The incorporation of extreme drought events improves models for beech persistence at its distribution limit

Context

Projections of species distribution models under future climate are usually based on long-term averages. However, singular extreme drought events presumably contribute to the shaping of distribution limits at the retreating low-elevation xeric limits.

Methods

The objectives of this study were to set up a distribution model based on extreme drought events (EDM), which uses sanitary logging information as a proxy of vitality response of beech, and compare it with the results of classical species distribution models (SDMs).

Results

Predictions of the EDM for 2025 were in agreement with those of the SDM, but EDM predicted a more serious decline in all regions of Hungary towards the end of the century.

Conclusion

These results suggest that the predicted increase in frequency and severity of drought events may further limit the distribution of beech in the future.