Postglacial change of the floristic diversity gradient in Europe

Thomas Giesecke,Steffen Wolters,Jacqueline F N Van Leeuwen,Simon Brewer,Pim W O Van Der Knaap,Michelle Leydet

doi:10.1038/s41467-019-13233-y

Abstract

Climate warming is expected to cause a poleward spread of species, resulting in increased richness at mid to high latitudes and weakening the latitudinal diversity gradient. We used pollen data to test if such a change in the latitudinal diversity gradient occurred during the last major poleward shift of plant species in Europe following the end of the last glacial period. In contrast to expectations, the slope of the gradient strengthened during the Holocene. The increase in temperatures around 10 ka ago reduced diversity at mid to high latitude sites due to the gradual closure of forests. Deforestation and the introduction of agriculture during the last 5 ky had a greater impact on richness in central Europe than the earlier climate warming. These results do not support the current view that global warming alone will lead to a loss in biodiversity, and demonstrate that non-climatic human impacts on the latitudinal diversity gradient is of a greater magnitude than climate change.

Highlights

Climate warming is expected to cause a poleward spread of species, resulting in increased richness at mid to high latitudes and weakening the latitudinal diversity gradient
In North America, the southern distribution limits shifted north for many trees with postglacial warming[11], but not in Europe[10]. These poleward shifts in distribution limits have been observed for some biota with recent climate warming[12] and are interpreted as plants tracking their climatic niche. This information has been used to drive correlative species distribution models (SDMs), which suggest that many taxa were restricted to southern Europe with the colder climate during the last glacial maximum (LGM), around 20 ka ago[13]
Our results suggest that rapid climate warming, as documented for the onset of the Holocene in Europe, does not lead to an increase in richness at higher latitudes

Summary

Introduction

Climate warming is expected to cause a poleward spread of species, resulting in increased richness at mid to high latitudes and weakening the latitudinal diversity gradient. These poleward shifts in distribution limits have been observed for some biota with recent climate warming[12] and are interpreted as plants tracking their climatic niche This information has been used to drive correlative species distribution models (SDMs), which suggest that many taxa were restricted to southern Europe with the colder climate during the last glacial maximum (LGM), around 20 ka ago[13]. This concentration of species at lower latitudes resulted in a strong latitudinal gradient in species richness. These provide an estimate of community turnover by showing the timing of changes in vegetation composition[27]

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Conclusion