Stability and Assembly Mechanisms of Butterfly Communities across Environmental Gradients of a Subtropical Mountain.

Mountain ecosystems harbor evolutionarily unique and exceptionally rich biodiversity, particularly in insects. In this study, we characterized the diversity, community stability, and assembly mechanisms of butterflies on a subtropical mountain in the Chebaling National Nature Reserve, Guangdong Province, China, using grid-based monitoring across the entire region for two years. The results showed that species richness, abundance, and Faith's phylogenetic diversity decreased with increasing elevation; taxonomic diversity played a considerable role in mediating the effects of environmental changes on stability. Moreover, our results showed that stochastic processes are dominant in governing the assembly of butterfly communities across all elevational gradients, with habitats at an elevation of 416-580 m subjected to the strongest stochastic processes, whereas heterogeneous selection processes displayed stronger effects on the assembly of butterfly communities at 744-908 m, 580-744 m, and 908-1072 m, with abiotic factors inferred as the main driving forces. In addition, significant differences were detected between the barcode tree and the placement tree for the calculated ß-NTI values at 416-580 m. Overall, this study provides new insights into the effects of environmental change on the stability and assembly of butterflies in Chebaling, which will be beneficial for biodiversity conservation and policy development.

Spatio-Temporal Evolutionary Patterns of the Pieridae Butterflies (Lepidoptera: Papilionoidea) Inferred from Mitogenomic Data.

Pieridae is one of the largest and almost cosmopolitan groups of butterflies, which plays an important role in natural ecosystems; however, to date, its phylogeny and evolutionary history have not been fully resolved. In this study, we obtained the complete or nearly complete mitochondrial genomes of 100 pierid taxa (six newly sequenced, sixty extracted from the whole-genome data, and thirty-four directly available from GenBank). At the same time, for the first time, we conducted comparative mitogenomic and phylogenetic analyses based on these mitogenomic data, to further clarify their spatio-temporal evolutionary patterns. Comparative mitogenomic analysis showed that, except for cox2, the GC content of each of the 13 protein-coding genes (PCGs) in the rapidly diverging subfamily Pierinae was higher than in its sister group Coliadinae. Moreover, the dN/dS values of nine genes (atp6, atp8, cox1, cox3, cob, nad1, nad3, nad5, and nad6) in Pierinae were also relatively higher than those in its sister group, Coliadinae. Phylogenetic analysis showed that all the resultant phylogenetic trees were generally in agreement with those of previous studies. The Pierinae family contained six clades in total with the relationship of (Leptosiaini + (((Nepheroniini + Arthocharidini) + Teracolini) + (Pierini + Elodini))). The Pieridae originated in the Palearctic region approximately 72.3 million years ago in the late Cretaceous, and the subfamily Pierinae diverged from this family around 57.9 million years ago in the Oriental region, shortly after the K-Pg mass extinction event; in addition, the spatio-temporal evolutionary patterns of Pierinae were closely correlated with geological events and environmental changes, as well as the host plant coevolutionary scenario in Earth's history. However, some incongruencies were observed between our results and those of previous studies in terms of shallow phylogenies for a few taxa, and should be further investigated.

Vietnamella chebalingensis, a new species of the family Vietnamellidae (Ephemeroptera) from China based on morphological and molecular data.

Vietnamella chebalingensis Tong, sp. nov. is described based on larval stage from China. The new species is distinguished from its congeners by the following combination of characters: body purple black with mottled white markings; length of inner pairs of cephalic projection approximately half of the outer pairs; posterior margin of abdominal tergites I-VI and VIII-X each with a pair of pointed projections, but tergite VII bearing only a single projection. The morphological evidence and molecular data (COI, Kimura 2-parameter) support that this new species represents the sixth species of the genus Vietnamella. An identification key to known larvae of the genus Vietnamella is provided.

Effects of ice storm on species richness and abundance of resident birds in subtropical forest in southern China.

Between January and February 2008, a severe ice storm occurred in southern China. The storm damaged nearly 21 million hectares of forest lands with broken branch, trunk breakage, and stem bending of many trees. This natural disturbance provides a unique opportunity to study impacts of extreme climatic event on forest birds. Using hierarchical multi-species occupancy model (species richness; 27 species) and N-mixture model (abundance; 3 species), we investigated how the storm affected resident bird species in subtropical forest in southern China. We sampled birds at Chebaling National Nature Reserve in Guangdong Province, monthly for 1 year each before and after the storm by mist nets. To take into account variations in temperature between years and between months, we incorporated monthly mean temperature into the models as an additional covariate. Observed species richness was greater before the storm. Estimated species richness (from the hierarchical model) also tended to be greater before than after the storm although 95% Bayesian credible intervals of these estimates were overlapped. Temperature showed a negative effect on estimated species richness, indicating greater species richness during winter. Among three species captured the most, abundance of Chestnut Bulbul (Hemixos castanonotus) significantly decreased after the storm. Other two species, Grey Treepie (Dendrocitta formosae) and Huet's Fulvetta (Alcippe hueti) showed insignificant responses to the storm. Our study indicates that the 2008 ice storm may not have a significant impact on species richness of resident birds in subtropical forest; however, the effect can be species-specific and negative to some species' population.