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Sex-specific facilitation and reproduction of the gynodioecious cushion plant Arenaria polytrichoides on the Himalaya-Hengduan mountains,SW China
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作者 Xufang Chen Yazhou Zhang +3 位作者 Lishen Qian Renyu Zhou hang sun Jianguo Chen 《Plant Diversity》 SCIE CAS CSCD 2024年第2期247-255,共9页
When benefiting other beneficiaries,cushion plants may reciprocally receive feedback effects.The feedback effects on different sex morphs,however,remains unclear.In this study,taking the gynodioecious Arenaria polytri... When benefiting other beneficiaries,cushion plants may reciprocally receive feedback effects.The feedback effects on different sex morphs,however,remains unclear.In this study,taking the gynodioecious Arenaria polytrichiodes as a model species,we aimed to assess the sex-specific facilitation intensity of cushion plant by measuring the beneficiary cover ratio,and to assess the potential costs in cushion reproductive functions by measuring the flower and fruit cover ratios.The total beneficiary cover ratio was similar between females and hermaphrodites.Females produced much less flowers but more fruits than hermaphrodites.These results suggested that females and hermaphrodites possess similar facilitation intensity,and female cushion A.polytrichoides may allocate more resources saved from pollen production to seed production,while hermaphrodites possibly allocate more resources to pollen production hence reducing seed production.The surface areas covered by beneficiaries produced less flowers and fruits than areas without beneficiaries.In addition,strong negative correlations between beneficiary cover and flower cover were detected for both females and hermaphrodites,but the correlation strength were similar for these two sex morphs.However,the correlation between beneficiary cover and fruit cover was only significantly negative for females,suggesting that beneficiary plants negatively affect fruit reproduction of females while have neutral effects on hermaphrodites.All the results suggest that to facilitate other beneficiaries can induce reproductive costs on cushion A.polytrichoides,with females possibly suffering greater cost than hermaphrodites.Such differentiation in reproductive costs between sex morphs,in long-term perspective,may imply sex imbalance in population dynamics. 展开更多
关键词 Facilitation intensity Feedback effect Sex-specific facilitation Nurse plant Population dynamics Reproductive function
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Patterns and drivers of plant sexual systems in the dry-hot valley region of southwestern China
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作者 Rong Ma Qi Xu +3 位作者 Yongqian Gao Deli Peng hang sun Bo Song 《Plant Diversity》 SCIE CAS CSCD 2024年第2期158-168,共11页
Sexual systems play important roles in angiosperm evolution and exhibit substantial variations among different floras. Thus, studying their evolution in a whole flora is crucial for understanding the formation and mai... Sexual systems play important roles in angiosperm evolution and exhibit substantial variations among different floras. Thus, studying their evolution in a whole flora is crucial for understanding the formation and maintenance of plant biodiversity and predicting its responses to environmental change. In this study, we determined the patterns of plant sexual systems and their associations with geographic elements and various life-history traits in dry-hot valley region of southwestern China, an extremely vulnerable ecosystem. Of the 3166 angiosperm species recorded in this area, 74.5% were hermaphroditic,13.5% were monoecious and 12% were dioecious, showing a high incidence of diclinous species. Diclinous species were strongly associated with tropical elements, whereas hermaphroditic species were strongly associated with temperate and cosmopolitan elements. We also found that hermaphroditism was strongly associated with showy floral displays, specialist entomophily, dry fruits and herbaceous plants.Dioecy was strongly associated with inconspicuous, pale-colored flowers, generalist entomophily, fleshy fruits, and woody plants, whereas monoecy was strongly associated with inconspicuous, pale-colored flowers, anemophily, dry fruits, and herbaceous plants. In addition, hermaphroditic species with generalist entomophily tended to flower in the dry season, whereas diclinous species with specialist entomophily tended to flower in the rainy season. However, independent of sexual systems, plants that produce dry fruits tended to flower in the rainy season and set fruits in the dry season, but the opposite pattern was found for fleshy fruit-producing plants. Our results suggest that in the dry-hot valleys, plant sexual systems are associated with geographic elements as well as various life-history traits that are sensitive to environmental change. 展开更多
关键词 Floral traits Fruit type Growth form Pollination system Reproductive phenology
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Central Asia revealed as a key area in evolution of Eremurus (Asphodelaceae)
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作者 Dilmurod Makhmudjanov Sergei Volis +4 位作者 Ziyoviddin Yusupov Inom Juramurodov Komiljon Tojibaev Tao Deng hang sun 《Plant Diversity》 SCIE CAS CSCD 2024年第3期333-343,共11页
Eremurus was described at the beginning of the 19th century.However,due to limited sampling and the small number of gene markers to date,its phylogeny and evolution are largely unknown.In this study,we analyzed plasto... Eremurus was described at the beginning of the 19th century.However,due to limited sampling and the small number of gene markers to date,its phylogeny and evolution are largely unknown.In this study,we analyzed plastomes from 27 species belonging to 2 subgenera and 3 sections of Eremurus,which are found in Central Asia(its center of diversity)and China.We also analyzed nuclear DNA ITS of 33 species,encompassing all subgenera and sections of the genus in Central Asia,southwest Asia and China.Our findings revealed that the genus was monophyletic,although both subgenera Eremurus and Henningia were found to be paraphyletic.Both plastome and nrDNA-based phylogenetic trees had three clades that did not reflect the current taxonomy of the genus.Our biogeographical and time-calibrated trees suggest that Eremurus originated in the ancient Tethyan area in the second half of the Eocene.Diversification of Eremurus occurred from the early Oligocene to the late Miocene.Paratethys Sea retreat and several orogenetic events,such as the progressive uplift of the Qinghai-Tibet Plateau and surrounding mountain belts(Altai,Pamir,Tian Shan),caused serious topographic and climate(aridification)changes in Central Asia that may have triggered a split of clades and speciation.In this transformed Central Asia,speciation proceeded rapidly driven mainly by vicariance caused by numerous mountain chains and specialization to a variety of climatic,topographic and soil conditions that exist in this region. 展开更多
关键词 ASPHODELACEAE Asphodeloideae PLASTOME Central Asia Qinghai-Tibet Plateau
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Image Segmentation-P300 Selector: A Brain–Computer Interface System for Target Selection
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作者 hang sun Changsheng Li He Zhang 《Computers, Materials & Continua》 SCIE EI 2024年第5期2505-2522,共18页
Brain–computer interface (BCI) systems, such as the P300 speller, enable patients to express intentions withoutnecessitating extensive training.However, the complexity of operational instructions and the slow pace of... Brain–computer interface (BCI) systems, such as the P300 speller, enable patients to express intentions withoutnecessitating extensive training.However, the complexity of operational instructions and the slow pace of characterspelling pose challenges for some patients. In this paper, an image segmentation P300 selector based on YOLOv7-mask and DeepSORT is proposed. The proposed system utilizes a camera to capture real-world objects forclassification and tracking. By applying predefined stimulation rules and object-specificmasks, the proposed systemtriggers stimuli associated with the objects displayed on the screen, inducing the generation of P300 signals in thepatient’s brain. Its video processing mechanism enables the system to identify the target the patient is focusing oneven if the object is partially obscured, overlapped, moving, or changing in number. The system alters the target’scolor display, thereby conveying the patient’s intentions to caregivers. The data analysis revealed that the selfrecognitionaccuracy of the subjects using this method was between 92% and 100%, and the cross-subject P300recognition precision was 81.9%–92.1%. This means that simple instructions such as “Do not worry, just focuson what you desire” effectively discerned the patient’s intentions using the Image Segmentation-P300 selector. Thisapproach provides cost-effective support and allows patients with communication difficulties to easily express theirneeds. 展开更多
关键词 Brain-computer interface deep learning ELECTROENCEPHALOGRAM P300 YOLOv7-mask
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Intraspecific floral colour variation in three Pedicularis species
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作者 Qiu-Yu Zhang Zhe Chen +1 位作者 hang sun Yang Niu 《Plant Diversity》 SCIE CAS CSCD 2024年第2期274-279,共6页
Flower constancy describes the phenomenon that pollinators tend to successively visit flowers of a single species during foraging,reducing reproductive interference in natural communities.The extent of flower constanc... Flower constancy describes the phenomenon that pollinators tend to successively visit flowers of a single species during foraging,reducing reproductive interference in natural communities.The extent of flower constancy is largely determined by the floral traits of co-flowering species.Both higher inter-specific and lower intraspecific differences of floral traits should contribute to a higher level of flower constancy.However,previous studies mainly focused on interspecific difference,and the intraspecific variation(consistency)of floral traits received much less attention.We hypothesise that selection may favour lower intraspecific floral trait variation in communities composed of multiple co-flowering congeners.We investigated the floral colour variation of three focal Pedicularis species that share pollinators in 19communities composed of either single or multiple Pedicularis species.Colour was quantified using image-based colour analysis as perceived by pollinators.We found that most of the intrapopulation floral colour variation was below the colour discrimination threshold of bumblebees,implying strongly constrained by the visual selection by pollinators.Contrary to the hypothesis,there is no significant difference in intraspecific floral colour variation between different community contexts.It may be due to the relatively large interspecific floral colour differences of most co-flowering species.The influence of community context on intraspecific variation may be reflected in floral traits other than colours. 展开更多
关键词 Flower constancy Floral colour variation Plantepollinator interactions Pollinator vision
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A model of five genes of tumor microenvironment predicts prognosis in Cholangiocarcinoma
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作者 Jin-Shan Yang Chuan-Xin Wu +6 位作者 Kai Li Ling-Xiang Xu Xing-Lang Wu Qin-Bo Wang Lun-Wei Chen Na Wang hang sun 《Cancer Advances》 2024年第2期1-12,共12页
Background:Cholangiocarcinoma(CCA)is highly malignant and has a poor prognosis has a high malignant degree and poor prognosis.The purpose of this study is to develop a new prognostic model based on genes related to th... Background:Cholangiocarcinoma(CCA)is highly malignant and has a poor prognosis has a high malignant degree and poor prognosis.The purpose of this study is to develop a new prognostic model based on genes related to the tumor microenvironment(TME).Methods:Derived from the discerned differentially expressed genes within The Cancer Genome Atlas(TCGA)dataset,this investigation employed the methodology of weighted gene co-expression network analysis(WGCNA)to ascertain gene co-expressed modules intricately linked to the Tumor Microenvironment(TME)among Cholangiocarcinoma(CCA)patients.The genes associated with prognosis,as identified through Cox regression analysis,were employed in the formulation of a predictive model.This model underwent validation,leading to the development of a risk score formula and nomogram.Concurrently,we validated the model’s reliability using data from CCA patients in the Gene Expression Omnibus(GEO)database(accession:GSE107943).Results:6139 DEGs were divided into 10 co-expressed gene modules using WGCNA.Among these,two modules(blue module with 832 genes and brown module with 1379 genes)showed high correlation with the TME.Five prognostic genes(BNIP3,COL4A3,SPRED3,CEBPB,PLOD2)were identified through Cox regression analysis,and a prognostic model and risk score formula were developed based on these genes.Risk score formula:Risk score=BNIP3×1.70520-COL4A3×2.39815+SPRED3×1.17936+CEBPB×0.40456+PLOD2×0.24785.Kaplan-Meier survival analysis revealed that the survival probabilities of the low-risk group were significantly higher than those of the high-risk group.Furthermore,the related evaluation indexes suggested that the model exhibited strong predictive ability.Conclusion:The prognostic model,based on five TME-related genes(BNIP3,COL4A3,SPRED3,CEBPB,PLOD2),could accurately assess the prognosis of CCA patients to aid in guiding clinical decisions. 展开更多
关键词 CHOLANGIOCARCINOMA tumor microenvironment prognostic prediction model NOMOGRAM
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Does pollinator dependence decrease along elevational gradients? 被引量:1
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作者 Yue-Wen Xu Lu sun +3 位作者 Rong Ma Yong-Qian Gao hang sun Bo Song 《Plant Diversity》 SCIE CAS CSCD 2023年第4期446-455,共10页
Plants have long been thought to be less dependent on pollinators for seed production at higher elevations due to adverse pollination environments.However,recent research has yet to consistently support the generality... Plants have long been thought to be less dependent on pollinators for seed production at higher elevations due to adverse pollination environments.However,recent research has yet to consistently support the generality of this expectation.In this study,we asked whether pollinator dependence decreases along an elevational gradient and how it varies with various reproductive traits.To answer these questions,we quantified pollinator-plant associations and various reproductive traits for 112 flowering plants spanning a large elevational gradient(990-4260 m a.s.l.)in the Qinghai-Tibet Plateau.We found that flowering plants in the Qinghai-Tibet Plateau region are highly dependent on pollinators for seed production(76.2%of seed production was contributed by animal pollinators and 44.6%of plants would produce no seed without pollinator visitation).Contrary to our expectation,there was no significant elevational gradient in pollinator dependence index.Although the pollinator dependence index was not significantly correlated with pollen limitation,flower size,floral longevity,or reward type,it was correlated with compatibility status and flowering time.These findings indicate that pollinator dependence does not decrease along an elevational gradient in the Qinghai-Tibet Plateau.Our study also highlights the severe vulnerability of flowering plant seed production to pollinator declines under global change in the Qinghai-Tibet Plateau region,particularly for early-flowering or self-incompatible plants growing at higher elevations(e.g.,subnival belt). 展开更多
关键词 Global change Pollen limitation Pollinator decline Qinghai-Tibet plateau Seed production
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Historical development of karst evergreen broadleaved forests in East Asia has shaped the evolution of a hemiparasitic genus Brandisia(Orobanchaceae)
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作者 Zhe Chen Zhuo Zhou +3 位作者 Ze-Min Guo Truong Van Do hang sun Yang Niu 《Plant Diversity》 SCIE CAS CSCD 2023年第5期501-512,共12页
Brandisia is a shrubby genus of about eight species distributed basically in East Asian evergreen broadleaved forests(EBLFs),with distribution centers in the karst regions of Yunnan,Guizhou,and Guangxi in southwestern... Brandisia is a shrubby genus of about eight species distributed basically in East Asian evergreen broadleaved forests(EBLFs),with distribution centers in the karst regions of Yunnan,Guizhou,and Guangxi in southwestern China.Based on the hemiparasitic and more or less liana habits of this genus,we hypothesized that its evolution and distribution were shaped by the development of EBLFs there.To test our hypothesis,the most comprehensive phylogenies of Brandisia hitherto were constructed based on plastome and nuclear loci(nrDNA,PHYA and PHYB);then divergence time and ancestral areas were inferred using the combined nuclear loci dataset.Phylogenetic analyses reconfirmed that Brandisia is a member of Orobanchaceae,with unstable placements caused by nuclear-plastid incongruences.Within Brandisia,three major clades were well supported,corresponding to the three subgenera based on morphology.Brandisia was inferred to have originated in the early Oligocene(32.69 Mya)in the Eastern Himalayas-SW China,followed by diversification in the early Miocene(19.45 Mya)in karst EBLFs.The differentiation dates of Brandisia were consistent with the origin of keystone species of EBLFs in this region(e.g.,Fagaceae,Lauraceae,Theaceae,and Magnoliaceae)and the colonization of other characteristic groups(e.g.,Gesneriaceae and Mahonia).These findings indicate that the distribution and evolution of Brandisia were facilitated by the rise of the karst EBLFs in East Asia.In addition,the woody and parasitic habits,and pollination characteristics of Brandisia may also be the important factors affecting its speciation and dispersal. 展开更多
关键词 BIOGEOGRAPHY Brandisia Evergreen broadleaved forests(EBLFs) KARST OROBANCHACEAE PHYLOGENY
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Genome assembly of the snow lotus species Saussurea involucrata provides insights into acacetin and rutin biosynthesis and tolerance to an alpine environment
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作者 Yanxia sun Aidi Zhang +4 位作者 Jacob BLandis Wei Shi Xiujun Zhang hang sun Hengchang Wang 《Horticulture Research》 SCIE CSCD 2023年第10期8-11,共4页
Dear Editor,Understanding the evolution and survival mechanisms of endangered wild medicinal herbs is crucial for their cultivation,utilization,and conservation.The snow lotus species Saussurea involucrata(Kar.&Ki... Dear Editor,Understanding the evolution and survival mechanisms of endangered wild medicinal herbs is crucial for their cultivation,utilization,and conservation.The snow lotus species Saussurea involucrata(Kar.&Kir.)Sch.Bip.(2n=32)(i.e.the well-known Tianshan snow lotus)which belongs to the eudicot family Asteraceae,is a famous traditional Chinese medicinal herb having anti-inflammatory. 展开更多
关键词 TIANSHAN belongs INVOLUCRATA
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Degeneration of foundation cushion species induced by ecological constraints can cause massive changes in alpine plant communities
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作者 Jianguo Chen Xufang Chen +6 位作者 Lishen Qian Yazhou Zhang Bo Li Honghua Shi Lu sun Christian Schöb hang sun 《Science China(Life Sciences)》 SCIE CAS CSCD 2024年第4期789-802,共14页
Foundational cushion plants can re-organize community structures and sustain a prominent proportion of alpine biodiversity,but they are sensitive to climate change.The loss of cushion species can have broad consequenc... Foundational cushion plants can re-organize community structures and sustain a prominent proportion of alpine biodiversity,but they are sensitive to climate change.The loss of cushion species can have broad consequences for associated biota.The potential plant community changes with the population dynamics of cushion plants remain,however,unclear.Using eight plant communities along a climatic and community successional gradient,we assessed cushion population dynamics,the underlying ecological constraints and hence associated plant community changes in alpine communities dominated by the foundational cushion plant Arenaria polytrichoides.The population dynamics of Arenaria are attributed to ecological constraints at a series of life history stages.Reproductive functions are constrained by increasing associated beneficiary plants;subsequent seedling establishment is constrained by temperature,water and light availability,extreme climate events,and interspecific competition;strong competitive exclusion may accelerate mortality and degeneration of cushion populations.Along with cushion dynamics,species composition,abundance and community structure gradually change.Once cushion plants completely degenerate,previously cushion-dominated communities shift to relatively stable communities that are overwhelmingly dominated by sedges.Climate warming may accelerate the degeneration process of A.polytrichoides.Degeneration of this foundational cushion plant will possibly induce massive changes in alpine plant communities and hence ecosystem functions in alpine ecosystems.The assessment of the population dynamics of foundation species is critical for an effective conservation of alpine biodiversity. 展开更多
关键词 alpine ecosystem biodiversity change climate change plant community dynamics foundation species global warming population dynamics
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A few words on our commemoration of 80 years at KIB
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作者 hang sun yongping yang zhekun zhou 《Plant Diversity》 SCIE CAS CSCD 2018年第4期139-140,共2页
Eighty years ago, a botanical institute called"the Yunnan Provincial Institute of Agricultural and Forestry Botany"was jointly founded by the Jingsheng Biology Institute and the Yunnan State Department of Ed... Eighty years ago, a botanical institute called"the Yunnan Provincial Institute of Agricultural and Forestry Botany"was jointly founded by the Jingsheng Biology Institute and the Yunnan State Department of Education in Kunming. At that time, the Heilong Dragon Park became the institute's home (Fig. 1) and the research conducted there mostly focused on taxonomy and economical botany. When the institute came under the auspices of the Chinese Academy of Science, it still had fewer than 20 staff members. 展开更多
关键词 云南 经济植物学 发展现状 科学研究
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Origins and evolution of plant diversity in the Hengduan Mountains, China 被引量:41
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作者 hang sun Jianwen Zhang +1 位作者 Tao Deng David E. Boufford 《Plant Diversity》 SCIE CAS CSCD 北大核心 2017年第4期161-166,共6页
1.Introduction The Hengduan Mountains region(HDM)in southwest China,one of the earth's 34 biodiversity hotspots,is characterized by its unique geology,dramatic topography,a climate where snow and below freezing te... 1.Introduction The Hengduan Mountains region(HDM)in southwest China,one of the earth's 34 biodiversity hotspots,is characterized by its unique geology,dramatic topography,a climate where snow and below freezing temperatures can occur on any day of the year,by its location at elevations averaging between(1400e)2000 and4500(e5300)meters above sea level(m a.s.l.),and by one of 展开更多
关键词 Origins and evolution of plant diversity in the Hengduan Mountains China HDM QTP
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Phylogenetic pattern of alpine plants along latitude and longitude in Hengduan Mountains Region 被引量:9
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作者 Xinhui Li hang sun 《Plant Diversity》 SCIE CAS CSCD 北大核心 2017年第1期37-43,共7页
To detect the horizontal pattern of phylogenetic structure shown by alpine plants, we measured phylogenetic structure using net related index(NRI) and net nearest taxon index(NTI), and analyzed the phylogenetic struct... To detect the horizontal pattern of phylogenetic structure shown by alpine plants, we measured phylogenetic structure using net related index(NRI) and net nearest taxon index(NTI), and analyzed the phylogenetic structure patterns of alpine plants along longitude, latitude and environmental gradients in the Hengduan Mountains Region(HDMR). Our results show that: 1) the phylogenetic structure tended to cluster with increasing latitude and longitude; 2) for NRI, latitude was closer related than longitude,while for NTI, longitude was closer related than latitude, though they both not significantly relate to NTI.The phylogenetic structure tended towards overdispersion in the southern HDMR, with good climate conditions of higher mean annual temperature and more mean annual precipitation. In contrast, with harsh climate conditions of lower mean annual temperature and less mean annual precipitation, the increasing environmental stress led to phylogenetic clustering in the northern HDMR. The results highlighted that in the alpine region of HDMR, environmental filters and geographical isolation had a great effect on the latitudinal and longitudinal alpine species distribution, respectively. 展开更多
关键词 Environmental filter Geographical isolation Hengduan Mountains Region Horizontal pattern NRI NTI
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Spatial phylogenetics of two topographic extremes of the Hengduan Mountains in southwestern China and its implications for biodiversity conservation 被引量:9
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作者 Yazhou Zhang Lishen Qian +3 位作者 Daniel Spalink Lu sun Jianguo Chen hang sun 《Plant Diversity》 SCIE CAS CSCD 2021年第3期181-191,共11页
Previous attempts to elucidate the drivers of speciation mechanisms and spatial distribution patterns of biodiversity in mountain regions have treated different floras within a single geological region as one flora,ig... Previous attempts to elucidate the drivers of speciation mechanisms and spatial distribution patterns of biodiversity in mountain regions have treated different floras within a single geological region as one flora,ignoring the potential contributions of high habitat/ecosystem heterogeneity.Furthermore,current conservation strategies largely focus on forest ecosystems and/or specific flagship species,ignoring marginal ecosystems,leaving species in these ecosystems at risk.Here,we compared the spatial patterns of biodiversity and the potential drivers of these patterns in the river valley and subnival ecosystems of the Hengduan Mountains region(HDM)in southwestern China.Specifically,we compared spatial patterns of diversity,endemism,and threatened species in these ecosystems based on both traditional measurements and recent phylogenetic approaches.We then examined how those patterns were related to environmental factors and human activity in these same regions.We found that the middle-southern HDM supports the highest diversity and endemism for the river valley and subnival ecosystems;however,the distribution patterns of neo-and paleo-endemism in these two ecosystems differ.Regression models indicate that habitat diversity and paleo-climatic fluctuation are important drivers of diversity and endemism for these two ecosystems.Temperature and precipitation,however,showed different influences on the spatial patterns in different ecosystems.Categorical analysis of neo-and paleoendemism(CANAPE)indicated that most endemism centers are not covered by current nature reserves.Moreover,the intensity of human activity is highest in the southern and southeastern HDM,which coincides with the distribution patterns of diversity,mixed-endemism and high-priority(and threatened)species.These findings suggest that different floras within a single geographic/floristic region respond differently to environmental factors and show different spatial phylogenetic patterns.We,therefore,recommend that future research into the drivers of biodiversity consider the contributions of various ecosystem types within a single geological region.This study also provides a theoretical basis for protecting habitat diversity.Our work confirms that current conservation efforts are insufficient to protect ecosystem diversity in the river valley and subnival ecosystems of the Hengduan Mountains.Therefore,we recommend the establishment of nature reserves in the regions identified in this study;furthermore,we strongly recommend improving current and establishing new management policies for biodiversity conservation in this region. 展开更多
关键词 Biodiversity conservation Human activity Nature reserves Plant diversity Subnival belt River valley
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Plant diversity in Yunnan:Current status and future directions 被引量:9
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作者 Li-Shen Qian Jia-Hui Chen +1 位作者 Tao Deng hang sun 《Plant Diversity》 SCIE CAS CSCD 2020年第4期281-291,共11页
Yunnan,located in southwestern China,harbors more than 19,000 higher plants,which represents the highest plant diversity in the country.However,plant diversity in Yunnan faces enormous threats today,including habitat ... Yunnan,located in southwestern China,harbors more than 19,000 higher plants,which represents the highest plant diversity in the country.However,plant diversity in Yunnan faces enormous threats today,including habitat destruction and fragmentation,environmental pollution,and over-exploitation of natural resources.Despite recent efforts to protect biodiversity,there are still thousands of threatened species,some of which have become extinct.We analyzed available data to gain a greater understanding of plant diversity and the status of plant conservation in Yunnan.We found that southern,southeastern,and northwestern Yunnan are hotspots of total species,endemic species,specimens,new species and threatened species,whereas southeastern Yunnan is a hotspot for plant species with extremely small populations.Moreover,we found that there are still conservation gaps and poorly protected areas in central,eastern,and northeastern Yunnan.We conclude that conservation of plant diversity in Yunnan requires modern field investigation,systematic research,the development of comprehensive databases,and government support.We recommend that conservationists pay more attention to building and improving functional protection systems and popularizing science. 展开更多
关键词 BIODIVERSITY Conservation status PROTECTION Yunnan Province HOTSPOT
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Phylogenetic analysis of Toxicodendron(Anacardiaceae) and its biogeographic implications on the evolution of north temperate and tropical intercontinental disjunctions 被引量:6
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作者 Ze-Long NIE hang sun +1 位作者 Ying MENG Jun WEN 《Journal of Systematics and Evolution》 SCIE CSCD 北大核心 2009年第5期416-430,共15页
Toxicodendron is a genus in the Rhus complex of Anacardiaceae with a disjunct distribution between eastern Asia and North America, extending to southeastern Asia and the neotropics. Nuclear (internal transcribed spac... Toxicodendron is a genus in the Rhus complex of Anacardiaceae with a disjunct distribution between eastern Asia and North America, extending to southeastern Asia and the neotropics. Nuclear (internal transcribed spacer, external transcribed spacer, and NIA-i3) and chloroplast (ndhF and trnL-F) sequences were used to construct phylogenetic relationships of Toxicodendron. Phylogenetic analysis of these data strongly support Toxieodendron as a monophyletic group distinct from other genera of the Rhus complex, and the phylogeny does not fully corroborate classification at the sectional level. Two temperate disjunct lineages were detected, one from section Toxicodendron and the other between the eastern North American Toxicodendron vernix and the eastern Asian Toxicodendron vernieifluum. Their divergence times were estimated to be 13.46 (7.95-19.42) and 7.53 (2.76-12.86) mya, respectively. The disjunction between section Griffithii (taxa from warm temperate to tropical Asia) and Toxieodendron striatum (from the neotropics) was supported and their divergence time was estimated to be 20.84 (11.1 6-30.52) mya in the early Miocene. Our biogeographic results and the paleontological data support the Bering land bridge as the most likely route to explain the temperate disjunctions, yet the tropical disjunction in Toxicodendron seems to be best explained by the North Atlantic land bridge hypothesis. 展开更多
关键词 ANACARDIACEAE biogeography DISJUNCTION eastern Asia NEOTROPICS North America PHYLOGENETICS Toxicodendron.
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Molecular phylogeny of Solms-laubachia(Brassicaceae) s.l.,based on multiple nuclear and plastid DNA sequences,and its biogeographic implications 被引量:7
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作者 Ji-Pei YUE hang sun +3 位作者 David A. BAUM jian-Hua LI Ihsan A. AL-SHEHBAZ Richard REE 《Journal of Systematics and Evolution》 SCIE CSCD 北大核心 2009年第5期402-415,共14页
The Hengduan Mountains region of south-west China is a noted biodiversity,hotspot, but the geographic origins and historical assembly of its rich endemic flora, including the sky-island species ofSolms-laubachia Musch... The Hengduan Mountains region of south-west China is a noted biodiversity,hotspot, but the geographic origins and historical assembly of its rich endemic flora, including the sky-island species ofSolms-laubachia Muschl. (Brassicaceae), have been little studied. Previous molecular studies on the phylogeny of Solms-laubachia showed it to be paraphyletic, leading to considerable expansion not only of its taxonomic limits, but also its geographic range, with the inclusion of taxa from outside the Hengduan region. However, these studies provided little resolution of interspecific relationships, preventing inferences about historical biogeography within the clade. In the present study, new sequence data from two nuclear genes (LEAFY and G3pdh) and two chloroplast intergenic spacers (petN-psbM and psbM-trnD) were combined with existing markers to increase phylogenetic signals. Phaeonychium villosum (Maxim.) Al-Shehbaz was found to be nested within Solms-laubachia s.l. In general, phylogenetic relationships appear to be a good predictor of geography, with the Hengduan Mountain endemics embedded in a paraphyletic grade of species from the western Himalayas and central Asia, but they also imply morphological homoplasy, lncongruence was detected between the nuclear and chloroplast gene trees, perhaps resulting from incomplete lineage sorting of ancestral polymorphisms. The crown age ofSolms-laubachia s.l. was estimated to be approximately 1.42-3.68 mya, using Bayesian relaxed molecular clock analysis. Historical biogeographic analysis using a parametric dispersalextinction-cladogenesis model inferred central Asia and the western Himalayas as most probable ancestral range of Solms-laubachia s.l., and estimated higher rates of eastward expansion than westward during the diversification of descendant lineages. In summary, our results suggest that Solms-laubachia s.l. originated during the Pliocene in central Asia, and subsequently migrated eastward into the Hengduan Mountains, colonizing sky-island, alpine scree-slope habitats that may have provided novel ecological opportunity and accelerated speciation, ultimately establishing this region as the present center of diversity of the genus. 展开更多
关键词 BIOGEOGRAPHY Brassicaceae Hengduan Mountains PHYLOGENY Solms-laubachia s.l.
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Current progress and future prospects in phylofloristics 被引量:7
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作者 Rong Li Lishen Qian hang sun 《Plant Diversity》 SCIE CAS CSCD 2018年第4期141-146,共6页
The species composition of regional plant assemblages can in large part be explained by a long history of biogeographical and evolutionary events. Traditional attempts of floristic studies typically focus on the analy... The species composition of regional plant assemblages can in large part be explained by a long history of biogeographical and evolutionary events. Traditional attempts of floristic studies typically focus on the analyses of taxonomic composition, often ignoring the rich context that evolutionary history can provide.In 2014, Swenson and Uma~na introduced the term ‘phylofloristics' to define a phylogenetically enabled analysis of the species composition of regional floras. Integrating phylogenetic information into traditional floristic analysis can provide a promising way to explore the ecological, biogeographic, and evolutionary processes that drive plant assemblies at multiple spatial scales. In this review, we summarize the current progress on the phylogenetic structure, spatial phylogenetic pattern, origin and diversification, phylogenetic regionalization of floristic assemblages, and application of phylogenetic information in biodiversity conservation. These summaries highlight the importance of incorporating phylogenetic information to improve our understanding of floristic assembly from an evolutionary perspective. The review ends with a brief outlook on future challenges for phylofloristic studies,including generating a highly resolved species-level phylogenetic tree, compiling detailed and refined information regarding the geographic distribution of all plant life, extracting trait information from publications and herbarium specimens, and developing technological and methodological approaches for big data analysis. 展开更多
关键词 植物区系学 生物多样性 植物学 科学技术
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How cushion communities are maintained in alpine ecosystems: A review and case study on alpine cushion plant reproduction 被引量:5
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作者 Jianguo Chen Yanbo Li +1 位作者 Yang Yang hang sun 《Plant Diversity》 SCIE CAS CSCD 北大核心 2017年第4期221-228,共8页
Cushion species occur in nearly all alpine environments worldwide. In past decades, the adaptive and ecosystem-engineering roles of such highly specialized life forms have been well studied. However, the adaptive stra... Cushion species occur in nearly all alpine environments worldwide. In past decades, the adaptive and ecosystem-engineering roles of such highly specialized life forms have been well studied. However, the adaptive strategies responsible for cushion species reproductive success and maintenance in severe alpine habitats remain largely unclear. In this study, we reviewed the current understanding of reproductive strategies and population persistence in alpine cushion species. We then present a preliminary case study on the sexual reproduction of Arenaria polytrichoides(Caryophyllaceae), a typical cushion species inhabiting high elevations of the Himalaya Hengduan Mountains, which is a hotspot for diversification of cushion species. Finally, we highlight the limitations of our current understanding of alpine cushion species reproduction and propose future directions for study. 展开更多
关键词 Alpine ecosystem Cushion plant Community recruitment Growth rate Life-span REPRODUCTION
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Cytological study on the genus Syncalathium (Asteraceae-Lactuceae),an endemic taxon to alpine scree of the Sino-Himalayas 被引量:5
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作者 Jian-Wen Zhang Ze-Long NIE hang sun 《Journal of Systematics and Evolution》 SCIE CSCD 北大核心 2009年第3期226-230,共5页
Cytological characters of four species in Syncalathium (Asteraceae: Lactuceae), a small genus with six identified species endemic to alpine scree of the Sino-Himalayan region, are surveyed in this report. Three spe... Cytological characters of four species in Syncalathium (Asteraceae: Lactuceae), a small genus with six identified species endemic to alpine scree of the Sino-Himalayan region, are surveyed in this report. Three species (Syncalathiumpilosum, Syncalathium chrysocephalum, and Syncalathium disciforme) are examined for the first time. Combined with our previous counts, five species have been cytologically investigated from the genus and the results indicated that all species are diploid with the basic somatic chromosome number of x=8. The karyotype asymmetry of Syncalathium souliei is 2A, distinct from the other four species of 1A, and the remaining species are divided into two subgroups with different karyotypes, consistent with their morphological features. The significance of the cytological evolution of Syncalathium is briefly discussed. 展开更多
关键词 Asteraceae chromosome numbers DIPLOIDY KARYOTYPE Syncalathium.
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