Disentangling plant management practices in Neolithic southwest Asia: a functional ecological perspective on habitat productivity and vegetation density

Abstract Research on agricultural origins in southwest Asia revealed a protracted process of developing plant management systems in the early Holocene that eventually led to the selection of domestication traits among a suite of seed crops. While the temporal and geographic spread of these developments is relatively clear, the specific sets of management practices and related (agro-)ecological conditions that characterised early plant management systems and underpin the selection of domestication traits remain poorly understood. Here we use plant functional ecology to develop models that distinguish productivity conditions between grasslands – a key crop progenitor habitat – and arable fields cultivated under low- and high-input regimes. Using specific functional trait combinations, we identify shade tolerance as an ecological mechanism among modern grassland and arable weed communities, allowing us to indirectly infer high vegetation density among non-arable habitats. We apply the productivity models to archaeological weed floras from four Aceramic Neolithic and Ceramic Neolithic sites in the Levant and central Anatolia, identifying increased productivity in later agricultural systems as opposed to lower productivity among ‘pre-domestication cultivation’ assemblages that match conditions of modern grasslands. Our findings confirm known patterns of soil disturbance throughout the southwest Asian Neolithic, while the functional ecological models provided will allow for a more systematic analysis of developing productivity conditions in early plant management systems in the future.