Comments

You must log in or register to comment.

Chilli-Papa t1_izs98h6 wrote

Generally, yes. Photosynthesis, of which oxygen is a byproduct, happens in the chloroplasts.

The vast majority of the chloroplasts are in the leaves, so a deciduous trees ability to produce oxygen is drastically reduced after shedding its leaves.

45

EcchiOli t1_izsfurf wrote

That said, I'll mention it just in case, that's not an issue at all if you were thinking of the "stock" of available oxygen.

A few months after that Avengers movie with the Thanos snap, there was this interesting reddit discussion, in which "what would happen if that snap also wiped half of the oxygen-producing plants and plankton" was asked. And the fascinating answer is that the atmosphere contains centuries of oxygen in stock before a risk to run out is even foreseeable. So, we're cool ;)

20

Mammoth-Mud-9609 t1_izsmler wrote

In addition the production of oxygen by cyanobacteria led to the first great extinction event and then to the longest ice age in the history of Earth. The Huronian glaciation saw the Earth turn into a gigantic snowball for 300 million years and could have seen the end evolution of advanced life on Earth. https://youtu.be/qx5VaEaNtKo

7

EcchiOli t1_izsudpd wrote

Pretty fascinating in its own right, that those microorganisms to whom we owe our oxygen supply initiated a worldscale genocide of the formerly dominating lifeforms, and almost wiped themselves in the process, hehe.

8

Game_Minds t1_izuf795 wrote

Also, plants and algae are mostly limited ecologically by direct proximal competition for light and other static resources, and half of them being gone randomly presumably just means literally twice as much room to grow in the next generation-- which could be a matter of months. Trees are harder to replace etc., but not impossible

5

Chlorophilia t1_izwli4h wrote

Additionally, most primary productivity occurs in the ocean by phytoplankton, which have a turnover time on the order of days. They are generally limited by light and/or nutrient availability rather than growth or reproductive rate, so it would be a matter of days before the marine system recovered.

2

Whoudini13 t1_izsblid wrote

There's some cool satellite visual data that shows the earth's oxygen, carbon dioxide cycles...seasons...you could almost call it breathing the way it looks..no link I just remembered seeing it somewhere..happy hunting

17

agate_ t1_izt1nyq wrote

Yes, seasonal trees cause measurable changes in the amount of co2 and oxygen in earth’s atmosphere.

Here is a graph of carbon dioxide in the atmosphere over time. The long term trend is due to humans, but the yearly wiggles are due to trees. Every summer they grow and pull down CO2 into their bodies, and every winter they decay and release that CO2. (You may wonder why the northern and southern hemispheres don’t cancel each other out. Answer: there are fewer trees experiencing winter in the south.)

And here is a graph of oxygen showing exactly the opposite trend, for exactly the same reasons. An important note: we are not going to run of oxygen. Because there’s so much oxygen in the air, the changes are relatively tiny: human activity has reduced it by about 0.08 %.

7

agate_ t1_izt271y wrote

Fun fact: the weather station that collects that co2 data is on Mauna Loa in Hawaii, and the road to it is currently blocked by a volcanic eruption. The weather station is not currently in danger though.

3

Mammoth-Mud-9609 t1_izsm92i wrote

Yes, in fact many trees in winter have a net intake of oxygen and release carbon dioxide, remember that normally as well as photosynthesising trees are respiring, but when doing it in the summer are net reducers of carbon dioxide.

3

PerspectivePure2169 t1_izsnuka wrote

Not just trees. Grasslands as well. Which considering that includes both natural ones and man made ones via agriculture - that's a LOT of acres.

It's compounded by the seasonal cycles of tillage. Farmers tend to plow in the fall thru spring so that the old crops' plant matter will have decomposed by the time they need to plant again. That decomposition releases CO2.

But there's a cycle to it, and much will be reabsorbed once plant growth kicks back into high gear with spring's warmth.

3