Temperature/Nitrogen assimilation

HiNtZ

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I was reading a website, here: https://www.waterjournal.org/volume-8/osborne

and read this particular part:
Water temperature can be problematic for SAV by increasing respiration rates and impairing enzyme function (Zimmerman et al. 1989; Lacoul and Freedman 2006; Riis et al. 2012), thus impairing nitrogen assimilation. However, SAV in spring runs generally do not experience thermal stress due to the thermal consistency of groundwater (unless exposed in shallow backwaters).

What are people's thoughts on this? Has anyone conducted any tests focusing on temperature or fluctuating temperatures vs plant growth?

Also, what specifically does it mean by respiration?
 

Nick72

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I can't talk to the technical nature of the above article, but before this thread becomes complex with discuss on such sciences, it appears to me that most plants have a comfortable range for healthy growth.

My tank sits at 28.4c which is above optimum for most plants, and seems optimum for most algae. I find algae control to be a major issue, and have to be very careful / lucky when choosing plants.

There are a number of websites that provide temperature ranges for plants. I find this one helpful .
https://www.flowgrow.de/db/aquaticplants?filter[fulltext]=Limnophila+aromatic(Mods - please break link or remove post if this is not allowed)

By selecting plants based on their advised temperature tolerance I have improved success in plant growth.
 

ceg4048

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Also, what specifically does it mean by respiration?
Respiration refer's functionally as the uptake and use of Oxygen to metabolize energy products such as glucose. Because Oxygen is involved in energy production, this is referred to as "Aerobic".

As much as possible, we want to have aerobic processes as this is the normal process and the byproducts, such as CO2 are not nearly as toxic as "Anaerobic" alternative processes which occur in the absence of sufficient quantities of oxygen.

An example of anaerobic byproduct is Hydrogen Sulfide. This is produced when Sulfur compounds are used to produce energy.
These anaerobic byproducts produce toxicity and tend to inhibit certain normal functions.

As Nick72 mentions, there is a range of acceptable temperatures. At lower temperatures there is higher level of dissolved oxygen in water, but the enzymes that function to produce energy and growth are less active. At higher temperatures the enzymes are more active and efficient but there is less dissolved oxygen. So it's all a compromise.

As noted, for tropical plants, temperatures between approximately 20C-30C are typical, depending on species preference. Again, at the upper end and beyond, the plants are stressed due to metabolic gasses being in short supply. At the lower end and beyond, enzymatic actions are curtailed, so even though more of the gasses are available, the plant is stressed from the inability to make use of them due to poor enzyme activity.

Cheers,
 

ceg4048

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Cheers mate. Hanging in there. Merovingian did a number on me...had to change my shell. I don't recognize myself in the mirror....
 

HiNtZ

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Thanks for the responses guys. I've been toying with O2 at night and different temperatures over the course of the last few months to see where my manageable balance lies.

Nice to see you back Clive.
 
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