Grasslands may trump forests at carbon storage in a warming world

[Judi Lynn]

by Morgan Erickson-Davis on 18 July 2018

. . .

Forests have a reputation as a big bulwark against climate change – and for good reason. They soak up massive amounts of carbon dioxide from the air and sequester it in their trunks, roots, and branches (collectively called “biomass”). This ability to reduce atmospheric greenhouse gases has led to huge multinational efforts to protect and plant forests in the hopes that doing so will keep the world from warming past the point of no return.

But non-forest ecosystems can also store lots of carbon. New research published recently in Environmental Research Letters finds grasslands in particular can be more effective than forests at storing carbon in places prone to drought and wildfire. Its authors say their findings highlight the important role grasslands can play in mitigating global warming.

Researchers from the University of California – Davis found grasslands and rangelands (open areas used for livestock pasture) in semi-arid regions of California tended to be better at long-term storage of carbon than are forests. This is because grass stores much of its carbon underground in its root mass whereas trees store most of their carbon aboveground. When a wildfire breaks out and a forest burns, much of its carbon is released into the atmosphere. But in a grassland fire, carbon remains tucked safely underground.

The team modeled several climate conditions, finding the only one where trees beat out grasslands is if global carbon emissions essentially stop and warming is kept below 1.7 degrees Celsius by the end of the century. This, they write, would require “even more aggressive global greenhouse gas reductions than the Paris Climate Agreement.” And as the world veers off its path to the 2-degree Celsius threshold set by the Agreement, such a scenario is looking increasingly unlikely.

More:
https://news.mongabay.com/2018/07/grasslands-may-trump-forests-at-carbon-storage-in-a-warming-world/

[mr_lebowski]

1. Pffft ... okay Ag school UC-Davis ... lol ... look I love Davis and I love the UC System ...

And I went to a CA State Ag-based Uni myself ...

But I ain't buying this. Sorry ...

Even if it were true, forests provide SO MUCH more value above and beyond what 'grass and rangelands' provide, it's not even comparable.

Chopping down forests to turn them into 'Rangelands' to 'help' with Global Warming? Is a joke of a strategy.

[Igel]

2. I don't think there's a policy implication in there.

I think that's the hook to get the reader intrigued.

It might have policy implications in that it's a waste of effort to convert grasslands to forest just for C sequestration. Not sure I've heard of anybody doing that, actually.

However, it fits a nice feedback pattern: If things get hotter and drier, the forests will suffer. Then a policy implication might be, "Don't stress out, let it happen," because while the dead forest will release carbon at least some will be sequestered by the grasslands that result. That would, of course, be a policy implication for later, not so much for now. Except to alleviate neurotic concern over, say, forest fires in places that are marginal because of drought.

[NickB79]

3. You do realize that prairie is rangeland, right?

Prairies are some of the most biologically productive, diverse ecosystems on the planet, whether grazed by cattle, bison or wildebeest.



And the authors aren't talking about cutting down forests where they naturally exist; they are talking about restoring prairie where it used to exist.

[NickB79]

4. Also, look into managed rotational grazing

Amazing potential to rapidly sink carbon, build soil and retain moisture during times of drought: https://landstewardshipproject.org/posts/838