Pretty amazing drone video of a landslide at a peat bog in Ireland earlier this week. More details here: https://blogs.agu.org/landslideblog/2020/07/01/dawn-of-hope-1/
Peatlands: aquatic regulators
This is a peat marsh or peatland found in Belarus. Peat marshes are locations dominated by soil layers known as, well, peat, a mixture of organic material in various states of decomposition, produced by centuries of plants growing and dying in the same location.
Plants growing and dying on top of each other, like in this bog, will pile up thick layers of organic material mixed with large amounts of water. That soil will then serve as an anchor for additional plants to grow, stabilizing the water lines and the ecosystem over time. Those layers can then serve as homes for all sorts of additional plant and animal life, dependent on the stabilized peat layers.
Peatlands are hugely important for mankind. They contain large amounts of stored organic carbon in them, so if they are damaged or destroyed, that carbon will rapidly release to the ecosystem and the atmosphere. Protecting peatlands therefore is a key step in fighting climate change.
Peatlands in many areas are in fact under siege as they sit at areas where fresh water, like that found in a river, becomes stagnant. Draining peatlands can give water supplies useful for farming, electricity generation, and shipping, and can create land that people can build on. Every time this happens, the end result is going to be additional CO2 pumped into the atmosphere.
These systems also serve as natural barriers against the weather. Peat bog soils can be up to 90% water, making them dense and capable of absorbing the force of storm surges and waves. Thick layers of peatlands can serve as natural protectors for cities upstream from hurricanes and typhoons, but only if they’re left in place. If the city upstream diverts the water that sustains them, the city may enjoy the water supply, but it also can put itself at greater risk from the oceans.
-JBB
Image credit: EGU Open Access http://imaggeo.egu.eu/view/614/
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Bog bodies
One of legacies of the ice age spread all over northern Europe is a layer of peat (a precursor to coal, see http://bit.ly/2AdN5EL) formed of a mixture of partly decayed soggy oxygen poor plant matter and living sphagnum moss. Its low oxygen levels, acid and tannin contents and the cool temperatures of these boreal regions make it an excellent preserver of archaeological organic remains, from wood to bodies. Sadly the European peatlands are fast disappearing; victims to the garden compost industry, removing a major carbon sink in the process (see http://bit.ly/2BhKhDB).
Iron Age people in the continent all seem to have valued watery liminal places for worship and sacrifice, and many votive hoards of weapons or valuables have been found sacrificed in such boggy places, rivers, lakes and ponds. Other grimmer remnants have also turned up over the years, though the debate runs between murder, capital punishment and human sacrifice to explain the excellently preserved bodies and their accompanying marks of savage violence that grace museums all over the northern reaches of the continent. Their skins and hair are often reddish brown due to the effect of the acids and tannins that mummified and pickled them, though the acids have usually dissolved any bone.
Found from Ireland to Poland and averaging between 2-3000 years old (in the iron Age, though the oldest is 8,000), Denmark and the Ireland have turned up the highest densities, mostly found by accident by peat cutters, since it was the common fuel of the poor well into the 20th century. Humans are not the only species represented; dogs are common finds as well. Since the people who left them were pre literate there are no records of what they represent or why these humans (male and female) were killed, though the cultures involved mostly cremated their dead, sending their ashes down river or out to sea so these are not ordinary funerals. Tacitus in his Germania mentions the practice but without giving much detail and it is hard with Roman writing to distinguish truth from propaganda since the only history was written by the victors.
Most of these people met very violent ends and were mostly buried naked or wearing just a hat, often from multiple injuries that frequently combined strangulation, blows to the head from blunt objects and a slit throat before being gently deposited in the bog. Some of them are pinned to the ground symbolically with forked branches, while a few show signs of torture such as deep cuts beneath the nipples or of being slit open for their viscera to be examined for auguries (again a practice recorded by Roman historians, in this case Caesar discussing the druids in De Belle Gallico).
Many of them had intact stomach contents, providing useful insights into ancient diets, though their last sacrificial meals may have been untypical. Many seem to have been upper class with manicured unroughened hands, and tests on hair and teeth record good nutrition during their lifetime. While they have been appearing for centuries it wasn't until the advent of radiocarbon dating in the mid 20th century CE that the theories that they were all recent murder victims was put to rest, and modern forensics can tell us a lot about how they lived. Either way they provide one of the most poignant reminders of ancient times.
Loz
Image credit: 1 Grauballe Man, the main attraction of the Moesgaard Museum, died when his throat was slit Robert Harding / Alamy Stock Photo 2: Tollund Man was found just 40m from Elling Woman with a noose still around his neck: Robert Harding / Alamy Stock Photo) 3 Head of bog body Tollund Man. Found on 1950-05-06 near Tollund, Silkebjorg, Denmark and C14 dated to approximately 375-210 BCE. Sven Rosborn
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Earth, wind, fire, and water
This image, from the MODIS instrument on NASA’s aqua satellite, shows James Bay, at the southern tip of Hudson Bay in Canada, and the interaction of several different processes.
This image shows wildfires burning on the eastern shore of the bay, sending a plume of smoke and ash into the air over the water. The water is still partially covered by sea ice formed during the winter, and in places, the sea ice is stained by a combination of soot and sediment.
The brown sediments near the southern tip are produced by the peat bogs surrounding the bay. The spring melting season causes the bogs to flood and the peat bogs release tannins that stain the water brown, producing the colors seen in the southern part of the bay.
-JBB
Image credit: NASA/Aqua Satellite: http://earthobservatory.nasa.gov/IOTD/view.php?id=81556
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Penguin Slope, The Snares
The Snares Islands, located about 200km south of New Zealand are a small group of islands formed out of basement granite and metamorphic rocks. Remarkably, the soils are composed of up to 8m of blanket peat that hosts forest, scrub, grassland and herb fields (more on this in a future post!). These islands are home to the entire population (~60,000) of the vulnerable Snares Crested penguins - a small penguin standing up to about 40cm and weighing up to 3kg.
The penguins use the dense forest of the islands to roost in, building nests out of stones, dirt, sticks and leaves. Penguin slope is, as the name suggests, a vegetation-free section of granite that the penguins use to go to and from their nests in the daisy forest.
The Snares Crested penguins are in the 'red list' of threatened species, as defined by the IUCN (International Union for Conservation of Nature and Natural Resources). As the birds are confined to such a small breeding site, they are susceptible to natural perturbations, as well and human-induced events (e.g. oil spills and competition with fisheries). Currently, they are a rather under-studied species, and hopefully with better knowledge we can have a better understanding about their future.
-MJA
More info/references: http://bit.ly/29wokIx http://bit.ly/29q6NRn
Image credit: My own//Heritage Expeditions http://smu.gs/29xdFuA
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Terra Preta: A solution to the world's growing soil crisis?
As the UN International Year of Soils comes to a close (see http://on.fb.me/1Qqhbqz and links therein), I thought it fitting to inject an optimistic note into a somewhat bleak scenario. It tells a fascinating story of lost peoples who once lived in the Amazon basin who died out from the waves of disease of the early colonial period, taking with them an extraordinary skill: how to make excellent, long lasting, nutrient holding and self regenerating man made soil. Resurrecting this skill may prove crucial over the next half century, as we respond to increased soil erosion, desertification and global warming.
The name comes from the Portuguese for black land of the Indian, reflecting its long term fertility, which endures to this day, over 5 centuries since the last zones of the Amazon basin were filled with manmade earth, and some 2,500 years after the earliest patches. It is rich in charcoal (fired slowly at a low temperature, the porosity retains water, organic matter and nutrients), bone, organic waste and manure alongside large numbers of pottery fragments, all mixed into the leached lateritic (washed out of its nutrients by tropical rains) and infertile soil of the Amazon Basin.
It has a high organic content, some 14% in its top A horizon. Somehow it retains its stability and nutrient content for a very long time, which in the wet climate of the tropics is no mean feat. Terra Preta also has high levels of active microbes, which promote growth and good soil chemistry. The most amazing bit is its capacity to renew itself, sequestering even more carbon into its organic content, as established by pedologists at Kansas University.
The main burst of creation of this wonder stuff was in the 1,500 years between 450BCE and 950CE, and the deepest are some 2 metres thick. This implies a multi generation project by those who lived on the land, ever recycling their organic waste and ash into the local soil on which they depended, permanently enriching it, though it now self renews at a rate of 1cm or so a year.
Estimates by various researchers of the scale of the project range from 0.1/0.3% of the Amazon basin having been enriched by man, through to about 10%. The crests of higher terraces above the rivers were the most usual geography where they chose to perform their enrichment, but specially built lenses in interfluvial zones and small hectare sized patches exist. A less enriched zone (known as Terra Mulatta) around the fertile core was enriched only with some charcoal. Plots average 20 hectares, but areas as large as 360Ha exist.
The peoples who built them are probably still living in the Basin, but went nomadic after the demographic crisis, partly in order to escape enslavement by the colonialists. They had (so the earliest reports suggest) a dense agrarian population, whose relics are only now really coming to the serious attention of archaeologists.
Similar soils have also turned up in Ecuador, Peru, French Guinea, Benin, Liberia and South Africa, showing that the idea occurred to other peoples elsewhere. Many scientists are working to recreate a modern version (look up biochar), and hopefully we will be able to use it to feed more people with a lighter footprint on the tired soils of our planet. There are also potential opportunities for long term carbon sequestration being explored. So, there you are, please share this hopeful post, and those of you with green thumbs who like gardening, feel free to research (some good starting links below) how to make it and try it out for yourself.
Loz
Image credit: from the Peruvian Andes, Pacific Biochar
http://bit.ly/1JLqyIW http://bit.ly/1ICrZyM http://bit.ly/1Ku8gBK
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Peat bog the size of England will help unravel Congo Basin's climate history.
Peat is a predecessor to coal, the partly rotted remains of plant life that contain a large proportion of organic matter, formed in low oxygen conditions that inhibit decay. It turns into the latter due to the heat and pressure as the peat is gradually covered in further sediments and the temperature and pressure increase, baking it into various grades of coal, from lignite to anthracite. They usually form in colder environments, since low temperatures inhibit rotting, so there was considerable surprise when satellite data implied a huge one was sitting pretty in a remote part of Africa's largest river basin spread over both the Congos (Kinshasa and Brazaville).
Researchers followed up the satellite data, venturing deep into the jungle on a 3 week trek in roadless areas to confirm the bog's existence, and found a layer some 8 metres thick gently accumulating. Not only has a major carbon sink been confirmed, but a careful analysis of the layers, their chemistry and the kinds and proportions of plant remains (including pollen) within should give us unprecedented climate data in a region whose history is poorly known. As one of the world's great basins it affects both regional and global climate, and being able to trace its internal evolution through this bog will help resolve the many complex interconnections within and between regions that form global climate. This in turn will allow more precise modelling of future climate in a fast changing world. We don't know yet how long it has been growing, but the team suggests at least 10,000 years.
The marsh is only accessible in the two months at the end of the dry season when the water level has fallen, but the team still had to build platforms to pitch their tents or cook due to the waterlogged conditions. Gorillas, elephants and crocodiles also complicated the expedition's progress, since this area is a haven for wildlife, being sparsely inhabited for obvious reasons. Such a major discovery also shows how there remain some places on our planet that are hard to reach and little spoiled, thanks to being uninhabitable by anything more complex than small groups of hunter gatherers.
Loz
Image credit of a peat bog in Tierra del Fuego, Argentina: Yann Arthus-Bertrand/Corbis
http://bbc.in/1jUGBeT http://bit.ly/1kma2H6 http://bit.ly/1k9fZIi
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Peatlands as a Carbon Sink In the past century, peatlands around the globe have proven to be particularly important as a long term sink for carbon. Though not very dramatic from afar, changes in peatland systems due to nitrogen deposition are now becoming quite prominent, particularly in the Northern Hemisphere, where loading of nitrogen has the capability to change large portions of the system and potentially decrease the system’s ability as a carbon sink. As 30% of the world’s soil carbon pool is stored in peatlands, a change in cycling of chemicals like phosphorus, potassium, and particularly nitrogen can have profound implications for global carbon concentrations, by creating changes in plant composition and size, and thus the system’s ability as a net sink, possibly even making the peatland’s chemical cycling a source of atmospheric carbon. Nitrogen can be introduced as a pollutant as reactive nitrogen from processes like fertilizer manufacturing and combustion of fossil fuels, as well as leaching from agricultural runoff and atmospheric deposition, which is a particular issue in the Northern Hemisphere, where boreal wetlands and peatlands cover a great deal of land. Wetlands are considered to cover between 4 and 6 percent of the Earth’s surface, of which peatlands comprise about 2- 3 percent. Wetlands are generally areas where the water table is at or near the soil level in an area, and wetlands can be with or without organic soil (peat). Current research utilizes eddy covariance techniques to measure exchange rates of trace gases in areas like peatlands, and can measure respond to chemical influx in controlled experimental areas. Understanding differences between short term and longer term effects of manipulations on a peatland system (draining, warming) is crucial, and has been described as the difference between “changed climate” and “climate change”. The former is the introduction of a disturbance to the equilibrium to the system (manipulation studies), and the latter is the longer term response of the system. So, scientific studies offering a glimpse at either long-term or short-term effects of changes to peatland systems will certainly prove to be especially powerful in the coming years. -BN Photo Credit: Self. Mer Bleue Bog in Ottawa, ON Further Resources: http://www.ipcc.ch/ipccreports/tar/wg2/index.php?idp=274 http://forest.mtu.edu/faculty/chimner/wetlandlab/carboncycling.htm http://www.scottish.parliament.uk/ResearchBriefingsAndFactsheets/S4/SB_12-28.pdf http://www.fao.org/docrep/015/an762e/an762e.pdf
Sunset This photograph of a fall sunset over Hücker Moor in Northwest Germany is impressive enough that I thought it could have instead been a painting on a museum wall somewhere. This lake is a moor, a boggy area dominated by grasses and peat. The peat in this area was, in the last century, cut out from here and used as a fuel source, leaving behind the calm scenery seen here. -JBB Image credit: https://www.flickr.com/photos/blavandmaster/10783979146
Peatlands: aquatic regulators This is a peat marsh or peatland found in Belarus. Peat marshes are locations dominated by soil layers known as, well, peat, a mixture of organic material in various states of decomposition, produced by centuries of plants growing and dying in the same location. Plants growing and dying on top of each other, like in this bog, will pile up thick layers of organic material mixed with large amounts of water. That soil will then serve as an anchor for additional plants to grow, stabilizing the water lines and the ecosystem over time. Those layers can then serve as homes for all sorts of additional plant and animal life, dependent on the stabilized peat layers. Peatlands are hugely important for mankind. They contain large amounts of stored organic carbon in them, so if they are damaged or destroyed, that carbon will rapidly release to the ecosystem and the atmosphere. Protecting peatlands therefore is a key step in fighting climate change. Peatlands in many areas are in fact under siege as they sit at areas where fresh water, like that found in a river, becomes stagnant. Draining peatlands can give water supplies useful for farming, electricity generation, and shipping, and can create land that people can build on. Every time this happens, the end result is going to be additional CO2 pumped into the atmosphere. These systems also serve as natural barriers against the weather. Peat bog soils can be up to 90% water, making them dense and capable of absorbing the force of storm surges and waves. Thick layers of peatlands can serve as natural protectors for cities upstream from hurricanes and typhoons, but only if they’re left in place. If the city upstream diverts the water that sustains them, the city may enjoy the water supply, but it also can put itself at greater risk from the oceans. -JBB Image credit: EGU Open Access http://imaggeo.egu.eu/view/614/ Read more: http://www.doeni.gov.uk/niea/biodiversity/habitats-2/peatlands.htm http://www.wetlands.org/Whatarewetlands/Peatlands/tabid/2737/Default.aspx http://www.peatsociety.org/peatlands-and-peat/what-peat