Ecohydrological feedbacks confound peat‐based climate reconstructions

Abstract

Water‐table reconstructions from Holocene peatlands are increasingly being used as indicators of terrestrial palaeoclimate in many regions of the world. However, the links between peatland water tables, climate, and long‐term peatland development are poorly understood. Here we use a combination of high‐resolution proxy climate data and a model of long‐term peatland development to examine the relationship between rapid hydrological fluctuations in peatlands and climatic forcing. We show that changes in water‐table depth can occur independently of climate forcing. Ecohydrological feedbacks inherent in peatland development can lead to a degree of homeostasis that partially disconnects peatland water‐table behaviour from external climatic influences. We conclude by suggesting that further work needs to be done before peat‐based climate reconstructions can be used to test climate models.