Root Death - Page 3 - Orchid Board

Dimples · #1 01-12-2022, 05:20 PM

Keith,
Throw me into a pool and I can hold my breath for awhile and come out just fine. Keep me underwater long enough and I'll die. Another person may be able to stay underwater longer and come out ok.

Same thing goes for plants. The length of time it will take to kill roots via submersion will depend on the species, and on the health of the individual plant, but all non-aquatic plants are adapted to tolerate and survive a flooding event of some duration (could be 5 min, 5 hours, 5 days, etc.). It seems your orchid is adapted to survive at least 24 hours of submersion when in good health.

Now, make me breath in a mixture of 95% air and 5% liquid water permanently? I'll die slowly as my lungs fill up with water.

Roots growing in conditions that are slightly wetter than the range they are adapted to can't maintain function, decline in health, and eventually die. The speed of root death depends on a variety of other factors, but in general the further the conditions are outside of the range of tolerance, the faster the roots will die. New roots adapted to the new conditions can grow, but the old ones won't make it. That's why the grasslands in Africa can survive the annual drought/flooding cycles. They grow new roots very quickly once soil conditions change in either direction. The old roots can keep them going temporarily as they slowly die, but they'll need to grow new roots if they want to survive the new conditions.

The need for the new roots comes down to gas exchange - it doesn't work the same way underwater as it does in an airy media, and soggy media is the crap side of both conditions so almost no roots will tolerate it for long (that's why bog plants are so neat!).

Time, temperature, plant health, and other factors contribute to the speed of root death, but the primary factor in moisture-related root death is limited gas exchange.

Now, the real question is - are the roots dying while the plant looks on in horror, or is the plant aborting the functionally-deficient root system on purpose? :P

Shadeflower · #2 01-13-2022, 08:21 AM

Quote:

Originally Posted by Dimples

Keith,
Throw me into a pool and I can hold my breath for awhile and come out just fine. Keep me underwater long enough and I'll die. Another person may be able to stay underwater longer and come out ok.

Same thing goes for plants. The length of time it will take to kill roots via submersion will depend on the species, and on the health of the individual plant, but all non-aquatic plants are adapted to tolerate and survive a flooding event of some duration (could be 5 min, 5 hours, 5 days, etc.). It seems your orchid is adapted to survive at least 24 hours of submersion when in good health.

Now, make me breath in a mixture of 95% air and 5% liquid water permanently? I'll die slowly as my lungs fill up with water.

Roots growing in conditions that are slightly wetter than the range they are adapted to can't maintain function, decline in health, and eventually die. The speed of root death depends on a variety of other factors, but in general the further the conditions are outside of the range of tolerance, the faster the roots will die. New roots adapted to the new conditions can grow, but the old ones won't make it. That's why the grasslands in Africa can survive the annual drought/flooding cycles. They grow new roots very quickly once soil conditions change in either direction. The old roots can keep them going temporarily as they slowly die, but they'll need to grow new roots if they want to survive the new conditions.

The need for the new roots comes down to gas exchange - it doesn't work the same way underwater as it does in an airy media, and soggy media is the crap side of both conditions so almost no roots will tolerate it for long (that's why bog plants are so neat!).

Time, temperature, plant health, and other factors contribute to the speed of root death, but the primary factor in moisture-related root death is limited gas exchange.

Now, the real question is - are the roots dying while the plant looks on in horror, or is the plant aborting the functionally-deficient root system on purpose? :P

I agree with everything you say, particularly that it depends on the orchid...

Like this next orchid is being grown in an enclosed terrarium with no ventilation, temp down to 12 degrees and roots submerged in water all the time.

I would not recommend anyone do it but this is a millieri hybrid...

It can tolerate cold + wet but maybe it is just this particular hybrid. The roots are still going strong after a year but I think they might go this year. I don't think the plant is deteriorating. I showed the latest lead to show since being giving max water for the past year it has decided to get a bit bigger on the latest bulb. But this is a bit of an experimenting plant. I've been experimenting with different ferts too and although the bulb has grown bigger I don't know how good it is doing. Anyway that isn't too imortant for this post.

Ray · #3 01-13-2022, 09:35 AM

Actually, sphagnum has been used on wounds because of its antiseptic properties.

How Humble Moss Healed the Wounds of Thousands in World War I | Science | Smithsonian Magazine

K-Sci · #4 01-13-2022, 11:39 AM

Quote:

Originally Posted by Ray

Actually, sphagnum has been used on wounds because of its antiseptic properties.

How Humble Moss Healed the Wounds of Thousands in World War I | Science | Smithsonian Magazine

Wow! This almost hurts just to read.

"Desperate to get their hands on something sterile that would keep wounds clear of infection, doctors started getting creative. They tried everything from irrigating the wounds with chlorine solutions to creating bandages infused with carbolic acid, formaldehyde or mercury chloride, with varying degrees of success. But in the end, there simply wasn’t enough cotton—a substance that was already in high demand for uniforms and its recently discovered use as an explosive—to go around."

BOOM!
-Keith