Aster mayangheense Z.Li (Asteraceae, Astereae), a new species from Guizhou, China, is described and illustrated here. Morphological and molecular analyses based on nuclear ribosomal DNA internal transcribed spacer (nrDNA ITS) confirm its distinct status. The species is morphologically similar to A. saxicola, but differs by its falcate, adaxially shiny upper leaves 3.5–5.0 × 0.8–2.0 cm with long-acuminate to caudate apices (versus oblong-lanceolate to lanceolate leaves in A. saxicola); 5-seriate, abaxially red-purple phyllaries (versus 3–5-seriate with purple-tipped phyllaries); and fewer florets (7–12 ray florets and 5–9 disc florets versus 9–14 ray florets and 10–18 disc florets). Phylogenetic analysis strongly supports its distinctness, with four samples forming a monophyletic clade (PP = 1.00, BS = 100%) nested within Aster.

The Mayanghe National Nature Reserve, a key habitat for the endangered François’ langur (Trachypithecus francoisi), faces significant anthropogenic disturbances, including extensive distribution of croplands, roads, and settlements. These human-modified features are predominantly concentrated at elevations between 500 and 800 m and on slopes of 10–20°, which notably overlap with the core elevation range utilized by François’ langur. Spatial analysis revealed that langurs primarily occupy areas within the 500–800 m elevation band, which comprises only 33% of the reserve but hosts a high density of human infrastructure—including approximately 4468 residential buildings and the majority of cropland and road networks. Despite slopes >60° representing just 18.52% of the area, langur habitat utilization peaked in these steep regions (exceeding 85.71%), indicating a strong preference for rugged karst terrain, likely due to reduced human interference. Habitat type analysis showed a clear preference for evergreen broadleaf forests (covering 37.19% of utilized areas), followed by shrublands. Landscape pattern metrics revealed high habitat fragmentation, with 457 discrete habitat patches and broadleaf forests displaying the highest edge density and total edge length. Connectivity analyses indicated that distribution areas exhibit a more continuous and aggregated habitat configuration than control areas. These results underscore François’ langur’s reliance on steep, forested karst habitats and highlight the urgent need to mitigate human-induced fragmentation in key elevation and slope zones to ensure the species’ long-term survival.

Understanding the diversity of pathogenic microorganisms in wild primates is essential for assessing their health and zoonotic risks. In this study, metagenomic sequencing was applied to investigate the composition and seasonal dynamics of potential pathogenic microorganisms in the feces of François’ langurs. A total of 77 potential pathogenic taxa were identified, mainly belonging to Bacillota and Pseudomonadota. The most abundant genera were Streptococcus, Staphylococcus, Salmonella, Listeria, and Pseudomonas, while dominant species included Staphylococcus aureus, Streptococcus pneumoniae, Salmonella enterica, Listeria monocytogenes, and Escherichia coli. Significant seasonal differences were detected in both α- and β-diversity indices, with higher microbial diversity in spring and distinct community structures across seasons. Several genera and species, including Vibrio, Chlamydia, Mycobacteroides, Vibrio cholerae, Yersinia enterocolitica, Chlamydia trachomatis, and Mycobacteroides abscessus, showed marked seasonal fluctuations. The findings reveal that the pathogenic microbial community of François’ langurs is strongly shaped by seasonal environmental factors. The detection of multiple zoonotic pathogens suggests a potential risk of cross-species transmission, providing valuable baseline data for primate disease ecology and conservation health management.

Understanding how climate and land-use change influence habitat suitability is essential for the conservation of the François’ langur (Trachypithecus francoisi). In this study, climatic, land-use, and topographic variables were integrated to model the current distribution and future dynamics of suitable T. francoisi habitats in southwestern China. The model performed well, climatic factors were the primary determinants of distribution, particularly precipitation of the driest month (BIO14), mean diurnal temperature range (BIO2), and precipitation seasonality (BIO15); additionally, forest cover, slope, and elevation further improved model performance. Suitable habitat currently covers 53,109 km² (10.75% of the study area) and is mainly concentrated in Chongqing and Guizhou, with smaller areas in Guangxi. Future projections indicate substantial habitat redistribution and an overall decline in suitable area under both scenarios. By the 2050s and 2070s, suitable habitats will show strong spatial turnover, with coexistence of retained, newly suitable, and lost areas. Suitable habitat is projected to shift toward northern areas. These results suggest that conservation priorities should shift focus northward under climate warming, with emphasis on protecting mountainous refuges and improving habitat connectivity.

Despite growing research on gut microbiota in wild primates, seasonal functional dynamics of the gut microbiota in this endangered folivorous species remain poorly understood. This study investigates the seasonal variations in the gut microbiota of François' langur (Trachypithecus francoisi) and their implications for dietary adaptation and conservation. Using shotgun metagenomic sequencing, fecal samples were collected across four seasons within the Mayanghe National Nature Reserve in China (n = 24). The study identified significant seasonal shifts in microbial diversity and composition. While alpha diversity metrics reflecting community evenness (Shannon and Simpson equivalents) remained stable (P_adj > 0.05), species richness (Hill number, q = 0) was significantly lower in Fall compared to Spring and Winter (P_adj = 0.013). Results revealed that dominant phyla included Bacillota and Bacteroidota, with a significant enrichment of Faecalibacterium during Fall. Functional analysis showed a predominance of carbohydrate metabolism, which remained stable at broad metabolic levels; however, fine-scale functional units (KOs and CAZy families) exhibited distinct seasonal signatures. A moderate correlation between taxonomic and functional profiles (Mantel r = 0.43, P = 0.001) suggests a partial decoupling. These findings highlight the ecological plasticity of the gut microbiota and underscore how taxonomic flexibility enables functional homeostasis, aiding the physiological resilience of endangered primates in fluctuating environments.