Human beings have always influenced and changed the environment. There are now new methods in order to explore how, even in the absence of the remains of tombs, dwellings, artwork, written documents or oral traditions.
” Sometimes it can be very difficult to find preserved archaeological relics in the forests. However, in spite of what seem to the people, for the most part don’t care about the living, the trees that are there, ” said Victor Caetano-Andrade at the Max Planck institute for the history of Jena, Germany.
Many of the trees have been grown there for a very long time. In the Amazon, there are paranötsträd, which is between 700 and 1000 years old. They were, therefore, already when the europeans first came to America, and it is, therefore, on the trail of what happened to the native americans.
“Paranötsträdet is an iconic species, which people have been using for a very, very long time,” said Victor Caetano-Leaves.
in brazil nuts is likely to have been in use and is cared for by the people of today’s france, at least 11, 000 years. Victor Caetano-Andrade and his colleagues have studied the growth rings in core samples from trees to see where they had ample room and were able to grow each and every year, and when the growth rate has slowed down. The chemical analysis of the variations of the carbon and oxygen atoms in the rings shows how the availability of light and water, and will help the researchers to make a distinction between what is due to human influence, and what are the natural effects of weather and climate.
” We could see people clearing away from the trees, as they do not have any advantage, in order to paranötsträden have been given more space. We can also see that new trees were able to germinate and grow.
paranötsträd in the Tapirapé-Aquiri national park, Brazil. Photo credit: Victor Caetano-Leaves
with the help of tree rings is called dendrochronology.
” This is a very old science. However, it has been used in areas with a temperate climate, where it’s easier to see the growth rings, ” said Victor Caetano-Leaves.
a long time, Researchers believed that there is a need for clear seasons for the trees to get the growth rings and dendrochronology, therefore, are not suitable for use in the tropics.
” But in the last few decades, there has been a lot. Now we have more than 200 bird species that form annual rings even in tropical areas.
In an article in this week’s issue of the journal Trends in Plant Science, describes Victor Caetano-Andrade and his colleagues, how the trees in the tropical regions are tidskapslar of the history of the area. By studying them, we can learn how we can better conserve our forests, which are the greatest risk to the environment of the earth, the ice at the poles, according to the researchers.
” We can answer a lot more questions. What we do is a combination of history, archeology, and ecology, ” said Victor Caetano-Leaves.
Victor Caetano-Andrade at the Max Planck institute for the history of Jena, Germany. Photo credit: Max Planck Institute for the Science of Human History,
in Addition to the growth rings, and the composition of the carbon and oxygen atoms to measure the scientists, the tree’s age by the carbon-14 method, when the rings are hard to see.
” we have been using, they have the techniques for a while now, even in the tropics. It’s a new thing we do is to make use of them in the winter, which has been very important to the people, in order to find out how the trees have been taken care of and managed. In addition, we use the genetic make-up, ” said Victor Caetano-Leaves.
the bark of the Trees, the dna can show where they have been cultivated, and mankind has grown up with them. Scientists have seen, for example, that cocoa has the dna variants that provide the beans, which is not so bitter, and that they are resistant to most common diseases. If a species has very little genetic variation between different individuals, it is a sign that people are, at some point in time, cut down, or tried to eradicate the species, perhaps in order to make room for other crops.
” Our goal is to combine all of this with the use of historical sources in order to get a clearer picture of what was going on.
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of Brazil, and was educated first at skogsingenjör before he got interested in historical ecology.
“I spent eight or nine months in the forests of the Amazon basin, collecting samples, both close to the archaeological sites, and many of them, so that we can compare the trees to people affected by the trees that are most likely never to have been cared for by the people,” he said.
with the arrival of Europeans to the Americas led to widespread death among the indigenous population. It can be seen in the woods.
the Plantations were abandoned, and the natural forest took over. There are no new paranötsträd began to grow.
But at the end of the 1800s, there was suddenly an enormous demand for rubber, the Brazil, ended up in the middle of a gummirusch.
“Then, along came the new settlers, and the people who influence and make use of the forest again, and the new trees that people use was and were able to take root again,” says Victor Caetano-Leaves.
Each day, 32 000 hectares of the tropical forest. In the middle of this century, the will of over half the world’s population that live in the tropics. It brings new and more serious threat to the forests. The researchers write in their article that it’s important to archaeologists, and ecologists work together to keep them safe, both for the trees and the vital role of the earth’s climate, and that they are documents of human history.
Victor Caetano-Andrade would be happy to look at other species, as well as the paranötsträdet has been important to the people in the story.
” I had a goal to collect samples of the mahogany, which has been used in other ways as well. However, they were almost impossible to find. They had the paranötsträden to stand still in order to get to the nuts. Mahogany wood, we have, instead, cut it down to use the wood, so, unfortunately, I did not find a sufficient number of.
One of the scientists will take samples from a paranötsträd in the Tapirapé-Aquiri nationalskog of the country. Photo Credit: Victor Caetano-Leaves
