Seagrasses can store as much carbon as forests

May 22, 2012 By Cheryl Dybas
Scientists take samples of seagrass beds at NSF's Florida Coastal Everglades LTER site. Credit: NSF Florida Coastal Everglades LTER Site

(Phys.org) -- Seagrasses are a vital part of the solution to climate change and, per unit area, seagrass meadows can store up to twice as much carbon as the world's temperate and tropical forests.

So report researchers publishing a paper this week in the journal Nature Geoscience.

The paper, " as a Globally Significant Carbon Stock," is the first global analysis of carbon stored in seagrasses.

The results demonstrate that coastal seagrass beds store up to 83,000 metric tons of carbon per square kilometer, mostly in the soils beneath them.

As a comparison, a typical terrestrial stores about 30,000 metric tons per square kilometer, most of which is in the form of wood.

The research also estimates that, although seagrass meadows occupy less than 0.2 percent of the world's oceans, they are responsible for more than 10 percent of all carbon buried annually in the sea.

"Seagrasses only take up a small percentage of global coastal area, but this assessment shows that they're a dynamic ecosystem for carbon transformation," said James Fourqurean, the lead author of the paper and a scientist at Florida International University and the National Science Foundation's (NSF) Florida Coastal Everglades Long-Term Ecological Research (LTER) site.

Dense seagrass meadows are a hallmark of the Florida Coastal Everglades LTER site. Credit: Florida Coastal Everglades LTER Site

The Florida Coastal Everglades LTER site is one of 26 such NSF LTER sites around the world in ecosystems from forests to tundra, coral reefs to barrier islands.

"Seagrasses have the unique ability to continue to store carbon in their roots and soil in coastal seas," said Fourqurean. "We found places where seagrass beds have been storing carbon for thousands of years."

The research was led by Fourqurean in partnership with scientists at the Spanish High Council for Scientific Investigation, the Oceans Institute at the University of Western Australia, Bangor University in the United Kingdom, the University of Southern Denmark, the Hellenic Center for Marine Research in Greece, Aarhus University in Denmark and the University of Virginia.

Seagrass meadows, the researchers found, store ninety percent of their carbon in the soil--and continue to build on it for centuries.

In the Mediterranean, the geographic region with the greatest concentration of carbon found in the study, seagrass meadows store carbon in deposits many meters deep.

Seagrasses are among the world's most threatened ecosystems. Some 29 percent of all historic seagrass meadows have been destroyed, mainly due to dredging and degradation of water quality. At least 1.5 percent of Earth's seagrass meadows are lost every year.

The study estimates that emissions from destruction of seagrass meadows can potentially emit up to 25 percent as much carbon as those from terrestrial deforestation.

"One remarkable thing about seagrass meadows is that, if restored, they can effectively and rapidly sequester carbon and reestablish lost carbon sinks," said paper co-author Karen McGlathery, a scientist at the University of Virginia and NSF's Virginia Coast Reserve LTER site.

The Virginia Coast Reserve and Florida Coastal Everglades LTER sites are known for their extensive seagrass beds.

Seagrasses have long been recognized for their many ecosystem benefits: they filter sediment from the oceans; protect coastlines against floods and storms; and serve as habitats for fish and other marine life.

The new results, say the scientists, emphasize that conserving and restoring seagrass meadows may reduce greenhouse gas emissions and increase carbon stores--while delivering important "ecosystem services" to coastal communities.

The research is part of the Blue Carbon Initiative, a collaborative effort of Conservation International, the International Union for Conservation of Nature, and the Intergovernmental Oceanographic Commission of UNESCO.

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Scottingham
3.3 / 5 (6) May 22, 2012
We should GM up some hardy strain that can survive in the Mississippi delta region where there's currently a huge deadzone. It'd not only help clean the water headed out to see, but also store a huge amount of carbon!
extremity
2.7 / 5 (3) May 22, 2012
That would be a great idea. With a little oxygen that dead zone would flourish.
NotParker
2 / 5 (12) May 22, 2012
Why do they spoil what could be useful research with untrue items?

"As a comparison, a typical terrestrial forest stores about 30,000 metric tons per square kilometer, most of which is in the form of wood."

Not true.

"Forests are carbon stores, and they are carbon dioxide sinks when they are increasing in density or area. In Canada's boreal forests as much as 80% of the total carbon is stored in the soils as dead organic matter."

http://en.wikiped...#Forests
Anorion
4 / 5 (9) May 22, 2012
but parker, before it become dead organic matter and ultimately soil, it was wood, leaves, flowers,... aka living plant matter, and animal who ate that living plant matter. its only after death and decay that it become dead organic matter and back to soil at end of cycle.
when they say most of which is in the form of wood. not sure if they account only living wood or also dead wood.
but if we cultivate sea grass, maybe we would need also sea cows ^___^

Jayded
5 / 5 (2) May 22, 2012
what would be interesting to establish is whether other marine based plant species have a similar retention ability. it makes sense to me that if sea grass has that capability then much river or estuary growth may be similar.
extremity
3.3 / 5 (7) May 22, 2012
Anorion is right. You're thinking living trees as only being wood, but that is incorrect, and not what they say. Wood is the appropriate wood. Plant matter could have worked too.
extremity
2.1 / 5 (7) May 22, 2012
I think someone is just rating people with (1)'s for no reason...
Scottingham
1 / 5 (4) May 22, 2012
I think so too...ah well.

Anti-AGW troll bots?
extremity
1.7 / 5 (6) May 22, 2012
I think its just that if someone disagrees with you, whether you are right or wrong they 1 star you...
NotParker
1.8 / 5 (10) May 22, 2012
The problem I see is this part:

"The results demonstrate that coastal seagrass beds store up to 83,000 metric tons of carbon per square kilometer, mostly in the soils beneath them.

As a comparison, a typical terrestrial forest stores about 30,000 metric tons per square kilometer, most of which is in the form of wood."

I think most of the carbon is in the soils for forests AND seagrasses. But it is not politically correct to cut down trees.

El_Nose
2.1 / 5 (7) May 22, 2012
And I would like to point out - forests - or plants for that matter are not Carbon dioxide sinks, high school biology teaches you this.

all living things respire or go through a respiration process in which Oxygen is consumes to use the sugar that has been stored.

Yes plants use CO2 to make energy -- but to use that energy they have to take in an equal amount of O2 to use the sugar they just made. that is why forest store carbon in wood -- and if it decays then it goes back into the atmosphere.

cutting down forests and burying the wood is the best way to store carbon in the form of wood. Then let trees grow on top of the dump site -- rinse and repeat -- but its not worth the energy used to accomplish such an effort.

In fact deciduous forest drop their leaves in the winter. Thus do not perform photosynthesis and only respire in the winter -- and at night for that matter.

Funny how all living energy forms on this planet are linked to Carbon and Hydrogen.
NotParker
1.6 / 5 (11) May 22, 2012
Good point El Nose. The money quote for me when discussing trees is:

"Forests are carbon stores, and they are carbon dioxide sinks when they are increasing in density or area. "

Once they stop increasing in density or area (ie mature) they produce more CO2 than they sequester.
MikPetter
5 / 5 (2) May 22, 2012
Tan, Z.-H., et al., An old-growth subtropical Asian evergreen forest as a large carbon sink, Atmospheric
Environment (2011),
extract "The inventory data within the footprint of the eddy flux show that 6 tC / ha/ yr was contributed by biomass and necromass. The large-and-old trees sequestered carbon. Approximately 60% of the biomass increment is contributed by the growth of large trees (DBH > 60 cm)"
NotParker
1.6 / 5 (7) May 22, 2012

"Scientists from the University of Cambridge have concluded that enhanced tree growth in tropical forests could stimulate micro-organisms and lead to a release of stored soil carbon."

http://www.tgdail...n-levels

Howhot
3 / 5 (6) May 23, 2012
Ponder... does that mean your actually concerned about CO2 level increases Mr NotPark? Are you concerned you could actually be wrong?

NotParker
1.7 / 5 (6) May 24, 2012
Ponder... does that mean your actually concerned about CO2 level increases Mr NotPark? Are you concerned you could actually be wrong?



No. We live in the Holocene, a short break in the current ice age.

The Eemian was the previous break in the ice age, about 130,000 years ago. It was so warm: " The Hippopotamus was distributed as far north as the rivers Rhine and Thames."

The Eemian started out at 190ppm CO2, as it warmed because of the Milankovich orbital changes, CO2 followed temperature up to 290ppm.

Then the Milankovich cycle progressed and it cooled and CO2 dropped back down to 190ppm.

Then ice age conditions returned.

On top of that ... this solar cycle is on track to be the smallest in 100 years.

http://solarscien...ct_l.gif

That could be a huge disaster as temperatures may drop 1C to 2C.

It is looking like solar cycle 14 - 1902 to 1913.

1909 was coldest year in 20th century.
Howhot
3 / 5 (4) May 27, 2012
Oh, sorry Mr Park. Your answer is incorrect. Not factually but morally. Face it, You hate life on earth.

And factually, gobal data indicates we are tracking the "AL-GORE HOCKEY STICK" pretty well.

NotParker
1.8 / 5 (5) May 27, 2012
Oh, sorry Mr Park. Your answer is incorrect. Not factually but morally. Face it, You hate life on earth.


Unlike you, I happen to know plant life has adjusted and survived the cooling and warming from the Holocene Optimum to the Minoan Warming to the Roman Optimum to the Medieval Warm Period and through to the LIA and the recovery from the LIA.

Colder was really bad. Warmer resulted in humans and flora and fauna thriving.

And all those ups and downs were natural.

And factually, gobal data indicates we are tracking the "AL-GORE HOCKEY STICK" pretty well.


Read this article.

Graph #1 or proxies

Red = Hockey Stick Lies
Green = Reality

http://climateaud...temirov/