Himalaya-Hengduan Mountains Research Articles

山地景观遗传学研究文献综述

PDF HTML阅读 XML下载 导出引用 引用提醒 山地景观遗传学研究文献综述 DOI: 10.5846/stxb202106191631 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金面上项目31970431；生态环境部生物多样性调查、观测与评估项目（2019HJ2096001006） Research progress and future outlook of mountain landscape genetics studies Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:山地生态系统是生物多样性分布与保护的热点。山地景观遗传学（Mountain Landscape Genetics）研究在山地景观尺度上野生生物的种群遗传格局及其驱动机制和影响因素，是景观遗传学（Landscape Genetics）的重要分支。山地景观遗传学研究对于深入理解物种的空间遗传结构、形成过程、物种形成与分化机制具有重要意义与价值，同时可以为珍稀濒危物种和山地生物多样性的有效保护与管理提供科学指导。为了更好地掌握目前山地景观遗传学的发展趋势与重点研究问题，为未来生物多样性与山地生态系统的保护管理提供科学参考，基于对Web of Science核心数据库和中国知网数据库的系统检索，全面汇总分析了1999-2020年山地景观遗传学领域发表的192篇英文文献与31篇中文文献。结果显示，该领域自2008年起迅速发展，截至2020年共有46个国家的研究机构发表了山地景观遗传相关研究，研究热点地区包括北美洲的落基山脉、内华达山脉、阿巴拉契亚山脉，欧洲的阿尔卑斯山脉、比利牛斯山脉，以及亚洲的喜马拉雅-横断山脉。研究对象类群涵盖真菌、植物、节肢动物、脊椎动物，其中脊椎动物是研究发表最多的类群，占发表文献总数的62.0%；脊椎动物中，又以对哺乳类（占脊椎动物发表文献总数的52.9%）与两栖类（23.5%）的研究最多。目前主要的研究方向包括：（1）识别山地景观中的基因流路径或阻碍；（2）量化山地景观特征对种群遗传结构时空变化的影响。中国是发表山地景观遗传学文章数量最多的亚洲国家，近十年来相关研究发展迅速，研究类群以植物（占在中国发表文献总数的62.3%）与脊椎动物（35.8%）为主，对脊椎动物的研究中以两栖动物为最多（占所有脊椎动物发文数量的52.6%），研究区域主要集中在喜马拉雅-横断山脉与秦岭。本文进一步对目前山地景观遗传学研究中存在的空缺及未来重点关注问题提出建议。 Abstract:Mountain ecosystems are hotspots of biodiversity distribution and conservation. Mountain landscape genetics is an important branch of the subject Landscape Genetics, which studies the genetic patterns of wild populations, their underlining mechanisms and influencing factors at the mountain landscape scale. Mountain landscape genetics research is of great significance for in-depth understanding of the formation of species’ spatial genetic structure, speciation and differentiation mechanism, and can provide important guidance for the effective conservation and management of rare and endangered species and mountain biodiversity. To better understand the development trend and key research issues in the field of mountain landscape genetics, and to provide scientific reference for protection and management of biodiversity and mountain ecosystems in the future, we systematically reviewed relevant studies retrieved from the core database of Web of Science and China National Knowledge Infrastructure (CNKI). A total of 192 English and 31 Chinese literatures in the field of mountain landscape genetics published from 1999 to 2020 were summarized and analyzed. The results showed that the field has been developing rapidly since 2008, with numerous research institutions from 46 nations involved in these published studies. The geographical research hotspots included the Rockies, Sierra Nevada, and Appalachians in North America, the Alps and Pyrenees in Europe, and the Himalaya-Hengduan Mountains in Asia. The studied taxa included fungi, plants, arthropods and vertebrates, where vertebrates were the most studied taxon accounting for 62.0% of the total number of published English articles. Among the vertebrates, mammals (accounting for 52.9% the total number of vertebrate articles) and amphibians (23.5%) were the most studied taxa. Current research directions of mountain landscape genetics mainly include: (1) identifying paths or barriers of gene flow in the mountain landscapes; and (2) quantifying the effects of mountain landscape characteristics on the temporal and spatial variations of population genetic structure. Of all Asian countries, China has published the largest number of articles on mountain landscape genetics. Research on mountain landscape genetics in China has been rapidly advancing in the past decade, with plants (accounting for 62.3% the total number of Chinese studies) and vertebrates (35.8%) being the focal taxa. The largest number of vertebrate studies were conducted on amphibians (accounting for 52.6% the total number of vertebrate publications). Himalayas and Qinling Mountains were the focal mountainous regions in China. In this review, we also provide suggestions about the gaps existing in mountain landscape genetics and the key research issues to be addressed for current and future studies. 参考文献 相似文献 引证文献

Evolution of Rosaceae Plastomes Highlights Unique Cerasus Diversification and Independent Origins of Fruiting Cherry.

Rosaceae comprises numerous types of economically important fruits, ornamentals, and timber. The lack of plastome characteristics has blocked our understanding of the evolution of plastome and plastid genes of Rosaceae crops. Using comparative genomics and phylogenomics, we analyzed 121 Rosaceae plastomes of 54 taxa from 13 genera, predominantly including Cerasus (true cherry) and its relatives. To our knowledge, we generated the first comprehensive map of genomic variation across Rosaceae plastomes. Contraction/expansion of inverted repeat regions and sequence losses of the two single-copy regions underlie large genomic variations in size among Rosaceae plastomes. Plastid protein-coding genes were characterized with a high proportion (over 50%) of synonymous variants and insertion-deletions with multiple triplets. Five photosynthesis-related genes were specially selected in perennial woody trees. Comparative genomic analyses implied divergent evolutionary patterns between pomaceous and drupaceous trees. Across all examined plastomes, unique and divergent evolution was detected in Cerasus plastomes. Phylogenomic analyses and molecular dating highlighted the relatively distant phylogenetic relationship between Cerasus and relatives (Microcerasus, Amygdalus, Prunus, and Armeniaca), which strongly supported treating the monophyletic true cherry group as a separate genus excluding dwarf cherry. High genetic differentiation and distinct phylogenetic relationships implied independent origins and domestication between fruiting cherries, particularly between Prunus pseudocerasus (Cerasus pseudocerasus) and P. avium (C. avium). Well-resolved maternal phylogeny suggested that cultivated P. pseudocerasus originated from Longmenshan Fault zone, the eastern edge of Himalaya-Hengduan Mountains, where it was subjected to frequent genomic introgression between its presumed wild ancestors and relatives.

Alpine community recruitment potential is determined by habitat attributes in the alpine ecosystems of the Himalaya-Hengduan Mountains, SW China.

The fragility and sensitivity to climate change of alpine ecosystems make it difficult to maintain the stability of their plant communities. Thus, it is important to determine which plant propagules are stored in the soils in order to understand community recruitment potential, especially under different environmental conditions. Based on a soil seed germination and seedling cultivation experiment, we aimed to identify differences in the soil seed attributes between three typical habitat types in the alpine subnival ecosystems of the Himalaya‐Hengduan Mountains and hence to predict the community recruitment potential of each of these different communities. We found that the seed assemblages in the soils differed between habitats. The most abundant taxa were from the genera Saxifraga, Kobresia, Arenaria, Polygonum, Draba, and Viola, while the taxa with lowest abundance were Apiaceae, Campanulaceae, Circaea, Crassulaceae, and Gentiana. Different habitats exhibited variable soil seed richness, diversity, and density. However, the patterns differed between study sites. Specifically, at Baima (BM) and Shika (SK) snow mountains, soil seed richness, diversity, and density were generally highest in grassland, followed by rock bed and bare ground. In contrast, on Jiaozi (JZ) snow mountain, the rock bed supported the highest soil seed richness and density, followed by grassland and bare ground. These results suggest that the attributes of habitats and communities can both affect the accumulation of soil seeds. Bare ground supports the lowest seed diversity and density but also harbors the most empty niches. We, therefore, predict that, once the thermal conditions become suitable as a result of global warming, this habitat has the potential to see greater changes than grassland and rock bed in terms of community recruitment.

Spatiotemporal Evolution of the Global Species Diversity of Rhododendron.

Evolutionary radiation is a widely recognized mode of species diversification, but its underlying mechanisms have not been unambiguously resolved for species-rich cosmopolitan plant genera. In particular, it remains largely unknown how biological and environmental factors have jointly driven its occurrence in specific regions. Here, we use Rhododendron, the largest genus of woody plants in the Northern Hemisphere, to investigate how geographic and climatic factors, as well as functional traits, worked together to trigger plant evolutionary radiations and shape the global patterns of species richness based on a solid species phylogeny. Using 3,437 orthologous nuclear genes, we reconstructed the first highly supported and dated backbone phylogeny of Rhododendron comprising 200 species that represent all subgenera, sections, and nearly all multispecies subsections, and found that most extant species originated by evolutionary radiations when the genus migrated southward from circumboreal areas to tropical/subtropical mountains, showing rapid increases of both net diversification rate and evolutionary rate of environmental factors in the Miocene. We also found that the geographically uneven diversification of Rhododendron led to a much higher diversity in Asia than in other continents, which was mainly driven by two environmental variables, that is, elevation range and annual precipitation, and were further strengthened by the adaptation of leaf functional traits. Our study provides a good example of integrating phylogenomic and ecological analyses in deciphering the mechanisms of plant evolutionary radiations, and sheds new light on how the intensification of the Asian monsoon has driven evolutionary radiations in large plant genera of the Himalaya-Hengduan Mountains.

Testing genome skimming for species discrimination in the large and taxonomically difficult genus Rhododendron.

Standard plant DNA barcodes based on 2-3 plastid regions, and nrDNA ITS show variable levels of resolution, and fail to discriminate among species in many plant groups. Genome skimming to recover complete plastid genome sequences and nrDNA arrays has been proposed as a solution to address these resolution limitations. However, few studies have empirically tested what gains are achieved in practice. Of particular interest is whether adding substantially more plastid and nrDNA characters will lead to an increase in discriminatory power, or whether the resolution limitations of standard plant barcodes are fundamentally due to plastid genomes and nrDNA not tracking species boundaries. To address this, we used genome skimming to recover near-complete plastid genomes and nuclear ribosomal DNA from Rhododendron species and compared discrimination success with standard plant barcodes. We sampled 218 individuals representing 145species of this species-rich and taxonomically difficult genus, focusing on the global biodiversity hotspots of the Himalaya-Hengduan Mountains. Only 33% of species were distinguished using ITS+matK+rbcL+trnH-psbA. In contrast, 55% of species were distinguished using plastid genome and nrDNA sequences. The vast majority of this increase is due to the additional plastid characters. Thus, despite previous studies showing an asymptote in discrimination success beyond 3-4 plastid regions, these results show that a demonstrable increase in discriminatory power is possible with extensive plastid genome data. However, despite these gains, many species remain unresolved, and these results also reinforce the need to access multiple unlinked nuclear loci to obtain transformative gains in species discrimination in plants.

Evolutionary and ecological factors structure a plant–bumblebee network in a biodiversity hotspot, the Himalaya–Hengduan Mountains

Abstract Species interactions, such as those between plants and pollinators, are known to be shaped by both evolutionary history and ecological factors. However, little is known about how multiple factors (e.g. phylogeny, phenology, abundance and functional traits) interactively affect interaction patterns. Using a plant–bumblebee network comprising 2,428 interactions between 29 plant species and 12 bumblebee species in the Himalaya–Hengduan Mountains, we tested for phylogenetic signal and whether phylogenetic pattern was explained by abundance, phenology and 13 plant and bumblebee functional traits. We also tested whether trait matching in two pairs of plant–bumblebee traits explained interaction frequencies at both species and individual levels. The network showed significant phylogenetic signal; closely related bumblebees tended to visit similar sets of plants, but not vice versa. Among all the measured factors, nectar volume and sugar concentration, rather than other phylogenetically constrained factors, were most important for explaining phylogenetic pattern (64% and 54% respectively). Although long–tongued bumblebee species tended to interact with long–tubed flowers, trait matching did not predict short–tongued bee interaction frequencies. Despite this, trait matching was apparent at the level of individual bees, reflecting intraspecific variation in tongue length and body size. Different selection pressures may exist within this bumblebee community, resulting in specialized, co–evolved traits in long–tongued species and adaptive generalization in short–tongued species to gain access to a variety of flowers. Together, these findings contribute to our understanding of phylogenetic trait–based structure in species interaction networks. In particular, this study provides new evidence for the importance of nectar rewards in structuring interaction patterns in pollination mutualisms. The results also demonstrate that trait matching may occur at the individual level, despite not being detectable at the species level, and underline the necessity of taking intraspecific trait variation into account in studies of community structure. A free Plain Language Summary can be found within the Supporting Information of this article.

Comparative phylogeography of Acanthocalyx (Caprifoliaceae) reveals distinct genetic structures in the Himalaya–Hengduan Mountains

Comparative phylogeography of Acanthocalyx (Caprifoliaceae) reveals distinct genetic structures in the Himalaya–Hengduan Mountains

Meta-analysis reveals severe pollen limitation for the flowering plants growing in East Himalaya-Hengduan Mountains region

BackgroundPollen limitation occurs widely and has an important effect on flowering plants. The East Himalaya-Hengduan Mountains region is a global biodiversity hotspot. However, to our knowledge, no study has synthetically assessed the degree of pollen limitation in this area. The present study aims to reveal the degree of pollen limitation for the flowering plants growing on East Himalaya-Hengduan Mountains and to test whether the reproductive features or the elevation is closely correlated with the degree of pollen limitation in this area.ResultsWe complied data from 76 studies, which included 96 species and 108 independent data records. We found that the flowering plants in this area undergo severe pollen limitation [overall Hedges’ d = 2.004, with a 95% confidence interval (1.3264, 2.6743)] that is much higher than that of the flowering plants growing in many other regions around the world. The degree of pollen limitation was tested to determine the correlation with the capacity for autonomous self-reproduction and with the pollination pattern (generalized vs. specialized pollination) of plants. In addition, we found a clear relationship between elevation and the degree of pollen limitation, which indicates that plants might undergo more severe pollen limitation in relatively high places.ConclusionsThis paper is the first to address the severe pollen limitation of the flowering plants growing in East Himalaya-Hengduan Mountains region. Moreover, we reveal the positive correlation between elevation and the degree of pollen limitation.

Taxonomy and biogeography ofDiapensia(Diapensiaceae) based on chloroplast genome data

AbstractDiapensiaL. is the second largest genus of Diapensiaceae. The taxonomic treatment withinDiapensiaand relationships within Diapensiaceae have been disputed. Chloroplast genome sequence data have proved to be useful for plant phylogenetic analyses and species delimitation. In this study, we de novo sequenced and assembled 22 chloroplast genomes of 15 species of Diapensiaceae, including all recognized species ofDiapensiawith multiple samples. A super‐matrix containing a total of 107 genes and 18 taxa was constructed for phylogenetic analyses to resolve phylogenetic relationships among genera of the family and withinDiapensia. The resulting phylogenetic tree showed the following strongly supported relationships: (Galax, (Pyxidanthera, (Berneuxia, ((Schizocodon, Diapensia), andShortia s.s.)))). The dated phylogeny and reconstructed lineage‐through‐time plot for the family indicated rapid diversification in the Neogene and an acceleration of diversification rate after c. 8 Ma. Biogeographic analysis suggested thatDiapensiaoriginated in the Northeast Asian mountains approximately 6.06 Ma, followed by northward dispersal to the Arctic and southwestward dispersal to the Himalaya–Hengduan Mountains. Phylogenetic relationships withinDiapensiawere well resolved. Based on the phylogenetic results, we proposed to reinstate the species status ofDiapensia bulleyanaForrest ex Diels, and raisedD. purpureaf.albidato the species rank (D. albida[W. E. Evans] J. F. Ye comb. & stat. nov.). The distribution ranges of all species delineated based on the phylogenetic results were revised accordingly based on specimen occurrences. Our study adds new examples for the power of plastid genome data for resolving phylogenetic relationships and clarifying taxonomic disputes among closely related species.

Geological and Climatic Factors Affect the Population Genetic Connectivity in Mirabilis himalaica (Nyctaginaceae): Insight From Phylogeography and Dispersal Corridors in the Himalaya-Hengduan Biodiversity Hotspot.

The genetic architecture within a species in the Himalaya-Hengduan Mountains (HHM) region was considered as the consolidated consequence of historical orogenesis and climatic oscillations. The visualization of dispersal corridors as the function of population genetic connectivity became crucial to elucidate the spatiotemporal dynamics of organisms. However, geodiversity and physical barriers created by paleo geo-climatic events acted vigorously to impact notable alterations in the phylogeographic pattern and dispersal corridors. Therefore, to achieve detailed phylogeography, locate dispersal corridors and estimate genetic connectivity, we integrated phylogeography with species distribution modelling and least cost path of Mirabilis himalaica (Edgew.) Heimerl in the HHM. We amplified four cpDNA regions (petL-psbE, rps16-trnK, rps16 intron, trnS-trnG), and a low copy nuclear gene (G3pdh) from 241 individuals of 29 populations. SAMOVA, genealogical relationships, and phylogenetic analysis revealed four spatially structured phylogroups for M. himalaica with the onset of diversification in late Pliocene (c. 3.64 Ma). No recent demographic growth was supported by results of neutrality tests, mismatch distribution analysis and Bayesian skyline plot. Paleo-distribution modelling revealed the range dynamics of M. himalaica to be highly sensitive to geo-climatic change with limited long-distance dispersal ability and potential evolutionary adaptation. Furthermore, river drainage systems, valleys and mountain gorges were identified as the corridors for population genetic connectivity among the populations. It is concluded that recent intense mountain uplift and subsequent climatic alterations including monsoonal changes since Pliocene or early Pleistocene formulated fragmented habitats and diverse ecology that governed the habitat connectivity, evolutionary and demographic history of M. himalaica. The integrative genetic and geospatial method would bring new implications for the evolutionary process and conservation priority of HHM endemic species.

The complete chloroplast genome of Leptodermis scabrida (Rubiaceae): an endemic shrub in Himalaya-Hengduan Mountains

Leptodermis scabrida is an important endemic species in Himalaya-Hengduan Mountains. Here, we report the complete chloroplast genome of L. scabrida. The cp genome was determined to be 154783 bp in length and the GC content was 37.5%. The sequence included a large single copy (LSC) region of 84190 bp, a small single copy (SSC) region of 17183 bp and two separated inverted regions of 26705 bp, respectively. It contained 132 genes, including 84 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. This complete genome of L. scabrida will provide valuable information to resolve the complex phylogeny relationship and to elucidate the mechanism of speciation of Leptodermis, as well as for the phylogenetic studies of Rubiaceae.

Genomic insight into “sky island” species diversification in a mountainous biodiversity hotspot

Abstract“Sky island” species diversification contributes greatly to mountainous biodiversity. However, the underlying genomic divergence and the inferred drivers remain largely unknown. In this study, we examined the diversification history of five diploid species with three exclusively endemic to the sky islands (mountains) of the Himalaya–Hengduan Mountains biodiversity hotspot. All of them together comprise a clade of the genus Eutrema (Brassicaceae). We resequenced genomes of multiple individuals of the found populations for each species. We recovered the inconsistent phylogenetic relationships between plastome and nuclear‐genome trees for one species. Based on nuclear population genomic data, we detected high genetic divergence between five species with limited gene flow. Four species seemed to diverge mainly through geographical isolation, whereas one arose through hybrid origin. The origins of the sampled five species were dated to within the late Miocene when mountains were uplifted and climates oscillated. All species decreased their population sizes since the inferred origin of each species initially, but only two of them expanded after the Last Glacial Maximum. Together, these findings suggest that geographic isolation plays an important role in driving the sky island species diversification of the sampled species in addition to the occasional gene flow that might have led to the hybrid origin of some sky island species, similar to the species diversification of sea islands.

Evaluating Population Genetic Structure and Demographic History of Quercus spinosa (Fagaceae) Based on Specific Length Amplified Fragment Sequencing.

Effectively identifying the genetic structure and related factors of a species can facilitate understanding the evolutionary history of the species. Phylogeographic patterns and genetic data are essential in investigating the species historical processes and diversification that response to environmental, climatic and geological influences. In this study, Specific Length Amplified Fragment Sequencing (SLAF-seq) data and ecological niche models (ENMs) are combined to identify the genetic structure and demographic modeling of Quercus spinosa, and evaluate the impacts of historical range shifts, climatic variation, and landscape factors on this species. The population topology and genetic divergence of the Cenozoic were inferred by a site frequency spectrum based composite-likelihood approach which is a novel strategy for maximizing the utility of linked SLAF markers. The overall genetic structure using model-based and model-free clustering methods was consistently identified as two geographically distinct genetic clusters. A deep divergence between two natural lineages (i.e., a western Himalaya-Hengduan Mountains lineage and an eastern Qin-ling Mountains lineage) was observed. The demographic modeling and Niche reconstruction indicated that the two groups were diverged in the late Miocene and then presented as two distinct genetic lineages. With the Quaternary glacial climate fluctuation, two groups had continuous asymmetrical secondary contact and gene exchange in the Sichuan Basin during the last glacial maximum. Besides, a significant relationship between genetic distance and geography in all individuals was identified by the Mantel test. Overall, this study 1) contributes to a better understanding of the role played by Quaternary climatic fluctuation in the present-day distributions of Q. spinosa; 2) provides a comprehensive view of the genome-wide variation of sclerophyllous forests in ecological adaptive evolution; 3) indicates that dispersal limitation and ecological divergence contribute to the genome-wide differentiation of Q. spinosa, which supports a hypothesis that complex geography and climatic changes strongly influence the evolutionary origin and history of the species.

Geoclimatic factors influence the population genetic connectivity of Incarvillea arguta (Bignoniaceae) in the Himalaya–Hengduan Mountains biodiversity hotspot

AbstractGeoclimatic factors related to the uplift of the Himalaya and the Quaternary climatic oscillations influence the population genetic connectivity in the Himalaya–Hengduan Mountains (HHM) biodiversity hotspot. Therefore, to explore the relative roles played by these two factors, we examined the population dynamics and dispersal corridors of Incarvillea arguta (Royle) Royle incorporating ensemble species distribution modelling (SDM).Thirty‐seven populations were genotyped using plastid chloroplast DNA and low copy nuclear gene (ncpGS) sequences. Phylogeographic analysis was carried out to reveal the genetic structure and lineage differentiation. Ensemble SDMs were carried out for distributional change in the last glacial maximum, present, and future. Finally, the least cost path method was used to trace out possible dispersal corridors.The haplotypes were divided into four clades with strong geographical structure. The late Miocene origin of I. arguta in the western Himalaya ca. 7.92 Ma indicates lineage diversification related to the uplift of the HHM. The variability in habitat connectivity revealed by SDM is due to change in suitability since the Pleistocene. A putative dispersal corridor was detected along the drainage systems and river valleys, with strong support in the eastern Hengduan Mountains group.Our results support the signature of geoclimatic influence on population genetic connectivity of I. arguta in the HHM. We proposed that the major drainage systems might have assisted the rapid dispersal of isolated riverine plant species I. arguta in the HHM. The population genetic connectivity, using the fine‐tuned ensemble SDMs, enables scientists and policymakers to develop conservation strategies for the species gene pool in the HHM biodiversity hotspots.

Are mountaintops climate refugia for plants under global warming? A lesson from high-mountain oaks in tropical rainforest

Climate refugia are locations where plants are able to survive periods of regionally adverse climate. Such refugia may affect evolutionary processes and the maintenance of biodiversity. Numerous refugia have been identified in the context of Quaternary climate oscillations. With climate warming, there is an increasing need to apply insights from the past to characterize potential future refugia. Mountainous regions, due to the provision of spatially heterogeneous habitats, may contain high biodiversity, particularly important during climate oscillations. Here, we highlight the importance of mountaintops as climate refugia, using the example of high-mountain oaks which are distributed on the ranges of the Himalaya–Hengduan Mountains, and at high elevations in tropical rainforests. The occurrences of cold-adapted high-mountain oaks on mountaintops amidst tropical rainforest indicate that such locations are and will be climate refugia as global warming continues. We examine factors that predict the occurrence of future climate refugia on mountaintops using recognized historical refugia. Future research is needed to elucidate the fine-scale processes and particular geographic locations that buffer species against the rapidly changing climate to guide biodiversity conservation efforts under global warming scenarios.

Upward elevation and northwest range shifts for alpine Meconopsis species in the Himalaya-Hengduan Mountains region.

Climate change may impact the distribution of species by shifting their ranges to higher elevations or higher latitudes. The impacts on alpine plant species may be particularly profound due to a potential lack of availability of future suitable habitat. To identify how alpine species have responded to climate change during the past century as well as to predict how they may react to possible global climate change scenarios in the future, we investigate the climatic responses of seven species of Meconopsis, a representative genus endemic in the alpine meadow and subnival region of the Himalaya–Hengduan Mountains. We analyzed past elevational shifts, as well as projected shifts in longitude, latitude, elevation, and range size using historical specimen records and species distribution modeling under optimistic (RCP 4.5) and pessimistic (RCP 8.5) scenarios across three general circulation models for 2070. Our results indicate that across all seven species, there has been an upward shift in mean elevation of 302.3 m between the pre‐1970s (1922–1969) and the post‐1970s (1970–2016). The model predictions suggest that the future suitable climate space will continue to shift upwards in elevation (as well as northwards and westwards) by 2070. While for most of the analyzed species, the area of suitable climate space is predicted to expand under the optimistic emission scenario, the area contracts, or, at best, shows little change under the pessimistic scenario. Species such as M. punicea, which already occupy high latitudes, are consistently predicted to experience a contraction of suitable climate space across all the models by 2070 and may consequently deserve particular attention by conservation strategies. Collectively, our results suggest that the alpine high‐latitude species analyzed here have already been significantly impacted by climate change and that these trends may continue over the coming decades.

Distributional responses to climate change for alpine species of Cyananthus and Primula endemic to the Himalaya-Hengduan Mountains

Global warming increases the vulnerability of plants, especially alpine herbaceous species, to local extinction. In this study, we collected species distribution information from herbarium specimens for ten selected Cyananthus and Primula alpine species endemic to the Himalaya-Hengduan Mountains (HHM). Combined with climate data from WorldClim, we used Maximum Entropy Modeling (MaxEnt) to project distributional changes from the current time period to 2070. Our predictions indicate that, under a wide range of climate change scenarios, the distributions of all species will shift upward in elevation and northward in latitude; furthermore, under these scenarios, species will expand the size of their range. For the majority of the species in this study, habitats are available to mitigate upward and northward shifts that are projected to be induced by changing climate. If current climate projections, however, increase in magnitude or continue to increase past our projection dates, suitable habitat for future occupation by alpine species will be limited as we predict range contraction or less range expansion for some of the species under more intensified climate scenarios. Our study not only underscores the value of herbarium source information for future climate model projections but also suggests that future studies on the effects of climate change on alpine species should include additional biotic and abiotic factors to provide greater resolution of the local dynamics associated with species persistence under a warming climate.

DNA barcoding of Corydalis, the most taxonomically complicated genus of Papaveraceae.

The genus Corydalis is recognized as one of the most taxonomically challenging plant taxa. It is mainly distributed in the Himalaya–Hengduan Mountains, a global biodiversity hotspot. To date, no effective solution for species discrimination and taxonomic assignment in Corydalis has been developed. In this study, five nuclear and chloroplast DNA regions, ITS, ITS2, matK, rbcL, and psbA‐trnH, were preliminarily assessed based on their ability to discriminate Corydalis to eliminate inefficient regions, and the three regions showing good performance (ITS, ITS2 and matK) were then evaluated in 131 samples representing 28 species of 11 sections of four subgenera in Corydalis using three analytical methods (NJ, ML, MP tree; K2P‐distance and BLAST). The results showed that the various approaches exhibit different species identification power and that BLAST shows the best performance among the tested approaches. A comparison of different barcodes indicated that among the single barcodes, ITS (65.2%) exhibited the highest identification success rate and that the combination of ITS + matK (69.6%) provided the highest species resolution among all single barcodes and their combinations. Three Pharmacopoeia‐recorded medicinal plants and their materia medica were identified successfully based on the ITS and ITS2 regions. In the phylogenetic analysis, the sections Thalictrifoliae, Sophorocapnos, Racemosae, Aulacostigma, and Corydalis formed well‐supported separate lineages. We thus hypothesize that the five sections should be classified as an independent subgenus and that the genus should be divided into three subgenera. In this study, DNA barcoding provided relatively high species discrimination power, indicating that it can be used for species discrimination in this taxonomically complicated genus and as a potential tool for the authentication of materia medica belonging to Corydalis.

The topological differences between visitation and pollen transport networks: a comparison in species rich communities of the Himalaya–Hengduan Mountains

Pollination networks are usually constructed and assessed by direct field observations which commonly assume that all flower visitors are true pollinators. However, this assumption is often invalid and the use of data based on mere visitors to flowers may lead to a misunderstanding of intrinsic pollination networks. Here, using a large dataset by both sampling floral visitors and analyzing their pollen loads, we constructed 32 networks pairs (visitation versus pollen transport) across one flowering season at four elevation sites in the Himalaya–Hengduan Mountains region. Pollen analysis was conducted to determine which flower visitors acted as potential pollinators (pollen vectors) or as cheaters (those not carrying pollen of the visited plants). We tested whether there were topological differences between visitation and pollen transport networks and whether different taxonomic groups of insect visitors differed in their ability to carry pollen of the visited plants. Our results indicated that there was a significantly higher degree of specialization at both the network and species levels in the pollen transport networks in contrast to the visitation networks. Modularity was lower but nestedness was higher in the visitation networks compared to the pollen transport networks. All the cheaters were identified as peripheral species and most of them contributed positively to the nested structure. This may explain in part the differences in modularity and nestedness between the two network types. Bees carried the highest proportion of pollen of the visited plants. This was followed by Coleoptera, other Hymenoptera and Diptera. Lepidoptera carried the lowest proportion of pollen of the visited plants. Our study shows that the construction of pollen transport networks could provide a more in‐depth understanding of plant–pollinator interactions. Moreover, it suggests that detecting and removing cheater interactions when studying the topology of other mutualistic networks might be also important.

Comparative intra- and interspecific sexual organ reciprocity in four distylous Primula species in the Himalaya-Hengduan Mountains.

Distyly is a mechanism promoting cross-pollination within a balanced polymorphism. Numerous studies show that the degree of inter-morph sexual organ reciprocity (SOR) within species relates to its pollen-mediated gene flow. Similarly, a lower interspecific SOR should promote interspecific isolation when congeners are sympatric, co-blooming and share pollinators. In this comparative study, we address the significance of SOR at both intra- and interspecific levels. Seventeen allopatric and eight sympatric populations representing four Primula species (P. anisodora, P. beesiana, P. bulleyana and P. poissonii) native to the Himalaya-Hengduan Mountains were measured for eight floral traits in both long- and short-styled morphs. GLMM and spatial overlap methods were used to compare intra- and interspecific SOR. While floral morphology differed among four Primula species, SOR within species was generally higher than between species, but in species pairs P. poissonii/P. anisodora and P. beesiana/P. bulleyana, the SOR was high at both intra- and interspecific levels. We did not detect a significant variation in intraspecific SOR or interspecific SOR when comparing allopatric versus sympatric populations for all species studied. As intraspecific SOR increased, disassortative mating may be promoted. As interspecific SOR decreased, interspecific isolation between co-flowering species pairs also may increase. Hybridisation between congeners occurred when interspecific SOR increased in sympatric populations, as confirmed in two species pairs, P. poissonii/P. anisodora and P. beesiana/P. bulleyana.