Vegetation and Climate Changes during the Bronze and Iron Ages (∼3600–600 BCE) in the Southern Levant Based on Palynological Records

This article presents the role of climate fluctuations in shaping southern Levantine human history from 3600 to 600 BCE (the Bronze and Iron Ages) as evidenced in palynological studies. This time interval is critical in the history of the region; it includes two phases of rise and decline of urban life, organization of the first territorial kingdoms, and domination of the area by great Ancient Near Eastern empires. The study is based on a comparison of several fossil pollen records that span a north-south transect of 220 km along the southern Levant: Birkat Ram in the northern Golan Heights, Sea of Galilee, and Ein Feshkha and Ze'elim Gully both on the western shore of the Dead Sea. The vegetation history and its climatic implications are as follows: during the Early Bronze Age I (∼3600–3000 BCE) climate conditions were wet; a minor reduction in humidity was documented during the Early Bronze Age II–III (∼3000–2500 BCE). The Intermediate Bronze Age (∼2500–1950 BCE) was characterized by moderate climate conditions, however, since ∼2000 BCE and during the Middle Bronze Age I (∼1950–1750 BCE) drier climate conditions were prevalent, while the Middle Bronze Age II–III (∼1750–1550 BCE) was comparably wet. Humid conditions continued in the early phases of the Late Bronze Age, while towards the end of the period and down to ∼1100 BCE the area features the driest climate conditions in the timespan reported here; this observation is based on the dramatic decrease in arboreal vegetation. During the period of ∼1100–750 BCE, which covers most of the Iron Age I (∼1150–950 BCE) and the Iron Age IIA (∼950–780 BCE), an increase in Mediterranean trees was documented, representing wetter climate conditions, which followed the severe dry phase of the end of the Late Bronze Age. The decrease in arboreal percentages, which characterize the Iron Age IIB (∼780–680 BCE) and Iron Age IIC (∼680–586 BCE), could have been caused by anthropogenic activity and/or might have derived from slightly drier climate conditions. Variations in the distribution of cultivated olive trees along the different periods resulted from human preference and/or changes in the available moisture.