Siberia 2012: Progress along the EmbenchimeJuly 14th, 2012 by Joanne Howl
Embenchime River 66° 2 min N 97° 49 min E
11:30 p.m. Siberia 11:30 a.m. EDT
71°F High 44°F low Sunny
Dr. Ranson reports:
We fought the river again today, but in the end, we have been successful. We’re now tucked away in camps – the one we wanted to reach yesterday. Again, our trip was a long struggle against the shallows and small rapids. Each spot is about 50 to 100 feet long, and filled with rocks. To get around them, we have to get out and pull the boat. Slava calls these rocky ripples “dragon’s teeth”, because they are sharp and will eat our boats if we let them. We’ve been careful, but the bottom of our boats have suffered, anyway.
We left camp late today, about 2:30 p.m. We got up early, but there was work to do, such as repairing the boats from yesterday’s rough river ride. We spent over 6 ½ hours on the Embenchime today, to go about 17 kilometers straight-line down river. Because of all twists and turns, we actually travelled 20 or 25 kilometers (12 to 15 miles). But still, that’s something like 4 or 5 kilometers an hour – that’s just two or three miles an hour. We could walk faster than that! But we have too much gear to carry on our backs, so that’s not an option. We’ll stick to the boats, and hope for deeper channels.
We were fortunate in our campground last night. This morning, Slava walked over the hill, and discovered an area where fire had burned about 60 years ago. This morning Slava and Sergei worked that area, collecting samples for the fire return studies. He was quite pleased, and gathered a good deal of useful samples.
Collecting data for fire return studies is a bit more invasive than our tree measurements. To learn a tree’s history, unfortunately, the tree must be sacrificed. We need to collect a disc all the way through the truck, so that we can count the age, look at growth rings, as well as to see when fires singed the bark. We get a tremendous amount of information out of each sample, but Slava makes careful selections, because we don’t want to be cutting down the forest. We sample very carefully and selectively. When we measure trees, we take measurements of every tree above 5 cm in diameter in our study plot. When Slava takes fire return samples, however, he will take only one or two carefully selected trees in the forest.
In order to gather his samples, Slava begins by locating an area that appears to have been affected by fire in the past. He likes to find trees that have a burn scar visible on the trunk. That way, once the sample has been collected, we have a positive date for one fire. He can then carefully analyze the growth pattern, and if there are any other fire scars inside, he can date the years between the fires.
Once a tree is scarred by fire, it keeps that mark for life. As it ages, the trunk will grow over the wound, and it no longer will be visible on the living tree. But the tree carries that mark, inside, for life. That’s what Slava is looking for – the internal scars to compare against external scars.
When we look at a forest, we can often tell if a fire has passed by in recent years. We can’t tell the distant past – that’s why we need the fire return samples. But we can tell if fire has scorched the trees in more recent times. The biggest clue is when we see a stand of scattered old trees that are dead or dying, surrounded by a thick growth of younger larch, all of the same age. Because fire damages or kills standing at the time of the fire, as well as provides great conditions for larch regeneration, a few years after a fire you get this pattern – a few sad old trees, surrounded by vigorous new growth.
We actually are seeing a lot of these spots along the river – areas with lots of big trees surrounded by heavy larch regeneration. So this area definitely has burned in years passed, but not very recently. The new trees look young and small, but it takes a long time for them to grow in this area, with the cold and harsh winters. Near our campsite, the new trees look pretty small, but we are estimating they are at least 60 years old. As the climate warms, however, we expect to see the regeneration grow more quickly. It’s been warming in this area for the last several decades, so we have to be a bit cautious in our age estimations. We’ll confirm the age by counting growth rings on the samples Slava has collected.
When a tree dies in northern Siberia, it doesn’t decompose like you would expect. We’re used to the southern climates, where decomposition is relatively rapid. But it’s cold and dry here, and dead trees stand for a very long time. We have written papers on fire return, not on this very spot, but in similar areas in Siberia, where we studies forests where the trees that had died in the Little Ice Age – back in the 1500’s – were still standing. Those trees are still here, 700 years or so later, with very little decomposition. Should the climate warm, we would also expect the rate of decomposition to pick up quickly. The old, dead trees of Siberia are holding a lot of carbon in their trunks. When they begin to decompose, that carbon will be released – one of the many reasons that the boreal forests, which are now considered carbon sinks that help slow climate change – may become carbon sources in a warming world.
We also have studied the line between the forest and the tundra. Trees can only survive under certain conditions, and in the far north, and at high elevations, the conditions become too harsh to support even the tough Larch trees. That’s where the forest – the taiga – gives way to the scrubby grasslands, which is called the tundra. We call this transition zone the taiga-tundra ecotone. We are interested in finding where this line lies today, and how it has changed from the past. We also are very interested in how it is changing.
Because dead trees stand so long here, we can find the tree line at the time of the Little Ice Age pretty easily, by looking at where those long-dead, or “fossil trees” are located. And we can compare that line to the very easily located modern taiga-tundra ecotone.
What we are seeing – and are able to measure and document – is that the forests are now surpassing the historical extent of those ancient forests. Trees are extending further north and at higher elevations that ever recorded before. That’s not just happening here, but also in the Sayani and the Altai mountains – and has been documented in many other places in the boreal forests, as well. The prediction is that as the climate warms, forests will continue to push upslope. This has been clearly happening for the last several decades. Scientists will continue to make these measurements, to track what is happening now, in the decades to come.
As for tomorrow, we plan to stay put and measure. We are close to a line of GLAS plots, and we’ll work those plots. However, it looks like the GLAS line heads up a river and up a steep hillside. That’s not so good. It’s hard to get to the plots, sure, but that’s not the real problem. The big problem is that, because GLAS was created to measure ice, not vegetation, that the GLAS data has some real limitations. It’s not that great for vegetation to begin with, but it’s particularly poor in steep slopes. We’ll get the data, however, so maybe we can learn something that will help us better use GLAS. But we really, really need an instrument designed for vegetation. The boreal forests are really important and we need a tool designed for measuring vegetation. We’re working on the problem – we’re hopeful that the G-LiHT system will prove useful. But our need is very great.
For now, we’ll spend tomorrow making measurements for the old (GLAS) and the new (G-LiHT) instruments, and we’ll look for potential fire return study samples. And we’ll also try to figure out how to get to Tura on time. It’s a balancing act – we have limited time, and we have need for time to measure, and more time than planned to travel.
We also need some time to repair our boats, and to dry out our generator and other gear that got soaked in the boats, because of all the leaks. It’s ironic – now that the data terminal works just fine, we lose our ability to connect because of a wet generator! It will dry, and will be fine. It’s just a communications delay, not a disaster.
At dinner tonight, talked about the river – its virtues and its evils. The Embenchime is a hard river. It makes us work in order to gain headway. The rapids, the shallow water at every turn, and so very many turns – this is so difficult. We want to go fast, but the Embenchime holds us back.
On the other hand, the Embenchime is incredibly scenic, and very beautiful. Today was sunny, with clean blue skies decorated with white clouds. A few mares tails were wispy in the sky, with high cirrus clouds scattered about. It was warm today, but the waters of the river were cool and refreshing At times, the Embenchime is kind and pleasant. But at every turn, she is also so very harsh.
We’re hoping that we will see more virtues and less evil as we head further down river. There will be some tributaries joining soon, and we hope that will mean more water and an easier ride. But the river will, no doubt, continue be what it is – both beautiful and difficult.