Forests burnt in Ice Age Europe

Quickies

Jed O. Kaplan et al., Large Scale Anthropogenic Reduction of Forest Cover in Last Glacial Maximum Europe. PLoS ONE 2016. Open access → LINK [doi:10.1371/journal.pone.0166726]

Abstract

Reconstructions of the vegetation of Europe during the Last Glacial Maximum (LGM) are an enigma. Pollen-based analyses have suggested that Europe was largely covered by steppe and tundra, and forests persisted only in small refugia. Climate-vegetation model simulations on the other hand have consistently suggested that broad areas of Europe would have been suitable for forest, even in the depths of the last glaciation. Here we reconcile models with data by demonstrating that the highly mobile groups of hunter-gatherers that inhabited Europe at the LGM could have substantially reduced forest cover through the ignition of wildfires. Similar to hunter-gatherers of the more recent past, Upper Paleolithic humans were masters of the use of fire, and preferred inhabiting semi-open landscapes to facilitate foraging, hunting and travel. Incorporating human agency into a dynamic vegetation-fire model and simulating forest cover shows that even small increases in wildfire frequency over natural background levels resulted in large changes in the forested area of Europe, in part because trees were already stressed by low atmospheric CO2 concentrations and the cold, dry, and highly variable climate. Our results suggest that the impact of humans on the glacial landscape of Europe may be one of the earliest large-scale anthropogenic modifications of the earth system.

Not sure what to think, really. In any case the data they manage and share with us is very much worth taking a look at.

Revisiting Bocquet-Appel 2005: the population of Europe in the Paleolithic.

Something I want to do in this new blog is to revisit some areas that I have explored in the past, hopefully with an improved approach. One of the key elements in understanding European Prehistory as a whole is the demographics of Paleolithic Europe.  Nothing better surely than this excellent survey of archaeological density and corresponding population estimates:

Jean-Pierre Bocquet-Appel et al. Estimates of Upper Palaeolithic meta-population size in Europe from archaeological data. Journal of Archaeological Sciences 2005. (PDF).

The paper evidences the demographic growth, specially after the Last Glacial Maximum (LGM), when it really explodes (from 5900 to 28,700 - average figures). 

But maybe even more interesting is the demographic tendencies of the various regions. Most outstandingly, the Franco-Cantabrian region comprises almost half of the all Europeans early on, reaching to 2/3 in the LGM.

Second is the Danube region, with 20-25% in the early period and a marked decrease in the LGM. Third is the related Rhine region with 6-9%, sharply declining to near zero in the LGM. 

These three regions are fused in the latest map (Late UP, Magdalenian), including together 95% of all Europeans some 15-10,000 years ago. These would be then something between 11,000 and 73,000 individuals, average: 29,000 (more than 27,000 in the Magdalenian area). 

Fig. 5 (2nd part). Population estimates for LGM (top) and Late UP (bottom)

Less important regions are East Europe (4% in the Gravettian era, declining after that) and Iberia (7% in the LGM, much less in the next period). Italy is not mentioned but does indeed show some sparse continuity (Gravettian/Epigravettian).

You can easily compare these maps and those of the patterns of R1b1b2a1a2; it seems clear to me that the best possible explanation for its subclades' dispersion patterns is at the post-LGM stage.