Modeling vegetation dynamics in the Southern Levant through the Bronze Age

We integrate modern spatial distributions of plant geographical regions with paleoclimatic trends to model vegetation change in the Southern Levant over the course of the mid-Holocene. This timespan witnessed the rise, collapse and redevelopment of urbanized society and settlement during the Bronze Age. This study applies GIS and statistical modeling tools (MAXENT) to vegetation data from 1696 historical and modern observation points across the region to chart potential vegetation for the present and at 100-year intervals between 5500 and 3000 calibrated years BP. A macrophysical climate model is used to create vegetation maps based on regional temperature and precipitation data. Environmental dynamics tracked over this time period, including past vegetation, temperature and precipitation, are applied to the interpretation of Bronze Age settlement and social change. Our results reveal a general trend of Mediterranean forest contraction through the Bronze Age. The "4.2 event" (ca. 4200 calibrated years BP) potentially links regional desiccation and urban collapse, and constitutes the last element in a trajectory of reduced potential forest vegetation through the Early Bronze Age. Rapid woodland expansion correlates with abrupt cooling and reurbanization at the outset of the Middle Bronze Age. Modeled vegetation shows minimum forest and maximum desert coverage consistent with a Late Bronze Age "crisis" ca. 3000 calibrated years BP. In comparison to the Bronze Age, modern potential vegetation includes the broadest extent of steppe.