Late Holocene vegetation dynamics in a mountainous environment in the Territory of Sagalassos, Southwest Turkey (Late Roman till present)

Anatolia is characterized by a very complex history of climate and human related vegetation change, which varies strongly from location to location. The region forms a bridge between Europe, Asia, and Africa for plants as well as human civilisation. The regional climate is equally influenced by North Atlantic, Asian, and African climatic forces and may vary regionally due to the rough topography of Anatolia. While palynological data are available for the Eastern Mediterranean, well dated records focussing on the period from the end of the Roman Imperial period to the present are rare for Anatolia and absent for SW Turkey. Additionally, while climatic data are available for the Eastern Mediterranean, no climatic records exist for SW Turkey. The aforementioned complexity of the climatic system makes it impossible to reliably use existing climatic proxies for locations for which such data are not yet available.The Sagalassos Archaeological Research Project has been involved in excavating the classical city of Sagalassos, in the Western Taurus Mountains, Turkey. Since 1993, the archaeological project has had an interdisciplinary character, not only focussing on classical archaeology, but also involving palaeo-environmental research in an effort to understand the history of not only the city itself, but also its surrounding rural landscape.In recent times, archaeological research has been focussed at the Late Roman and Early Byzantine periods, while in the next years, the focus will shift towards the interval from the Early Byzantine period to the present. The present research has been performed as part of the Sagalassos Archaeological Research Project, and the research results may contribute to a better understanding of vegetation dynamic and human impact within the territory, while the archaeological data may help explain the nature of the environmental changes observed in the data. Additionally, the climatological aspect of the research, as well as the fact that no detailed palaeoecological records exist which cover the most recent 2000 years in detail in SW turkey, give the research results a regional significance, providing an important new insight in the complex patterns of vegetation and climate change in the Middle East.Two well dated palaeoecological records from the territory of Sagalassos provide a first relatively detailed record of vegetation dynamics in Southwest Turkey focussing on the period from late Roman times until the present. Combining pollen, non-pollen palynomorphs and charcoal data with multivariate statistics, sedimentological and archaeological data, allows for the disentangling of climatic and anthropogenic influences on vegetation change in this under-researched region of the Eastern Mediterranean.The palynological and sedimentological data revealed several periods of human occupation in the pollen record, previously unknown for SW Turkey. Signs of intensive crop cultivation in the two records started to decline after the mid 3rd century AD, completely disappearing from one basin. A further, more complete shift from crop cultivation to livestock herding, possibly (semi)pastoralism, occurred in the mid 7th century. Resurgence in human impact, in the form of deforestation, livestock herding, and limited crop cultivation occurred from the mid 10th to the mid 12th century AD, after which human impact declined abruptly and completely, allowing for the establishment of a pine forest at both sites. This pine forest persisted until the mid 16th century, after which there was a gradual deforestation of the area, in combination with signs of grazing, perhaps linked to livestock herding. A pollen spectrum representative of the modern day agricultural practices in the study area only occurred in the topmost part of the available pollen record.The numerical analyses revealed a succession of relatively wet and relatively dry bioclimatic trends occurring throughout the study area and surrounding territory, and corresponding with well-defined European climate shifts, allowing the assessment of the exact timing and impact for the first time in this region of Anatolia. The data show a shift towards increased moisture availability occurs during the 3rd century and from the mid 10th to the early 14th century AD. Relatively dry conditions prevailed prior to the mid 3rd century AD, from the mid 7th to the mid 10th century AD, and from the early 13th century AD onwards. A shift towards moister environmental conditions in the 18th century may be an artefact caused by the deforestation of the study area at that time.The available sediment records from the study area, as well as an external tree ring record, implied that a more realistic estimate for the end of the second wet phase was the mid 13th century AD. Additionally the tree ring record indicated that both the bioclimatic proxy and calcium carbonate record from one of the locations were accurate records of regional climatic change and that the estimated chronology for this location was also highly accurate.Statistical analyses performed on the charcoal record from both records revealed that fire activity in the rural landscape from the Early Byzantine period onwards was limited. Only a few fires were recorded and these were mostly reasonably small, no fires were recorded simultaneously at both sample sites. Only a small amount of the recorded fires appeared to be connected to human activity. Most others were primarily connected to fuel availability, and their occurrence was not related to specific environmental conditions.Research into the pollen production and dispersal of some important plant taxa in the study area revealed that for many of the plant taxa included in the analyses, the relevant source area of pollen is relatively small, likely due to the rough topography of the study area. As a consequence, when researching regional changes in climate and vegetation through time, it is vital to study multiple records from the same study area in order to distinguish between local and regional environmental phenomena. When studying more local phenomena, such as human impact in the vicinityof a sample site of a pollen record, it is vital to keep in mind that the pollen signal may only represent the vegetation within a relatively short distance around the sample site. Changes in human activity, especially when they occur simultaneously in multiple records, may still be representative of larger scale changes in human impact in the research area, especially when coinciding with marked changes observed in the climatological or archaeological record, but they must not be seen as representative of how human impact changed throughout the territory.Comparing the research results with the historical and archaeological record of Sagalassos and historical, archaeological, and palaeoecological data from the wider region of Anatolia revealed how human impact and climate drove environmental change, both together as well as individually.The decrease in intensive crop cultivation at both sample sites differed from the regional trend of increased anthropogenic activity during this relatively moist period, and is also at odds with the archaeological record of Sagalassos, which indicates the city and territory remained relatively prosperous during this period. The decrease in human impact may be a local phenomenon and a result of the local wetlands increasing in size, encroaching onto formerly arable land. However, the possible role of political, economical and military instability throughout the wider region may not be ignored. The further shift to animal grazing/herding coincided with a climatic deterioration during the mid 7th century, as well as the start of Arab incursions into Anatolia. During the 8th/9th centuries AD, the Byzantine Empire underwent a political, economical and military revival, but at Sagalassos, as well as at other locations, a true increase in human impact only occurred during the mid 10th century, coinciding with the start of the Medieval Climate Anomaly (MCA) in the Eastern Mediterranean. It is proposed that, while the local population had the financial means to expand their agricultural practices; it was the start of the MCA which made the rural basins in the territory of Sagalassos suitable for agriculture. The disappearance of agriculture during the 12th century does not appear to be connected to environmental change, and may be driven by the political instability of that period and changes in land ownership at the cost of small-scale independent farmers. Gradual deforestation occurring from the 16th century onwards has been linked to changes in landscape use during the ottoman reign, rather than climatic change.nrpages: 239status: publishe