Extreme Greenhouse Effect Experiment. How do plants survive.

[POLLITO110]

I have a greenhouse (41º of latitude, like 750m of height), and last year i had maximums of over 70ºC, (70º max 18ºCmin etc) and there was still all June left (the heath only depends on the height of the sun so the max is in the solstice), but i had to put blankets because some plants inside where beginning to die as it was a frost, and maximums dropped to 63-65ºC. At the rate max temperatures were increasing, i may have got 80ºC, but i do not know if my thermother is able to record this temperature.

I can use the greenhouse as a sauna, from February to november. The point with the plants here is that:

 

A):heath and big themperature changes make a lot of flowers fall-off without making seeds .

B):when the average temperature is over 35º, seeds die without emerging.

C): Some plants explode like if it was a frost (leaves get slightly different and rot much faster if there is a lot of moisture) when temperatures are above 35ºC on daily average. This also happens to plants that are too young.

D): At least in my greenhouse, live insects are rare when it is so hot, i never had whitefly inside the greenhouse.

 

Last year i had a extreme drought (all the summer without raining), and i did not have enough water So i also observed that:

 

The plant that has proven for me more likely to reproduce (from roots) in this conditions is lemmon grass. these plants got leaves brownish, but once the drought ended they countinued growing. It's the only thing i could harvest from my greenhouse all summer long. It also tastes better with the heath. Also a weed similar to lemmon grass survived and reproduced.

 

Then i had tomatillos, and yard-long beans, that dropped flowers and leaves, but survived.

From the tropical malvae (I have Jamaica, Okras and Melokhia), almost all of them dried out, but after the drough, surprisingly, 50% of them sprouted again in just one week.

 

I watered the okras a bit, but they made pink small okras that could not be eaten, the jamaica was also watered a bit, keept most leaves perfectly alive,but did not grow . The melokhia, is the second plant that resisted the most. I could harvest some leaves, but once their leaves began to dry out, i hat to wait until the end of the drought to see them sprout because a bit of warter didn't help them.

I have giant bottlegourds that droped leaves while keeping the trunk green, lather they sprouted and made flowers, but did not reproduce.

 

Furthermore, a lot of seeds that i planted when the weather was too hot did not emerge. But in auntumn or winter,

 

There are also some plants that died by the head shock, like charts, tomatoes...

 

This year i will try more plants, but i will also have more water.

 

 

Conclusion: With such high temperatures, many plants could sirvive, but they would need a frost-free colder season to reproduce. Frost Resistant plants, are the ones that are less likely to live in very high temperatures. While these that are able, are not frost resistant (usually original from climates that are under monson regimes).

 

Results change a lot depending if whether the plant has enough space to fully deploy root systems (ie.directly to the floor), or not. Plants in a pot can dry much faster, sometimes they dry out in just a day if the pot is very small.

Edited February 13, 2013 by POLLITO110

[vampares]

Wow that is hot (158ºF-176ºF BTW). What is the relative humidity at those temperatures?

[POLLITO110]

It depends. if the greenhouse is very dry, maybe 15-20%, but i remember to have seen days with 30 or 35% min humidity (the humidity during the day max temp), with a maximum of 65ºC and minimum of 24ºC, when it has been raining the day before. Often i get inside the greenhouse and my glasses get covered with condensed water instanly, so i have to clean them. Furthermore i need a towel, because after 5 minutes inside there i get like if someone throwed me a bucket of water. With 46-51ºC, that is the usual temperature that i find at the afternoon of spring-summer when i get there, it's enough for it to happen. Sometimes i take 3 or 4 sauna sessions in a row. And as I have to take care of plants there, sometimes i enter with 50ºC for then minutes, leave, after 10 minutes i enter again, and i'm 2 hours there while the temperature is slowly dropping. I also need to bring like 2 liters of water to go to the greenhouse when it happens.

 

When it's hot and i have been crunching, then often i need to stand up and look to the sky because when the blood accumlates in my head i get sick quicker. Sometimes i have to wait until the temperature drops, before crunching. The worst is when there are 50ºC inside and 15 outside, because when i get out there i havea lot of cold, this is when the towel is more useful.

 

Note that when the greenhouse is closed, it also keeps the air humidity from scaping outside.

Edited February 16, 2013 by POLLITO110

[vampares]

I think I'm close to 40º latitude, elevation 200-300 feet (>100 meters). I don't think I would be able to achieve those temperatures consistently where I live except in extreme heat. Unfortunately, I cannot make conclusion regarding the environment in my garden because of herbicidal usage in the near proximity.

 

Most of the houses and other buildings do not accommodate for the heat we have had in past years. They tend to be lossy but also tend to build up a lot of heat.

 

I have wondered if this is because the environment was different *then*, when houses were first engineered. Structures that were built prior to the invention of heat pump AC technology may provide some clues.

 

Obviously humans cannot survive, by ordinary means, in environments which would elevate body temperature.

 

Note that when the greenhouse is closed, it also keeps the air humidity from scaping outside.

 

Where do you get CO2 from?

Edited April 13, 2013 by vampares