Persistent resilience and bimodal stability of herbaceous peatlands in the Southeastern Tibetan Plateau over 600 years of climatic shifts

Abstract

Tibetan Plateau peatlands exhibit exceptional climate sensitivity. Climate serves as a primary driver of resilience dynamics and potential regime shifts. Critical knowledge gaps remain regrading in peatlands historical resilience trajectories and climate triggered potential threshold of tipping points. By analyzing palaeoecological records spanning approximately six-century period, we reconstruct the temporal dynamics of diatom assemblages and plant communities succession in the representative herbaceous peatland ecosystems from the southeastern Tibetan Plateau. The Wulongbu peatland initiated at approximately 498 cal yr BP due to the increasing temperature and precipitation, its autogenic process was disrupted by continuous precipitation enhancement subsequently, coupled with the valley terrain led more runoff which maintained the water table and nutrient conditions, keeping it in fen stage. Until around 60 cal yr BP, peat accumulation exceeded the threshold, runoff was no longer as the main water source, ultimately shifted into bog stage. The early warning signals based on palaeoecological records in peatlands exhibit a non-monotonic fluctuation pattern, reflecting the persistent resilience and bimodal stability of the peatland development which highlights the robustness of peatlands under climate change, with both Wulongbu and Nancuo peatlands maintaining their integrity and avoiding collapse. This resilience was further modulated by the interplay between autogenic process (like organic matter accumulation) and allogenic factors (like increased humidity). Our study offers important insights for understanding how high-altitude peatlands around the world respond resiliently to climate change.