Complex evolutionary dynamics of Sichuana, an endemic katydid genus in the Hengduan Mountains illuminated by mitochondrial phylogenomics and morphological evidence.

The species/lineage delimitation and possible hybridization/introgression are prerequisites in the management of invasive organism. Phragmites australis invaded diverse habitats and displaced the native lineages in North America as a consequence of the introduction from the Eurasia. Such species threatened the biodiversity safety of the invaded regions, in particular the biodiversity hot spots. Southwest (SW) China is a biodiversity hot spot with the occurrence of Phragmites species, both native and introduced. However, the genetic identity of Phragmites species in this biodiversity hot spot remains unclear, hampering effective ecological managements. In this study, we explored the phylogenetic lineages of Phragmites species in SW China. A total of 44 accessions sampled across SW China were analyzed using two chloroplast DNA (cpDNA) markers and amplified fragment length polymorphisms. Two genetic lineages were recovered, i.e., (1) the tropical lineage which primarily consisted of native Phragmites species represented by cpDNA haplotypes I, Q, and U in relatively low altitude and (2) the common lineage including native species at higher elevations in the Hengduan Mountains as well as artificially planted species represented by cpDNA haplotype P. The between-lineage hybridization was suggested for five analyzed accessions collected from either natural or artificial habitats. The putative hybrids might have originated from the maternal native tropical lineages and paternal introduced common lineage. Our results suggest the likelihood of introgressive hybridizations in SW China and thus provided implications for future research and ecological management.

The dispersal and diversification of earthworms (Annelida: Oligochaeta) related to paleogeographical events in the Hengduan Mountains

Cryptic speciation in the Chinese white pine (Pinus armandii): Implications for the high species diversity of conifers in the Hengduan Mountains, a global biodiversity hotspot

Abstract. The Hengduan Mountains, with their strong altitudinal vegetation zonation, form a biodiversity hotspot which offers the potential for comparison between sites in order to understand how this zonation arose and how it has responded to climate change and human impacts through time. This paper presents a 22 570-year pollen record of vegetational and climatic change based on a core 320 cm in depth collected from Wenhai Lake on Jade Dragon Snow Mountain, one of the highest peaks in the Hengduan Mountains region of Yunnan, Southwest China. From 22 570 to 21 140 cal yr BP, the vegetation was dominated by broad-leaved forest (comprising mainly Quercus, Betula and Castanopsis), accompanied by needle-leaved forest (mainly Pinus and Abies), indicating a rather cold and dry climate relative to the present followed by cold and wet conditions. In the period between 21 140 and 19 350 cal yr BP, the vegetation was still dominated by broad-leaved forest and needle-leaved forest as before but with a notable increase in Betula pollen and a sharp decrease in Quercus pollen, implying a relatively cold and dry climate with several fluctuations in humidity. The period 19 350 to 17 930 cal yr BP was a transition stage from broad-leaved forest to needle-leaved forest, with a dramatic decrease in Quercus pollen and a maximum reading for Abies pollen, reflecting the coldest and driest climate since 22 570 cal yr BP. The expansion in needle-leaved forest dominated by Pinus and Abies (22 570–17 930 cal yr BP) along with an increase of Betula might correspond to the Last Glacial Maximum (LGM; the start of the LGM perhaps occurred prior to the basal age of the core). Between 17 930 and 9250 cal yr BP, needle-leaved forest declined and broad-leaved forest began to increase at first, suggesting increases in temperature and humidity, while towards the end of the period, needle-leaved forest expanded and broad-leaved forest shrank, indicating a colder and drier climate, possibly corresponding to the Younger Dryas. From 9250 cal yr BP to the present, the vegetation has been dominated by needle-leaved forest (comprising mainly Pinus, Abies and Tsuga), interspersed with broad-leaved Quercus and Betula, reflecting a significant decline in humidity from the early to late Holocene. During this period, human activity likely increased in this region, with impacts on the vegetation such as a distinct decrease in Pinus and Quercus pollen and an increase in Polygonaceae pollen in the upper 30 cm of the core. The marked decline in Quercus pollen compared with the early stage of this period, in particular, in the Wenhai core can be correlated with that observed in the Haligu core (situated about 2 km away) between 2400 cal yr BP and the present.

Many examples of phenotypic modifications resulting from high‐elevation adaptation have been documented, however, the underlying processes responsible for these modifications and whether the continuity of the adaptation process remain elusive, particularly in plants. The alpine plants distributed along wide elevational gradients provide an ideal system to address this question. Here, we collected transcriptomes from multiple tissues of three species with different elevations (~1500, ~2500, and ~3600 m in the Hengduan Mountains, Southwest China) in two genera Fargesia and Yushania of alpine bamboos, respectively, and conducted evolutionary and expressional analyses. Results showed that high‐elevation adaptation emerged earlier in the evolutionary history of both genera and evolved continuously as the elevation increased. Moreover, convergence of genetic changes was observed in the two genera, with amounts of candidate genes responsible for high‐elevation adaptation identified under positive selection. Overall, our study provides an empirical example and valuable genetic resource for further investigation of high‐elevation adaptation in plants and sheds new light on how plants adapting to high‐elevation environments in a biodiversity hotspot.

Quantitative Western-blot profiles of factor H and factor H-related proteins in atypical haemolytic uraemic syndrome and C3 glomerulopathy

This paper aimed to explore the division of the southern and northern Hengduan Mountains based on gradients in species similarity and richness, and to analyze species richness in each sub‐region. The Hengduan Mountain region was divided into nine latitudinal belts using one degree of latitude to define the belt after which distribution of seed plants within each latitudinal belt was recorded. Latitudinal patterns of species similarity were measured using the Jaccard similarity index for each pair of adjacent latitudinal belts. Non‐metric multidimentional scaling (NMDS) was also used to analyze the similarity in species composition among the nine latitudinal belts. The latitudinal pattern of species similarity and the NMDS ordination both showed a great change in species composition across the 29°N latitudinal line, essentially dividing the Hengduan Mountain region into southern and northern sub‐regions. Species richness, shown by the c‐value of the species–area power function, and species–area ratio along a latitudinal gradient both showed a sharp decrease across the latitudinal belt from 29°0′ to 29°59′N. The southern sub‐region occupied 40% of the total area of the Hengduan Mountain region, but contained more than 80% of all the seed plants in the region. The higher species richness and endemism in the southern sub‐region showed it to be the core of the Hengduan biodiversity hotspot, a result not unexpected because of the greater extremes of topography and wider diversity of habitats in the southern portion.

Small mammals as a bioindicator of mercury in a biodiversity hotspot – The Hengduan Mountains, China

A common hypothesis for the rich biodiversity found in mountains is uplift-driven diversification-that orogeny creates conditions favoring rapid in situ speciation of resident lineages. We tested this hypothesis in the context of the Qinghai-Tibetan Plateau (QTP) and adjoining mountain ranges, using the phylogenetic and geographic histories of multiple groups of plants to infer the tempo (rate) and mode (colonization versus in situ diversification) of biotic assembly through time and across regions. We focused on the Hengduan Mountains region, which in comparison with the QTP and Himalayas was uplifted more recently (since the late Miocene) and is smaller in area and richer in species. Time-calibrated phylogenetic analyses show that about 8 million y ago the rate of in situ diversification increased in the Hengduan Mountains, significantly exceeding that in the geologically older QTP and Himalayas. By contrast, in the QTP and Himalayas during the same period the rate of in situ diversification remained relatively flat, with colonization dominating lineage accumulation. The Hengduan Mountains flora was thus assembled disproportionately by recent in situ diversification, temporally congruent with independent estimates of orogeny. This study shows quantitative evidence for uplift-driven diversification in this region, and more generally, tests the hypothesis by comparing the rate and mode of biotic assembly jointly across time and space. It thus complements the more prevalent method of examining endemic radiations individually and could be used as a template to augment such studies in other biodiversity hotspots.

A major question in evolution and ecology is why biodiversity is so unevenly distributed across the planet. The most obvious and salient diversity pattern is the order-of-magnitude greater species richness in the tropics compared with the temperate zones. Superimposed on this latitudinal diversity gradient is a much more complex and intricate pattern of regional and more local biodiversity hotspots (1, 2). These are places with unusually high concentrations of species and especially endemic species. Documenting these patterns is of great significance, most obviously for conservation, with ever more sophisticated and higher-resolution biodiversity hotspot maps becoming available as the world’s biota are mapped in greater detail (3). More fundamentally, we need to document hotspots to understand the underlying macroevolutionary and ecological processes shaping the distribution of diversity across the Earth. Most globally significant biodiversity hotspots lie firmly within the tropics or in the Mediterranean climate zones of the world, such as California and the Cape Floristic Region of South Africa. Several coincide with major mountain ranges, including most notably the tropical Andes and the temperate Hengduan Mountains, two of the world’s hottest hotspots (2, 4). It is this Hengduan Mountain hotspot that is the focus of Xing and Ree’s study in PNAS (5), which provides the first integrated analysis of the evolutionary origins and biotic assembly of Hengduan plant diversity. Although formal quantification of biodiversity hotspots really only started 30 y ago (1), the outstanding plant species richness of the Hengduan Mountains has been known for more than 150 y, having been first revealed by the intrepid 19th century plant collectors—Joseph Hooker, Ernest Wilson, George Forrest, Frank Kingdon-Ward, and others. These explorers penetrated into the deeply dissected and remote mountains and river gorges of Yunnan, Sichuan, Sikkim, and eastern Tibet in search of botanical novelties and especially garden plants, … [↵][1]1Email: colin.hughes{at}systbot.uzh.ch. [1]: #xref-corresp-1-1

<p indent="0mm">Mountain amphibians are exposed to a multitude of threats from climate change and anthropogenic disturbances. However, a lack of data hinders the understanding of the responses of mountain amphibians to these threats, which is becoming a conservation concern. Using frogs in the Hengduan Mountains, a biodiversity hotspot in Southwest China as indicators, we attempted to assess the extent and magnitude of changes in alpha diversity (species richness) and beta diversity (community turnover) between two periods (1930–2005 and 2006–2022). We compared elevational patterns for total, endemic and non-endemic frogs between the two periods, evaluated community turnover (i.e., Sørensen and Jaccard binary dissimilarity), and further quantified whether significant homogenization or differentiation of the frog communities occurred over time. Our results showed that the present species richness is greater than the historical species richness. The elevational patterns of total, endemic and non-endemic frogs were similar with slight changes across the two periods and clear increases in richness occurring at low and middle elevations. Although there was no significant biotic homogenization or differentiation over time, the community composition shifted dramatically. This study highlights the importance of assessing spatiotemporal changes in biodiversity in response to environmental changes and contributes to mountain species conservation as global change intensifies. We therefore call for greater efforts in community resurveys to assess biodiversity changes and provide useful insights for conservation strategies and action implementation.

AimsIt has been assumed that montane species will undergo upslope shifts in response to climate warming and their range sizes are therefore predicted to decrease. However, this view has been challenged because a recent study (Elsen &amp; Tingley, ) indicated that land surface area increases with increasing altitude in some mountains. To test this prediction, we used one of the world's biodiversity hotspots as a study system to examine overall patterns of plant distribution shift in response to climate warming.LocationThe Hengduan Mountains and adjacent regions.MethodsBased on distribution data for 151 species at a resolution of 2.5 arc minutes, we employed ecological niche modelling to model their distributions under the climatic conditions of the Last Glacial Maximum, Current (2017), and 2050 separately. We examined the distributional shifts of these species, especially with respect to altitude and range size, in response to two periods of stepwise climate warming.ResultsAll the montane plants sampled shifted upward during the two warming stages, but not only northward, some shifted westward or in other directions. In contrast with the expected consistent loss of range when shifting upward, 63.6% of the plants expanded their range size continuously since the LGM. Only 11.9% of the plants contracted their range size continuously from the LGM to 2050. Estimates of species richness in the regions studied changed greatly, but in an unbalanced manner, from the LGM to the Current and from the Current to 2050.Main conclusionsNumerous montane plants in the Hengduan Mountains are predicted to expand their range sizes as they shift upslope in response to climate warming. Our results highlight the possibility that more available land surface area due to the heterogeneous topography along altitudinal gradients and the adjacent large Qinghai‐Tibet Plateau sensu stricto can mediate the range loss of the montane plants under climate warming. These findings are crucial for estimating the future range sizes of plants and planning biodiversity protection for mountain ecosystems under the anticipated warming of the world's climate.

AimThe Hengduan Mountains (HDM) of southwest China is a biodiversity hotspot and harbours one of the world's richest temperate floras. However, the origin and evolution of its biota remain largely unresolved. Here we explore the impact of mountain uplift on the diversification process of biodiversity in this hotspot using alpine bamboos.LocationThe HDM region, southwest China.TaxonAlpine bamboos.MethodsWe used ddRAD‐seq data from the most complete sampling of alpine bamboos undertaken to date (79% of the species diversity), to investigate their evolutionary history. The ancestral area of these bamboos was reconstructed using a time‐calibrated phylogeny in BioGeoBEARS and diversification rates were inferred using BAMM analyses. In addition, the impact of mountain uplift on the divergence of alpine bamboos was evaluated using trait‐dependent models of diversification.ResultsThe alpine bamboos were strongly supported as monophyletic, and the relationships within them were robustly resolved.Fargesiawas found to be polyphyletic andYushaniawas resolved as monophyletic. Alpine bamboos originated outside the HDM region during the late Miocene, and spread to this region in the Pliocene, undergoing a significant acceleration in net diversification, which is temporally congruent with the orogeny. The speciation rate increased with altitude and a high diversification rate, estimated to be 0.75 species per million years, was detected for alpine bamboos distributed in high elevations.Main ConclusionsOur study demonstrates that heterogeneous mountain habitats and geographical isolation of alpine bamboos, which have limited dispersal ability, are important drivers for their rapid diversification. This study also highlights the power of complementary analyses in revealing the link between species diversification and past geological changes.

The Hengduan Mountains (HDM) of China are a biodiversity hotspot whose temperate flora and fauna are among the world’s richest. However, the origin and evolution of biodiversity in the HDM remain poorly understood, especially in mammals. Given that the HDM shows the highest richness of vole species in the world, we used whole-exome capture sequencing data from the currently most comprehensive sampling of HDM voles to investigate their evolutionary history and diversification patterns. We reconstructed a robust phylogeny and re-estimated divergence times of the HDM voles. We found that all HDM voles could be divided into a western lineage (Volemys, Proedromys, and Neodon) and an eastern lineage (Caryomys and Eothenomys), and the two lineages originated from two migration events from North Eurasia to the HDM approximately 9 Mya. Both vole lineages underwent a significant acceleration of net diversification from 8–5 Mya, which was temporally congruent with the orogeny of the HDM region. We also identified strong intertribal gene flow among the HDM voles and hypothesized that frequent gene flow might have facilitated the speciation burst of the HDM voles. Our study highlights the importance of both environmental and biotic factors in shaping the biodiversity of mammals in mountain ecosystems.

The geographic distribution of plant diversity matches the gradient of habitat heterogeneity from lowlands to mountain regions. However, little is known about how much this relationship is conserved across scales. Using the World Checklist of Vascular Plants and high-resolution biodiversity maps developed by species distribution models, we investigated the associations between species richness and habitat heterogeneity at the scales of Eurasia and the Hengduan Mountains (HDM) in China. Habitat heterogeneity explains seed plant species richness across Eurasia, but the plant species richness of 41/97 HDM families is even higher than expected from fitted statistical relationships. A habitat heterogeneity index combining growing degree days, site water balance, and bedrock type performs better than heterogeneity based on single variables in explaining species richness. In the HDM, the association between heterogeneity and species richness is stronger at larger scales. Our findings suggest that high environmental heterogeneity provides suitable conditions for the diversification of lineages in the HDM. Nevertheless, habitat heterogeneity alone cannot fully explain the distribution of species richness in the HDM, especially in the western HDM, and complementary mechanisms, such as the complex geological history of the region, may have contributed to shaping this exceptional biodiversity hotspot.