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Environment, Vegetation, and Land Use

Preliminary archaeobotanical work (Miller 1999), geomorphological studies (Marsh 2005), archaeological survey (Kealhofer 2005), and ethnoarchaeological studies (Gürsan-Salzmann 2005) all show that the 20th-century landscape of the Sakarya valley is quite different from that of 3000, 300, or even 30 years ago. Even so, the present-day climate and vegetation provide a baseline against which one can assess the macrobotanical remains. Palynological studies from neighboring regions give independent information with some time depth.

Strong Mediterranean influence on the climate gives much of Turkey cool or cold wet winters and hot dry summers. Elevation, local topography, and distance from the coast create great variation—the climate becomes more continental in the interior, and there is some rain in the summer. Thanks to adequate rainfall, the natural vegetation of the coastal regions of Turkey is forest. Oak and pine dominate the Mediterranean forests of the west and south, and mixed hardwoods are characteristic of the Pontic (Black Sea coast) forests to the north (Zohary 1973:Map 7). Going inland past the coastal mountains ranges, overall precipitation declines; in general, lower elevations experience less rainfall. The lower boundary of the central Anatolian true steppe is approximately 700 m, depending on local conditions. Gordion straddles that elevation boundary, so short-term climate anomalies could have a disproportionately strong effect on the land and the agricultural economy. Even in the absence of climate shifts, normal interannual rainfall variability or human actions that alter such factors as the water table or drainage could affect the natural vegetation cover and moisture available for crops.

Topography, Soils, and Water

Some “natural” processes that might affect plant life occur regardless of human intervention, such as long-term and short-term climate shifts. More locally, down-cutting of the Sakarya River or its opposite, a shifting bed of aggrading streams, would alter the land. At the time scale considered here, the archaeobotanical record reflects predominantly human manipulation of the landscape—intentional earth movement as well as erosion that results from deforestation and overgrazing.

The Sakarya River originates in the western highlands of Anatolia; it flows north through Gordion toward its outlet in the Black Sea. The Porsuk river, which flows through Eskişehir, meets the Sakarya about 4 km north of the site. Over time, the bed of the Sakarya has shifted; with canalization in the late 1950s, it is now down-cutting, but through the first part of the 20th century it meandered and flooded annually. Ben Marsh’s geomorphological studies (2005) show several major shifts in the river over the occupation of the site. In fact, until sometime after 600 BC, the river flowed to the east of the Citadel Mound (Marsh 1999).

Gordion is situated in a fertile alluvial valley (Fig. 2.1). Within about 5 km of Gordion, the soils and geological substrate as mapped by Marsh (2000, 2005) occur in several different zones. Today, a narrow riparian strip supports an assortment of woody and herbaceous vegetation. The east side of the valley bottom, annually flooded before the river was straightened in the 1950s, consists of a strip of deep soils eroded from the eastern hillsides, at most 2 km in width but usually narrower. Just east of the floodplain are some marls and gypsum outcrops; further east is siltstone pediment with basalt intrusions (Marsh 2000, 2005). To the west of the river are marls and conglomerate plateaus. The arable soils of today include a relatively small area of alluvial marls that are not suited to dry-farming. To the east, marls and upland basaltic soils eroded from the hills above fill the valley (Marsh 2000, 2005). Alternate-year fallow allows the lighter soils to store moisture; the basalt-derived soils are “highly porous and permeable and holding and releasing groundwater throughout the year” (Marsh 2005:164). Most of the soils within 5 km of Gordion fit into this category, and prior to mechanized pump-driven irrigation, the major land use was dry-farmed cereal production and grazing (Gürsan-Salzmann 2005).

Fig. 2.1 Sakarya Valley and Gordion region (digitized by Nina Johnson).

Groundwater availability in antiquity would have been greater than it is under the eroded, devegetated conditions of today. According to Marsh, “The streams are shallower and they flow less in the dry (summer) season. Springs also flow much less through the year and they have also been buried if they were close to the streams” (2000); he also points out that recent massive irrigation is lowering the water table. Traces of ancient settlement tend to be located near springs and streams throughout the sequence (Kealhofer 2005).

Climate near Gordion

The nearest town for which meteorological information is available is the district center of Polatli, which is about 20 km northeast of Gordion at an elevation of 875 m (Meteoroloji 1974). For the forty-one years between 1930 and 1970, the average temperature was 11.9°C, with about 65.5 days/year with the lowest temperature below freezing. Average yearly precipitation was 346.6 mm, with a moisture deficit from June to October (Figs. 2.2, 2.3). The average number of days with snow was 12. These data suggest that Polatli is within the territory of reasonably secure rainfall agriculture (allowing for some variation hidden by the use of averages, 250 mm/yr is considered the minimum for dry-farmed cereals in the Middle East). The 61-year precipitation average for the July to June agricultural year is 347 mm, with a standard deviation of 62. This suggests fairly erratic rainfall, but generally enough for dry farming. Summers can be cool, and in contrast to much of the Near East, summer downpours are a normal, if occasional, aspect of the climate.

In inner Anatolia, precipitation tends to decline as elevation decreases. Available moisture for natural vegetation as well as for rain-fed crops would be somewhat less in the Sakarya valley near Yassihöyük, because it is nearly 200 m lower than Polatli in elevation. The relatively benign variability in Polatli, therefore, might indicate a high proportion of serious drought years at Gordion. Indeed, from the balcony of the Gordion excavation house, it is common to see summer rainclouds skirt the edge of the valley without dropping any moisture. Even with pump irrigation, farming in Yassıhöyük seems risky; the bumper crop of a very wet year, 1988, gave way to nearly total crop failure in 1989. In those years (July to June), precipitation reported in Polatli was 376.0 mm and 228.9 mm.¹

Fig. 2.2 Polatlı climate diagram (39°35’N 32°08’E). Based on 41–yr average. Average monthly minimum always >0°C; absolute minimum <0°C January and February (source: Meteoroloji Bülteni 1974).

Fig. 2.3 Polatlı precipitation, by growing season (July–June), 1929 to 2007. Seventy-eight-year mean: 349.4 mm, S.D. 64.0 mm (source: Meteoroloji Bakanlik and Polatli Meteoroloji Istasyonu).

Modern Vegetation Overview

Michael Zohary (1973:579) describes the natural vegetation of the Anatolian plateau between 700 and 2000 m as “steppe forest,” commenting that the term forest is “not always appropriate to a formation in which the arboreal elements are sometimes so remotely scattered, that one can hardly catch two trees at one glance.” This description certainly fits the modern landscape. One should think of this vegetation type as “a steppe sprinkled with solitary trees which under certain conditions may become condensed and turn into a forest-like formation” (ibid.). At an elevation of just under 700 m, Gordion itself would be at the upper boundary of the treeless Anatolian steppe, though terrain at 700 m elevation lies as close as 2 km.

Today, the land around Yassihöyük is largely devoted to farming and grazing. Any land that can be irrigated is, but all irrigation is carried out with motordriven pumps. Since the mid-1990s, a government water project has brought irrigation to the slopes, greatly expanding the area of irrigable and irrigated land. In and near the village of Yassihöyük itself, trees grow primarily in protected gardens and along the banks of the Sakarya River. Isolated trees (Elaeagnus angustifolia, Ulmus glabra, Prunus amygdalus, Salix sp.) grow near the edges of some fields.

Between Şabanözü and Avşar, oak (Quercus pubescens) grows as close as 15 km from Gordion. To the northwest, the closest stands of junipers (Juniperus excelsa and J. oxycedrus) mixed with oak en route to Hamidiye are near Ahirozu, about 30 km by road from Gordion (elev. c. 1000 m). About 40 km from Gordion, the soil changes and oak becomes more common. Continuing on to Hamidiye (Yag Arslan), about 50 km from Gordion, oak (Q. pubescens, Q. cerris) and pine (Pinus nigra) grow. Just past Hamidiye, larger trees, mainly pine with an understory of oak and juniper (J. oxycedrus), grow in the forest (Figs. 2.4, 2.5). The extent to which the poor aspect of the vegetation is due to climate or human interference (fuel gathering, grazing, and, in antiquity, construction projects) is not entirely clear, but the analyses of archaeological woods from Gordion illuminate this question.

Since 1988, I have conducted informal vegetation surveys in the region, most intensively within 2 km of Gordion. Uncultivated habitats lying within this radius include the riverside, former floodplain, and degraded steppe on a marly siltstone substrate in which Artemisia sp. and wild thyme (Thymus sp.) dominate. A small patch of grassy steppe vegetation that was relatively undisturbed until the mid-1990s straddles the boundary between Yassihöyük’s fields and those of a neighboring village, Şabanözü (about 13 km to the northeast). Perennial grasses mixed with a variety of other plants covered the slope in 1992, but after irrigation came to the adjacent fields, annual grasses began to replace the native steppe vegetation.

Recent Land Use—Agriculture, Animal Husbandry, Fuel

Even since 1988, land-use patterns in the Sakarya valley near Yassihöyük have changed. Most obvious to the occasional visitor are the expansion of irrigation to previously dry-farmed fields and the increase in weekend day-trippers from Polatli and Ankara. At a scale of centuries and millennia, climate fluctuations, shifting river channels, periods of erosion, and many other human and natural factors have affected the landscape, so arguably there is no “ethnographic present.” Gürsan-Salzmann (2005) is conducting a comprehensive historical and ethnographic study of the region; here I present a general description based on her work, other published sources, my own observations, and conversations and discussions with some of the villagers who worked for the project (mainly Ekrem Bekler and Remzi Yilmaz) and team members Ayşe Gürsan-Salzmann and Ben Marsh.

Fig. 2.4 Immediate environs of Gordion: a. Sakarya vegetation with Kuş Tepe in background; b. overgrazed pasture with Tumulus MM in right midground and Kızlarkayası outcrop in background; c. “grassy steppe” in 1992, before irrigation wrought land-use changes; d. former “grassy steppe” in 2007, after irrigation led to intensified agricultural activity in adjacent fields (Tumulus MM visible in center background).

Crops

Agriculture is still the main occupation of the Yassihöyük villagers, at least during the growing season. The most important field crops are macaroni wheat, two-row barley, sugar beet, onion, sunflower, and melon. The last two of these are also grown in smaller gardens, along with tomato, eggplant, peppers, okra, and other vegetables for home consumption and market sale. Lentils and chickpeas are also grown. Several crops that were common in recent memory are no longer grown: rye, which is still a common weed of wheat fields, and cumin. One retired farmer (pers. comm., July 8, 1994) mentioned three kinds of barley that were once grown: beyaz arpa (white barley), siyah arpa (black barley), and peygambar arpa (pilgrim barley; common oat?). Several crops were grown for oil: keten (linseed, flax; Linum usitatissimum), konjit/susam (sesame; Sesamum indicum), and a plant he called zira (possible mishearing or variant of zeyrek [flax], Ertuğ 2000). An older farmer remembers growing burçak (bitter vetch; Vicia ervilia). Bitter vetch is harder to harvest than other fodder crops, so its culture declined after mechanization (H. Firincioglu, pers. comm., July 12, 2001). These discontinued crops were not irrigated, as the villagers did not have pumps then. Rye was and barley is grown primarily for fodder.

Fig. 2.5 Woodland vegetation in the Gordion region: a. oak (Quercus pubescens) below Avsar, ca. 900m; b. juniper (J. oxycedrus) and oak (Quercus pubescens) en route to the pine forest at Hamidiye, over 1000 m; c. pine (Pinus nigra), juniper (J. excelsa and J. oxycedrus) and oak (Q. pubescens) grow together in pine forest zone, ca. 1400 m; d. juniper (J. excelsa) en route to pine forest, ca. 1200 m; e. pine (Pinus nigra) in clearing in pine forest.

Grain yields depend on moisture availability, the crop rotation, and the application of fertilizer (see Gürsan-Salzmann 2005). One farmer (E. Bekler, July 18, 1994) said that barley yields can be relatively low because wheat is more likely to be planted after a fallow year, when the soil is more fertile. He used to sow unirrigated wheat at a rate of 20 kg/dunam (ca. 20 kg/ha), for an expected yield of about 10 teneke (130–150 kg). In a dry year, a field would yield 7–10 teneke; the best years’ yields are about 15–20 teneke. Irrigated wheat, which takes a lot of fertilizer and water, will typically yield 25–30 teneke; yields in a dry year would be 13–15 teneke, and in the best years could be as high as 35 teneke. Twenty-six kg of unirrigated barley planted after a fallow year ordinarily yield 20 teneke. The yield in a dry year would be only 5 or 6 teneke, and in a wet year would be 20. For irrigated barley, if you plant two teneke, you can expect a return of 30–35 teneke; in a dry year the yield would be 7 or 8 teneke, and 40 in the best year (Table 2.1).

Farmers’ yields mentioned to Gürsan-Salzmann averaged about 200–250 kg/dunam for unirrigated, and 450–500 kg/dunam for irrigated wheat (about the same or slightly higher than E. Bekler’s estimates of about 150 up to 300 kg/dunam for unirrigated wheat in a good year, and 325–450, up to 500 kg/dunam for irrigated wheat in a good year).

Table 2.1. Ekrem Bekler’s yield estimates (pers. comm., July 18, 1994)

*1 teneke ≈13–15 kg

Table 2.2. Seasonal round according to Remzi Yılmaz (pers. comm., 1992)