Monday, May 1, 2017

Familiar Biomes and Anthropogenic Biomes

As Polynesians conquered the Pacific, one place they didn't conquer was Alaska, because it is freaking cold there.  Plus, coconuts don't grow in minus thirty.

This is an important principle for understanding human migration, whether in a genealogical time-frame or in early prehistory.  People tend to stick to biomes they are familiar with because it is efficient to do so; and this is true in contemporary life.
Volgograd Oblast (Russia Trek.org)
When looking at genetic relatedness of people before the Bronze Age, we should expect that any natural environment like the one above will attract people who are adapted to it.  The picture above is near Volgograd, but it could easily be thousands of miles from there.  And you might end up thousands miles from there because of overgrazing.

Battle Axe, British Museum 1964,1201.1474AN780948001 (FI-000918735)

One of the more intriguing aspects to the third millennium of temperate Europe is the creation of new anthropogenic biomes.  It appears that people were opening up the canopies with axes and burning the understory, most likely to encourage perennial grasses.  The high esteem of the socketed axe in the CWC can be partly understood within this context.  It wasn't just a tool, it was the equivalent of a plow for the herdsman.

Where's the Forrest?  Salsbury Plain (Visit Wiltshire)
The Salsbury Plain wasn't always so.  It was cut and burned in the Bronze Age.  So who would do that anyway?

4 comments:

  1. I've read that the Yamnaya/Catacomb Culture(to form CWC) migrated into GAC & Funnel Beaker Culture areas because of overgrazed PC Steppe. Also, I believe 3000-2000 BCE, the climate warmed & dried. "When looking at genetic relatedness of people before the Bronze Age, we should expect that any natural environment like the one above will attract people who are adapted to it. The picture above is near Volgograd, but it could easily be thousands of miles from there. And you might end up thousands miles from there because of overgrazing." Indeed! The Volgograd Oblast Russia image reminds me of the Ohio River "bottoms" area in Indiana, USA. Many of the folks related to the Yamnaya, Catacomb Cultures, CWC did end up thousands of miles and an ocean away! (Hope to visit Germany, Denmark & Netherlands someday and see the CWC artifacts)

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    1. The Paleoecology of the Caspian steppe indicates an abrupt aridization occurred about the time of the steppe migration into Europe, among other places.
      At the end of the 3rd millennium the steppe was already deteriorating, but then it abruptly and completely went to heck.

      https://en.wikipedia.org/wiki/Dust_Bowl

      It's possible that is the reason for the suddenness of a steppe migration.

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  2. Regarding the clearing of forest. A fire will burn any brush or saplings in dry weather, but the big diameter trees are another matter. Unless you have drought conditions, the fire just won't last after the brush fuel burns out. So the best way to clear trees with large trunks is to pile up brush around them and burn the brush. Then, with your axe, chip out the charred black ash until you hit fresh wood, and repeat. Each big tree that comes down can contribute firewood for the next burns. It would take time to clear an entire forest, but in the meanwhile your animals are browsing in the openings. And the axe work is much less than lumberjack style.

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  3. Curious. I was reading recently a book about the archaeology and the evolution of the landscape of Galicia, NW Iberia, which comes to the conclusion that the natural landscape is anything but natural... Long story short, Galicia was covered by brushes and grassland 11000 years ago, but 4000 years later she was covered by a forest of, mostly, oaks. Then, the woodland cover descended to a 50%, showing probably the arrival of the European first farmers, but soon it increased to a 60%. All along this period the content of carbon in the soil increased slowly from ~0 to 0.5‰, but some +5000 years ago, suddenly, the oak forestland descended to a 20% and the carbon in the soil grew to a 3.5‰. Then, during the Bronze, Iron and Roman ages woodland recovered to a 40-50% and carbon in soil descended to 1-1.5‰. But again 1500 years ago, coinciding with the arrival and settlement of the Suebi (who arrived with the Vandals and the Iranians Alans), the woodland cover descended to a 10%, and the carbon proportion in the soil grew to a 4‰. Woodland didn't recovered to a 20% until recently.

    So... We know what happened 1500 years ago: the uneasy settlement of the Central-European Suebi... But what happened +5000 years ago? Something cultural, climatic, or a new people?

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