# Potential Range Shifts of Two Sympatric Fagus Species

## TL;DR

This study models how two related beech species in China may shift habitats due to climate change, finding one is more vulnerable.

## Contribution

The study reveals divergent climate change vulnerabilities of two closely related Fagus species using MaxEnt modeling.

## Key findings

- Fagus longipetiolata's suitable habitats are mainly influenced by precipitation, while Fagus lucida's are more temperature-sensitive.
- Fagus lucida faces greater habitat fragmentation and suitability loss under future climate projections compared to Fagus longipetiolata.
- Both species' high-suitability habitats are concentrated in the Yangtze River Basin, but Fagus lucida is more vulnerable to climate change.

## Abstract

Fagus longipetiolata Seemen and Fagus lucida Rehder & E.H. Wilson are the dominant species in subtropical deciduous broad‐leaved forests of China, playing crucial ecological and economic roles. As ecologically and economically important trees, it is critical to understand their responses to climate change. This study employed MaxEnt modeling to discover the range shifts from their historical distributions to future projections. The distribution of suitable habitats of F. longipetiolata is more affected by precipitation, and that of
F. lucida
is more sensitive to temperature. High‐suitability habitats for both species were concentrated predominantly in the Yangtze River Basin. While both species showed substantial distribution centroid shifts since the Last Glacial Maximum (LGM),
F. lucida
exhibited greater habitat fragmentation and more pronounced reductions in high‐suitability areas under projected climate change compared to F. longipetiolata. Our results suggest that despite close phylogenetic relationships, these sister species face divergent climate change threats, with
F. lucida
being more vulnerable. These findings not only advance the conservation strategies for
F. lucida
but also provide critical insights for mitigating the impacts of intensifying global warming on subtropical forest ecosystems.

Using MaxEnt modeling, we found that Fagus longipetiolata's habitat suitability is primarily precipitation‐driven while
F. lucida
's depends more on temperature, with both species concentrated in the Yangtze River Basin; despite their shared ancestry,
F. lucida
exhibits greater vulnerability to future warming due to accelerated habitat fragmentation and suitability loss, underscoring urgent conservation priorities for subtropical forest resilience.