An ecological model of settlement expansion in northwestern Morocco

Abstract

This study is an application of the ideal free distribution (IFD) model to understand settlement patterns during the Mauretanian and Roman periods in northwest Morocco. We use proxies for potential agricultural productivity and distance from a viable harbor for each of the locations of known settlement sites. There is a clear relationship between the distance from harbors and habitat suitability, with sites that were established earliest all on or close to a point of access to the ocean. This is consistent with a focus on maritime trade and a connection with the Mediterranean Sea. Agricultural potential is also an important factor influencing settlement, although to a lesser extent, with earlier, low-density settlement more focused on trade potential. Consistent with predictions of the IFD, there is an expansion through time to progressively lower ranked habitats, with persistent settlement at the highest ranked habitats, including at Lixus, which is generally considered to be the earliest city in northwest Africa. During the Roman period, there is a focus of interior settlement near Volubilis. Subsidiary sites likely benefit from their proximity to this important political site, despite their relatively low rank within the IFD, perhaps reflecting patterns consistent with an ideal despotic distribution. This study demonstrates how the IFD can be used in a simple context with limited available survey data to assess the important environmental variables influencing settlement decisions. It has broad implications for understanding the formation of urban centers prior to and during the Roman period.