Vegetation and Climate

silver, and copper, to various mineral ores.7 Copper is the most common metal, with notable concentrations in the central south Caucasus, forming an arc around the top of Lake Sevan and also extending along the spine of the main mountain range. Gold is well represented, too, both as primary and placer deposits, and cover the same general areas as copper, though with far fewer occurrences. Silver, on the other hand, is conspicuous for its scarcity with the north-east mountains of Dagestan harbouring the majority of deposits. The presence of tin, in the form of cassiterite and stannite deposits, located along the central region of the Greater Caucasus, is particularly noteworthy, given that the region is characterised, as we shall see, by arsenical bronzes in the earliest stages of metallurgy. Finally, there is iron. Here again the basins of the Kura and Araxes rivers are peppered with many deposits.

VEGETATION AND CLIMATE

Dramatic altitudinal differences require vegetation in the Caucasus to be categorised into zones based on both height above sea level and horizontal spread. Seven such zones have been recognised, which incorporate fourteen regional sequences.8 The driest area is a narrow strip of desert vegetation located along the shore of the Caspian Sea north of Baku. Semi-deserts are located considerably higher. In southern Armenia and Nakhichevan, the upper boundary of mountainous xerophytes is 1,500 m, gradually dropping to 250 m where they merge with arid woodlands. Steppes are particularly prevalent in the northern foreland where various species of Stipa (feather grass) cover vast areas. Grasslands also occur in Armenia and the adjacent region of Dzhavakheti, though in some areas they are a recent development, having replaced woodlands as areas were cleared in recent centuries. Sparse arid woodlands survive in parts of eastern Georgia, Azerbaijan, and Karabakh, and trees mostly comprise pistachio (Pistacia mutica), pear (Pyrus salicifolia), and Caucasian hackberry (Celtis caucasica). Below them, various shrubs and grasses cover the ground. Montane forests vary greatly in the Caucasus depending on altitude, precipitation, humidity, and temperature.9 There are oak trees along the southern foothills and the Surami massif,and in northern and eastern Armenia.Beech forests, on the other hand, stretch along the full length of the Caucasus Mountains, where pine forests have a more restricted distribution in the central region. Girding the humid lowlands of Colchis, characterised by marshy pedalfers and red and yellow soils, are chestnut forests and dark coniferous forests (firs and spruce), which reach out into the Pontian (Colchis) Mountains and foothills, where humus-carbonate soils are widely distributed.

7 Courcier 2010: 76–9, map 2; 2014: 579. See also the map in Gambashidze and Stöllner 2016: 22.

8 Gulisashvili et al. 1975;Volodicheva 2002: 363–73.

9 Volodicheva 2002: fig. 15.6.

When we come to examine the archaeological evidence, we need to bear in mind the changes in vegetation through time. This will inform us on the setting of sites and how human communities managed their prehistoric environments. Some of the clearest palynological evidence is to be found for the Tsalka Plateau and the Samtskhe-Dzhavakheti region, in southern Georgia, which today comprises three broad vegetation zones: semi-arid steppe lowlands where Chenopodiaceae and grasses are preponderant; a forest belt covered by deciduous trees, especially oak (Quercus); and the high altitude region above the snow line where pine (Pinus) and Poaceae form the main vegetation. To determine the accuracy of the ancient pollen evidence, a useful test is to verify the relationship between modern pollen and contemporary vegetation.

Are they comparable? Although the correspondence is not exact, Simon Connor concludes that for southern Georgia, at least, it is on the whole trustworthy.10 The main discordance derives from the high levels of grasses (Poaceae), whose pollen morphology does not enable the distinction between plants from the wetlands and dry land, and thereby makes them ‘a major source of “noise” in the pollen data from this region.’11 Another factor to consider is the pollen production characteristics of various plants. Some trees such as ash (Fraxinus) and hazel (Corylus) that grow in the lower tree line, for instance, emit a limited quantity of pollen. Xerophyte scrub, too, is very difficult to detect in a pollen spectrum, and its presence is established by association, namely by high levels of Plantago and Artemisia. By contradistinction, trees such as pine (Pinus) have a very efficient pollen dispersal system, accounting for the abundance of its pollen. Finally, there is the human factor – the impact that farmers and stockbreeders have had on the environment.

Connor has provided a very clear and detailed synthesis of palynological research in Georgia.12 Here we focus on two important pollen cores Connor took from lake sediments in the Tsalka (Trialeti) Plateau. One is the pollen diagram from Lake Aligol that stretches back 14,350 years; the other is the core taken from the deposits at Lake Imera, which covers the past 7,000–8,000 years (Figures 1.2 and 1.3).13 In the earliest pollen zone of the Lake Aligol core, corresponding to the late-glacial period, the region was a hyper-arid desert or semi-desert steppe landscape.This is indicated by the preponderance of Ephedra, juniper (Juniperus), wormwood (Artemisia), and goosefoot (Chenopodiaceae).As in other parts of the Near East, the climate was most severe around 10,000 BC during the ‘Younger Dryas’ stadial.Then precipitation began to rise and with it the region witnessed an expansion of tree species such as hazel (Corylus) and birch (Betula), within an otherwise arid, open steppe.

10Connor 2011.

11Connor 2011: 87.

12Connor 2011.

13Connor and Sagona 2007: 23–6.