cause of deforestation, as proposed by Diamond, is population expansion.

It may (and should) be clear by now that the theories behind Easter’s collapse are highly contested. Population expansion, as suggested by Jared Diamond and many other scholars COULD be a cause behind Easter Island’s demise, but it should be obvious that t his is only one side to the argument. Theories already discussed, such as the rat theory, and theories to come, for example, the arrival of the Europeans and slave trade are also supported by archaeological and anthropological evidence, and are no less important. I am only saying this because it is easy to be caught up in the more popular idea that the Easter Islanders caused their own demise….’suicide’, without looking at all the arguments and evidence. That said, I will investigate a couple of papers that suggest population expansion was the cause behind the Easter Island collapse.

The Malthus prediction that:

‘Population growth would eventually lead to natural resource depletion, economic decline, starvation, violent conflict and population decline’

seems remarkably close to the Easter Island story suggested by Diamond.

Bologna and Flores (2008) implement a mathematic model that explains the rise and fall of Easter Island. The model considers the interaction between natural resources and population, and generates an estimation of the civilisation’s collapse time. The diagram below shows the model predicted population and amount of resources.

They predict a population increase to 7000 by AD 1400. This estimate is similar to those made by Bahn and Flenley (1992) from the pollen record, and by Diamond (2007) and Rainbird (2002). In addition, this peak population is also supported by the fact that moai construction peaked between 1100 and 1400 A.D. Moai construction indicates the presence of a large population since their construction requires intensive labour, and it also suggests a complex society that were able to organise such large-scale projects.

Bologna and Flores use their model to determine the civilisation’s equilibrium point where humans can coexist with the available natural resources indefinitely. They estimate the equilibrium population size to be around 2000 people, as it was around 1175. Meith and Bork (2005) suggest that sustainable agriculture existed up until A.D 1300, perhaps implying that humans and natural resources were in equilibrium. Considering the year 1175 falls into this phase of sustainable agriculture, Bologna and Flores’ predicted equilibrium population size seems entirely likely.

The model then shows a population decline to 2000 by 1600 A.D that coincides with a sharp drop in resources, as shown by the diagram.

However, Wolcott and Conrad (2011) advocate that using the interaction between humans and resources to drive the model is not accurate, and the influence of soil erosion must be factored into population estimates from mathematical modelling. Their research proposes that population decline occurred because soil erosion caused agriculture to fail, which can be seen in the diagram below.

Either way, both studies show the general trend that Malthus predicted, where population increased past the equilibrium population size, resources were depleted (with the help of soil erosion causing agricultural failure), causing population decline. Bologna and Flores conclude by stating:

‘The model could be, with the opportune changes, applied to the planet…of course there are many differences but surely the planet can be considered an isolated system as Easter Island was’

which sums up not only their view, but many other scholars as well. Of course, as I have already mentioned, this popular viewpoint is only one side of the story…there is much more to be discovered and told about Easter Island yet!

Easter and erosion: Could soil erosion have been a contributing factor?

Now that we’ve looked at the impacts of deforestation on Easter Island, its time to look into a couple of other causes, and whether or not they contributed to Easter’s demise. Using a study by Meith and Bork (2005) in their paper, ‘History, origin and extent of soil erosion on Easter Island (Rapa Nui)’, the existence and contribution of soil erosion on Easter’s demise will be examined. Meith and Bork (2005) follow the view shared by Jared Diamond that:

“The isolated Easter Island (Rapa Nui) is an outstanding example of land degradation caused by land use in a sensitive ecosystem”

Meith and Bork (2005) use a detailed analysis of the causes, chronology and spatial pattern of soil erosion on the Poike peninsula on Easter Island to answer the following questions:
   1. Did erosion of Rapa start with the rise of Polynesian agriculture?
   2. Can phases of different chronological differentiation of soil erosion processes?
   3. Was soil erosion a less significant problem in the prehistory of Rapa or was the loss of fertile soils an important reason for the complete change in way of life and culture about AD1400/1500?

Phases of prehistoric land use and soil erosion were investigated in the most eastern part, northwest and southwestern parts of Poike peninsula, whereby all the investigation sites were all characterised by severe erosion. The method for reconstructing past soil erosion is an entire topic in its own right, and a comprehensive methodology is outlined in the paper, however I won’t go into that right now.

Figure 1. Complex of land use and soil erosion in the most eastern part of Poike peninsula near Cabo Cumming

Figure 2. Soil profile from the most eastern part of Poike peninsula

The two figures above represent the soil profile of the Poike peninsula. Historically, the most interesting part of the bottom of the soil profile is the existence of root channels, which have been identified as the Jubaea chilensis palm found on Easter Island when the Polynesians first settled. Above this layer is yellowish soil that shows evidence for planting pits, which indicated agricultural land use. The absence of soil erosion and quality of the soil in both these layers suggests a phase of successful soil protection and sustainable agriculture up until AD 1300. Meith and Bork propose the reasoning for this is because the palm trees protected the soil against intensive radiation, strong winds and heavy rainfall.

The soil profile shows that this phase ended suddenly with the appearance of charcoal in the soil profile. Meith and Bork state that ‘obviously the palm forest was subjected to an extended woodland clearance’, which (in my opinion) is a rather sweeping statement, as if I have shown anything so far in this blog, the controversy surrounding deforestation and the evidence to support deforestation are certainly not clear, and do not merit a statement such as this one.

However, my opinion aside, Meith and Bork continue to suggest that woodland clearance in AD 1400 had dramatic consequences for soil erosion:
   1. Loss of protection from the palm trees caused sheet erosion
   2. Agriculture under open land conditions might have destabilised slope
   3. Erosion and accumulation process shown in soil layer were caused by heavy rainfall and started at downslope areas

This erosion was thought to be the main cause for the abandonment of agriculture in AD 1500, where after AD 1400/1500, human influence can longer be seen in the soil profile.

So what can we infer from soil erosion, and was a contributing factor for the collapse of Easter Island? Well Meith and Bork propose that the sudden shift from the bottom layers to those influenced by humans suggests that the techniques of land use shifted suddenly from traditional sustainable agro-forestry to intensive non-sustainable land use in open land, however the reasons behind this shift are unknown. They suggest that soil erosion and consequently a decrease in soil fertility caused abandonment of agriculture and moai construction on the Poike peninsula, and the burial of settlements. They conclude that:

‘On the basis of results from Poike peninsula, we hypothesis that soil erosion may have had a dominant role in the break down of Easter’s stone culture’

However, soil erosion has only been investigated in detail on the Poike peninsula. We cannot reconstruct whether soil erosion was a contributing factor in Easter’s demise based on one area, thus much more research on soil erosion on Easter Island should be conducted before we can make such conclusions.

That said, it is an interesting thought that soil erosion may have been a contributing factor to Easter Island’s collapse….

A simplified Easter Island story....

So you may be forgiven for getting a little confused over the dates and series of events that happened on Easter Island during its settlement, expansion, collapse and post-collapse….so for your benefit only, I will post this VERY simplified (and potentially controversial due recent research that disputes many of these dates and events) table.

I hope this makes the story a little clearer, as its most definitely going to get more complicated as we bring in more suggested theories for collapse!

Deforestation: A Conclusion

So the intriguing question we can conclude from the last few posts is: Did the Easter Islanders completely destroy the island’s dense subtropical forest, or was Rapa Nui since the beginning of human colonization, a poor environment covered only with local spots of forest, and was it drought and the introduction of rats in combination with humans that finally triggered the extinction of the already rare plant species (Jubaea chilensis).


Due to problems and inaccuracies associated with dating human arrival, deforestation, climate variability and the impact of rats, it is hard to tell which was the dominant cause, or what combination of causes could have triggered and brought about the deforestation of Easter Island. Nonetheless, what we can be sure of, is the deforestation on Easter Island was a complex process. Many scholars researching the collapse of Easter advocate that deforestation played an important, or even central role in the collapse of Rapa Nui, for example Jared Diamond’s highly popularised ‘Ecocide’ theory that humans caused deforestation, which in turn caused their own collapse. However, there are numerous other theories that try to explain the collapse of Rapa Nui, for example overpopulation, soil erosion, warfare and conflict, and the arrival of the Europeans and slave trade. The subsequent posts will investigate these theories as a cause of collapse. 

Easter Island Ecocide: Deforestation due to Humans?

Easter Island underwent deforestation between the arrivals of the Polynesians c. AD 800,and the arrival of the Europeans 1722. The circumstances, causes and triggers of this environmental change have been partly discussed in the last few posts, now this post will attempt to uncover whether humans caused deforestation on Easter Island. This is perhaps the most researched, written about, and debated cause of deforestation, not only because of evidence and support from Jared Diamond’s much publicised view of ‘Ecocide’, but also because of the parable it has for today’s society.

In their paper ‘Humans, climate or introduced rats – which is to blame for the woodland destruction on prehistoric Rapa Nui (Easter Island)?’ Meith and Bork (2010) investigate the causes of deforestation on Easter Island, and concluded that it was humans who caused their own demise…thus it was ‘suicide’.

After settlement on Rapa Nui, population rapidly expanded to a peak of maximum 10,000 (Diamond 2007). The now extinct Jubaea chilensis palm provided numerous uses, including firewood and timber, the construction of canoes, possible transportation methods for the Moai, edible fruits and seeds, and palm leaves that could be used for thatching and rope. As the population expanded, not only did the need for the palm increase, but also more open space was essential for the increased agriculture and number of dwellings and gardens.

One of the best ways to investigate whether anthropogenic deforestation has occurred is to distinguish if charcoal appears in both the pollen diagrams and the soil profile, as this is a clear indicator of man’s influence on the forests. Soil profiles on Rapa Nui provide evidence of ‘slash and burn’ fires in the former palm woodland (as shown by Figure.1), where some of the charcoal layers (specifically on the Poike Peninsula and the southwest of Rapa Nui) contained burned nutshells of the Jubaea chilensis.

Figure 1. Two segments of soil profile in South West Poike. Summarized stratigraphy: (1) Weathered volcanic bedrock. (2) Cone of palm root molds. (3) Pre- clearing garden soil. (4) Accumulation of charcoal from a burned palm stump containing in situ aggregates of burned soil. Result of intentional burning by humans. (5) Charcoal layer. Charcoal layers are best preserved in concave down-slope sections. (6) Post-clearing garden soil with planting pits. (7) Fine layered sediments, resulting from post-clearing sheet erosion of unprotected soil. 

Carbon dating these burnt nutshells indicate that the oldest date of charcoal is around AD 1244-1254, and therefore supports the conclusion made by Meith and Bork (2010) that deforestation and ‘slash and burn’ on Rapa Nui started around the 13^th Century. These findings by Meith and Bork are supported by Hunt and Lipo (2006), where Figure 2 sums of Hunt and Lipo’s work by showing the chronological sequence of slash and burn for 12 sites of Rapa Nui. The suggestion by Meith and Bork (2010) that anthropogenic deforestation started in the 13^th Century is supported by this chronological sequence.

Figure 2. The chronological sequence of slash and burn for 12 sites on Rapa Nui.

From looking at Figure 2, and Figure 3 below, which provides probability distributions for 15 calibrated radiocarbon dates in context with woodland clearance from different sites around Rapa Nui, Meith and Bork (2010) have built up a picture as to what happened on Easter Island.

‘Clearance occurred in phases of deforestation on Poike Peninsula between approximately 1250 and 1510 AD, and at the slopes of Rano Kao roughly between 1400 and 1520 AD. All data demonstrate that the destruction of the palm woodland on Rapa Nui probably lasted no longer that 300-400 years….the main slash and burn activity occurred between 1200 AD and 1600AD.’

Figure 3. Probability distributions for 15 calibrated radiocarbon dates in context with woodland clearance from different locations on Rapa Nui. 

Meith and Bork (2010) thus conclude that:

‘Both the temporal placement (after the onset of human colonization) and the sequential chronology of woodland clearance in different parts of the island underscore that the deforestation was an act of humans’

 This paper also investigate the role that rats play in deforestation (see previous post), and from looking at the nutshells in the soil profile, less than 10% of these charred palm nuts actually contained teeth marks from rats, therefore they conclude that rats are NOT the cause of deforestation on Rapa Nui. They also use a several other lines of evidence to support this conclusion. Firstly, they found that the Jubaea chilensis palm in La Campana National Park, Central Chile, sustains a healthy population of 80,000 palms whilst coexisting with a similar type of rat that is suspected to have inhabited Rapa Nui. And secondly, these rats simply could not have felled mature trees.

Pollen proxies in the lake sediment (Flenley and King 1984) also verify a long existence of the palm woodland (around 35,000 years) on Rapa Nui before the arrival of humans, suggesting that the palms survived all climate variations from the late Pleistocene to the late Holocene.

‘What were the Easter Islanders thinking when they cut down the last tree’?

Once the last tree had gone, they no longer had firewood and timber, ropes, thatching, possible transportation of the Moai, and canoes (their only way off the Island). This then starts the ‘Ecocide’ theory that Jared Diamond suggests….

A quick note: The uses of the palm on Rapa Nui, and the anthropogenic deforestation theory is summed up very well in a paper by Rosalind L. Hunter Anderson (1998). I havn’t used it in my post here as some of the research is slightly out of date, however it does provide a perfect summary of what has been indicated in this post!