Were rats behind Easter Island mystery?
crunch
"In their new study, however, Mieth and Bork, both of Germany's
Christian Albrechts University of Kiel, 'disagree with the hypothesis
of a major rat impact' to explain Easter Island's demise. In their
study, they look at the charcoal remains from fires, evidence of the
spread of slash and burn agriculture from the island's shore to its
peak."
-----
"Of course, Hunt acknowledges, the early colonists likely brought rats
with them. 'But it's unlikely they could have seen ahead to the
results of either farming or bringing rats,' he says. 'Blaming humans
for everything is too simple.'"
-----
David Christainsen
SolomonW
Rats are not a new theory in Easter Island collapse.
crunch
> On Sun, 15 Nov 2009 12:55:27 -0800 (PST), crunch wrote:
>
> > "In their new study, however, Mieth and Bork, both of Germany's
> > Christian Albrechts University of Kiel, 'disagree with the hypothesis
> > of a major rat impact' to explain Easter Island's demise. In their
> > study, they look at the charcoal remains from fires, evidence of the
> > spread of slash and burn agriculture from the island's shore to its
> > peak."
>
> > -----
>
> > "Of course, Hunt acknowledges, the early colonists likely brought rats
> > with them. 'But it's unlikely they could have seen ahead to the
> > results of either farming or bringing rats,' he says. 'Blaming humans
> > for everything is too simple.'"
>
> > -----
>
> > David Christainsen
>
>
> - Show quoted text -
Can you speak more to a satisfactory explanation of
the Easter Island collapse?
Peter Jason
"crunch" <pchris...@yahoo.com> wrote in message
news:fe1b82de-ddbd-4e36...@n35g2000yqm.googlegroups.com...
Perhaps there was a plague.
George
> "crunch" <pchristain...@yahoo.com> wrote in message
> Can you speak more to a satisfactory explanation of
> the Easter Island collapse?
>
> Perhaps there was a plague.
Basically it was a problem of too many people and too little land.
VtSkier
Yes, read 'Collapse' by Jared Diamond. In addition
bad decisions made by leaders as to land use caused
population increases which then led to ecological
collapse.
George
The Polynesians normally corrected overpopulation by migrating to
other islands.
However the trees available on Rapa Nui were not suitable to build the
waka/vaka capable of the voyages required.
Just imagine.
We would now be dealing with the archaeology of Polynesian settlements
in South America....
Peter Jason
"George" <gbl...@hnpl.net> wrote in message
news:e3553c03-a74d-4301...@d9g2000prh.googlegroups.com...
Ancients always had means of controlling their populations,
usually by killing newborns.
It beggars all belief that the Easter Islanders could not
simply plant more trees when the supply began to run out.
How much effort and brains does this take? If they had no
grazing animals then pasture was not at a premium.
Stop listening to academic boffins.
George
In order to have the trees to build waka/vaka from you need the seeds
and the hundred or so years for them to mature.
Look up the trees available on Rapa Nui and their suitability for
constructing waka/vaka of any sea going ability...
VtSkier
Yes Rapa Nui was the end of the line. No more
people passing by. All the trees cut to move
and erect statues, etc. etc. Bad decisions all
around.
From Diamond I understand that Rapa Nui had
sizeable trees when the Polynesians got there.
VtSkier
Peter Jason
"VtSkier" <vts...@somewhere.net> wrote in message
news:12588292...@r2d2.vermontel.net...
I can't find any reference to the types of trees on Easter
Island before the Europeans. Palms of course, but Hawaii
and other volcanic islands had all sorts.
benl...@ihug.co.nz
> "VtSkier" <vtsk...@somewhere.net> wrote in message
There seems to be no indication that Rapanui ever supported the kind
of rich forest resources one finds in Hawaii, Samoa, or New Zealand.
The largest species, which formed forests in its heyday, was a palm
(Jubaea sp.). Palm wood is not much good for canoe building, but
Flenley suggests it may have been used because they had nothing
better. (He cites Roger Green p.c. saying that palm wood is used for
canoes in the Marquesas.) There were also mako'i (Thespesia populnea,
probably introduced by the Polynesians) and the endemic toromiro
(Sophora toromiro), which may have provided nice wood for carving
small objects, but are never more than small trees.
See John R.Flenley, The Paleoecology of Easter Island, and its
Ecological Disaster, in S.R.Fischer (ed), Easter Island Studies. Oxbow
Books, 1993. Also Catherine Orliac in the same volume on types of wood
used in Rapanui carving. Some of the palynological evidence is in
Flenley & King, Late Quaternary pollen records from Easter Island,
Nature 307: 47-50 (1984).
Ross Clark
Jack Linthicum
Some more on Rapa nui wood, document is under peer review
Rapa Nui subtropical broadleaf forests (OC0111)
Peer review in process - unreviewed document presented
Rapa Nui subtropical broadleaf forests
Rapa Nui, Chile
Rapa Nui, also known as Easter Island, is one of the more famous
islands on Earth. It is also the most geographically isolated and
forms the eastern geographic and cultural boundary of Polynesia.
Although paleobotanical studies suggest that the island was originally
covered by palm and broadleaf forest, the island is now completely
grass-covered, except for a few isolated stands of ornamental trees
and shrubs. Rapa nui is one of the most isolated islands in the world
and thus has an interesting biogeographic and ecological history.
Location and General Description
Located in the South Pacific at about 27ºS latitude, Rapa Nui is 3,700
km west of Chile and about 2,200 km east of Pitcairn Island. It is the
most remote inhabited spot on Earth. The climate is subtropical, with
southeast trade winds from October to April. Annual rainfall averages
1,250 mm, with a rainy season occurring in the winter. Average
temperatures range from 19ºC in winter to 24ºC in summer.
Rapa Nui is the youngest and westernmost of a chain of submarine
volcanoes that probably formed as a volcanic hotspot track on the
Nazca Tectonic Plate, located on the eastern side of the East Pacific
Rise. The island is roughly triangular with an area of 166 km2 and a
maximum elevation of 600 m. It is composed of three main volcanic
summits, Rano Kau, Poike, and Terevaka, as well as several smaller
vents. The oldest is Poike, which erupted in two episodes, one 9
million years ago and the other 2.5 million years ago. Lavas from Rano
Kau are as old as 940,000 years, and lavas from Terevaka are the
youngest with flows as young as 300,000 years. The last volcanic
eruptions on Rapa Nui occurred about 13,000 years ago. The famous
statues, or moai, of Rapa Nui were carved from the island’s yellowish-
gray basaltic tuff, and their red topknots were carved from basaltic
spatter.
Sala-y-Gomez is a small reef 415 km to the northeast of Rapa Nui. It
is only 300 m long at low tide, and shrinks to a mere 70 m at high
tide. Constantly subjected to salt spray, only four species of
terrestrial plants grow here. A small depression sometimes contains
fresh water. Large populations of seabirds use the tiny island for
breeding. The terrestrial portion of the island is designated as a
nature sanctuary.
The topography and the biota of Rapa Nui have been shaped by repeated
climatic changes over the last 38,000 years, as well as by the most
recent volcanic eruptions.
Compared to other subtropical volcanic islands, Rapa Nui is
floristically species-poor, owing to its extreme isolation, and the
fact that it has never been connected to any continental landmass.
Carlquist (1967) estimated that more than 70 percent of the island’s
indigenous plants were introduced by birds. Recent estimates put the
total number of extant plant species at about 150, with 45 considered
indigenous, including 3 endemic species of grass (Paine 1991). The
precise nature of the flora is uncertain as studies are ongoing and
many authorities disagree on the identification and classification of
many plants.
The arrival of the first humans in the Fifth Century AD, and the
subsequent arrival of Europeans, profoundly altered the flora so that
little of the original vegetation is left.
Today, the island is almost completely grass-covered, except for a few
isolated stands of ornamental trees and shrubs. In fact, it was almost
treeless when first visited by Europeans in the early eighteenth
century. At that time, the only trees were found on the steep inner
slopes of the Rano Rakau crater (Fosberg 1998).
However, recent paleobotanical studies of fossil pollen and volcanic
tree molds indicate that, prior to the arrival of the first Polynesian
settlers, the island hosted an extensive array of trees, shrubs,
ferns, and grasses. Vegetation communities were distributed in zones
at different elevations, especially on the flanks of the volcanoes
Rano Aroi and Rano Raraku. Over time, these communities varied in
composition and structure, due to the climatic fluctuations occurring
during the final phases of the Pleistocene and the beginning of the
Holocene. Some of the tree species that dominated these ancient
forests included a now-extinct palm, related to the Chilean palm,
Jubaea chilensis, and the toromiro (Sophora toromiro). Shrubs included
the hau hau (Triumfetta semitriloba), which is still present, and
Coprosoma spp., which have since disappeared from the island (Rauch et
al. 1996, Mueller-Dombois & Fosberg 1998).
Sophora toromiro was the only species of tree known on the island in
historic times; it is now extinct in the wild. During botanical
investigations between 1920 and 1953, Skottsberg found one remaining
individual of S. toromiro, which has since died (Fosberg 1998). Most
of the grasslands are now covered by introduced Stipa spp., Nasella
spp., Sporobulus indicus and native Cynodon dactilon.
The long-extinct Jubaea palm is thought to have been the principal
wood used to transport the immense stone statues of Rapa Nui. Recent
carbon-14 dating, using mass spectrometer analysis, shows that Jubaea
was present on the island as recently as the middle of the Seventeenth
Century (Arnold et al. 1990). It has been hypothesized that over-
exploitation by the island’s early inhabitants caused the extinction
of this once dominant palm. However, Arnold et al. (1990) speculate
that climatic change may have been at least partly responsible.
The bottom of Rano Rakau crater is covered with thick stands of tall
bulrushes, Scirpus tautara, which may have been brought to the island
by prehistoric voyagers from South America (Fosberg 1998).
The fauna of Rapa Nui includes four species of terrestrial birds, and
three species of marine birds. There are no mammals except introduced
rodents and carnivores. Two terrestrial reptiles, Lepidodactylus
lugubris and Ablepharus boutoui poecilopleurus, are found on the
island. There are several micro-lepidoptera, most are widespread in
the Indo-Australian tropics and all are believed to have dispersed
from the west. Although three of the species on Rapa Nui are
cosmopolitan in nature, there appears to be no connection with South
America. One species, Asymphorodes trichograma, is restricted to Rapa
Nui and the Marquesas (Holloway 1990).
Biodiversity Features
Rapa Nui is the most isolated island in the Pacific and that makes it
extremely valuable for studying the biogeographical distribution of
species. It is currently the focus of numerous paleobotanical studies
that are rapidly changing the understanding of its native flora.
Ferns are one of the few higher plants that can be considered
indigenous to Rapa Nui (Aldén 1990). Just 4 of the 15 reported species
are endemic: Doodia paschalis, Polystichum fuentesii, Elaphoglossum
skottsbergii, and Thelypteris espinosae (Rauch 1996).
Triumfetta semitriloba, a woody shrub, was once thought to have been
introduced to the island because it is an important textile plant.
However, pollen analyses have shown that it existed on Rapa Nui at
least 35,000 years ago. For some time, it was thought to be extirpated
from the island, but at least four individuals were found in 1988
(Aldén 1990).
Current Status
The first Polynesians settlers reached Rapa Nui in the Fifth Century
AD. It is uncertain when extensive deforestation began, though the
island was basically deforested by the time the first Europeans
arrived in 1722. Many exotic species have been introduced to the
island. In recent studies, Zizka (1991) identified a total of 46
indigenous plant species of which 9 were endemic and 166 introduced.
Alien plants and animals make conservation and restoration of remnant
natural communities and species challenging. For example, grazing by
horses and other herbivores must be controlled before native species
can regenerate. Recent efforts to reintroduce the toromiro have been
undertaken by Kew Gardens.
Types and Severity of Threats
Although the 68 km2 Rapa Nui National Park was established as a
protected area in 1935, islanders do not recognize the authority of
the Chilean government and commonly ignore park regulations (Paine
1991). Alien plants, introduced grazers, and fires represent a major
threat to remnant native plant communities and populations. Other
current environmental problems include damage from archaeological
investigations, erosion, and tourist-caused damage. Chile has recently
announced plans to increase the pace of development on Rapa Nui.
Justification of Ecoregion Delineation
Easter Island is arguably the most isolated island in the world.
Before the arrival of Polynesians, the island was forested with trees
(Sophoro toromiro, Triumfetta sp.) and a palm (Jubaea disperta)
(Mueller-Dumbois & Fosberg 1998, Steadman 1995). Steadman (1995)
identified the remains of at least six species of land birds from four
families in prehistoric sediments. On the basis of its unique
prehistoric fauna and extreme isolation, Rapa Nui has been delineated
as a distinct ecoregion.
References
Aldén, B. 1990. Wild and introduced plants on Easter Island: A report
on some species noted in February 1998. Pages 209-216 in H.M. Esen-
Baur, editor. State and Perspectives of Scientific Research in Easter
Island Culture. Courier Forschungsinstitut Senckenberg, Frankfurt,
Germany.
Arnold, M., M. Orliac, and H. Valladas. 1990. Données nouvelles sur la
disparition du palmier (cf. Jubaea) de l’Ile de Pâques. Pages 217-219
in H.M. Esen-Baur, editor. State and Perspectives of Scientific
Research in Easter Island Culture. Courier Forschungsinstitut
Senckenberg, Frankfurt am Main, Germany.
Fosberg, F.R. 1998. Chapter 8: Eastern Polynesia. Pages 385-460 in D.
Mueller-Dombois and F.R. Fosberg, editors. Vegetation of the Tropical
Pacific Islands. Springer-Verlag New York, Inc.
Holloway, J.D. 1990. The Lepidoptera of Easter, Pitcairn and Henderson
Islands. Journal of Natural History, 24: 719-729.
Mueller-Dombois, D. and F.R. Fosberg. 1998. Vegetation of the Tropical
Pacific Islands. Springer Press, New York.
Paine, J.R. 1991. IUCN Directory of Protected Areas in Oceania. World
Conservation Monitoring Centre in collaboration with IUCN Commission
on National Parks and Protected Areas and the South Pacific Regional
Environment Programme.
Rauch, M., P. Ibañez, and J. M. Ramirez. 1996. Vegetación de Rapa Nui:
Historia y uso tradicional. Ministerio de Agricultura, Corporación
Nacional Forestal, Parque Nacional Rapa Nui.
Zizka, G. 1990. Changes in the Easter Island flora: Comments on
selected families. Pages 198-207 in H.M. Esen-Baur, editor. State and
Perspectives of Scientific Research in Easter Island Culture. Courier
Forschungsinstitut Senckenberg, Frankfurt am Main, Germany.
Zizka, G. 1991. Flowering plants of Easter Island. Palmengarten,
Frankfurt am Main, Germany.
Prepared by: Sandra Zicus
Reviewed by: In process
http://www.worldwildlife.org/wildworld/profiles/terrestrial/oc/oc0111_full.html
Peter Jason
"Jack Linthicum" <jackli...@earthlink.net> wrote in
message
news:9ab5f6ff-3913-485a...@m11g2000vbo.googlegroups.com...
Location and General Description
Located in the South Pacific at about 27�S latitude, Rapa
Nui is 3,700
km west of Chile and about 2,200 km east of Pitcairn Island.
It is the
most remote inhabited spot on Earth. The climate is
subtropical, with
southeast trade winds from October to April. Annual rainfall
averages
1,250 mm, with a rainy season occurring in the winter.
Average
temperatures range from 19�C in winter to 24�C in summer.
Biodiversity Features
indigenous to Rapa Nui (Ald�n 1990). Just 4 of the 15
reported species
are endemic: Doodia paschalis, Polystichum fuentesii,
Elaphoglossum
skottsbergii, and Thelypteris espinosae (Rauch 1996).
Triumfetta semitriloba, a woody shrub, was once thought to
have been
introduced to the island because it is an important textile
plant.
However, pollen analyses have shown that it existed on Rapa
Nui at
least 35,000 years ago. For some time, it was thought to be
extirpated
from the island, but at least four individuals were found in
1988
(Ald�n 1990).
Current Status
Justification of Ecoregion Delineation
References
Ald�n, B. 1990. Wild and introduced plants on Easter Island:
A report
on some species noted in February 1998. Pages 209-216 in
H.M. Esen-
Baur, editor. State and Perspectives of Scientific Research
in Easter
Island Culture. Courier Forschungsinstitut Senckenberg,
Frankfurt,
Germany.
Arnold, M., M. Orliac, and H. Valladas. 1990. Donn�es
nouvelles sur la
disparition du palmier (cf. Jubaea) de l�Ile de P�ques.
Pages 217-219
in H.M. Esen-Baur, editor. State and Perspectives of
Scientific
Research in Easter Island Culture. Courier
Forschungsinstitut
Senckenberg, Frankfurt am Main, Germany.
Fosberg, F.R. 1998. Chapter 8: Eastern Polynesia. Pages
385-460 in D.
Mueller-Dombois and F.R. Fosberg, editors. Vegetation of the
Tropical
Pacific Islands. Springer-Verlag New York, Inc.
Holloway, J.D. 1990. The Lepidoptera of Easter, Pitcairn and
Henderson
Islands. Journal of Natural History, 24: 719-729.
Mueller-Dombois, D. and F.R. Fosberg. 1998. Vegetation of
the Tropical
Pacific Islands. Springer Press, New York.
Paine, J.R. 1991. IUCN Directory of Protected Areas in
Oceania. World
Conservation Monitoring Centre in collaboration with IUCN
Commission
on National Parks and Protected Areas and the South Pacific
Regional
Environment Programme.
Rauch, M., P. Iba�ez, and J. M. Ramirez. 1996. Vegetaci�n de
Rapa Nui:
Historia y uso tradicional. Ministerio de Agricultura,
Corporaci�n
Nacional Forestal, Parque Nacional Rapa Nui.
Zizka, G. 1990. Changes in the Easter Island flora: Comments
on
selected families. Pages 198-207 in H.M. Esen-Baur, editor.
State and
Perspectives of Scientific Research in Easter Island
Culture. Courier
Forschungsinstitut Senckenberg, Frankfurt am Main, Germany.
Zizka, G. 1991. Flowering plants of Easter Island.
Palmengarten,
Frankfurt am Main, Germany.
Prepared by: Sandra Zicus
Reviewed by: In process
http://www.worldwildlife.org/wildworld/profiles/terrestrial/oc/oc0111_full.html
Some photos of one of the Easter Island shrubs..
http://www.flickr.com/photos/cactushorridus/3987291522/in/photostream/