Clonal reproduction(i.e.,production of potentially independent offspring by vegetative growth)is thought to provide plants with reproductive assurance.Thus,studying the evolution of clonal reproduction in local floras...Clonal reproduction(i.e.,production of potentially independent offspring by vegetative growth)is thought to provide plants with reproductive assurance.Thus,studying the evolution of clonal reproduction in local floras is crucial for our understanding of the adaptive mechanisms plants deploy in stressful environments such as alpine regions.In this study,we characterized clonal plant species in the subnival belt of the Hengduan Mountains(a global biodiversity hotspot with extreme environmental conditions in southwest China),in order to determine the effects of sex system,growth form,and elevational distribution on clonality.We compiled clonality data of angiosperm species belonging to 41 families in the subnival belt of the Hengduan Mountains using published information.Of the 793 species recorded in the region,47.92%(380 species)are clonal species.Both sex system and growth form had significant effects on the occurrence of clonal reproduction:unisexual species(79.79%)were more likely to be clonal than bisexual species(43.63%),and herbaceous species(51.04%)were more likely to be clonal than woody species(16.67%).Compared with non-alpine-endemic species(44.60%),alpine-endemic species(58.33%)showed a significantly higher proportion of clonal reproduction.Further logistic regression analysis showed a positive association between incidence of clonality and elevational range,indicating that species distributed at high elevations are more likely to be clonal.Furthermore,the elevational gradients in clonality were contingent on sex system or growth form.This study reveals that plants in the subnival belt of the Hengduan Mountains might optimize their probability of reproduction through clonal reproduction,a finding that adds to our growing understanding of plant's adaptations to harsh alpine environments.展开更多
This paper presents the results of systematic, ecopathological, and chorological studies of the diversity of the subnival belt （zone） flora of the Caucasus Mountains, peculiarity of altitudinal distribution, endemis...This paper presents the results of systematic, ecopathological, and chorological studies of the diversity of the subnival belt （zone） flora of the Caucasus Mountains, peculiarity of altitudinal distribution, endemism and florogenesis. Comparative analysis of the diversity of the subnival flora on different types of stone and at different altitudes in various parts of the Caucasus has been made. It is based on field investigation and on literature research. 226 species, 96 genera and 35 families were recorded in the subnival belt of the Caucasus within a range of 2,800 （2,900）-4,000 m a.s.l. Among these 117 species or 51% are common endemics of the Greater Caucasus and Caucasus. It is proved that floristic elements of different origin （authochronic and aloctonic） and age （Miocene-Pliocene and Pleistocene） contributed to the florogenesis of the subnival belt of the Caucasus. The Caucasian, the Eu-Caucasian, the Eastern Asian, the Minor Asian, the Dagestan-lranian, the Caucasia-European groups plaied an important role in the florogenesis. Criophilic evolution on the of the some plants was related to oreophytizacion during formation of the Caucasus mountains （in the second half of the Tertiary）, as well as the glaciations scale. Species composition and coenotic role are different in various parts of the Caucasus and within each part. This is conditioned by the different hypsometry of various parts of the Caucasus, the character of glatiations, edaphic and climatic conditions, lythological diversity. Compared with the Greater Caucasus, the relative floristic poverty of the Lesser Caucasus is due to low elevations and extensive rather recent vulcanism.展开更多
The Qinghai-Tibet Plateau(QTP),the“Third Pole of the Earth,”boasts the most complex,diverse,and unique ecosystem in the world.From tropical vegetation on the southern slopes of the Himalayas to alpine subnival ecosy...The Qinghai-Tibet Plateau(QTP),the“Third Pole of the Earth,”boasts the most complex,diverse,and unique ecosystem in the world.From tropical vegetation on the southern slopes of the Himalayas to alpine subnival ecosystems,and from humid forests in the east to arid Gobi or desert vegetation in the west,the QTP encompasses nearly all the ecosystem types found in the Northern Hemisphere(The Comprehensive ScientificExpedition to Qinghai-Xizang Plateau,Academia Sinica,1988).展开更多
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
Aims studying the ecological significance of highly specialized morpho-logical traits evolved by alpine plants could help us to understand the adaptation and evolution of these plants under severe alpine environ-ment....Aims studying the ecological significance of highly specialized morpho-logical traits evolved by alpine plants could help us to understand the adaptation and evolution of these plants under severe alpine environ-ment.We explored the adaptive significance of woolly and overlap-ping leaves for reproduction in Eriophyton wallichii,a perennial herb native to the subnival belt of the Himalaya-Hengduan mountains.Methods We examined whether the trichomes could influence the leaf wet-tability,temperature and leaf reflectance spectra in the lab.and we investigated the thermal benefits of the woolly and overlapping leaves for flowers and fruits in the field.Pollen viability and seed germination were also examined in the lab to assess whether these leaves enhance reproductive fitness.Important Findingsour results showed that dense trichomes impart good water repel-lency,absorption of solar radiation and accumulation of leaf heat.The woolly and overlapping leaves increased the interior tempera-ture of flowers and fruits to an optimal level on sunny hours,but prevented them from overheating when transient intense solar radi-ation occurs.This kept optimal temperatures in plants’reproduc-tive organs,thus promoting the development of pollen and seed in alpine environment.展开更多
基金This work was supported by the Science Research Foundation of Yunnan Provincial Department of Education(2019J0551 to Y.Q.Gao).
文摘Clonal reproduction(i.e.,production of potentially independent offspring by vegetative growth)is thought to provide plants with reproductive assurance.Thus,studying the evolution of clonal reproduction in local floras is crucial for our understanding of the adaptive mechanisms plants deploy in stressful environments such as alpine regions.In this study,we characterized clonal plant species in the subnival belt of the Hengduan Mountains(a global biodiversity hotspot with extreme environmental conditions in southwest China),in order to determine the effects of sex system,growth form,and elevational distribution on clonality.We compiled clonality data of angiosperm species belonging to 41 families in the subnival belt of the Hengduan Mountains using published information.Of the 793 species recorded in the region,47.92%(380 species)are clonal species.Both sex system and growth form had significant effects on the occurrence of clonal reproduction:unisexual species(79.79%)were more likely to be clonal than bisexual species(43.63%),and herbaceous species(51.04%)were more likely to be clonal than woody species(16.67%).Compared with non-alpine-endemic species(44.60%),alpine-endemic species(58.33%)showed a significantly higher proportion of clonal reproduction.Further logistic regression analysis showed a positive association between incidence of clonality and elevational range,indicating that species distributed at high elevations are more likely to be clonal.Furthermore,the elevational gradients in clonality were contingent on sex system or growth form.This study reveals that plants in the subnival belt of the Hengduan Mountains might optimize their probability of reproduction through clonal reproduction,a finding that adds to our growing understanding of plant's adaptations to harsh alpine environments.
文摘This paper presents the results of systematic, ecopathological, and chorological studies of the diversity of the subnival belt （zone） flora of the Caucasus Mountains, peculiarity of altitudinal distribution, endemism and florogenesis. Comparative analysis of the diversity of the subnival flora on different types of stone and at different altitudes in various parts of the Caucasus has been made. It is based on field investigation and on literature research. 226 species, 96 genera and 35 families were recorded in the subnival belt of the Caucasus within a range of 2,800 （2,900）-4,000 m a.s.l. Among these 117 species or 51% are common endemics of the Greater Caucasus and Caucasus. It is proved that floristic elements of different origin （authochronic and aloctonic） and age （Miocene-Pliocene and Pleistocene） contributed to the florogenesis of the subnival belt of the Caucasus. The Caucasian, the Eu-Caucasian, the Eastern Asian, the Minor Asian, the Dagestan-lranian, the Caucasia-European groups plaied an important role in the florogenesis. Criophilic evolution on the of the some plants was related to oreophytizacion during formation of the Caucasus mountains （in the second half of the Tertiary）, as well as the glaciations scale. Species composition and coenotic role are different in various parts of the Caucasus and within each part. This is conditioned by the different hypsometry of various parts of the Caucasus, the character of glatiations, edaphic and climatic conditions, lythological diversity. Compared with the Greater Caucasus, the relative floristic poverty of the Lesser Caucasus is due to low elevations and extensive rather recent vulcanism.
基金funded by Key Project of Regional Innovation and Development Joint Fund of National Natural Science Foundation of China(U23A20149)the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2019QZKK0502,2024QZKK0200).
文摘The Qinghai-Tibet Plateau(QTP),the“Third Pole of the Earth,”boasts the most complex,diverse,and unique ecosystem in the world.From tropical vegetation on the southern slopes of the Himalayas to alpine subnival ecosystems,and from humid forests in the east to arid Gobi or desert vegetation in the west,the QTP encompasses nearly all the ecosystem types found in the Northern Hemisphere(The Comprehensive ScientificExpedition to Qinghai-Xizang Plateau,Academia Sinica,1988).
基金This study was supported equally by the National Key R&D Program of China(2017YFC0505200 to H Sun)the Major Program of the National Natural Science Foundation of China(31590823 to H Sun)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA20050203 to H Sun)USDA National Institute of Food and Agriculture(McIntire Stennis#101869 to DS).
文摘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.
基金Natural National Science Foundation of China(U1136601 to H.S.,31360049 to Z.M.L.and 31270005,31470321 to Y.Y.)Strategic Priority Research Program(B)of the Chinese Academy of Science(XDB03030112 to H.S.).
文摘Aims studying the ecological significance of highly specialized morpho-logical traits evolved by alpine plants could help us to understand the adaptation and evolution of these plants under severe alpine environ-ment.We explored the adaptive significance of woolly and overlap-ping leaves for reproduction in Eriophyton wallichii,a perennial herb native to the subnival belt of the Himalaya-Hengduan mountains.Methods We examined whether the trichomes could influence the leaf wet-tability,temperature and leaf reflectance spectra in the lab.and we investigated the thermal benefits of the woolly and overlapping leaves for flowers and fruits in the field.Pollen viability and seed germination were also examined in the lab to assess whether these leaves enhance reproductive fitness.Important Findingsour results showed that dense trichomes impart good water repel-lency,absorption of solar radiation and accumulation of leaf heat.The woolly and overlapping leaves increased the interior tempera-ture of flowers and fruits to an optimal level on sunny hours,but prevented them from overheating when transient intense solar radi-ation occurs.This kept optimal temperatures in plants’reproduc-tive organs,thus promoting the development of pollen and seed in alpine environment.
