Biomass Carbon Stocks, Sources & Sinks
Forest biomass carbon sources (-) and sinks (+) in tons C/ha/yr
This is the first study to analyze the carbon pool in the woody biomass of temperate and boreal forests of the northern hemisphere using satellite data. These
forests cover an area of about 1420 million hectares.
This study provides relatively high spatial resolution (8x8 km) estimates of the biomass pools, sinks and sources. Contrast this with what we knew about carbon sinks on land prior to this study
, as reported in Chapter 3 of IPCC-2001 (Heimann, M., Max-Planck Institute fuer Biogeochemi, Technical Report 2, 2001) -- only that about one to two billion of
tons of carbon are somehow being stored in various pools on land in the north.
We estimate the biomass pool in 1420 million hectares of northern temperate and boreal forests to be about 61 billion tons of carbon during the late 1990s.
See this image for more information.
The average pool size (tons carbon per hectare) in Europe and the USA is larger than in Canada and Russia (54-58 vs. 38-44). Amongst the European countries,
Austria, France and Germany have notably large average pools (60, 67 and 73, respectively). The estimates for Finland, Norway and Sweden are comparable to Russia
(35-40 vs. 38).
Our estimate for the woody biomass sink in 1420 million hectares of northern temperate and boreal forests during the 1980s and 90s is 680 million tons of
carbon per year. This is about one-half the total land sink in the north which suggests a similarly large sink in other land carbon pools.
We found that nearly 70% of the biomass sink is in Eurasia (470 million tons of carbon per year) which is in proportion to Eurasian forest area but in disproportion
to the biomass stock (see this image for details)
We provide detailed country wise estimates of biomass pool and sinks (see this image). The three large countries, Canada, Russia
and the USA account for 78% of the pool, 73% of the sink and 77% of the forest area.
We do not know the reasons for carbon storage in these northern forests, but the spatial pattern of sources and sinks offers some clues. Increased incidence of
fires and infestations in Canada, fire suppression and forest regrowth in USA, declining harvests
in Russia, improved silviculture in the Nordic countries, woody encroachment and
longer growing seasons from warming in the northern latitudes possibly explain some of the changes.
The fact that we do not know the reasons for these carbon sinks means uncertainty regarding the future of biomass sinks and hence the need for monitoring with
ground based inventories and space based sensors.
Most of the industrialized nations (with the exception of Australia and New Zealand) are in our study region. Biomass sources and sinks in these nations are a
topic of discussion in the development of the Kyoto Protocol, because these countries can use some of these sinks to offset their greenhouse gas emission
reduction commitments under this protocol.
See how the Annex I countries rank by: | sinks
| sinks to emissions
| sinks to emissions per capita |
Identifying Kyoto sinks is a topic for further investigation. Our study shows that such sinks can be potentially estimated from satellite data, and this third-party
imprint is valuable in a monitoring program for verification of compliance under the treaty.
Forest biomass, most of which is in the wood, is a multi-billion dollar industry. Therefore, wood volume data is highly valuable. The detailed data are generally
with held and only summary statistics are available publicly. Our study shows that we can estimate forest woody biomass from satellite data at a high resolution.
This has important implications on the forest sector.
This work contributes to global carbon cycle research in four ways.
Biomass Carbon Stocks, Sources & Sinks