One challenge of using National Forest Inventory data for GHG estimates of forest carbon uptake is that only a share of the inventory plots are sampled each year, meaning the last 5 years or so is a guestimate. In Sweden, it looks like forest uptake has stabilised, but... 1/ - ThreadSky

glenpeters.bsky.social • 96 days ago

One challenge of using National Forest Inventory data for GHG estimates of forest carbon uptake is that only a share of the inventory plots are sampled each year, meaning the last 5 years or so is a guestimate.

In Sweden, it looks like forest uptake has stabilised, but...

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danielspiro.bsky.social•96 days ago

I don't understand the biophysics. How can dead wood have negative emissions? I thought it would decompose and gradually emit all its carbon.

glenpeters.bsky.social•96 days ago

Yes, technically, the inventory gives the change in living biomass stock (above ground), which is not the same as emissions to the air... There are lots of obscurities like this in LULUCF (and GHG inventories more generally)

jeannetteeggers.bsky.social•96 days ago

The deadwood pool is increasing due to increased mortality, I would say. The inventory monitors deadwood, too.

glenpeters.bsky.social•96 days ago

Yes, agreed. But, the carbon is still sitting in the deadwood, not yet in the atmosphere. People think / assume that the inventory is giving when emissions go to the air, but it is not really, because there is the deadwood pool. The carbon will take time to go from deadwood to atmosphere.

glenpeters.bsky.social•96 days ago

Or maybe I need to check with the Swedish inventory report, as it could be different to Norway. So perhaps ignore what I said. Here is Norway, for good comparison...

glenpeters.bsky.social•96 days ago

Ok, I think you can ignore what I said. Sweden does a stock-change approach, Norway a gains-loss. You can see the increased loses in Norway lead to an "emission", but the losses are most likely deadwood and not yet emissions.

Not sure how this works in the Swedish inventory.

jeannetteeggers.bsky.social•96 days ago

I work at the department where they do the Swedish NFI and know the people who do the reporting to the Swedish EPA. So in case you have specific questions, I can find out.

jeannetteeggers.bsky.social•96 days ago

Yes.

glenpeters.bsky.social•96 days ago

Sweden has updated its method. The gains in living biomass have basically gone to zero in the last years & uptake has declined more than the data originally showed (previous tweet).

(They include HWP in their figure it seems, I have not, explaining the different uptake)

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glenpeters.bsky.social•96 days ago

It is not so well explained what they have done in the revision, but here is some info.

https://www.naturvardsverket.se/om-oss/aktuellt/nyheter-och-pressmeddelanden/2024/december/lagre-utslapp-av-vaxthusgaser-men-upptaget-i-skog-och-mark-minskar/

3/3

robbieandrew.bsky.social•96 days ago

Here's a screendump from their webinar with my rough translation (and apologies to Swedes...)
https://www.youtube.com/live/ClRopu8e4Ss

robbieandrew.bsky.social•96 days ago

Not sure why I didn't just type the whole lot into Google Translate. Saved myself maybe all of 2 minutes... I've always been better at designing workflows after I've already done the job!

jakobsa.bsky.social•96 days ago

Something similar was done last year to the Norwegian GHGi. Additional data is used to estimate the harvest using GFW's forest loss data (https://www.globalforestwatch.org), as only 1/5 of the plots are measured yearly.

gideonrichards1.bsky.social•96 days ago

Is there an English version of this report Glenn? It would be a useful reference piece

glenpeters.bsky.social•96 days ago

I have not found one...

climatenews.bsky.social•96 days ago

Perhaps they recognise that tree plantations are practically dead zones with very little carbon uptake.

Forests capture carbon from the atmosphere, while tree plantations don’t.

A major part of carbon capture is driven by all the other plants and soils of a forest.

@irishrainforest.bsky.social

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