Leaf morphometric analysis and potential distribution modelling contribute to taxonomic differentiation in the...

Area of Science:

• Botany
• Evolutionary Biology
• Ecology

Background:

• Mexico is a biodiversity hotspot for the Quercus genus, particularly for scrub oaks, which are understudied.
• Taxonomy and geographic distribution of Mexican scrub oaks remain largely unresolved.
• Scrub oaks represent a significant portion of Mexican oak diversity but lack focused research.

Purpose of the Study:

• To analyze morphological and climatic niche differentiation in a complex of six named scrub oak species and a distinct morphotype.
• To investigate evolutionary radiation and taxonomic resolution within Mexican Quercus.
• To provide evidence for taxonomic revision of understudied scrub oak groups.

Main Methods:

• Geometric morphometrics of leaf shape and trichome trait quantification were used for morphological analysis.
• Climatic niche differentiation was assessed across 35 sampling sites in northern and central Mexico.
• Comparative analysis of morphological and ecological data was performed.

Main Results:

• Two main morphologically distinct groups of scrub oaks were identified with geographic concordance.
• The Quercus striatula II morphotype showed distinct characteristics, supporting its taxonomic separation.
• Significant climatic niche differentiation was found among all pairwise comparisons, even with low morphological distinction.

Conclusions:

• The study supports the distinctness of the Quercus striatula II morphotype, necessitating a taxonomic revision.
• Integrative approaches combining morphology and niche analysis are crucial for resolving complex Quercus groups.
• Geographic and ecological factors play a significant role in the differentiation of Mexican scrub oaks.