A study on the long-term ecological impacts of specialized behavior can provide valuable insights for biodiversity conservation and ecosystem management, particularly in the context of climate change. The endangered primate Rhinopithecus bieti in temperate forest ecosystems relies primarily on the lichen Usnea longissima as its fallback food source. To investigate whether this specialized diet sustains forest health through trophic interactions, our study employed a three-tiered approach: (1) We first examined the impact of U. longissima on trees by comparing the health of branches covered with and without lichen. Findings reveal U. longissima exhibits harm to host trees, as lichen-covered branches displayed significantly higher rates of dieback. (2) Using habitats with varying extinction timelines of R. bieti , we quantified how the presence of R. bieti contributes to reducing U. longissima biomass. Results showed lichen biomass tripled in habitats where the species vanished 40 years ago compared to occupied habitats. (3) We finally used controlled artificial experiments that demonstrated that R. bieti's feeding activities may enhance U. longissima dispersal and growth. Our findings suggest that R. bieti may function as a natural regulator of lichen biomass, potentially helping to prevent overgrowth that could destabilize forest health. Notably, the monkeys' foraging behavior may not only control lichen proliferation but also help to promote its regeneration. This study underscores that restoring R. bieti populations would synergistically benefit both U. longissima viability and forest resilience, advocating for integrated conservation strategies that preserve specialized ecological interactions. Due to the fact that specialized diet species face severe survival challenges in the context of climate and environmental changes, future efforts should be focused on their ecological adaptation mechanisms and improving sustainable management strategies.

Lineages undergoing rapid evolutionary diversification may evolve a set of mixed traits as a result of hybrid speciation, gene flow, or incomplete lineage sorting (ILS). However, how best to quantify these alternative processes impacting phenotypic variation remains unclear. Here, we examined trait evolution in two sister genera of endangered Asian primates, Trachypithecus and Semnopithecus. By assembling a de novo genome of the Trachypithecus pileatus group, which is geographically located in a transitional zone between these two genera, our integrated phylogenomic analyses clarified the evolutionary relationship of the T. pileatus group with other Trachypithecus species. We also identified that morphological similarities shared between this species group and Semnopithecus are the result of ILS, rather than gene flow or hybrid speciation. Across all chromosomes of the T. pileatus group, ILS contributed 8.9% of whole genome segments. Across these segments, we distinguished 77 genes such as FGFBP1 and FOXO1 that are involved in pathways of bone development and osteoblast differentiation. Functional experiments indicate that FGFBP1 genotypes shared by species of the T. pileatus group and Semnopithecus appear to enhance osteogenic capability and mineralization, possibly resulting in larger body size and similarities in skull morphology compared with other species of Trachypithecus. The study reveals that ILS has shaped the evolution of mixed traits within gene-regulatory networks, driving phenotypic diversity during periods of rapid species divergence in this highly successful primate radiation. ILS appears to be more common than previously thought and represents a critical step in accurately assessing the phylogeny of closely related taxa.

Genetic variation provides the raw material for natural selection, enabling species to maintain adaptive potential, respond to environmental changes, and resist pathogens. Reduced genetic diversity can severely compromise long-term viability, particularly in small, isolated populations prone to inbreeding, genetic drift, and restricted gene flow-a vicious cycle known as the "extinction vortex". Assessing genetic diversity in threatened species is therefore critical for effective conservation strategies. The black-and-white snub-nosed monkey (Rhinopithecus bieti) is an Endangered primate that has experienced significant population decline and habitat fragmentation, raising concerns about its genetic diversity. We utilized major histocompatibility complex (MHC) class I genes, whose encoded proteins recognize antigens central to immune responses, to assess the adaptive genetic diversity of a semi-provisioned subpopulation of this species. Species-specific multi-locus primers targeting exons 2 and 3 of MHC class I genes were designed using published R. bieti whole-genome sequences. Amplicon-based next-generation sequencing was employed to genotype these exons in the studied subpopulation inhabiting Baima Snow Mountain National Nature Reserve, Yunnan, China. A total of 16 MHC class I sequences (7 exon 2 sequences and 9 exon 3 sequences) were identified from 47 individuals and assigned to 5 loci. Exon 2 exhibited low heterozygosity (H e = 0.349) and moderate polymorphism (PIC = 0.281), whereas exon 3 showed extremely low heterozygosity (H e = 0.147) and low polymorphism (PIC = 0.131). In addition, positive selection signatures were detected in both exons, and phylogenetic analyses indicated trans-species evolutionary patterns in class I loci. These results underscore the role of balancing selection in maintaining adaptive genetic variation. However, low genetic diversity is likely to have diminished the studied subpopulation's capacity to adapt to environmental change, thereby undermining its long-term viability. This study emphasizes the urgent need to assess adaptive genetic diversity across all R. bieti populations in order to develop targeted management strategies. The data generated in this studied subpopulation provide the baseline for comparison.

The “SLOSS” (Single Large or Several Small) debate remains one of the most enduring and influential issues in conservation biology, with divergent findings continuing to shape the application of theory in protected area design and biodiversity conservation. Here, we argue that resolving this debate requires explicit consideration of both taxonomic groups and ecological context, alongside the development of actionable, scenario-specific management recommendations. Focusing on primates, we investigated SLOSS dynamics and optimal reserve size ranges in western Yunnan, China, a global biodiversity hotspot, at both patch and landscape scales. At the landscape scale, under a constant total area, a network of several small patches supported higher cumulative species richness than a single large patch (SS > SL), driven by the capacity of spatially dispersed fragments to collectively intercept highly heterogeneous elevational gradients and diverse micro-habitats. In addition, the relationship between primate species density and patch area followed a unimodal pattern, peaking at 6.92 km². We further demonstrate that the highly fragmented Xiaoheishan Provincial Nature Reserve, composed of multiple small patches, effectively sustains seven primate species, representing 28% of China’s primate fauna and 46.7% of the regional species pool. These findings underscore the critical role of small habitat patches and their network configuration in maintaining primate biodiversity. We recommend that protected area planning prioritize the identification of optimal area ranges that maximize species density, thereby optimizing the spatial efficiency of biodiversity representation (i.e., maximizing species protection per unit of dedicated area), and adopt a hierarchical, context-dependent design framework to develop more effective and resilient conservation networks.

The genus Acantholabus Heinrich, 1974 is reviewed. The three previously known species are re-described, and a new species, Acantholabus yunlingensis Reshchikov & Kikuchi sp. nov., from Northwestern Yunnan, is described and illustrated. An identification key to the species of the genus is also provided.

High-altitude animals rely on vertical spatial adaptation to cope with harsh environments, yet the underlying drivers of their seasonal altitudinal distribution remain poorly understood. This study investigated how solar radiation, seasonal high-quality food resources and stable foods shape the altitudinal distribution of the highest-altitude primate Rhinopithecus bieti, to uncover its survival strategies. Through systematic environmental data collection and three-year field tracking of a wild group in the Lasha Mountains, northwest Yunnan, China, we identified consistent seasonal patterns: spring in low-altitude habitats, summer at highest elevations, and intermediate ranges during autumn/winter. Statistical modeling revealed seasonally shifting environmental dependencies. Summer showed no resource limitations, while autumn introduced solar exposure and mature leaves as positive synergistic factors (50% model explanatory power). Winter exhibited peak environmental pressure (80%), with solar and buds becoming critical, though revealing a trade-off between foraging and thermoregulation. Spring demonstrated the strongest environmental coupling (86%), where solar and high-quality food showed significant positive synergy, enabling physical recovery. The species displays remarkable ecological plasticity, with solar being the core cold-season driver. The winter-to-spring transition from resource trade-off to synergy reflects dynamic behavioral adaptations to seasonal climate and nutritional bottlenecks, offering new insights into primate survival strategies in extreme environments.

Seasonal body mass fluctuations in mammals reflect fundamental trade-offs between ecological constraints and reproductive effort, yet few studies have simultaneously linked these dynamic changes with activity budgets in high-altitude primates inhabiting extreme-temperature environments. We examined the effects of environmental stress and mating effort on body mass dynamics in black-and-white snub-nosed monkeys (Rhinopithecus bieti). Using monthly non-invasive monitoring over a full annual cycle, we obtained 464 body mass records from free-ranging adults (127 male records, 337 female records). Both sexes showed marked seasonal variation: body mass peaked in spring and autumn, declined moderately in winter (males: -7.4%, females: -2.9%), and dropped more sharply during the mating season (males: -11.1%, females: -12.9%). Male mass loss was positively correlated with the number of mates. Seasonal shifts in activity budgets accompanied these patterns: in summer, males increased movement and females increased both movement and social interaction, while both sexes reduced resting; in winter, both sexes increased feeding time, with females additionally reducing social activities. These findings reveal two distinct phases of body mass loss. Body mass decline was more pronounced during the mating season than in winter, a pattern that may be associated with higher energetic costs related to reproductive activity. Our study demonstrates how high-altitude primates balance survival and reproduction through flexible energy allocation, offering key insights into their seasonal energy allocation resilience in provisioned high-altitude habitats.

Primate interspecific interactions with both other primates and non-primate species range from predator–prey dynamics to affiliative behaviors such as grooming, play, and carrying. While many primates participate in interspecific associations or commensal relationships, to our knowledge interspecific social interactions have never been systematically synthesized. Here, we present the first comprehensive review of such interactions, compiling 427 cases from the literature, media sources, and a global survey of primatologists. These involved 88 primate species and 127 non-primate species (including mammals, birds, reptiles, amphibians, malacostracans, and insects) across wild (n = 311) and captive (n = 111) contexts. The most frequent interactions occurred within or between primate families (e.g., Cercopithecidae–Cercopithecidae, Cebidae–Atelidae), though affiliative behaviors were also directed toward distantly related taxa such as dogs and birds. Play (n = 139) and grooming (n = 136) were most common. Juveniles and infants predominantly engaged in play, while adult females were more likely to groom. Adult males were less affiliative overall. Contrary to expectations, affiliative behaviors were not more often directed toward immature than adult heterospecifics. Primates were the initiators in most interactions. These findings offer new insights into the diversity and contexts of heterospecific sociality in primates and suggest that some behavioral tendencies relevant to later forms of human–animal companionship – such as caregiving, tolerance, and exploratory play – may be more widespread among primates than previously recognized.

The energy and nutrient costs associated with body mass, age, and sex can influence variation in primate behavior and diet. However, comparatively little is known about how these factors affect the behavioral and dietary flexibility of Asian colobines in response to intra-annual climate shifts. We collected data on an isolated population of black-and-white snub-nosed monkeys (Rhinopithecus bieti) at Mt. Lasha in the Yunling Provincial Nature Reserve, Yunnan, China, using instantaneous and scan sampling across 32 months between May 2008 and August 2016 to assess the association of temperature on the activity budgets and diets among and within age-sex classes. Adult females spent more time feeding, juveniles spent more time moving and less time resting, and adult males spent less time moving and more time resting than other age-sex classes. We did not detect any significant variation in diet across age-sex classes. This population spent more time feeding and less time moving and resting in colder months than in warmer months; however, we only detected these temperature-related effects within age-sex classes for moving and resting, not feeding. This population also spent more time feeding on lichen during colder months than during warmer months, a finding that cannot be explained by temperature-related dietary shifts within age-sex classes because their diets remained stable throughout the year. Our results suggest that intra-annual variation in temperature may amplify the distinct physiological demands among different age-sex classes, leading to greater shifts in activity patterns than in diet composition.

Oxidative damage, oxidative inflammation, and a range of downstream diseases represent significant threats to human health. The application of natural antioxidants and anti-inflammatory agents can help prevent and mitigate these associated diseases. In this study, we aimed to investigate the effectiveness of walnut green husk (WNGH) as an antioxidant and anti-inflammatory agent in an in vitro setting. HepG2 cells were treated with tert-butyl hydroperoxide (t-BHP) to establish a cellular model of oxidative damage and inflammation. We assessed the biocompatibility of walnut green husk aqueous extract (WNGH-AE) on HepG2 cells using MTT and LDH assays (WNGH-AE concentration: 0.05, 0.1, 0.2, 0.4, 0.8, 1.6, 3.2, 6.4, and 12.8 mg/mL). Additionally, we measured intracellular oxidative stress indicators, such as ROS and 8-OHdG, along with inflammatory factors TNF-α and IL-1β through ELISA to evaluate the antioxidant and anti-inflammatory capacity of WNGH-AE (concentration: 0.025, 0.05, 0.1 mg/mL) in HepG2 cells. We also determined the free radical scavenging capacity of various extracts of WNGH using DPPH and ·OH methods. The total phenols, total polysaccharides, and total flavonoids in WNGH-AE were analyzed using the Folin-Ciocalteu’s reagent, the phenol-sulfuric acid method, and the spectrophotometry, respectively. The bioactive components of WNGH-AE were analyzed using LC-MS/MS. Our results demonstrated that WNGH-AE was highly biocompatible with HepG2 cells. The antioxidant effect of WNGH-AE involved the scavenging of intracellular ROS, while its anti-inflammatory effect was linked to the down-regulation of the NF-κB pathway. Compared to other extractants (ethyl acetate, n-butanol, 75% ethanol, and petroleum ether), WNGH-AE exhibited the strongest free radical scavenging ability. Through LC-MS/MS analysis, we identified 403 compounds in WNGH-AE, with gentisic acid being the most abundant and possessing high antioxidant capacity, suggesting it may be a key active component contributing to the antioxidant activity of WNGH-AE. In conclusion, our findings indicate that WNGH-AE is a natural, high-quality antioxidant and anti-inflammatory biomaterial deserving further research and development, with significant potential applications in healthcare. (311 words)

The study on the connectivity among monkey groups is one of the critical issues in the conservation of the Black-and-white Snub-nosed Monkey (Rhinopithecus bieti, BWSM). Constructing ecological corridors is a vital strategy for restoring and maintaining the ecological connectivity of the BWSM’s habitat. This study utilized the Linkage Mapper tool, integrating the MaxEnt model, least-cost distance model, and gravity model, to extract and classify potential ecological corridors, identify potential ecological nodes, and analyze these corridors and nodes in terms of human disturbance index and land use/ cover. The results indicate that: 1) 53 ecological sources (3814.86 km²) were identified, with 42.79% located outside existing protected areas; 2) 97 potential ecological corridors, 136 ecological barrier points (666.38 km²), and 112 ecological pinch points (25.64 km²) were identified; 3) The number of corridor level, the primary, secondary and tertiary corridors were 22, 41, and 34. The corresponding areas of ecological barrier points and pinch points account for 0.39%, 15.06%, 84.55% and 2.70%, 18.82%, 78.48%, respectively; 4) Human activities and complex land cover types are the primary factors impeding the migration of the BWSM. Specifically, 46 potential corridors were disturbed by residential areas and roads, with a total disturbance index of 0.50. The disturbance index of third-level corridors (0.67) was significantly higher than the overall level. Furthermore, within a 50m corridor width and within barrier areas, the absolute proportions of unsuitable forest, grassland, and farmland increased landscape resistance to monkey migration. In the future, ecological corridor restoration can be carried out according to the priority of ecological circulation. From the corridor level, the primary corridor > secondary corridor > tertiary corridor. In terms of the location of the study area, the middle section > the southeast section> the north section. These findings provide a scientific basis for the planning, construction, and ecological restoration of BWSM corridors across their entire range.

Understanding how wildlife behavior relates to habitat characteristics is essential for ecology and conservation, particularly in remote, structurally complex landscapes. In this study, we examine seasonal and behavior-specific habitat preferences in black-and-white snub-nosed monkeys (Rhinopithecus bieti), an endangered primate endemic to high-elevation forests in Yunnan, China. We combined long-term behavioral observations (2008–2018) with UAV-based LiDAR data on forest structure (collected in 2022–2023), and camera trap data on human and wildlife activity (2017–2018), to assess how these factors are associated with space use across different behaviors and seasons. Using machine learning models, we identified structural and disturbance-related attributes that were consistently associated with R. bieti behavior at the home-range scale. Vertical forest structure, particularly canopy height and vegetation layering, showed strong associations with foraging and sleeping locations across both wet and dry seasons. These patterns varied depending on behavioral context, supporting the idea that R. bieti adjusts its space use in response to seasonal and structural variation. Human and livestock presence were also negatively associated with habitat use during feeding and movement. While our findings align with established ecological expectations for semi-arboreal primates, they provide one of the first fine-scale, spatially explicit analyses of habitat preferences in R. bieti. We acknowledge the temporal mismatch between datasets as a limitation, and interpret our results conservatively as correlational. Nonetheless, this study highlights the value of combining behavioral, structural, and disturbance data to inform habitat conservation in montane forest ecosystems.

The southeastern edge of the Qinghai-Tibet Plateau (Yunnan, China) exhibits high biodiversity but stark differences in species richness between its western Longitudinal Range Gorge (LRG) and eastern Yunnan Plateau (YP). We collected distribution data for 16 primate species in Yunnan and analyzed palynological records over the past 20 ka from 21 localities to identify the biogeographic, climatic, and anthropogenic factors that have driven the present-day distribution of primates in this region. By integrating local ecological knowledge, field surveys, species distribution models, niche utilization rates, and historical vegetation and land use changes, we found that spatial-temporal shifts in the monsoon climate have been a critical factor in shaping primate species richness on the southeastern edge of the Qinghai-Tibet Plateau. Compared to the YP, the LRG receives more precipitation, has more limited seasonal temperature variation, and has higher minimum temperatures during the coldest month. These conditions have facilitated the development of moist evergreen broadleaf forests, which represent a more suitable habitat for the 14 primate species that inhabit this area. In contrast, the drought-adapted forests of the YP support only one primate species. Palynological records indicate that the differentiation of the LRG and YP predates human influence. However, over the past 2000  years, anthropogenic habitat loss and hunting have significantly affected the distribution of primates. The ranges of gibbons, langurs, and snub-nosed monkeys are now restricted to the central and northern regions of the LRG and have disappeared from lower elevations. Lorises have disappeared from their northernmost range. In contrast, the distribution of macaques has remained relatively stable. The Yangtze-Red River-24° N line marks the biogeographic boundary of high primate species richness and biodiversity in the LRG and southeastern Yunnan. Our research suggests that changes in monsoon climate have fundamentally shaped contemporary species richness, while recent anthropogenic pressures have caused 'range contraction' for many taxa.

Wildlife camera trap (CT) surveys typically employ two-dimensional equal-area grid sampling, which often neglects the influence of complex mountainous terrain on species distribution, potentially yielding misleading outcomes. A watershed, incorporating diverse habitats from high to low elevations and from rivers to ridges, aligns with complex mountains. Monitoring based on watersheds might address this. In southwest China's mountain forests, under comparable sampling intensities, we contrasted the capture rate (CR), species richness, and relative abundance index (RAI) of dominant species among watershed, 1 x 1 km(2) grid, and elevation gradient patterns. Also, habitat factor correlations and heterogeneities were analyzed. Results reveal higher CR, species richness, and habitat heterogeneity in the watershed pattern. The elevation gradient pattern shows more stable species and RAI than the grid pattern. In small-scale mountains, topographic factors indirectly affect CT survey results via vegetation distribution. Analysis of similarities (ANOSIM) indicates significant differences in species and community among watersheds. Using watersheds as sampling units for CTs can match the mountains' elevation differences and complex topography well, aids in capturing wildlife diversity and understanding mountain species distribution. Therefore, we recommend that the spatial sample design in mountainous areas should be based on watersheds, taking elevation gradients and topography into consideration.

Primates, 69% of which are threatened with extinction, are the third most specious order of mammals. We used primates as model taxa to examine the umbrella effects of primates on ecosystem services and the protection of other vertebrates and seed plants in Yunnan Province, China. We identified areas of conservation priority for 16 primate species and determined which other threatened and endemic terrestrial vertebrates and seed plants would be protected through a program targeting primate conservation. Areas of high primate species richness were spatially correlated with the distribution of 601 species of threatened and endemic vertebrates and 4010 seed plants. Primate species richness was positively correlated with carbon sequestration and enhanced water and soil conservation and coincided with future areas of climate refugia. If 30% of Yunnan's land area were designated as primate conservation priority areas, then 52.3% of the province's average annual carbon sequestration, 51.7% of its water conservation, 54.1% of its soil retention, and 30-33% of its climate-stable areas would be protected. Protecting primates as umbrella taxa uniquely contributes to maintaining biodiversity and ecosystem services that promote ecosystem stability. Although we focused on a single mammalian order in a single region, our approach for umbrella taxa evaluation has broad applicability and can help achieve multiple conservation targets of the Kunming-Montreal Global Biodiversity Framework.

This study addresses a critical challenge in global conservation: understanding how rare species contribute to ecosystem structure and resilience. The ecological role of the endangered black-and-white snub-nosed monkey in China’s temperate mountain forests was examined, with the hypothesis that its tree-shaking behavior alters forest structure and microclimates to enhance ecosystem health. To assess long-term impacts, current monkey-inhabited forests were compared with historical sites abandoned over decades, by analyzing tree gaps, forest structure, and environmental conditions. Monkeys’ canopy-disturbing actions were also directly observed. Findings revealed monkey activity created more canopy gaps (38.3% in current habitats vs. 29.9~33.5% in abandoned sites) and altered microclimate conditions, which boosted plant diversity and optimized the community’s vertical and age structures. Current forests supported nearly twice as many tree species, 2.5 times as many shrub species, and threefold more herb species than areas abandoned for 40 years. Even 20 years after monkeys disappeared, abandoned sites retained higher diversity and gaps, showing lasting ecological benefits. These results confirm the monkey’s vital role as a resilience promoter, demonstrating how rare species can shape healthier ecosystems. This highlights the need to prioritize protecting such species, as their survival not only preserves biodiversity but also sustains ecosystem functions crucial for human well-being.

The global outbreak of the COVID-19 pandemic has led to a series of human lockdowns. Studying human–animal linkages during these periods is essential in conserving global biodiversity, maintaining ecosystem integrity, and preventing zoonotic diseases. This especially applies to the matters between human and nonhuman primates—their coexistence. In this study, we used community interviews and camera traps to analyze behavioral responses and changes in human–monkey relationships regarding a semi-wild group of macaques (Macaca mulatta) in a tourism area during the lockdown. The results indicate that food provision for macaques from tourists substantially declined. As a result, macaques moved to communities for food, causing increased human–monkey conflicts; consequently, local communities’ attitudes toward macaques prominently changed: those who have experienced severe conflicts are far less tolerant of the macaques than those without experience. Thus, to maintain a cordial coexistence between humans, primates, and other animals in ecotourism areas, we suggest (a) establishing long-term monitoring to maintain a sustainable balance between animal population size and available food resources provided by humans and the environment; (b) improving emergency management policies for controlling monkey populations to prevent the unwanted conflicts between macaques and communities, responding to exceptional circumstances such as the COVID-19 lockdown; (c) strengthening the establishment of conduct code for tourists to avoid conflicts between tourists and primates and the spread of pathogens; and (d) upgrading compensation policies for the damages caused by human–wildlife conflicts and strengthening the cooperation between the community and tourist management; an amicable relationship between communities, economic development, and animal conservation is highly demanded.

The dual impact of climate change and human activities has led to a sharp decline in global primate biodiversity.China,which has the most diverse primate species in the northern hemisphere,faces severe eco-logical threats during its transition from an agricultural to a modern society due to the expansion of modern ag-riculture,over-exploitation and consumption of natural resources,and excessive land development.In re-sponse,China has implemented various ecological conservation measures,including habitat restoration and protection.These efforts have made substantial progress in biodiversity conservation,with certain regions see-ing an increase in primate populations.This study conducted a systematic review of historical documents and field research data related to Chinese primates,evaluating the endangered status of primate species in China.Despite improvements in the habitats of most primate species and some population growth,many species still face severe threats,including declining and small populations.Species such as the Myanmar snub-nosed mon-key(Rhinopithecus strykeri),eastern black crested gibbon(Nomascus nasutus),and Hainan gibbon(N.hainanus)remain particularly vulnerable due to their limited distribution ranges and extremely small popula-tions.Insufficient scientific data,fragmented information,and a lack of comprehensive studies in conservation biology further exacerbate these challenges.Additionally,there is a notable lack of detailed population monito-ring data for species such as the Bengal slow loris(Nycticebus bengalensis),Pygmy slow loris(N.pygmae-us),Indochinese gray langur(Trachypithecus crepusculus),Shortridge's langur(T.shortridgei),and capped langur(T.pileatus),hindering the development of practical and targeted conservation management strategies.Therefore,for national biodiversity conservation,there is an urgent need for specialized primate surveys,enhanced habitat protection and restoration,and increased focus on cross-border conservation strate-gies and regional cooperation.Establishing a comprehensive and systematic research database platform,con-ducting continuous and in-depth research in primate biology.Additionally,strengthening public awareness on wildlife conservation remains essential.Such integrated and systematic efforts will provide scientific support for the current and future conservation and management of primate species in China.

Soil seed bank (SSB) play an essential role in the restoration and regeneration of plant communities. Grazing is a common disturbance factor that exerts an important effect on the diversity and composition of the SSB community in forests. Here, we evaluated the structure and composition of SSB along a grazing disturbance gradient of two types of vegetation (broad-leaved forests and mixed coniferous broad-leaved forests) in southwest China. A comparison of the similarity of SSBs with the above-ground vegetation strata (tree, shrub and herb layers) was also analyzed. The experiment revealed the germination of 25 species that belonged to 14 families and 24 genera. The density of SSBs did not show significant differences along the grazing disturbance. The alpha diversity of SSBs was the highest at moderate grazing intensity in broad-leaved forests, and not significantly different along disturbance intensities in mixed coniferous broad-leaved forests. No significant changes were observed in the species composition of SSB along the grazing gradients. Nonmetric multidimensional scaling analyses revealed low similarities between SSBs and above-ground vegetation, with the lowest similarity occurring under medium grazing disturbance intensity. Overall, our research offers significant insight into the response of SSBs to grazing in different vegetation types. It serves as a guide for designing grazing management strategies tailored to natural forests.

AbstractFallback foods (FBF), categorized into staple and filler types, are suboptimal food sources chosen by animals in response to a scarcity of preferred food items during specific periods. Using lichens as FBF by Yunnan snub‐nosed monkeys (Rhinopithecus bieti) represents a distinctive ecological adaptation and evolutionary development within nonhuman primates. This study delves into the annual dietary choices of the species to address issues, elucidate the nutritional value, and understand the ecological significance of lichens for this primate species, which resides at the highest altitudes and experiences the coldest weather among global primates. The findings reveal that the lichens consumed by the monkeys serve as the staple FBF, with Bryoria spp. and Usnea longissima being the primary dietary species. The former is the preferred choice, providing higher digestible fiber (neutral detergent fiber) levels but lower tannin, fat, ADF, and energy levels. During the dry season, lichens dominate as the monkeys' primary food and nutritional resources. In the wet season, they act as a fundamental food selection rather than an ideal dietary choice, substituting nutrients from fruits, seeds, and leaves. Compared to other Asian colobine counterparts, this species exhibits the highest lichen consumption but the lowest proportions of leaves, flowers, and seeds. This study provides valuable evidence and information for developing or amending conservation strategies and guidelines for the dietary management of captive breeding of monkeys, one of the world's critically endangered primate species.