European Plant Diversity is Threatened by Climate Change

Human-induced climate and atmospheric changes are affecting a wide variety of forms of life. Being able to build models predicting the effects of climate change is of crucial importance to enable environment policy makers to engage adapted actions to reduce greenhouse gas emmissions.

European Commission 16.03.2006.

An international team involving researchers from France, Portugal, South Africa, Sweden, and the United Kingdom has recently developed predictions on the potential effects of climate change on a sample of 1,350 plants, representative of the European plant species, for the period 2051-2080. To build their predictions, the authors used four of the scenarios proposed by the Intergovernmental Panel on Climate Change (IPCC), namely scenarios A1, A2, B1, and B2. These scenarios differ on their assumptions on the evolution of technology and economic and population growths. The authors also assessed three climate models relating species distributions to bioclimatic variables. However, only the most consensual model was considered for each scenario.

The authors used two hypotheses concerning the potential migration of plant species across Europe to find a more suitable climatic area for their survival: no migration and universal migration. The “no migration” hypothesis was used to estimate the potential number of species losses after the disappearance of their climatic niche. In contrast, the “universal migration” hypothesis was used to estimate the potential gains and turnovers of plant species following climate changes.

The results of this study led to great variations in predictions of plant species losses across scenarios. However, the authors estimate that more than half of the European plant species could be vulnerable or threatened by 2080. The authors also suggest that plant species losses and turnovers correlate two climatic key factors: temperature and moisture conditions.

Within a single scenario, authors report great variations across regions. The obtained results suggest that plants in mountainous regions are the most vulnerable. In contrast, plants in the Mediterranean and the Pannonian regions seem to be the most resistant to the effects of climate change. The authors also identified a transition zone including the Boreal and Pannonian regions where great species mixing is expected to occur between 2051 and 2080.

This study has considered the potential consequences of different climate change scenarios on the survival of European plant species. Its conclusions indicate that plant species are unevenly but substantially threatened by climate change. Continuing the ongoing efforts to reduce greenhouse gases emissions could mitigate the climate change detrimental effects on the conservation of biodiversity.

Source: Thuiller W. et al. (2005) « Climate change threats to plant diversity in Europe », Proceedings of the National Academy of Sciences, 102(23):8245-8250.
Contact: thuiller@sanbi.org