[perrygeo]

Forests and grasslands are critical for the climate because of the carbon they lock away. So long as the plants stay alive, they store carbon in the cellulose structures of roots and stems.

Conserving these ecosystems is less about their daily respiration and more about keeping existing carbon out of the atmosphere. It's a defensive strategy. Not "carbon capture" per se but more "avoid loosing the carbon we've already captured". We're interested in the sink, not the flow.

Of course when the plant dies and decomposes or burns up, it all goes back. Long term, it's almost exactly net zero. The ONLY way to use plants for long term carbon sequestration is to make sure that plant matter gets treated or literally buried so that aerobic microbes and fungi can't break it down.

[culi]

This is true but I have to admit I despise the reductionism inherent in arguments for valuing forests in this way. There are so many important ecosystem services played by forests and "wildlife" that is missed when focusing solely on carbon sink capacity. Not to mention the rights of nature itself to exist.

We would be dealing with so many more diseases if it weren't for vultures, opossums, etc. Our soils would not have the capacity to hold top soil if it wasn't for the critical microclimates plant roots create for mycorrhizal fungi. Landslides, floods, and desertification would all simultaneously be more common. Biodiversity would plummet leading to even more fragile ecosystems. Rainfall would be reduced while flooding increases. Temperatures would rise and food systems of humans and more-than-humans would collapse.

I just think the carbon sink capacity of forests and grasslands are a minor point compared to everything else they do for us

[perrygeo]

Good point. I didn't mean to imply that carbon was the only value. The "services" provided by these ecosystems are incalculable.

The myopic focus on carbon is an easy trap to fall into; it's the quantifiable part of the system. In this world, that which gets measured gets managed.

I would hope we'd conserve these ecosystems because of a deeply-held spiritual connection to life. Or at least a realization of the value they provide to humanity by simply existing. But carbon remains the objective metric by which conservation interacts with the financial market.