Climate, people, fire and vegetation: new insights into vegetation dynamics in the Eastern Mediterranean since the 1st century AD

摘要

Anatolia forms a bridge between Europe, Africa and Asia and is influenced byall three continents in terms of climate, vegetation and human civilisation.Unfortunately, well-dated palynological records focussing on the period fromthe end of the classical Roman period until subrecent times are rare forAnatolia and completely absent for southwest Turkey, resulting in a lacunain knowledge concerning the interactions of climatic change, human impact,and environmental change in this important region. Two well-datedpalaeoecological records from the Western Taurus Mountains, Turkey, providea first relatively detailed record of vegetation dynamics from late Romantimes until the present in SW Turkey. Combining pollen, non-pollenpalynomorphs, charcoal, sedimentological, archaeological data, and newlydeveloped multivariate numerical analyses allows for the disentangling ofclimatic and anthropogenic influences on vegetation change. Results showchanges in both the regional pollen signal as well as local soil sedimentcharacteristics match shifts in regional climatic conditions. Both climaticas well as anthropogenic change had a strong influence on vegetationdynamics and land use. A moist environmental trend during the late-3rdcentury caused an increase in marshes and wetlands in the moister valleyfloors, limiting possibilities for intensive crop cultivation at suchlocations. A mid-7th century shift to pastoralism coincided with aclimatic deterioration as well as the start of Arab incursions into theregion, the former driving the way in which the vegetation developedafterwards. Resurgence in agriculture was observed in the study during themid-10th century AD, coinciding with the Medieval Climate Anomaly. Anabrupt mid-12th century decrease in agriculture is linked tosocio-political change, rather than the onset of the Little Ice Age.Similarly, gradual deforestation occurring from the 16th centuryonwards has been linked to changes in land use during Ottoman times. Thepollen data reveal that a fast rise in Pinus pollen after the end of theBey?ehir Occupation Phase need not always occur. The notion of highPinus pollen percentages indicating an open landscape incapable of countering theinflux of pine pollen is also deemed unrealistic. While multiple firesoccurred in the region through time, extended fire periods, as had occurredduring the Bronze Age and Bey?ehir Occupation Phase, did not occur, and nosigns of local fire activity were observed. Fires were never a majorinfluence on vegetation dynamics. While no complete overview of post-BOPhase fire events can be presented, the available data indicates that firesin the vicinity of Gravgaz may have been linked to anthropogenic activity inthe wider surroundings of the marsh. Fires in the vicinity of Bereketappeared to be linked to increased abundance of pine forests. There was nolink with specifically wet or dry environmental conditions at either site.While this study reveals much new information concerning the impact ofclimate change and human occupation on the environment, more studies from SWTurkey are required in order to properly quantify the range of the observed phenomena and the magnitude of their impacts.