The Association of Arable Weeds with Modern Wild Cereal Habitats: Implications for Reconstructing the Origins of Plant Cultivation in the Levant

Reconstructing the origins of plant cultivation in southwest Asia is crucial for understanding associated processes such as the emergence of sedentary communities and domesticated crops. Among the criteria archaeobotanists developed for identifying the earliest plant cultivation, the presence of potential arable weeds found in association with wild cereal and legume remains has been used as a basis for supporting models of prolonged wild plant cultivation before domesticated crops appear. However, the proposed weed floras mainly consist of genus-level identifications that do not differentiate between arable weeds and related species that characterise non-arable habitats. Here we test, for the first time, whether the potential arable weed taxa widely used to identify wild plant cultivation also occur in non-cultivated wild cereal populations. Based on modern survey data from the southern Levant we show that the proposed weed taxa characterise both grasslands and fields. Our findings, therefore, do not support the use of these taxa for reconstructing early cultivation. Instead, for future studies we suggest an approach based on the analysis of plant functional traits related to major agroecological variables such as fertility and disturbance, which has the potential to overcome some of the methodological problems.