Holocene agricultural activities revealed by cereal Poaceae pollen in eastern China

Abstract

Knowledge of agricultural activities during the Holocene can enhance our understanding of the human-land relationship and help develop sustainable ecosystems management strategies. In this study, we compared cereal Poaceae pollen abundances between cropland and non-cropland across eastern China and employed a logistic regression model to establish a threshold for distinguishing these two land-use types. Our results indicate a significant difference in cereal Poaceae pollen abundances between cropland and non-cropland, and they can be differentiated by a cereal Poaceae pollen threshold of 3.8 %. We applied this threshold to fossil pollen records to reconstruct agricultural activities in eastern China during the Holocene. This threshold likely reflects the intensification rather than the beginning of agricultural activities in fossil pollen records. The appearance of cereal Poaceae pollen at the beginning of the Holocene may indicate that agricultural activities were already present. The reconstructed results indicate that agricultural activities in eastern China intensified significantly around 5.5 cal. ka BP mainly due to favorable climatic conditions; were concentrated in lower elevation regions; and began to expand to higher elevation regions around 2 cal. ka BP in response to subsistence pressures from a rapidly growing population. This research demonstrates the importance of cereal Poaceae pollen in reconstructing agricultural activities and enhances our understanding of agricultural history in China.