DOI: 10.5061/dryad.51c59zwpg
title: Data from: Climate stability drives multidimensional nestedness of amphibian assemblages in a Chinese sky island system

description: The nested subset pattern (nestedness) has been widely used to explain
 species distributions in island and fragmented systems. Mountain sky
 islands serve as critical natural laboratories for understanding the
 evolutionary consequences of geographic isolation and climate change, but
 their species distribution patterns remain poorly understood. Compared to
 lowland fragmented habitat islands, biodiversity patterns in mountainous
 regions are more complex, and traditional drivers may not adequately
 explain the nestedness of sky islands. To uncover the underlying
 mechanisms of mountain biodiversity, this study sampled amphibians across
 30 sky islands in the Dabie Mountains, China, aiming to explore the
 nestedness of amphibian assemblages and their formative mechanisms from
 taxonomic, functional, and phylogenetic perspectives. Taxonomic nestedness
 was quantified by constructing species incidence matrices and calculating
 nestedness metrics, while functional and phylogenetic nestedness were
 assessed by integrating species similarities in ecological traits and
 phylogenetic relationships. Seven sky island characteristics and eight
 amphibian species traits were then selected as predictors of nestedness.
 Results showed that amphibian assemblages in the Dabie Mountains exhibited
 significant nestedness across taxonomic, functional, and phylogenetic
 dimensions. Spearman rank correlations between the selected predictors and
 nestedness ranks revealed that sky island area, climate stability, and
 species traits associated with extinction vulnerability were strongly
 correlated with taxonomic nestedness. Additionally, sky island area and
 climate stability significantly influenced functional and phylogenetic
 nestedness. These findings support the "selective extinction"
 and "habitat nestedness" hypotheses. To explain these results,
 we propose a climate stability hypothesis specific to sky islands: stable
 climatic conditions sustain greater species diversity, whereas climatic
 instability exacerbates the extinction of lineages lacking adaptive
 traits. This study presents the first empirical evidence of nestedness in
 sky island systems, extending classical hypotheses beyond lowland
 ecosystems, and offering new insights into climate-driven assembly
 mechanisms affecting vulnerable taxa. Our results indicate that
 conservation efforts should prioritize sky island regions with high
 climate stability, large areas and diverse habitats as core areas for
 biodiversity protection. Moreover, species with narrow elevation ranges,
 large area requirements, high habitat specificity, and long larval stage
 durations should also be preserved to prevent local extinction.
description: # Data from: Climate stability drives multidimensional nestedness of
 amphibian assemblages in a Chinese sky island system Dataset DOI:
 [10.5061/dryad.51c59zwpg](https://doi.org/10.5061/dryad.51c59zwpg) ##
 Description of the data and file structure Data information for Amphibian
 Assemblages in a Chinese Sky Island System ### Files and variables ####
 File: FE_Data.xlsx **Description:** Worksheet1 included island
 characteristics of the 30 study sky islands in the Dabie Mountains, China.
 The abbreviated variables are list as below: * DSDT, detrended standard
 deviation of temperature * MSTR, mean monthly spatial temperature range *
 Isolation1, Distance to nearest largest sky island (km) * Isolation2,
 Distance to nearest larger sky island (km) * HD, Habitat diversity *
 Scom-site, survey completeness with the sampling unit being a single
 island.Variables Worksheet2 included the habitat-by-site matrix for the 30
 study sky islands in the Dabie Mountains, China. Worksheet3 included the
 eight species traits of the 21 observed amphibians in the sky islands of
 the Dabie Mountains, China. ## Code/software Excel is recommended to view
 our data