1 Introduction
The geographical distribution of plant populations is influenced by both
the biological characteristics of the plant species and their
environment (Thuiller et al., 2005; Ge et al., 2012). Primarily, the
climate within large-scale regions serves as the principal determinant
affecting species distribution. Changes in climate consequently alter
species’ responses and selection to climate and habitat (Ma et al.,
2022). In recent times, exacerbated by climate change and human
interference, species habitats have suffered severe degradation. This
degradation is particularly notable in the significant reduction of
suitable growth areas for endangered plants, leading to diminished
resources for wild species (Lenoir et al., 2008; Liu et al., 2015).
Consequently, investigating the impacts of changing climates on species
distribution patterns is crucial for understanding historical and future
changes in species range and can furnish a scientific foundation for
conserving germplasm resources in endangered plants (Li et al., 2021).
Species distribution models (SDMs) rely on various environmental
variables such as climate and soil, closely related to the real growth
and distribution of species. These models can predict potential suitable
distribution areas of species using specific algorithms, thereby
elucidating the predominant environmental factors influencing their
distribution and exploring the ecological requirements of species
(Araújo et al., 2012). Among the myriad of models, SDMs encompass 19
different methodologies, including the rule-set genetic algorithm model
(GARP), maximum entropy model (MaxEnt), and ecological factor analysis
models (ENFA) (Phillips et al., 2008). The MaxEnt model stands out due
to its relative maturity, ease of operation, and high prediction
accuracy (Hao et al., 2020). It can infer and predict from incomplete
known information, making it widely applicable in studying the
introduction and cultivation of relict plants, horticultural tree
species, and invasive plants (Elith et al., 2006).
Tetracentron sinense Oliv., a Tertiary relict plant,
represents the sole surviving species in the Tetracentron genus
of the Trochodendraceae family (Fan et al., 2021). This species holds
significant importance in the discussion of the systematic evolution of
angiosperm plants. Unfortunately, due to its ornamental, furniture, and
medicinal value, T. sinense has been subjected to extensive
exploitation by humans, resulting in poor regeneration of its natural
populations (Pang et al., 2018; Lu et al., 2020; Wang et al., 2023).
Consequently, it has been designated as a national secondary protection
plant in China and listed in Appendix III of the Convention on
International Trade of Endangered Species (Fu, 1992). The preservation
of germplasm resources has garnered considerable attention from
researchers (Duan et al., 2019; Zhang et al., 2019).
Fossil records indicate that Tetracentron Oliv. was once widely
distributed across Europe, North America, and East Asia during the
Pleistocene era (Rix, 2007). A phylogeographical analysis based on the
chloroplast genome suggests that the current geographical distribution
pattern of T. sinense may have been shaped by Quaternary climate
oscillations, with Southwest China potentially serving as a biological
refuge during glacial periods (Sun et al., 2014). Li et al. (2018)
observed a correlation between the phenotypic variation of T.
sinense and environmental factors such as mean annual sunshine
duration, mean temperature in July, and annual mean precipitation.
However, the specific influence of these environmental factors on the
geographic distribution of T. sinense remains ambiguous.
Additionally, how will the distribution pattern of T. sinense evolve in the context of past and future climate changes? What are the
primary environmental factors constraining its geographical
distribution? And how do these factors influence its distribution? These
questions remain unanswered, impeding the effective protection and
management of T. sinense germplasm resources.
Utilizing the MaxEnt model and ArcGIS spatial analysis technology, this
study examines potentially suitable areas for T. sinense across
historical periods (the last interglacial period, the last glacial
maximum, and the Middle Holocene) as well as current and future periods
(2050s and 2070s). The objectives of this study are to (1) analyze the
dynamic changes in potentially suitable areas, (2) investigate the main
environmental factors driving changes in the distribution pattern ofT. sinense , and (3) furnish a scientific basis for the effective
protection and management of T. sinense .