Part II Archaeological Excavations - Center for the Study of Eurasian ...

Kurgans, Ritual Sites, and Settlements: Eurasian Bronze and Iron Age
Methodology
In the field, samples were taken from sediments that contained
charcoal fragments and pieces of wood. The charcoal and wood
were separated from the sediments in the laboratory by sieving
(to 2 mm) and flotation. The woody material was then observed
under the microscope and identified on the basis of the wood
structure (Schweingruber 1990). The species and diversity revealed
the types of wood chosen for use by the population, in
addition to the particular methods of exploitation for the different
types of wood.
When possible, the growth ring widths were systematically
measured. This data can provide information on the growing
conditions of the trees, including climate, the type of soil, and
the density of the forest. Narrow rings correspond to restrictive
growing conditions, while, in contrast, large rings reveal favorable
growing conditions.
In the field, cores were made in living birch, pine and poplar
trees growing in different types of environment. The purpose
of obtaining these samples was to enable a comparison to be
made between the ring widths of living trees with those observed
in the subfossil samples. The relationship between modern
tree ring patterns and their environments can provide information
on the origin of the wood charcoal recovered during
archaeological excavations.
Finally, when possible, the tree ring curves of the charcoal pieces
were noted. This characteristic can enable the identification of
which part of a tree was used (Marguerie 1992). A smooth curve
corresponds to the tree trunk, while a marked curve corresponds
to the branches.
Results
The results appeared to be very homogenous between the
samples from a given site regardless of the method of analysis
(species diversity, tree growth, and tree element). For the first
approach to the problem, the samples were grouped by site.
Note that graphs for some sites are not presented, especially
for tree growth and tree elements, because there was no data or
too little data for the results to be representative.
Species diversity
No major differences between the charcoal species identified
from the settlements and the burials sites were noted (Fig. 3).
Pine and birch were the most common species recovered from
all sites. These two species were found to occur exclusively at
the Prygovsky and Scaty sites. In addition to these two forest
trees, river bank taxa were also found to be present at the B.
Kazakbaievo site and, to a lesser degree, at the Gaiova and
Baitovo sites. At Malakazakbaievo, however, no pine samples
were found, and because of its diverse species assemblage without
pine, the Malakazakbaievo site appears to be unique.
Tree growth
The distribution of birch ring widths is wide, particularly at the
Skaty and Baitovo sites, the two sites situated along the Tobol
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River (Fig. 4a). This finding may indicate that the samples had
probably originated from many forest types, which contained
a variety of growing conditions. In contrast, the coarse range
of the pine ring width distributions probably means that the
Iron Age populations only retrieved pines from one particular
forest type characterized by specific growing conditions. The
only possible exception to this situation is found at the Gaiova
site (Fig. 4b).
If the measurements made on living samples are compared with
the mean values per site of the subfossil material, more information
can be gleaned concerning the nature of the environment
in which the trees were grown. In the case of birch (Fig.
5a), the analysis of living trees would tend to indicate that narrow
rings are found in coppice formations, while large rings
are found in humid forests. Medium ring widths (values in between
the narrow and large rings observed in living trees) were
observed on the birch charcoal (subfossil material), making it
difficult to draw conclusions concerning the nature of the environment
from which the trees had originated.
The results appear to be clearer in the case of pine charcoal
(Fig. 5b). Cores made in living pines show two patterns of
growth depending on the forest type - c. 0.5mm radial growth
per year in an ancient forest, and 2–3 mm in exploited small
forests located near rivers. The rings of the pine charcoal
samples (subfossil material) have, in general, an average width
of approximately 1 mm. At Scaty, however, the pines were found
to have very narrow rings with a mean width of less than
0.5mm. Therefore, it would appear that the Iron Age people
probably collected these trees from fully developed forests. This
type of forest environment leads to restrictive growing conditions
which are related to the competition which exists between
trees for nutriments, light, water, etc.
Tree elements
At the Prygovsky, Gaiova, and Malakazakhbaievo sites, results
obtained from the tree ring curves indicate that the birch charcoals
had originated equally from trunks and branches (Fig.
6a). In the case of pine, all tree elements were also used at the
Prygovsky and Gaiova sites (Fig. 6b). In contrast, at Baitovo
and Scaty, in most cases, the pine and birch charcoals had originated
from tree trunks. This finding may indicate that the Iron
Age people had deliberately selected large pieces of wood at
these two sites located along the Tobol River.
Discussion and Conclusions
The data obtained from charcoal analyses can provide pertinent
ecological information. In comparison to the actual living
regional vegetation, our results seem to show that, during the
Iron Age, the forests were composed of the same species as
today, namely pine and birch trees. In the samples obtained
from the Malakazakhbaievo site, however, pines was conspicuously
absent. Following the hypothesis that the presence of a
tree species near a site (particularly at settlements such as those
of the current study) results in its exploitation by the population,
it is possible to infer that pines were not available at the