LAUSR

Changes in vegetation biomass have a great impact on many aspects of the Arctic ecosystem, and historical variations of biomass in Svalbard during the Holocene remain poorly understood. In this study, we collected a palaeo-notch sediment profile in Ny-Ålesund, Svalbard, performed organic biomarker and geochemical analysis on the sediments, reconstructed the photosynthetic biomass record during the interval of 9400–2200 BP, and examined the relationship between the photosynthetic biomass changes and Holocene temperature records in the Arctic region. The photosynthetic biomass production in Ny-Ålesund experienced four development periods. It rose steadily at the beginning of the Holocene and became stabilized at a high level during the Holocene thermal maximum. However, the photosynthetic biomass dropped sharply during the mid-Holocene transition. After that, it showed a small peak during the interval of 3000–2500 BP. The historical photosynthetic biomass record is in good agreement with the temperature records: the photosynthetic biomass production increases during warmer periods, and vice versa. Therefore, temperature is likely the driving factor controlling the photosynthetic biomass production. This study improves our understanding of the terrestrial ecosystem and its responses to climate change in the Arctic.