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Science

Prehistoric Garbage Piles Created "Tree Islands" 111

Posted by samzenpus from the there's-some-lovely-filth-down-here dept.
sciencehabit writes "Piles of garbage left by humans thousands of years ago may have helped form 'tree islands' in the Florida Everglades--patches of relatively high and dry ground that rise from the wetlands. They stand between 1 and 2 meters higher than the surrounding landscape, can cover 100 acres or more, and host two to three times the number of species living in the surrounding marsh. Besides providing habitat for innumerable birds, the islands offer refuge for animals such as alligators and the Florida panther during flood season. The trash piles—a mix of discarded food, charcoal, shell tools, and broken pottery—would have been slightly higher and drier than the surrounding marsh, offering a foothold for trees, shrubs, and other vegetation."
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Prehistoric Garbage Piles Created "Tree Islands" More

Prehistoric Garbage Piles Created "Tree Islands"

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  • McDonald's wrappers could be the swamp saving trash of the future?

    • Re:Soooo.... (Score:5, Informative)

      by mcrbids ( 148650 ) on Wednesday March 23, 2011 @11:11PM (#35595242) Journal

      To be fair, the historic "garbage" was quite different in composition than the garbage we generate today.

    • McDonald's wrappers could be the swamp saving trash of the future?

      Apparently; so that was the plan behind the environmentally conscious crowd bullying them into no longer using those easily recyclable styrofoam containers! The switch to waxy cups and paper is designed to provide future ecosystems.

      • Apparently; so that was the plan behind the environmentally conscious crowd bullying them into no longer using those easily recyclable styrofoam containers!

        I am afraid that you are totally incorrect in thinking a switch to paper increases the volume of waste.

        There is a persistent myth that the McDonalds foamed polystyrene containers were more recyclable than their current paper packaging. This myth is used by people to try and show the environmental movement is emotional, rather than pragmatic & forwar

        • Re:This one again. (Score:4, Insightful)

          by demonlapin ( 527802 ) on Thursday March 24, 2011 @01:12AM (#35595676) Homepage Journal
          Correspondingly, there is a real ignorance of why polystyrene foam was originally considered such an environmental bugbear - after all, we're surrounded by the stuff; it's not as though a landfill full of foam would be likely to contaminate groundwater or hurt anyone (inks/dyes aside). The real reason? It was originally blown with nonflammable, nontoxic, non-oxidizing CFCs. "Styrofoam is bad" has been absorbed, but the disappearance of the original reason why has been ignored.

        • Re:This one again. (Score:4, Funny)

          by Locke2005 ( 849178 ) on Thursday March 24, 2011 @04:32AM (#35596354)

          (most McDs food packaging is unsurprisingly contaminated by food)

          Well, if you call that food, yes.

        • 1) Food contaminated products are not recycled

          Um, what? Maybe you mean "Food contaminated products are not reused", because aluminum cans, glass, newspaper, and cardboard are all recycled after food contamination. Heck, glass is even reused after food contamination.

          • The parent is half right. What he should have said is:

            1) contaminated cardboard is not recycled into food packaging.

            Just a few days ago, a few companies were told to stop using recycled cardboard for their food products (possibly kellogs?). The reason was that the cardboard contained lots of nasty chemicals, encrusted burger sauce, poo, etc, that could contaminate the food, and therefore pose a health risk to consumers....

            • Just a few days ago, a few companies were told to stop using recycled cardboard for their food products (possibly kellogs?). The reason was that the cardboard contained lots of nasty chemicals, encrusted burger sauce, poo

              Trix cereal, now with realistic rabbit pellets! Silly Rabbit, poo is for flinging!

        • However, the facts are that:

          1) Food contaminated products are not recycled (most McDs food packaging is unsurprisingly contaminated by food)
          2) Almost no foamed polystyrene is recycled in any case.
          3) Switching to paper reduced McDonald's waste by around 90%

          1) It can be cleaned, 2) that it isn't doesn't mean it can't be. It can be, see #1. 3) sure, but see #2: if the foam were all recycled, waste volume from packaging would be reduced 100%.

          My point is not about what IS done, but what COULD be done. What IS done is that Styrofoam not recycled much, but that wasn't my point. It IS easily recyclable, should we choose to do so, and that is NOT a myth. Wax or plastic coated paper is NOT recyclable and this is NOT a myth; please cite any source claiming

          • Re: (Score:2, Insightful)

            by Whiney Mac Fanboy ( 963289 )

            My point is not about what IS done, but what COULD be done

            Well, we COULD all have horses painted pink & use them to ride around collecting rubbish & the horses carefully lick clean each piece prior to sending to the recycle centre, but in the real world, new polystyrene is so cheap, that the cost of recycling is simply not worth it.

    • Re:Soooo.... (Score:4, Funny)

      by ozmanjusri ( 601766 ) <aussie_bob@nOspAm.hotmail.com> on Wednesday March 23, 2011 @11:27PM (#35595304) Journal

      trash of the future?

      In Florida, trashy is always in.

      • Maybe we can look forward to a new continent in the Pacific where our current floating garbage is.

      • Isn't florida basically the compressed skelletons of billions of sea creatures anyway? What's a little trash on top of that...

        • Isn't that where they ship all the old folks? Sort of like an elephant graveyard for old farts in bermuda shorts.

          • I was talking about the ancient coral beds....

          • Yes, it is. Spent several years there and they got like 800 handicapped parking spaces in front of any major food outlet. If you try to shop in a grocery store the aisles are full of old folks walking around real slow. If you commute to work in the early am you get cut off by folks whose medicines have not kicked in yet. All in all, it's got great beaches, wonderful fishing but lots of retired folks. If you can handle that it's great. Oh, forgot about the hard to get house insurance, constant boom and

          • But I live in Florida you insensitive clod!

            And I think my UID shows I am nowhere near retirement.

      • Re: (Score:2)

        by plopez ( 54068 )

        Yeah, it is a part of Jersey after all......

  • History repeats itself.

  • Worth a try... (Score:5, Funny)

    by zill ( 1690130 ) on Wednesday March 23, 2011 @11:14PM (#35595254)
    "But officer, it's not littering. I'm building a habitat for endangered species!"

    • "But officer, it's not littering. I'm building a habitat for Future endangered species!"

      There, fixed it for you.

    • >> "But officer, it's not littering. I'm building a habitat for endangered species!"

      The US Navy have run this scam a few times...

      "It's not a derelict hulk scuttled in a delicate ecosystem! It's a hub for a new coral reef!"

      • Re:US Navy have run this one a few times... (Score:4, Informative)

        by realityimpaired ( 1668397 ) on Thursday March 24, 2011 @05:50AM (#35596680)

        When they scuttle a ship, they usually pick an area that's completely devoid of life. Having dived multiple such sites in various stages of their evolution, I can tell you that it's actually a pretty effective way to build an artificial reef. In parts of the carribbean, you can dive down, and see a completely empty and devoid plane of nothing but sand on the floor of the sea, save for a ship rising up out of the mud, which is home to crustaceans, corals, anemones, fish, and other forms of life that just aren't seen anywhere else in the area.

        When a ship sinks by accident, however, they don't have that kind of control.

      • Actually that is true, coral does grow well on sunken ships. They strategically sink old ships in carefully selected areas in australia for this exact reason. Or maybe the Australian government and the scuba divers in Australia have been bought off by the US Navy to propagate your lie. Oh and not just Australia, other countries do this too.

      • Re: (Score:2)

        by mangu ( 126918 )

        The US Navy have run this scam a few times...

        "It's not a derelict hulk scuttled in a delicate ecosystem! It's a hub for a new coral reef!"

        The procedure for creating artificial reefs takes several months. The ship is carefully scrubbed clean, all toxic substances are removed before scuttling.

  • Correlation is not causation (Score:3)

    by jklovanc ( 1603149 ) on Thursday March 24, 2011 @12:06AM (#35595442)

    How do we know that the garbage didn't collect because the land was drier so people lived there?

    • Re:Correlation is not causation (Score:5, Insightful)

      by Psychotria ( 953670 ) on Thursday March 24, 2011 @12:22AM (#35595504)

      How do we know that the garbage didn't collect because the land was drier so people lived there?

      Yes, well... there are a few obvious things to look at

      a) Humans do not generally live on top of their rubbish dumps; if they did they'd have to continually rebuild their homes on top of the accumulated rubbish. While not completely implausible, the evidence would still be there if this is the course of action the people took
      b) The important thing is not the current height of the "islands" but the height of the islands minus the accumulated rubble/rubbish

      Do you think that the people writing the study didn't consider these two items that I just pulled off the top of my head? I'm sure if they didn't then their peers would have throughout the review process.

      The "correlation is not causation" argument is valid, but I tend to think it's overused; it's only really valid if you read the original paper and the limitations, assumptions and methodology within.

      • Re:Correlation is not causation (Score:4, Interesting)

        by wvmarle ( 1070040 ) on Thursday March 24, 2011 @01:13AM (#35595688)

        The rubbish in this situation was

        a mix of discarded food, charcoal, shell tools, and broken pottery

        While of course people do not likely live on top of their trash, lack of motorised transport means that trash likely wasn't moved far away. Especially charcoal which can be re-used as fuel. Broken pottery well from daily accidents. Shell tools just left behind. Discarded food smells and attracts predators so that one is something they would likely try to at least take to the perimeter of their settlement.

        So indeed I think it's likely a combination: dryer patches where humans started to live, making the patches even dryer with their activities. And considering we're talking humans here, I wouldn't be surprised if those activities were intentional. Like bringing in rocks or soil, or even deliberately keeping their broken pottery as foundation, to make the area better to live on. Maybe they were involved in agriculture already? The article indeed mentions that in some cases there was clear evidence of trees and shrubs growing at that place before the arrival of the human settlers.

        • The rubbish in this situation was

          a mix of discarded food, charcoal, shell tools, and broken pottery

          While of course people do not likely live on top of their trash, lack of motorised transport means that trash likely wasn't moved far away. Especially charcoal which can be re-used as fuel. Broken pottery well from daily accidents. Shell tools just left behind. Discarded food smells and attracts predators so that one is something they would likely try to at least take to the perimeter of their settlement.

          So indeed I think it's likely a combination: dryer patches where humans started to live, making the patches even dryer with their activities. And considering we're talking humans here, I wouldn't be surprised if those activities were intentional. Like bringing in rocks or soil, or even deliberately keeping their broken pottery as foundation, to make the area better to live on. Maybe they were involved in agriculture already? The article indeed mentions that in some cases there was clear evidence of trees and shrubs growing at that place before the arrival of the human settlers.

          Excellent response, and I agree with everything you state. None of these scenarios, however, invalidate the hypothesis that prehistoric garbage piles (helped) create tree islands.

          In colonies of people that I've experienced who have no kind of motorised transport or anything else your summary is indeed what happens -- rubbish is not far removed from the villages and will naturally accumulate over time. But, the original height of the land is still something you can measure (if there are garbage fragments in

      • Re: (Score:3)

        by c0lo ( 1497653 )

        Yes, well... there are a few obvious things to look at

        a) Humans do not generally live on top of their rubbish dumps; if they did they'd have to continually rebuild their homes on top of the accumulated rubbish. While not completely implausible, the evidence would still be there if this is the course of action the people took

        How insightful items you can pull from the top of you head !!! Given the mortgage and the price of labor, it is highly unlikely that constantly/frequently rebuilding their homes would ever occur. And, indeed, the "buried under trash" home would have been preserved, the today's diggers would certainly find the concrete foundations, beams, fragments of windows glass and frames, and why not...possibly some remains of split air conditioning systems?

        Here's [wikipedia.org] an artist impression of how a villa of that time would

      • <quote>
        <p>The "correlation is not causation" argument is valid, but I tend to think it's overused; it's only really valid if you read the original paper and the limitations, assumptions and methodology within.</p></quote>

        " So residents' trash may have helped the island grow, but it didn't get the ball rolling, he says. ... it's just as likely, if not more so, that the phosphorous that nourishes a tree island's vegetation comes from the prodigious amounts of guano left by birds attrac
      • If they are nomadic people returning on an annual basis to the same shellfishing grounds, then they would be "rebuilding their homes on top of the accumulated rubbish" every year anyway. Tents aren't that hard to move. I'd suspect these "islands" are mostly shell, and humans aren't the only animals that leave piles of shells lying around after eating. As for (b), when you pile stuff up in a swamp, the underlying ground tends to sink, so I'm not sure how accurately that can be measured.

      • Remember you are talking about a swamp. there is no dry land to walk away on and throw away the garbage.

        As for "peer review", I do not believe that Science Now is a peer reviewed journal. Another issue is that many scientists have a theory and then set out to prove it. That is not the scientific method. That do not consider alternate scenarios and work hard to prove themselves right.

        A very plausible explanation for raised areas is alligator nesting. Alligators mound up muck, sticks and vegetation to lay the

      • a) Humans do not generally live on top of their rubbish dumps

        I've been in rural China. While they don't live literally on top of their rubbish dumps, they just open the front door and throw rubbish into the street where it forms a big pile down the road. Very colorful, very stinky, very huge.

      • This is Florida we are talking about, they probably had to rebuild every 5 years anyways.

    • Re: (Score:1)

      by rtb61 ( 674572 )

      These are pretty large. So think of piled up debris from hurricanes, up rooted trees et al. Now after a hurricane the debris piles are cleaned up or at least relocated and compacted.

      Not to worry with record extreme weather, perhaps after the next couple of record hurricanes and the stripping of government services to feed tax cuts for millionaires, the next bunch of debris piles will be around for long enough so you can see the ecology develop in abandoned Florida suburbs.

  • There is no way human activity can contribute to the creation of habitat for wild animals and other organisms. Human activity can only destroy and kill. :rolleyes:

  • cause/effect? (Score:4, Interesting)

    by argStyopa ( 232550 ) on Thursday March 24, 2011 @05:52AM (#35596690) Journal

    It seems like they simply found middens with some regularity deep in/on these tree islands.

    Therefore one scientist contends that some of the islands may have grown from middens. Isn't it substantially more plausible that primitive humans, who generally tend to want to stand/sit/live on dry ground, would have sought out these relatively isolated (and thus somewhat safer) locations for habitation? That the middens are found deep in the islands only seems to me to mean that this - the value of a secure home - was even obvious to primitive humans?

    One comment in the article bothered me: "The authors say the findings show that human disturbance of the environment doesn't always have a negative consequence." That seems...a rather insipid comment.

  • Those Islands Form Anyway (Score:5, Informative)

    by b4upoo ( 166390 ) on Thursday March 24, 2011 @06:11AM (#35596790)

    Without humans having a thing to do with it those islands form all the time. They form to a degree that the state has a machine that goes in and destroys the island. All that happens is that any irregularity that causes a bottom to be slightly shallower in a spot will tend to attract plants which over time build a thicker and thicker mat of cast off materials held in place by the roots of the plants. At a certain point the mat becomes heavy enough to actually press down against the bottom and trees and shrubs flourish making the little islands even more solid.
                  The device that eats these islands looks like a paddle wheel boat with the paddle wheel in the very front of the boat. That wheel beats into the vegetation and pushes it onto a barge like deck. The operator keeps the wheel chopping at the island until the entire island is loaded on the barge. Sadly large nuimbers of bass and other fish as well as snakes and turtles are also loaded onto the barges.

  • I often visit the everglades. 2 meters would be a mountain in the everglades. When walking through the tree islands (called "hammocks" or "heads") I don't recall seeing anything this high in the everglades at all. There are differences in elevation, yes, and they do affect or reflect differences in plant species. But you're mostly talking about a difference of a few inches. Certainly not meters. The park guides always point out how the hardwood hammocks occur in areas maybe a few inches higher than

  • I read TFA, and seriously, it meanders and sort of wilts away before it's even halfway through. It's almost like the people interviewed to support the theory abandon the theory mid-sentence and just give up trying to say that, seriously, people threw all this trash into one spot and did this.

    Are we to go against all of our understanding of native Americans being a people who utilize every single remnant of every possible thing in some design, or tool set, or medicine? All of a sudden there's this idea to ju

    • Re: (Score:1)

      by parens ( 632808 )
      Are you aware that middens are found nearly everywhere humans habitate for any appreciable length of time ? Middens of discarded oyster shells are all over the New York City-area, not to mention the UK, parts of Kentucky and Tennessee around the Mississippi River, among many others.
      Your assertion that Native Americans are some sort of mythical creature who used "every last remnant of the buffalo" or whatever is pretty outdated - perhaps in comparison to white settlers, they used more, but it's not like th

  • shell middens common throughout the state (Score:3)

    by datapharmer ( 1099455 ) on Thursday March 24, 2011 @08:30AM (#35597572) Homepage
    This is hardly news to anyone living in Florida. There are shell middens all over the state... They are almost always by water and nearly all contain broken pottery, oyster and clam shells and broken artifacts. The natives essentially threw hard garbage in a spot, waited until it stopped smelling and then used it to keep above the water line and the mosquitos. Pretty smart really. A lot of roads in florida have the shell middens underneath instead of limestone. It wasn't until the last couple decades that they started protecting them as something of historical/archeological value. God only knows how much history was lost as we paved our way to suburbia in the 50s and 60s.

    • A lot of roads in florida have the shell middens underneath instead of limestone.

      The loose and unconsolidated shell material under most roads in Florida are the remains of sandbars and shallows that accumulated over the millenia that Florida was mostly sandbars and shallows and then later bulldozed up. Not shell middens. Left alone that material would eventually have become coquina and with more time and pressure, limestone.

      God only knows how much history was lost as we paved our way to suburbia i

  • We're still doing it (Score:4, Interesting)

    by dtmos ( 447842 ) * on Thursday March 24, 2011 @08:30AM (#35597576)

    By far the highest points in south Florida are its landfills; see, for example, this beauty [google.com] on Florida's Turnpike in Deerfield Beach. When global warming floods the area in [insert date of your choice here], these landfills will become tree islands in the new Everglades.

  • Correlation or Causation (Score:1)

    by Anonymous Coward

    Is the trash there because humans also took shelter in these tree islands, or did the trash create the tree islands?

  • Canadian researchers had a winter in Florida on expenses and got a publication out of it? Win!

    Ok, so wading through the everglades to dig for ancient garbage while avoiding the alligators isn't everyone's idea of vacation, but Montreal got some real snow this winter.

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