Oxygen generation deciduous vs coniferous

[wesdor]

A friend and I were discussing oxygen generation by trees. 
In a normal 12 month period which type of tree produces more oxygen Deciduous or coniferous 

Thanks in advance. From my limited research this may be a complex topic

[doc henderson]

I am not a tree bio person, but my background is in human biology.  I did 1.5 years of plant research to see if certain plants could change their metabolism when water stressed, to conserve moisture.  Normally the leaf opens its pores (stomata) when the sun shines and do energy production from start to finish.  The open pores on the bottom of the leaf also loses moisture as it takes in CO2 and produces O2.  Cactus can open its pores at night and take in CO2 and turn it into an acid to store in liquid form.  closes its pores in the day to conserve water but release the CO2 inside the leaf and make sugar/stored energy.  The sugar/starch can be used for metabolism and growth.  so, growth rate in terms of mass might be a good indicator.  Deciduous trees are dormant in the winter (loss of leaves).  So, on an annual based, the softwood trees have an advantage.  not all, as the bald cypress loses its leaves in the winter also.  In our research, we would grind up leaves and measure pH and then desiccate and weigh the end product.  Samples in the am and pm, at progressively longer days of no water.  We were looking at a Kansas weed portulaca mungulla.  it had thicker leaves like creeping flock, and we hoped it change to CAM during water stress, like a cactus.  Dr. Martin said if it were a positive result, we would rip plant physiologists a new ash hole.  It was a negative result. 

I am not a climate denier per sei but do think the whole mess is greatly exaggerated for political purpose.  But I think a tree requires certain stuff to make more energy and produce O2 as a byproduct and scrubbing CO2.  Water is a limiting factor needed for the reaction, and CO2.  Is it possible that more CO2 in the environment, increases plant metabolism and therefore a cycle of O2 production?  Probably. 

CO2 + H2O + sun = O2 + C6H12O6 (sugar)

Animals do the opposite, take in sugar and oxygen and produce energy (ADP to ATP remember that? )

As usual in these academic discussions, I did not answer your question directly but had fun doing it! 

[Ianab]

I'd suggest that the average annual O₂ production would relate to the amount of dry cellulose (Carbon) the tree produces for the year. 

My reasoning is this... Plants produce oxygen because they are taking in CO₂ , using the carbon in their structure, and releasing the oxygen back into the air. So the amount of O₂ must must relate to the amount of Carbon retained. 

I'm ignoring the seasonal / weather / water related fluctuations as we are only worried about the annual average. Also leaves and needles can be ignored, because any carbon going into creating those is only stored temporarily. Leaves are constantly being eaten / rotting on the ground for both tree types, and that's releasing CO₂ at about the same rate as creating new leaves is absorbing it. Same for flowers / nectar / pollen / fruit etc, those are temporary and get eaten each year. So over the course of the year their carbon is released and oxygen used in the process. 

So I'd say the most Oxygen is produced annually by the fastest (by dry weight) growing trees, because they have created the most cellulose, so must have released the most Oxygen to obtain the carbon needed. 

Cellulose is (C₆H₁₀O₅)_n , Basically chains of glucose. But you can see how the formula basically would need 6 x CO₂ + 5 x H₂O to create each portion, and that 6 x O₂ are left over. 

Working out exactly WHEN the Oxygen is produced is much more complicated of course. As well as the carbon, the tree also needs water to photosynthesize, as well as sunlight light and a sensible temperature. So an evergreen tree may have green leaves / needles in Winter, but isn't doing much because of the cold and low sunlight, and that shows up in the growth rings of both tree types. Some tropical trees don't show annual rings, because they can grow all year round, while others have slower growth due to a Dry Season. In that case their growth is limited by lack of water, even if all the other parts of the equation are there. 

[Ron Scott]

In a typical 12-month period, deciduous trees generally produce more oxygen compared to coniferous trees. [color=var(--cib-color-foreground-accent-secondary)]This is primarily due to their larger leaf area and higher photosynthetic rates during the growing season[/color]^{[color=var(--cib-color-foreground-neutral-secondary)]1[/color][color=var(--cib-color-foreground-neutral-secondary)]2[/color]}. Deciduous trees, such as maples and oaks, have broad leaves that capture more sunlight, which enhances their ability to produce oxygen^{[color=var(--cib-color-foreground-neutral-secondary)]1[/color]}.
However, it's important to note that coniferous trees, like pines and spruces, retain their needles year-round, allowing them to photosynthesize throughout the year, albeit at a lower rate^{[color=var(--cib-color-foreground-neutral-secondary)]1[/color][color=var(--cib-color-foreground-neutral-secondary)]2[/color]}. This continuous, albeit slower, oxygen production can be beneficial in different ecological contexts.

[Ron Wenrich]

Looking at Doc's post:  CO2 + H2O + sun = O2 + C6H12O6 (sugar)
Looking at Ian's post:  Cellulose is (C₆H₁₀O₅)

Does that mean that the difference between sugar and cellulose is 1 H2O?

[Ianab]

Does that mean that the difference between sugar and cellulose is 1 H2O?

Basically yes. 

Glucose is the simplest sugar, and created by photosynthesis. It can then be joined into longer chains to create more complex sugars, starch and cellulose, but as the glucose molecules are joined up they have to lose one of the outlying OH chemical bonds, to enable them to link to the next glucose molecule. Regular sugar is basically 2 glucose molecules joined together. Starch and cellulose are LOTS of glucose molecules all linked up. 

[TreefarmerNN]

This is one of those "stumpifying" questions for sure and one that the carbon exchange people have tried to quantify with limited success.

The idea that a simple calculation is based on the amount of cellulose a tree produces during a year is probably the best approximation.

But to say is a coniferous or deciduous tree (forest) produces more cellulose is more difficult as it gets into the growing cycle of a tree.  Coniferous trees tend to be quicker out of the starting gate, putting on a lot of growth as compared to most deciduous although some poplars are close.  So to answer the question, I think you need to stratify the age of the trees (forest).  Then look at the total life cycle of the forest considering a coniferous forest may very well have 2-4 harvests during a deciduous forest life cycle. 

And as someone alluded to, if the trees are allowed to die and rot some of the carbon is released into the air.  Some is sequestered in soil carbon which is why the early pioneers cleared forest for planting and then allowed the "worn out" land to go back into trees. 

As a quick comparison, consider two forests planted at the same time.
Year 1- neither forest really does much as really most of the growth is underground with only minimal photosynthesis taking place. 

Year 5- Conifers are probably 5-10' tall with 2-3" stumps.  Significant but not huge cellulous sequestration.  Deciduous trees are still in the sprout stage- 3-5' tall, 1-2" stump.

Year 15- Conifers should be 25-30' tall with 4-6" stump.  Deciduous trees probably about 10-15' tall with 3-4" stumps.

Up to age 15-20, conifers clearly sequester more carbon and free up more oxygen.  This probably continues until about age 30-40 when the deciduous trees are starting to produce larger crowns while some of the conifers may be dying out due to crowding unless they are thinned.

Age 100- most conifers are dying out to be replaced by younger trees while deciduous are still growing although some have also lost the race for sunlight. 

All of that is subject to wide variation depending on location, soils, planting and management, storm damage etc.  A very complex discussion which might not reach and one or the other answer.

[doc henderson]

and since it is linked up, it takes us longer to digest.  so, eating table sugar C6H12O6 is quickly absorbed, whereas starches like spaghetti noodles, take longer.  the enzymes that break down starches can only work from one end at a time. Protein (ammino acids) can be metabolized into sugar by removing nitrogen (thus nitrogenous waste in urine).  and sugar can be stored as fat and fat broken back down into sugar.  fat has 9 calories per gram but weighs less than other tissues and water.  fat folks float easier.  If you are heavy, it may be harder to walk, but if you had to carry a bunch of calories, it is better to carry fat then protein at 4 calories per gram.  but more protein (muscle) might make you able to carry more weight.  It is a perfect system in many ways.

[Magicman]

Sounds to me like N2,O2,H2,CO2,CH4.  What say you doc?

[doc henderson]

that is out of my ballpark.  Is that a hydrogen cell generation formula?

[Magicman]

No but it is very close to the chemical makeup of a fart. 

[doc henderson]

still explosive!!!           

[vratarneli7]

This is one of those "stumpifying" questions for sure and one that the carbon exchange people have tried to quantify with limited success.

The idea that a simple calculation is based on the amount of cellulose a tree produces during a year is probably the best approximation.

But to say is a coniferous or deciduous tree (forest) produces more cellulose is more difficult as it gets into the growing cycle of a tree.  Coniferous trees tend to be quicker out of the starting gate, putting on a lot of growth as compared to most deciduous although some poplars are close.  So to answer the question, I think you need to stratify the age of the trees (forest).  Then look at the total life cycle of the forest considering a coniferous forest may very well have 2-4 harvests during a deciduous forest life cycle. 

And as someone alluded to, if the trees are allowed to die and rot some of the carbon is released into the air.  Some is sequestered in soil carbon which is why the early pioneers cleared forest for planting and then allowed the "worn out" land to go back into trees. 

As a quick comparison, consider two forests planted at the same time.
Year 1- neither forest really does much as really most of the growth is underground with only minimal photosynthesis taking place.  https://spartan-agency.com/en/services/seo

Year 5- Conifers are probably 5-10' tall with 2-3" stumps.  Significant but not huge cellulous sequestration.  Deciduous trees are still in the sprout stage- 3-5' tall, 1-2" stump.

Year 15- Conifers should be 25-30' tall with 4-6" stump.  Deciduous trees probably about 10-15' tall with 3-4" stumps.

Up to age 15-20, conifers clearly sequester more carbon and free up more oxygen.  This probably continues until about age 30-40 when the deciduous trees are starting to produce larger crowns while some of the conifers may be dying out due to crowding unless they are thinned. https://knife-market.com/listing/category/kitchen-knives

Age 100- most conifers are dying out to be replaced by younger trees while deciduous are still growing although some have also lost the race for sunlight. 

All of that is subject to wide variation depending on location, soils, planting and management, storm damage etc.  A very complex discussion which might not reach and one or the other answer.

deciduous trees catch up over time