Invading a new niche: obligatory weeds at Neolithic Atlit-Yam, Israel

A characteristic group of obligatory weeds was found in the well of the submerged Pre-Pottery Neolithic C site of Atlit-Yam, Israel. Identifying these finds to species level was crucial for defining them as obligatory weeds. We deal here with the earliest and largest assemblage of obligatory and facultative weeds in the southwest Asian Neolithic. Atlit-Yam may reflect a stage in the establishment of weeds in cultivated fields. Weeds are an important resource for reconstructing the agricultural situation in archaeological sites, as weed-crop interactions reflect an agricultural lifestyle. Some of the weeds of Atlit-Yam grow in fields as well as in Mediterranean herbaceous habitats. This may indicate that the local herbaceous ecosystem was the original habitat of the weeds and the place where the first fields were planted. Presence in a single context of the earliest identified obligatory grain pest beetle (Sitophilus granarius) along with obligatory weeds reflects a novel change made to the ecosystem by the farmers, in which stored crops were invaded by pests.