Naked Science Forum
General Science => General Science => Topic started by: Titanscape on 13/01/2005 00:47:11
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In a basketball sized enclosed glass container containing earth water and a pot plant and of course air, sealed, how long do you think the plant would live for?
Titanscape
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Well I don't really know for sure but seem to think that it could live for a good while given the right type of plant and amount of sunlight etc. And providing the glass doesn't magnify the sun too badly and just burn the plant to hell.
I think with a proper mix of oxygen and CO2, it could use and produce both in the normal way. My only thought is would things get out of balance and there be a toxic build up of something eventually killing the plant.
Tim
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It would certainly live for a long time. How high would the roof be ?..anyway, eventually the air would run out, and it would need a dose of carbon dioxide too,assuming it's airtight then I suppose if you knew all the details like , water consumption, amount of sunlight,variety of plant, speed of photosynthesis etc....cripes !!..there's so many variables....actually Tim, sorry you mentioned most of this already didn't you...sorry.
Bren, do you mean it to me in a sealed unit with no one attending to it ?
'Men are the same as women...just inside out !'
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Yes, sealed air tight in a choice sunny place.
Titanscape
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How big is the plant? That will govern the answer.
If I assume the plant is about the size of an African violet, say 6 inches (15 cm), I would say it will live about 3 days, assuming correct temperature and insolation. The plant will consume atmospheric CO2, and go through its stored reserves of sugar in that time.
How long it take to die after it is done living also depends on the plant. Plants can allow parts to die off, and conserve a core of stem and root for a much longer time. So its not a black-and-white situation, like it would be if an animal were sealed in the container.
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It would have all the basics. Earth and water, fertiliser, inside.
Titanscape
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You make it sound as thought it won't have a source of CO2 after a while gsmollin, but it will produce CO2 itself as it respires. Then again I could have simply misinterpretted your post.
Tim
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Plants don't respire nearly as much CO2 as they need to build plant tissue. I happen to know that, because as it turns out, I do grow plants in a bottle. I have a cylinder of CO2 that I feed them. Without it, they die.
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Really? Thats cool. What sort of plants? Do you measure the amounts they tend to produce and use? if so Do they use/produce similar sorts of levels of carbon dioxide and oxygen?
Tim
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This is a great thread.
I built my own ecosphere about 12 years ago. I used a jam jar to which I added water from a pond, some of the gloop from the bottom of the pond and oxygenating weed (Elodea) from the water.
I sealed it with the lid and placed it in a sunny position on a window sill. 2 years later there were still small water bugs swimming around. Unfortunately my mother inadvertently chucked it away so I never got to continue the experiment, but it was obviously stable if it had persisted 2 years containing animals that live about 2 weeks.
Interestingly, when I first set it up it contained a broad selection of different small invertebrates. But within 2 weeks most of the big ones had disappeared leaving a stable population of mcuh smaller animals. Presumably a larger ecosphere would have sustained more larger animals.
I suspect that the gloop at the bottom harboured enough bacteria to digest organic matter that collected there and recycle the CO2 to keep the plants happy.
It was great fun, however, and I'd strongly advise people to try it. Just make sure it gets plenty of sun.
Chris
"I never forget a face, but in your case I'll make an exception"
- Groucho Marx
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quote:
Originally posted by chris
This is a great thread.
I built my own ecosphere about 12 years ago. I used a jam jar to which I added water from a pond, some of the gloop from the bottom of the pond and oxygenating weed (Elodea) from the water.
"I never forget a face, but in your case I'll make an exception"
- Groucho Marx
Chris,I have got to give that a try, There's a lake just round the corner from me, having said that, I have a bird bath in the garden, I suspect I could get away with a jar full of some of that eh ? Wifey will love the adornment of a jar full of ' lake stuff ' on our kitchen windowsill.
'Men are the same as women...just inside out !'
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quote:
Originally posted by gsmollin
Plants don't respire nearly as much CO2 as they need to build plant tissue. I happen to know that, because as it turns out, I do grow plants in a bottle. I have a cylinder of CO2 that I feed them. Without it, they die.
What about Cacti ?..would they be substantial in their longevity ?
'Men are the same as women...just inside out !'
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quote:
Originally posted by chris
This is a great thread.
I built my own ecosphere about 12 years ago. I used a jam jar to which I added water from a pond, some of the gloop from the bottom of the pond and oxygenating weed (Elodea) from the water.
I sealed it with the lid and placed it in a sunny position on a window sill. 2 years later there were still small water bugs swimming around. Unfortunately my mother inadvertently chucked it away so I never got to continue the experiment, but it was obviously stable if it had persisted 2 years containing animals that live about 2 weeks.
Interestingly, when I first set it up it contained a broad selection of different small invertebrates. But within 2 weeks most of the big ones had disappeared leaving a stable population of mcuh smaller animals. Presumably a larger ecosphere would have sustained more larger animals.
I suspect that the gloop at the bottom harboured enough bacteria to digest organic matter that collected there and recycle the CO2 to keep the plants happy.
It was great fun, however, and I'd strongly advise people to try it. Just make sure it gets plenty of sun.
Chris
"I never forget a face, but in your case I'll make an exception"
- Groucho Marx
You kept water bugs alive for two years in a sealed jam jar?? I can't believe it. Really, I have never heard of such a thing. There are so many eco-sphere, train-wreck stories in the literature. Some how, you established a nitrogen cycle, CO2 cycle, water cycle, and food chain that self-perpetuated for two years, in a jam jar. Whew! Does your mother know how much science she threw away?
OBTW, my elodea died after the anchor worm outbreak.
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What about Cacti ?..would they be substantial in their longevity ?
I don't know. Desert plants are actually pretty specialized, and aren't any more robust than average plants. Of course, if your eco-sphere were a desert eco-sphere, then cacti would last longer than average plants.
As far as I know, the eco-sphere experiments have had a troubled history. Despite the best laid plans of mice and men, somthing always goes wrong and the ecology crashes in the sphere. I still marvel at chris's jam jar
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I was devastated when I found out it had gone.
Maybe this spring, when all the pond life returns, I'll set up another one and see how long we can keep it going.
Others have managed to set up a sea-water eco-sphere in which a couple of shrimp and a lump of weed co-exist for a few years at a time. I think it would be good to able to buy them, sealed in glass, as an attractive living 'desk tidy'. During stressed moments in the office you could glance at your shrimps bobbing about inside your paperweight and think...if only my life was that simple... be a bit boring eating weed all day every day though !
Chris
"I never forget a face, but in your case I'll make an exception"
- Groucho Marx
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In the aquatic forums that I frequent, these kinds of items are assailed as hell-spawn. There are a number of them, the mini-aquariums, beta-plants, and others I haven't seen. Aquarists set up elaborate aquariums, some fresh water, or with plants, marine, and coral reef aquariums. They are quite elaborate, and I don't think anybody would believe Chris's jam jar.
Personally, I stick with freshwater plants and ciclids. Marine is too difficult. Reefs are too expensive and difficult.
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I didn't realise that people had problems with sustaining these things long term. There were clearly tiny water insects buzzing around inside my sealed jar for 2 years after it was set up !
I am now determined to repeat the experiment. I should point out that the jar was on a south facing windowsill and received a lot of sun. It also had a healthy layer of pond debris at the bottom which presumably sustained anaerobes fairly well.
Chris
"I never forget a face, but in your case I'll make an exception"
- Groucho Marx
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Anerobes, yes. That is one way to kill everything. Anerobic soil conditions will produce poisonous hydrogen sulfide. You must have had aerobic conditions to sustain the nitrifying and nitrafying bacteria necessary for the nitrogen cycle.
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My Venus Fly Trap died :(
Tim
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I've killed every plant I ever tried to maintain. Usually within a month. But I'd love to try the experiment with a sealed jar. I have a couple of ponds that I've always suspected were generating new life forms on a daily basis.
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John - The Eternal Pessimist.
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hey chris, how did you seal the jar, and was it clean when you started the experiment?
Important quotes from important people
"Hey my chocolate bar melted!" Percy L. Spencer
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Hi tronix
I just took a jam jar from the cupboard and screwed the lid on tight. It was definitely airtight because the water level did not change. If it had been exchanging with the environment to an appreciable degree, I would have expected to see a drop in water level (it was on a hot sunny window sill) over the course of a year or so.
Chris
"I never forget a face, but in your case I'll make an exception"
- Groucho Marx
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then that is very facsinating. i havent grown too much in a jar yet, but i am interested in the excersice. i found a really fascinating terarium growing naturally outside. quite a few actually. the best one is a clear glass soda bottle (might have been yoohoo, but the label decayed away long ago) half buired at a roughly 45 degree angle in a pile of soda cans and bottles that laid quite and undisturbed under a hackberry tree(?) for many years. It was filled with a moss variety that grew stalks with seed pods, and the stalks where a full inch taller than another clump of moss i found growing on an abandoned (and never used) septic tank. Its like a little rainforest in there, and very alive. however, its an open container, and was probably sitting there for twenty year accumulating leaves from the tree. i have pictures of it if anyone wants to see it, just not with me as i post this.
my dad has been making this "compost tea" he found of a website. essentially its supposed to be a bacterial soup made from compost, water, a bit of molassess, and 1-3 days of areation. maybe a bit of that coudl get one growing until it can be self sustained. Fish oil maybe good to add as well. i dont know wheter its areobic or anarobic however.
good luck on trying again, and maybe next time you could tie it down with chain (not too much though, it it will block out the sun)[8D]
Important quotes from important people
"Hey my chocolate bar melted!" Percy L. Spencer
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the sealed ecosystems with shrimp are available to buy from the gadget shop www.gadgetshop.com cant find them of hand on the website but the Glasgow shop does have them