Faruk Gençöz wrote:
So it's not just one exception to the "rule", but huge things that suggest other conditions are a lot more important than the theory's idea. I'd have to say, when you're looking at conditions in the wild, you're the local expert for the rest of us homebodies--what do you think is happening?The location theory is interesting and seems to have evolutionary base. I myself observe the same location spesificity in lakes and rivers here in Turkey although not exactly as it is mentioned in the theory. The evolutionary explanations summerize million years of life experince and I think this kind of viewpoint surpasses little individual variations. Sometimes I see vallisneria or sagittaria species in the middle of a deep river and find a huge colony of myriophyllum or potamogeton species in very shallow sections.
On the other hand I agree with the location theory that different collonies of one specific species tend to be located in theThat's interesting--for an aquarist, of course you start wondering about things that are hard to test for, such as relative light levels in different depths. In one area, perhaps the water clarity is different, and it's the light levels that are controlling where they are.
similar environmental conditions (e.g. light, speed of stream, depth) in the
Yes, that's one of my problems with the "area" theory, aside from over-generalizing about "jungle" streamside conditions such as streamside canopy, or lack of it. And the water volume and velocity could vary enormously in a stretch of a kilometer.Another interesting thing is that crypto melting seems a unique phenomena among cryptos not among rosette plants.
Other rosette plants which shouldAs best I recall, both vals and swords are New World (correct me if I'm wrong) and all the crypts are in various areas of Southeast Asia, but it can't be just regional or monsoon-based. The crypts alone cover very different water chemistries. I know more about the easy Sri Lankan hard-water crypts, for example (and I'm no expert, by any means) but something that would affect plants in both very hard and very soft waters over such a broad area, without causing the same event in other rosette plants, sounds really strange. Why is it an advantage to the crypts so they all do it, to varying degrees, but other plants have not developed parellel traits to match that advantage?
share the same location (according to the location theory) do not show an
immediate decay reaction. I never saw any echinodorus melted in one day
though vallisneria sometimes gets brown within one night.
-----Original Message----- From: email@example.com [mailto:firstname.lastname@example.org]On Behalf Of Heather J Gladney Sent: 22 Eylül 2005 Perþembe 09:29 To: Aquatic Gardeners Association Member Chat Subject: Re: [AGA-Member] SYMPOSIUM ON AQUATIC PLANTS January 2006 Brussels
Faruk Gençöz wrote:
I remember the article. Thanks.
"might be adaptation to flood/dry cycles with sudden water-level and water chemistry changes?"
This seems to be a very rational argument, if melting actually occurs
in the wild. I wonder if someone actually observed such an event in
the wild. I also want to know why this plant has a unique adaptation
skill unlike what the stem plants regularly do.
I recall reading in a sometimes-unreliable older aquarium book that these types occupy different depth and "width" zones along the stream banks, where the small rosettes would be growing up on shady banks, while the stem plants are out in deeper water but more direct sun (where the water imposes a clearing between the trees that overhang the smaller plants on the banks, is the theory). It seems to me that too might have appeared in one of the recent articles, possibly remarks by Diana Walstad?? Stem plants were cited as being in reliably deeper water than the rosettes like smaller "groundcover" crypts, and when the crypts are suddenly plunged in deep, different water after being grown emersed (dry season in the wild) or semi-emersed (as they often are being grown before sale in aquarium shops) then the CO2 difference alone might be enough signal to tell them it's no use flapping leaves out there in the flood, you won't get any light anyway, it's time to live on food stored in the rhyzomes. It's a theory. I'm not sure how you'd go about proving it, but there's probably some people who might've worked on issues like this (say, "dry-matter productivity in diferent seasons," etc.) on plants in the wild. Hope this is some help!
----- Original Message ----- From: "Heather J Gladney" <email@example.com> To: "Aquatic Gardeners Association Member Chat" <firstname.lastname@example.org> Sent: Wednesday, September 21, 2005 10:45 PM Subject: Re: [AGA-Member] SYMPOSIUM ON AQUATIC PLANTS January 2006 Brussels
Weren't there comments in the magazine awhile back (I believe in a travel article with pictures showing crypts on-site?!? There may have been more than one reference?) suggesting that it might be adaptation to flood/dry cycles with sudden water-level and water chemistry changes? Speculation by the aquarists, as best I recall, no proof of it. Anybody remember? Heather
Faruk Gençöz wrote:
"Cryptocoryne melting" might be a good title for an aquarist to submit a paper to the symposium. Has anyone encountered an example to crypto melting in their natural habitat? And would you have an idea about the ecological role of crypto melting? I am not questioning the role of regular melting seen among aquatic vascular plants. In this case, the lower portion of the stem decays so that the living upper part separates itself from the lower part to travel down the river. This way seems very practical and functional to find a suitable new place to reproduce and to enlarge the original colony. Crypto melting seems to be a liltle different. It occurs very fast and in general only the roots remain alive. So, rather than trying to survive in another place, this plant seems to try to re-generate possibly a more resistant generation. Why is that difference?
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