High phylogenetic diversity is preserved in species-poor high-elevation temperate moth assemblages

Area of Science:

• Ecology
• Zoology
• Evolutionary Biology

Background:

• Understanding species assemblage diversity and determinants is a key ecological challenge.
• Geometrid moths (Lepidoptera: Geometridae) are important indicators of forest health and biodiversity.
• Elevational gradients are known to influence species distribution and community structure.

Purpose of the Study:

• To investigate the alpha-diversity and phylogenetic composition of geometrid moth assemblages along an elevational gradient.
• To identify biotic and abiotic factors shaping these moth communities.
• To compare high-elevation temperate moth assemblages with low-elevation and tropical communities.

Main Methods:

• Sampling of geometrid moths across an elevational gradient in Changbai Mountain temperate forest.
• Identification and quantification of species richness and abundance.
• Phylogenetic diversity analyses, including mean pairwise distances (MPD) and phylogenetic diversity (PD).

Main Results:

• A total of 9285 geometrid moths from 131 species were collected, with many showing wide elevational ranges.
• Moth alpha-diversity decreased monotonically with increasing elevation.
• Standardized effect sizes of MPD and PD significantly increased with elevation, indicating greater phylogenetic distinctness at higher altitudes.

Conclusions:

• High-elevation moth assemblages comprise habitat generalists that are more phylogenetically distinct.
• Lower elevations may foster higher speciation rates, leading to species-rich assemblages.
• Higher elevations show increased importance of excluding closely related species, suggesting greater resilience to environmental change and a larger proportion of genetic diversity compared to tropical communities.