LIANE HANSEN, host:
Four hundred years ago, English settlers arrived at the southern fringes of the Chesapeake Bay and established the Jamestown Colony. Every history student knows that part of the story.
But, what they may not know is what the settlers brought with them completely altered the landscape, eventually giving them the advantage over native populations. In the words of Charles Mann, the English did not discover a new world. They created one. Mann's article, "America Found & Lost" appears in this month's National Geographic magazine. And he joins us from member station WFCR in Amherst, Massachusetts. Welcome to the program.
Mr. CHARLES MANN (Author, "America Found & Lost"): Delighted to be here.
HANSEN: One of the first things you mentioned in your article is the earthworm. Did the colonist bring earthworms on purpose?
Mr. MANN: No. They would've imported them inadvertently, either just simply in the mud that they brought along, or more likely in the ballast for ships. What happened was, then the earthworms - once it came to Jamestown - were then spread by people into other parts of North America. And earthworms are these tiny, ecological engineers that completely change the entire ecosystem, both under the soil and on top in that they eat all the litter and the leaves and so forth that fall down.
HANSEN: Describe a forest with earthworms and without earthworms.
Mr. MANN: Well, the main difference would be twofold. First is a physical difference. If you go into the extreme north, what happens there is that the leaf litter just builds up on the forest floor. What happened when the earthworms come in is that they just gobble that up. It can disappear it in weeks, and then they tunnel into the soil, which takes this tremendous flush of nutrients deep into the soil where the plants that are now there can't get out of it.
And the second thing that happens is that all the kind of understory species that need that litter to survive can't get the nutrients anymore and they tend to die off. And then, the third thing that happens is that the trees themselves begin to change, and that's a much, much slower process.
It isn't like that what's left is a worst ecosystem that doesn't function as well, but it's a dramatically different one. And it's just one of the thousands of different ways that the arrival of these people changed the American landscape.
HANSEN: What were some of the other unintentional items that the colonists brought with them, you know, some of the other stowaways?
Mr. MANN: Well, rats, of course, which had a huge impact. You know, they practically wiped out the native food supplies in places like Bermuda, and had an enormous impact up and down the Eastern Seaboard. But there are lots and lots of disease organisms that they brought. The biggest one was probably smallpox, which first came to New England. And then there's the successive waves of these diseases. Then, in addition to those, there are the ones they did intend to bring, which are like cows and horses and pigs.
HANSEN: Hmm. One of the domestic animals - I guess you could call it more like a domesticated insect - that you say had a very large ecological impact: the honeybee.
Mr. MANN: Yes. They didn't know about pollination, which is the honeybee's main ecological role. And they brought it to make honey and to make mead. And of course, it escaped. And the European honeybee is a very unusual bee in that it is promiscuous by insect standards. Most bees will pollinate, you know, one or two species of a plant. The European honeybee will do, you know, practically anything. And the result is that without it, all these other things that the Europeans brought wouldn't have been able to thrive. You know, Johnny Appleseed might not have been able to plant his apples without the honeybee. Georgia wouldn't have been the peach state without the honeybee.
HANSEN: You also write that the colonists' ideas on managing the land were quite different from those of the native population. How so, and what did it mean? Why did that matter?
Mr. MANN: The way the natives treated the landscape was very different than the way that the English. It's so different that the English, in many cases, simply didn't understand that the landscape was being managed. In England, it was important to have a fenced land, and there is a kind of a rigid separation between land that was a pasture or a cropland and land that was woodland. It's quite different for the natives. They would have, you know, actively farmed land. It would be surrounded by fallow land and then, sort of, interpenetrated in with this would be woodland.
But the woodland would be managed by regular burning. They would burn down the underbrush, and so it's very open and park-like. John Smith said that he could ride at full tilt gallop to the fourth, so it's that open. And the reason that they kept the burning there was so that they could bring in game; animals that liked to eat the tender new shoots of recent growth. And so the landscape was this managed patchwork of habitats that were all mixed in with each other in a way that the English simply see as owned and occupied and used.
HANSEN: Of everything the colonists brought with them, what do you think changed the environment the most?
Mr. MANN: Probably, the answer would be the diseases that they brought. And the reason that this had this huge impact is that all up and down the Eastern Seaboard, and of course way inland, were these fairly large-scale native societies that were managing the landscape. When these diseases came, they radiated into the interior of the Americas as far ahead of the colonists. And the result was to depopulate the landscape something, you know, like, three quarters, perhaps more, of the native population died.
And one of the, sort of, impacts that it had was that it moved the landscape management scheme that have been there before. And the landscape reverted to, sort of, a semi-wilderness. It was like something that hadn't existed for thousand of years, hundreds of years. And then, the English moved into this and they think that that's what's always been there. In fact, it's a recent phenomenon.
HANSEN: Charles Mann is the author of "America Found and Lost," published in this month's National Geographic Magazine. He's also the author of "1491: New Revelations of the Americas Before Columbus." He joined us from the studios of member station, WFCR in Amherst, Massachusetts.
Thanks so much for your time.
Mr. MANN: Oh, it's my pleasure.
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