Archived Chat with John MoriartyChat messages appear from newest to oldest. Scroll to the bottom of the page to read chronologically.
Cindy Hale: logs off
Moderator:
Great chat session everyone! I would like to thank Cindy for spending time with us this hour answering our many questions. That concludes our chat sessions for this week. Stay tuned to our website for more chats and other fun activities!
Cindy Hale:
The worms were originally brought over by European settlers. They brought with them plants and animals and the worms probably hitchhiked along. Anything that moves dirt or litter (leaves, straw, hay, etc.) can move worms or their coccoons. Worms have been around human habitations since but they really started finding their way around because they get used as fishing bait. So, people carry them very long ways and when they are done they dump them out, which seemed like a perfectly OK thing to do since we have always been told that worms are good for the soil. Once the worms establish near a lake shore or boat ramp or fishing resort. they can spread out as the population grows, though this happens very slowly, maybe 3-5 yards a year, if you do the math, it can take hundreds of years for them to go 1/2 mile on their own. Most of the spread is due to human activites, just like boats can move exotic plants from lake to lake, all the things we do that move soil around can move worms around. So, if we become more aware of this, and prevent more spreading, we will have a LOT more time to find solutions to the problem.
Moderator:
Our last question this afternoon comes from Jill in Madison. She wants to know how the worms got into the forest in the first place.
Cindy Hale:
Everyone keeps asking me that! I think I would like to teach at a small college and keep doing research with the students. I have also considered working for the Nature Conservancy in northern Minnesota as one of their ecologist or stewardship people. Either way, I would like to remain involved in some kind of research and teaching, whether it is with traditional students or the general public is yet to be determined.
Moderator:
Seth from Anoka is wondering, What are you going to do when you are done with your Ph.D?'
Cindy Hale:
Yes, but they don't eat it nearly as fast, and that's one of the problems. Slugs, fungus, bacteria and a whole bunch of different insects feed in and on the forest floor. So, when the worms come in and eat it all really fast the other organisms can be in trouble. That goes for animals that don't eat the forest floor, but use it for other things, like the blue spotted salamander, shrews, voles and ground nesting birds. These all rely on the cover and moisture that the forest floor provides and once the worms remove it they can have problems surviving.
Moderator:
James from Madison wants to know, 'Are there other animals living in the woods that eat the same things earthworms eat?'
Cindy Hale:
We haven't had a chance to analyse the data yet since we just finished the experiment last week. But just from what we saw happening each week it appeared that the really heavily worm wormed ones might have used more water.
Moderator:
We have another follow up question from Brian in St. Paul. 'Did you find out that the wormed buckets had less water in it than the un-wormed buckets?'
Cindy Hale:
We wanted to use plants that appeared to respond differently to worm invasion based on our observation at our field study sites. Two herbaceous plants (those are the non-woody ones like ferns & flowers)we used appeared to be hurt by the earthworm invasion since they dissappeared quickly when the worms invaded. One was a grass-like plant called sedge, that appears to do very well and even expand after the worms invade. Then finally, we use sugar maple seedlings since we see their nubmer decrease rapidly after worms invade too.
Moderator:
Brett from Duluth wants to know, 'How did you decide what plants to use in the experiment?'
Cindy Hale:
If a worm has one of those bands on it (called a clitellum, only adult worms have these) then the head in the end closest to the clitellum. With juvenile worms that don't have a clitellum, the head has a mouth, though that can be hard to see without a magnifier. When the worm isn't streched out, the head end is thicker than the tail end. For the nightcrawler and the leaf worm, when they move they often spread the tail out flat, with the others you just have to watch them and use your best judgement. Though they can move either direction, they tend to move along head first.
Moderator:
We have a follow up question from Alissa. 'How can you tell which end is the worm's head and which end is the worm's tail?'
Cindy Hale:
Wow! Great question. We only ran our experiment for 4 months. So that wasn't a problem for us. But if we were to run a longer experiment that could be a big problem. We might assume that if the worms reproduce, that they will have about the same number of babies in each bucket, since we started with the same number of worms, but you would have to collect and count all the worms and classify them by age class at the end of a longer experiment to be sure that this wasn't a problem.
Moderator:
Dante from Jamestown wants to know. 'What if the worms have babies in the buckets - will it mess up your experiment?'
Cindy Hale:
sorry to be the one to tell you...nope. Most worms can grow a new tail if a part of it gets cut off, but the tail can't grow a new head
Moderator:
Alissa from St. Paul is wondering, 'Is it true that if you cut a worm in half it will grow into two worms?'
Cindy Hale:
Two of the three species we used (Lumbricus terrestris = nightcrawlers; Lumbricus rubellus = leaf worms) we got from bait shops. But the thrid one we had to collect in the field, which involved hauling hundreds of gallons of mustard solution into the woods, since we needed over 3,000 of them!! It was pretry crazy.
Moderator:
Jamie from Shakopee wants to know 'Where did you get the worms for your experiment?'
Cindy Hale:
If I remember correctly, they were weighing and watering the buckets. One of the hypothesis that we wanted to test was whether or not the wormed buckets dried out faster than the un-wormed buckets (it looks like this happens in the field, so we wanted to test that theory). In order to do that we had to measure every drop of water that went into each bucket. Then at the end, we can see if there was a difference in total amount of water used by the different treatments.
Moderator:
Brian from St. Paul has a question about your students. 'In the video, what were those people doing in the greenhouse while you were talking?'
Cindy Hale:
I remembered being pretty bored sometimes in school, but then I took a "Humanities" course that covered all kinds of interesting things I had never thought about before like philosophy and logic and creative writing. I remember one of the most interesting and difficult assignments we had was to write a paper on "What is Beauty". It's amazing that once you really start thinking about questions like that it isn't always as simple as you might think at first.
Moderator:
Katherine, also from Minneapolis, has a question for you. What was your favorite subject in school before you went to college?'
Cindy Hale:
We looked very hard!! One way to "extract" worms from the forest floor is to pour a solution of mustard water over it. As it soaks in, it irritates the worms skin and they come up to try to avoid and we can see them. The magic recipe is about 1/3 cup ground yellow mustard to one galon water. try it in you garden or back yard (after it thaws out again)
Moderator:
Kendra from Cooperstown is wondering, 'How did you know the chunks of forest floor you used didn't already have worms in them?'
Cindy Hale:
Amy,
We had a total of 280 buckets, which is a lot but turns out was barely enough! We wanted to test the affects of different worms on different plants. We used 4 plant species three worms species. In order to be able to tell what is doing what in an experiemtn like this we have to have every possible combination of worm and plant type as well as controls, which are "no plants" and "no worms". So, we had buckets that had...
plant 1 X worm 1
plant 2 x worm 1
plant 3 x worm 1
plant 4 x worm 1
plant 0 x worm 1
And the same for worm 2, and worm3, and a combination of worms 1,2&3, and finally a set with no worms.
So, 5 plant treatments X 5 worm treatments = 25 buckets
Then, we have lots of "replicates" of each set of buckets so we can be sure the resutls we get are not just by random chance.
Sorry, this was so long, but this is actually a very complex question
Moderator:
The next question comes from Amy in Minneapolis. 'How many buckets did you have in the greenhouse and why do you need so many?'
Cindy Hale:
Hi David,
I attended a conference on Forest Soils in Bemidji in 1996. A soil scientist from the Chippewa National Forest took us on a field trip to see one of the sites he had been watch for over 10 years. Over those 10 years he had noticed big changes in the plants but didn't know what was causing them. In 1995 he read an article that suggested invasive worms might be the problem. So, he went out and looked and sure enough in the sites that he had seen big changes there were worms and in the sites that looked normal there were no worms. I was so blown away by actually seeing the difference on that field trip that when it came to pick a research topic for my Ph.D. that was the one that seemed the most unique and unstudied!
Moderator:
I believe he is talking about your research project.
Moderator:
Alright, let's start the chat. Our first question come to you form Stillwater. David wants to know how you started working on this project.
Moderator:
Hello Cindy! Welcome everyone to this afternoon's host researcher chat session. I see we have some good questions lined up already. We will start the chat at 2:00 p.m. CST.
Cindy Hale:
Hi, Cindy Hale Here
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