Pastoralist Settlement Ecology

(Kazakhstan)

Archaeological context and methods:

For pastoralists, perhaps the most important resource to their subsistence economy is green pasture.  In the Dzhungar Mountains of eastern Kazakhstan, the size and productivity of pastures are directly correlated with seasonality and altitude.  As a general rule, high altitude pastures (> 1400 m.a.s.l.) are more than three times as productive as pastures below 800 m a.s.l.

The environment of eastern Kazakhstan varies between sandy deserts, semi-arid grasslands, open steppe grasslands, and mountainous regions.  The ecological variation between these gross zones is associated with extreme differences in precipitation, annual temperature change, soil quality, and elevation, all which affect the potential strategies for human occupation in each zone.  In the Dzhungar region for example, the annual cycle of the continental climate traditionally played a considerable role in the patterns of movement of both animals and nomadic populations, especially in the mountain and desert regions where the difference between summer and winter pasture resources is pronounced.

To accurately render the pasture resources in the Koksu Valley of Kazakhstan, an NDVI (Normalized Difference Vegetation Index) image was calculated in ERDAS Imagine using Landsat TM 7 base data. An NDVI image assigns values ranging from –1 to 1 to land-cover, according to the intensity of reflected chlorophyll in the vegetation (i.e. “greenness”).   Using ArcGIS 8.2, the NDVI image was reclassified, assigning qualitatively ranked “productivity values” to vegetation indices greater than 0.  Vegetation indices less than 0 represent poor vegetation coverage, i.e. areas of inadequate pasture potential.  This revalued NDVI image was then resolved into four classes of grassland types according to known botanical composition of pastures at various altitude horizons.  These include:  1) Alpine meadows; 2) Sub-alpine meadows; 3) Mountain steppes; and 4) semi-arid steppes. With a proposed map of the summer pasture resources we can then begin to model the potential movements of pastoral groups across the landscape.

This pathway map reflects the widest scale possibility for traveling across the landscape, provided good grass resources, and as pathways flow into one another (i.e. share a common track), the pathway is ranked as more likely (i.e. given a higher value).

Discovery Highlights

In the Dzhungar Mountains of eastern Kazakhstan, the size and productivity of pastures are directly correlated with seasonality and altitude.  As a general rule, high altitude pastures are more than three times as productive as pastures below 800 meters.

The ecological variation between these gross zones is associated with extreme differences in precipitation, annual temperature change, soil quality, and elevation, all which affect the potential strategies for human occupation in each zone. 

Using a variety of technological methods to measure pasture resources, we can thus begin to model the potential movements of pastoral groups across the landscape.

Relevant Publications:
2008  FRACHETTI, Michael D. Variability and dynamic landscapes of mobile pastoralism in ethnography and prehistory.  In The Archaeology of Mobility: Nomads in the Old and in the New World, eds. H. Barnard and W. Wendrich, 366-96. Cotsen Advanced Seminar Series 4. Los Angeles: Cotsen Institute of Archaeology, UCLA

2006  FRACHETTI, Michael D.  Digital archaeology and the scalar structure of space and time: modeling mobile societies of prehistoric Central Asia.  In Digital Archaeology, eds. Evans T. and P. Daly, 128-47.  London: Routledge.

2006  FRACHETTI, Michael D.  The Dzhungar Mountains Archaeology Project: Reconstructing Bronze Age life in the mountains of Eastern Kazakhstan. In Beyond the Steppe and the Sown, eds.D.L. Peterson, L.M. Popova and A.T. Smith, 122-41.Boston: Brill Academic Publishing

2003  Aubekerov, B. Zh., S.A., Nigmatova, and Michael D. FRACHETTI. Geomorfologicheskie Osobennosti Raiona Arkheologicheskogo Pamyatnika Begash Severnoi Dzhongarii (Geomorphology of the region and archaeological monument of Begash, Northern Dzhungaria). In Aktual’nie Problemy Geosistem Aridnikh Territorii, 287-89. Almaty: National Kazakh University.