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joe_jr317

Earthworms Discussion

joe.jr317
15 years ago

First, let me say that I'm not attacking bpgreen because he/she was repeating info that is widely accepted as truth. He/she didn't just pull the info out of his/her rear. That being said, in another thread it was written:

"Earthworms were pretty much wiped out over much of North America during the ice age and much of the rich prairie soil developed without any earthworm activity at all. The soil was black and rich in organic matter (OM) largely because prairie grasses have deep root systems. The roots would penetrate deep into the soil, but there is constant new growth and death of old roots going on. In some areas, particularly forests, worms are becoming a real problem, because the forests evolved with no earthworm activity and the earthworms that have been introduced are devastating the forest floor."

This is not fact. I've read this, too. I even thought, "well that makes sense". Until I started realizing the common claims are based on a complete elimination of any other variables. Also, the research is so incomplete it is shameful that they make any claims. They even make a point to say in every article words like "may" and "probably" because the claims are based largely on assumptions. One thing every study I have read leaves out is the human element aside from Europeans carrying in invasive worms starting a few hundred years ago.

1) It is claimed the worms are causing the soil to erode in these forests. What is not mentioned in any study or article I have read on invasive worms is the fact that most of these forests have been deforested in the last 200 years. The root systems of the old forests were much more extensive and held a lot of soil in place and the young trees just can't do the job as well. Plus, those young trees didn't naturally occur. They are largely planted by people in ways nature doesn't accommodate so well. Deforestation also has caused the forest floor to be more susceptible to the wind and drifting of leaves. This exposes the bare floor to the elements to increase erosion. Bigger trees provided higher windblocks and soaked up more of the water that now runs off with the soil.

2) Native Americans. Their agricultural abilities have been strongly downplayed by a Eurocentric culture meant to demonize these once advanced people as savages. It's so easily forgotten that they were here cultivating the lands for thousands of years before the European settlers, yet every study I have seen only attributes the spread of the earthworm by European settlers rather than concentrating on the species that could only have been introduced by those settlers such as the L. Rubellus. That should be throwing a red flag up to anyone that has even the slightest modern grasp of the extent of Native American culture and trade throughout the entire N. American continent which our high school textbooks amazingly still choose to downplay. There are over 100 native species of earthworm in the US. It stands to reason that those worms traveled the same with Native American trade as it is claimed the exotic species traveled with European infiltration.

3) Deer. These studies mention the seedlings of trees disappearing. They fail to mention that man has caused a huge imbalance in the population of herbivorous animals that once were kept in check by predators such as wolves. This over population is, as always happens, causing the animals to eat everything and even turn to eating things they wouldn't otherwise when there are natural population controls beyond eventual starvation. Plenty of people recognize this and it is one reason there are so many "special" hunts for population control.

4) It is claimed that earthworms only travel a half mile in 100 years. Well that's incredibly misleading. I could say that an acorn travels 0 miles in 1000 years and this would be equally misleading in any study. We all know that the plants didn't move in the glaciated regions. They were moved. Humans, land animals, birds, and weather such as flooding move bacteria, plants, animals, and yes even worms and their cocoons. It didn't just start with the Europeans.

5) bpgreen said the trees evolved without the worms. No study makes such a claim. Most the trees we know today didn't evolve to the point they are at just since the last glacial period. And even these inaccurate studies claim that earthworms were around prior to the galciers and were forced south.

The changes that are occurring because of invasive worms is largely due to the changes man is making with industrialization, deforestation, and the multitude of other ways. Leaving out the pertinent variables and contributors is misleading at the least. My opinion: some people must come up with new findings to keep their jobs or advance their careers and repeating the same old mantra of "man is damaging the planet" doesn't cut it unless your name is Al Gore.

Some of you may read this and think I am saying we are like a virus and man is bad. No. I believe man is as much part of the natural process as a tree or a worm and we are just part of the evolving planet. Arrogance leads us to think otherwise, I feel.

So, why put this in the soil forum? Because I think plenty of evidence supports that the earthworm truly is an amazing creature that will improve your soil in the lawn or garden (even if you have trees) and reading claims that seem to make sense without considering why so many real variables are not considered can lead one to think otherwise.

Comments (18)

  • joepyeweed
    15 years ago
    last modified: 9 years ago

    So are you questioning the FACT that in the glaciated midwest forests evolved without earthworms, or are you questioning the supposition that earthworms are harming the forest?

    I'm not quite sure if you are questioning both parts or just the conclusions that certain types of worms are damaging certain types of forests?

    Here is a link that might be useful: forest soil

  • soilguy
    15 years ago
    last modified: 9 years ago

    joe.jr317 - didn't know you were a wormguy - hat's off to you. And you sure do know how to 'step up to the plate'.

    Couple of questions:
    1) How were worms introduced into the previously-glaciated midwest US forests (Native Indians?), and if so, where did the worms come from (if not from Europeans)?

    2) Please define 'invasive' worm versus 'other' worms.
    Are you saying invasive worms are bad, and if so, why?

    I'm a bit of a wormguy as well, having raised wigglers, manure worms and nightcrawlers in Florida for many years - and plan to start a new bed here in Texas once I get my trees/shrubs in the ground.

    This subject belongs on this forum (in my opinion).

    Robert

  • joe.jr317
    Original Author
    15 years ago
    last modified: 9 years ago

    Joepyeweed:
    It's not a "FACT", joepyeweed, it's an assumption completely based on only a handful of researcher's claims. Primarily Cindy Hale and Lee Frelich. Take a look at the sources of information on nearly every article and you will find those two names most mentioned. The real fact is that we have no good way of knowing that. The "FACT" you speak of is based on the glaciers' effects on earthworm populations and their ability to transport themselves. It doesn't take any consideration whatsoever for the millions of humans that have lived on this continent for thousands of years (maybe longer), the animals that could have transported them, or the very dynamic weather patterns this continent has undergone. Also, look at the home page of the site you reference. Even they say that the glaciers wiped out the worms. You can't wipe out what isn't there to begin with, now can you?

    Ever seen an American Robin carry a worm and drop it? Blows the "FACT" of a worm not being able to travel more than 1/2 a mile in 100 years out the window, now doesn't it? The research is based on "FACTS" that aren't facts. Thus the result of the research hardly constitutes "FACT". Not to mention the fact that research that uses the word "may" in pretty much every instance can't be used to establish fact.

    As I said, we have no good way of knowing if there were or were not earthworms. Even these researchers seem to believe they were present and then pushed south if you actually read the sources your reference used. I've read some of Cindy Hale's stuff, so that's why I'm challenging you to if you still feel it's "FACT". In a worm bin, you rarely find dead worms. Why? Because they decompose really fast and leave no bones. The likelihood of ever finding fossil evidence is very low. That doesn't mean they weren't present. It's completely an assumption. Fossils of worm burrows and cocoons are quite rare and to assume their absence means there were never worms is just foolishness, not research.

    So, yeah, I question that it's a fact in the first place since there is not sufficient reason to call it that. Yes, I also question the supposition that earthworms are damaging the forest because it doesn't take into account that the damage was started by something else. They may be preventing the repair process or at least inhibiting it along with many other factors. Any system tipped out of balance does that. Like I said, we tipped it with the deer and wolf and look at the damage it's causing. Is it because of the deer? No. It's because we killed the wolf and tipped the balance.

    Soilguy:
    1) I'm not pretending to have that answer. I'm saying those that are pretending to are do just that. . . pretending. They are not considering all the variables and thus the claims shouldn't be considered accurate. I certainly feel it stands to reason that birds, animals, and humans were doing much the same things thousands of years ago as they are today. They helped transport species while searching for food, trading (humans, not the birds), and with seasonal migration.
    2) That's a philosophical question, there. I don't know that any of them are really invasive because I'm not sure I agree that anything can be. Hence my statement about us being part of the natural process as opposed to being outside it. "Experts" say that if it's alien to a region and causes harm to the ecosystem (environmental, economic, or human). If you believe in evolutionary theory (I do), then everything living came from the same place and thus at one point had to "invade" another region. I am curious how long a species has to be resident before it is no longer considered "invasive". The primary invasive worm the "experts" are referring to is L. Rubellus.

    Sorry if I keep repeating stuff. I'm typing a few sentences at a time in between actually working. Unfortunately, work is slow enough to allow these long posts.

  • joepyeweed
    15 years ago
    last modified: 9 years ago

    I'm not sure we are on the same page of geology. Generally we are speaking about the redevelopment of soil, grasslands and forests after most recent Ice age. The Quaternary period during which glaciers scraped all of earth to bed rock on portions of North America. Neither Worms nor Trees survived the areas covered by glaciers. As the glaciers retreated all that was left was rock and rubble carried by the glaciers.

    I know a geologist who studies soil horizons from a geologic perspective. She explains the drift and soil reformation after glaciation. From when I've heard her speak, Plants played a huge role in reforming the soil of the Illinois plains, she never mentions worms.

    I don't necessarily disagree with possibility that eventually worms could have migrated (from adjacent unglaciated areas) and been transported (by animals and people) back into the soils re-forming after glaciation... however, soil would have had to form first. Worms can't live in rock.

    I think the problem eluded to in other posts is that foreign worm populations are exceeding that which the forest floor can sustain. No matter how the worms got there now, they are voracious eaters and they were not present as the woodlands evolved after the glaciers retreated.

    I'm not familiar with geology enough to know the exact soil record, but i Know they have extensive evidence about what existed when and where because it does show up in the soil horizons. Are other geologists questioning or confirming the worm information? Or is this just something that you have assumed? And if you are making these assumptions then I need to know how much do you know about the post-glacial geology of upper mid-west?

  • joe.jr317
    Original Author
    15 years ago
    last modified: 9 years ago

    Joepyeweed,

    No. I am not a geologist - amateur or professional. Likewise, the articles don't seem to care to quote geologists. Do you know of where geologists are verifying one way or another and on what the verification is based?

    I do know that many don't consider the science behind geological history to be, well, definitive science. I remember a recent (recently watched, not recently made) PBS documentary on some of the arguments that ensue amongst geologists on certain issues of historical geology. Historical geology is largely based on guesses and a confirmation of said guesses by groups of other geologists. They never say the claims are fact, to their credit, but they do present claims as if they are fact when they can all come to a general agreement. It is based on theories that can't be proven or disproven because the processes can't be repeated in a lab and not enough recorded data over a long period of time exists to verify any theories. Granted, those guesses aren't just fly by night guesses. They are educated guesses. But still nothing I would take as absolute and most definitely not as so accurate as to be able to identify presence of specific animals over a several thousand year or longer time frame.

    To be clear, your referenced site was about Minnesota. Not Illinois. Illinois actually has recognized indigenous species of earthworm. It appears only 30% or so of the state was covered by the last glacier according to the Illinois State Museum glacier map and that was actually 18,000 years ago if it's correct. Much more than that was grassland prairie. I didn't know that about the glacier until just now, though. I actually thought it was a lot more of Illinois and nearly comparable to my own state which was more like 60%.

    You're right. The OM was necessary for worms to live. That doesn't mean the evolution of the plants, especially trees that don't grow in rock either, occurred without worms. I believe the grass and the trees came from somewhere and didn't occur from some divine intervention instantaneously right where they stood. Actually, millions of people do believe that is what happened and I want to make clear I am not in anyway ridiculing literalist Christians, Jews, or Muslims.

  • joepyeweed
    15 years ago
    last modified: 9 years ago

    There are worms that are indigenous to Illinois. So you do comprehend that biologists and natural historians do recognize which worms are indigenous and which ones are not.

    And the damage being done to the humus layer in the forest is in areas where non-indigenous species are dominating the soil fauna and its in these glaciated forests where indigenous worms were historically not prevalent.

    The glaciated forests evolved with a fungal based ecology to break down organic matter.

  • val_s
    15 years ago
    last modified: 9 years ago

    Okay - I have a really dumb question. I've been trying to follow this conversation and it's way over my head.

    From a gardening/composting aspect are you saying worms are good or bad or neither? Or is it just certain worms?

    I looked up L. Rubellus and the pictures looked like what we refer to here as "night crawlers". Are these the invasive species? If so, they are not good, why?

    Like I said, I've been trying to follow what you guys are saying and I've read (sort of) the link but I'm still not certain what it all means. Does anyone have a cliff notes version?

    Val

  • gardengal48 (PNW Z8/9)
    15 years ago
    last modified: 9 years ago

    Val, earthworms in our gardens are our friends.......I doubt many would argue this point. However, issues arise when non-indigenous species colonize to a large extent natural areas or native plantings and just by shear numbers alter the existing ecosystem. It is exactly the same as with any exotic (read non-native) insect, animal or plant species - the lack of natural predators and often very hospitable living conditions create imbalances that can have far ranging and/or long lasting effects on the ecosystem.

    In parts of the east and the upper midwest, that is exactly what has happened. Non-native worms, those that have European or Asian origins, have colonized large areas and have allegedly altered the natural ecosystems of hardwood forests in these areas. There's a lot of literature available on the subject......just Google "invasive earthworms" and you will get literally hundreds of hits explaining the issues and outlining the problem. Then I guess it's up to you how you interpret or apply this information to your specific situation.

  • joepyeweed
    15 years ago
    last modified: 9 years ago

    Cliffs notes: Worms are good.

    Some non-indigenous worms are voraciously consuming the organic matter in post-glacial forests. There is some evidence that these worms are out competing the fungal colonies that would be building the the humus layer in the forest. There is concern that this will have a detrimental impact on the soil and the forest in some areas.

  • val_s
    15 years ago
    last modified: 9 years ago

    Thanks JPW and GG.

    It never ceases to amaze me the wealth of knowledge on this board. I know that there are invasive species. I worry about the "killer bees" getting up here and in our own Illinois River is some kind of carp that's taking over. I just never would have put "worms" into that category. LOL

    It makes perfect sense that they too can have and "invasive" element to them but I would never have thought about it with out this thread.

    Val

  • joe.jr317
    Original Author
    15 years ago
    last modified: 9 years ago

    Joepyeweed, I can comprehend that biologists make claims of what is or is not indigenous. I also comprehend that they can't all agree and that is why you don't see solid numbers for how many are indigenous for your state or even for this country. Some say 7 for Illinois. Some say 5. If it's so definitive as to claim a fact, there would be no question, now would there? When speaking of numbers of indigenous earthworms in the country, you see "over 100" rather than solid numbers from the majority of claims because when you find the solid numbers you find that the numbers differ. Stating "over 100" is general enough to give the idea of solidarity and agreement without discrediting the field.

    Oh, and just because something grows somewhere and adapts doesn't mean it evolved there. Maybe I'm just too picky on using the word evolved correctly. Natural evolution of trees takes a lot longer (supposedly) than the post glacial forests have even existed. That's why those same trees are found outside of those forests, too. The point (which I got away from on a tangent) is that it was claimed that the trees and grasses evolved without worms. Not true. The trees and grasses of glacial regions largely evolved outside of those regions in areas it is recognized were inhabited by earthworms by the biologists and natural historians you apparently hold so dear. Are you suggesting that maples and oaks and ferns just evolved over the last 8k to 10k years? The research I've read says maples and oaks didn't even evolve into trees in North America. They evolved in Asia and Europe, where many of the "invasive" worms are from.

    Val, the cliff notes: I don't feel there is enough evidence to claim the worms are the problem. There is certainly not enough data given the issue hasn't been studied long enough. The biggest factors that are affecting the changing face of the planet are largely left out of this so called research. Our changing weather, the acidity of rain changing, the nitrogen in the air and water, the human deforestation and harvesting of tree products such as maple syrup in these maple forests, human traffic and increased deer traffic, and the list goes on. Somebody needed to make a name for herself and has because there is a perception of a ton of information but in reality, the sources boil down to the same inaccurate research that doesn't consider all pertinent variables. Worms are good. Mismanagement of our forests and grasslands plus the irreversible changes man has wrought on them is bad and the real culprit.

  • joepyeweed
    15 years ago
    last modified: 9 years ago

    Local ecotype. The trees in the post-glacial region develop or evolve into a genetic ecotype that performs specifically well in the soil, light and moisture conditions that exist in that area. 18,000 years is plenty of time for genetic selection of the fittest.

    When we transport the same species of varying ecotypes into other climates, soils, etc; they don't perform as well. That is the type of evolution that one refers to when discussion post-glacial evolution.

    I don't necessarily disagree that human impact on forest ecosystems have made irreversible changes. And wouldn't importing the worms be just one more of those man made impacts?

    And in our area lack of fire has done more damage to the natural balance of the ecosystem and if there is any soil left, worms are low on the priority list of issues...

  • joe.jr317
    Original Author
    15 years ago
    last modified: 9 years ago

    Joepyeweed, yes. I agree that importing a new species will cause an impact. I'm not denying that whatsoever. This discussion was originally about the claims not being fact. That is why I said, "This is not fact." Not about them being impossible. I think it's important to consider all factors. And I think it's equally important to find research suspicious if it purposely doesn't. Like I said, it should be throwing up a red flag. Especially since most of this stuff leads people to make large leaps of statements like your first one. You claim "FACT" even though it is not one and the researchers aren't even confident enough to claim it is. Critical thinking of scientific research is incredibly important and far too often it isn't applied because either a lack of interest in putting time into it by colleagues or a lack of will to contradict an authority by the laymen (me and I presume you but I don't know your background). I don't know how many times people think that if it's in writing by a PhD then it must be true or someone would have kept it from being published. It's sickening, really. People deify the PhD and abandon all reason in support of it. I, for one, am very glad many people chose not to abandon reason when 20 years ago the majority of scientists said that global warming was not happening because they had a financial stake in the matter. And I am just saying we shouldn't here just because a handful of people rely on their findings and their unique interpretation of data that includes a total disregard for all other factors to pay their bills and remain employed as the leading authority on the matter.

  • peter_6
    15 years ago
    last modified: 9 years ago

    It seems entirely plausible to me that the species we call "earthworms" are not native to North America; they don't seem to have been native to New Zealand. There are of course lots of other soil-dwelling worms that are native. One way of providing supporting evidence would be to prospect the soils in high creeks in the Western wildernesses, where -- if earthworms were totally absent --the cae would be supported. But not proven. Regards, Peter.

  • joepyeweed
    15 years ago
    last modified: 9 years ago

    We can't proove that the earth revolves around the sun, however most of the evidence supports that hypothesis, so much so that many people believe it to be FACT.

  • david52 Zone 6
    15 years ago
    last modified: 9 years ago

    From the University of Minnesota, we have Great lakes Worm Watch:

    "Earthworms are not native to the Great Lakes Region. They were all wiped out after the last glaciation. The current population, brought here by early Europeans, is slowly changing the face of our native forests. Learn more by exploring the links ...."

    You can find out, via the linked identification stuff, to tell what kind of worm is on your hook.

    Here is a link that might be useful: Yes, you too can be part of the research team

  • david52 Zone 6
    15 years ago
    last modified: 9 years ago

    Effects of invasion of an aspen forest by Dendrobaena octaedra on plant growth - Canada - Lumbricidae

    "The native earthworm fauna of North America became entirely extinct during glaciation periods (Gates 1982) except in the Pacific coast region (McKey-Fender and Fender 1982). Lumbricid earthworm species introduced by European settlers are now widespread throughout Canada (Reynolds 1977, Scheu and McLean 1993). Invasion of earthworms to eastern Canada presumably started early during settlement, and the distribution and species composition is documented (Reynolds 1977). In contrast, the invasion of earthworms to western Canada occurred more recently, and is barely documented. Currently a variety of ecosystems are being invaded by earthworms in southern Alberta (Scheu and McLean 1993).

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    The soil fauna and microflora of an aspen forest in the mountain ranges of the Rocky Mountains [approximately equal to]80 km west of Calgary (Kananaskis Valley, Alberta) has been investigated in detail since 1969 (cf. Visser and Parkinson 1975, Mitchell and Parkinson 1976, Lousier and Parkinson 1984). No earthworms were present until 1984 (D. Parkinson, unpublished data). Today the forest is colonized by two earthworm species, Dendrobaena octaedra (Savigny) and Dendrodrilus rubidus (Savigny). D. octaedra dominates and is found in high numbers (P. Dymond, S. Scheu, and D. Parkinson, unpublished data). D. octaedra is a litter-dwelling species (epigeic, sensu Bouche 1977), and until recently no major changes in soil structure were found. However, the earthworms presumably caused major changes in the composition of the indigenous soil fauna and microflora and may have affected nutrient cycling and plant growth in this ecosystem. Earthworms are major soil-forming agents (Kubiena 1948, Bal 1982) and it is well known that earthworm activity may result in an increase in nutrient cycling (Lee 1985, Scheu 1994) and plant growth (Stockdill 1959, Hoogerkamp et al. 1983, Haimi et al. 1992).

    The linked paper goes on to describe what is happening in the aspen soils / worms in the rocky mts, as well as gives valuable references re this worm issue.

    Here is a link that might be useful: worms out in Western Canada

  • joe.jr317
    Original Author
    15 years ago
    last modified: 9 years ago

    Great link, David. And a good read.

    David, you may not have take the time to read all the novels in the thread and I can't blame you, but the University of Minn relies on the exact same research I've been talking about being the core of all of this so pasting anything from them is just essentially repeating what joepyeweed linked and also supports my claim that there isn't that much study out there supporting the work I question. Only many sites repeating the same source. Note that your other info (pasted, not the link) is very reliant on such words as "presumably" and "may". In other words, reliant on assumptions made and thus can't be presented as fact because it isn't one. Of course, they are much more able to admit this than the UofM group, it seems.

    I read the whole article, but I read it fast. So if I got something wrong here, please correct me:

    1) The author readily admitted that the experiment used adult worms while in the natural site there were primarily hatchlings. I'm guessing on this, but I have a feeling there is a reason they didn't find many adults and it might have something to do with a reduced lifespan in colder climates. This leads to longer incubation periods of the cocoon and so the adult feeders aren't around that long. Using adult worms essentially nullifies the experiment because the adults have at least a month of voracious feeding that the hatchlings won't have. Hardly replication of nature.

    2) It is mentioned that the growth of plants increased. Not decreased because of the worms changing the environment.

    3) It is mentioned that the most pronounced change in microbial composition was caused by "Time". Not worms. And if the correct age of worms were used in the first place I imagine the rate of change caused by worms would have been even less. It mentioned that water was next in affecting microbial change and that water also affected the rate at which worms could make any changes. Kind of stands to reason that the amount of climate change we have experienced the last 30 years could have more to do with the soil issues than the claims of UofM that its the evil invasive earthworm. The earthworm is simply showing an ability to withstand climate change better in comparison to many of the other life forms in the soil. Not to mention (actually I already did earlier) the chemical changes in rain due to pollution. pH of water greatly affects microbes and worms are much more resilient than many microbes to these changes. Just because there are now more worms in one spot and less microbes doesn't mean that the worms are the culprits. It could also mean that the worms are simply surviving changes that microbes can't and taking advantage of any changes they might have the means to take advantage of.

    This study actually takes other variables into consideration and admits shortcomings. It's a REAL study that presents real findings from what appears to be an objective standpoint rather than an "I need to make a name" standpoint.

    Joepyeweed, the heliocentric theory is also one that was refuted for quite some time even though there is a ton more evidence supporting it. Mathematical evidence. But, it is important to note that we all take this as FACT because we think it makes sense. Not because we all understand the mathematical evidence. Why is that important? Because at one time the other theory, geocentricity, made sense to everyone because those in authority told them it does. And when it was challenged with heliocentricity everyone ridiculed those that challenged geocentricity and many people died supporting the use of reason to refute the accepted "scientific" claims. Just like the global warming example I used (except for the killing the opposition part). Thanks for your support in pointing out that just because scientists make claims, it doesn't make it fact and using reason can punch holes in unreasonable claims that don't take all evidence into account.

    What example is next, the round earth? I'll head you off at the pass. Scientists laughed at the square earth theory based in the Bible, which mentions the corners of the earth several times. Obviously it's a flat round disc! It leaves a round shadow on the moon. But wait! It's a sphere! No it's not, the authorities say it can't be because the bible says the earth sits on four pillars and has edges! It took quite some time for people to use reason to refute what authorities on subjects wanted us to believe in order to uphold reputations and control. And don't try to tell me those people were less intelligent. Ancient peoples were able to survive in environments most of us would die in because they were much better thinkers. Yet, they were able to fall for "an authority says it, it must be true".

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