A Forest Grows in Antarctica Antarctica, for the most part, is a lifeless continent of rock and ice. Over the last 15 years, scientists have come to believe that the stark and frigid landscape we see today has existed for a very long time; the climatic message embedded in sea sediments is that once an ice sheet enveloped East Antarctica 15 million years ago, it never let go.
Now, however, scientists working on the continent itself have uncovered the wooden remains of what they believe was an extensive forest that flourished only 400 miles from the South Pole about 3 million years ago.
The idea of a permanently ice-clad Antarctica first began to melt a few years ago when Webb, a paleontologist at Ohio State University in Columbus, and his co-workers discovered marine microfossils in the Transantarctic Mountains (SN: 7/2/83, p. 6). Webb concluded that 4 million years ago, as well as at earlier times, the ice sheet had retreated and seaways stretched across East Antarctica. Then, when the sheet advanced, it carried the fossils from the ocean basin to the mountains.
The new find of roots and stems of wooden plants and of pollen in an area stretching about 1,300 kilometers along the Transantarctic Mountains means not only that the ice retreated but also that the climate was warm enough to support a shrublike beach forest. "The presence of the wood means that there was deglaciation on a major scale, with conditions radically different than they are today," says David Elliot, chief scientist of the recent National Science Foundation polar expedition, of which Webb's group was part. "This is a very significant find." Webb thinks the forest region a few million years ago must have resembled the present-day fjords of Chile and Norway.
According to Webb, before the forest developed, the region was covered by a considerable amount of ice. So an important question is where the forest and pollen came from. "Had the forest been living there all the time, and are we overestimating the severity of the earlier glacial record?" he wonders. Had life developed on its own in Antarctica? Or had the plants and pollen been carried to Antarctica from other continents?
Webb notes that 40 million years ago, Antarctica was the middle link in a migration path for marsupials and other life traveling from South America to Australia, when both continents were much closer to Antarctica. By a few million years ago, Australia had moved very far away from Antarctica, so that "any migrations that took place along the same route would have come to a rather disastrous end," he says. "However, in my wilder moments I think that Antarctica may have received these migrations from lower latitudes." Just in case, Webb's group is on the lookout for remains of insects and other creatures that might have lived in the Antarctic forest.In addition to finding evidence that the recent glacial history of Antarctica is more dynamic than was previously thought, Webb's group concluded that the continent may have been more tectonically active as well. The researchers discovered that the deposits containing the wood fossils are sliced by faults, which displaced sediment layers by as much as 1,000 meters. This indicates that the Transantarctic Mountains have risen very rapidly in the last few million years. Previously scientists had assumed that they had risen slowly, over a 40-million-year period
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Antarctica was the middle link in a migration path for marsupials and other life traveling from South America to Australia, when both continents were much closer to Antarctica.
This is topographic map of Antarctica after removing the ice sheet and accounting for both isostatic rebound and sea level rise. Hence this map suggests what Antarctica may have looked like 35 million years ago, when the Earth was warm enough to prevent the formation of large-scale ice sheets in Antarctica.
Isostatic rebound is the result of the weight of the ice sheet depressing the land under it. After the ice is removed, the land will rise over a period of thousands of years by an amount approximately 1/3 as high as the ice sheet that was removed (because rock is 3 times as dense as ice). Approximately half the uplift occurs during the first two thousand years . If the ice sheet is removed over more than a few thousand years, then it is possible that a majority of the uplift will occur before the ice sheet fully disappears.
As indicated in the map, Antarctica consists of a large continental region (East Antarctica) and group of seas and smaller land regions (West Antarctica). Since the West Antarctic ice sheet is partially anchored below sea level, this region is less stable and more likely to be affected by global warming. Even so, it is likely that during the next century increased precipitation over Antarctica will offset melting.
Even in the event of severe sustained warming, it would take many thousands of years for Eastern Antarctica to be fully deglaciated.
""Boys," said the senator, "remember the words of Chairman Mao: It's always darkest before it's totally black." - John McCain
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Don’t ever let anyone tell you that there are no forests in Antarctica. There are! The forests are forests of large brown macroalgae, also called seaweeds, here along the western Antarctic Peninsula. Pretty much every dive we make at Palmer Station is a dive into a forest, or at least it starts and ends that way.
The biggest “trees” in the forest are four species: Desmarestia menziesii, Desmarestia anceps, Himantothallus grandifolius, and Cystosphaera jacquinotii. Over on the right side of this post you can see still photographs I’ve taken of some of these. But still photos don’t really convey the extent of these forests. Videos do not completely do so either, but come closer.
One new thing we are doing this season here on UAB in Antarctica is putting up videos from our stay here. If you click on the YouTube link that is below the photos on the right you’ll be taken to our UAB in Antarctica YouTube Channel. We’ll try to post short, informal videos of our life here regularly. But we also have two videos there that are a little longer and have information on the undersea life.
If you click on the following link to The Forests of Antarctica it will take you to a new page or tab with the video on the macroalgae. There you will see more still photographs along with underwater video of all four of the main, large brown seaweeds that dominate these communities.
There are three types of macroalgae and they are color coded: brown, red, and green. The difference in color is because they have different types of pigments which capture light and channel it to a pigment they all share, chlorophyll a. Special chlorophyll a molecules bound to special proteins are able to pass the energy from the light to other proteins. These other proteins use it to take carbon from carbon dioxide molecules in the water and convert them into sugars.
The plants then use the energy stored in the sugar and the carbons connected into the sugars themselves to grow. So instead of getting energy and carbon-based molecules for growth from eating other things like animals do, like plants, macroalgae capture their own energy from sunlight. I like to say that algae and plants suntan for a living. Good work if you can get it.
Brown macroalgae dominate the undersea forests here in terms of covering the bottom. In many places, nearly 100% of the bottom is covered by them as you can see in the video. The biomass, or total weight, of all the macroalgae in these locations is comparable to what you would find in a giant kelp forest off the coast of California. When I said these are forests, I wasn’t joking!
Even though brown algae are the kings in terms of biomass, red algae are the kings in terms of numbers of species. There are more species of red macroalgae here than there are browns, so they are very important in terms of the biodiversity of the area. They can be numerically dominant at some places too, although in my experience mostly in very shallow waters. They are often the most abundant macroalgae growing in deeper waters on vertical walls where we also find lots of bottom-dwelling invertebrate animals.
In very deep water – water too deep for us to dive to the bottom in and also too deep for enough sunlight to penetrate to allow the macroalgae to grow – the invertebrate animals take over. If we go to deep (30-40 m, or 100-130 feet) depths on vertical walls the macroalgae do not grow quite as well as otherwise so the animals can grow there with them without getting smothered. We will have another post later on about these animals, but if you would like to see video on them, just click on the YouTube channel link on the right and select the “Invertebrates at Palmer Station” video.
I’m a phycologist, which means that I am a scientist who studies algae (“phycos” is the Greek word for algae). These rich macroalgal forests at Palmer Station are a wonderful place to me! We’ll look forward to telling you about ways these forests are unique compared to undersea communities in other parts of the world in upcoming posts.They should plant trees in Antarctica.Forestry if they had a proper government and became a country then a tree planting program could start to make manmade forests there. http://marvel.com/universe/Savage_Land http://en.wikipedia.org/wiki/Savage_Landhttp://www.mbendi.com/indy/agff/an/aq/index.htm http://penrose-press.com/forestry/antarctica.idd