The lowland rainforests of Meghalaya, India represent the westernmost limit of the rainforests north of the Tropic of Cancer. These forests, on the Shillong plateau, are akin to Whitmore's ‘tropical lowland everg...The lowland rainforests of Meghalaya, India represent the westernmost limit of the rainforests north of the Tropic of Cancer. These forests, on the Shillong plateau, are akin to Whitmore's ‘tropical lowland evergreen rainforest' formation and exhibit striking similarities and conspicuous differences with the equatorial rainforests in Asia-Pacific as well as tropical seasonal rainforests in southwestern China near the Tropic of Cancer. We found these common attributes of the rainforests in Meghalaya: familial composition with predominance of Euphorbiaceae, Lauraceae, Meliaceae, Moraceae, Myrsiticaceae,Myrtaceae and Rubiaceae; deciduousness in evergreen physiognomy; dominance of mega-and mesophanerophytic life-forms; abundance of species with low frequency of occurrence(rare and aggregated species); low proportional abundance of the abundant species; and truncated lognormal abundance distribution. The levels of stand density and stand basal area were comparable with seasonal rainforests in southwestern China, but were lower than equatorial rainforests. Tropical Asian species predominated flora, commanding 95% of the abundance. The differences include overall low stature(height) of the forest, inconspicuous stratification in canopy, fewer species and individuals of liana, thicker understory,higher proportion of rare species, absence of locally endemic species and relatively greater dominance of Fagaceae and Theaceae. The richness of species per hectare(S) was considerably lower at higher latitudes in Meghalaya than in equatorial rainforests, but was comparable with seasonal rainforests. Shannon's diversity index(H’=4.40 nats for ≥10 cm gbh and 4.25 nats for ≥30 cm gbh) was lower on higher latitudes in Meghalaya in comparison to species-rich equatorial rainforests, but it was the highest among all lowland rainforests near the Tropic of Cancer.展开更多
The upper montane evergreen broad-leaved forest in Yunnan occurs mainly in the zone of persistent cloud and has a discontinuous,island-like,distribution.It is diverse,rich in endemic species,and likely to be sensitive...The upper montane evergreen broad-leaved forest in Yunnan occurs mainly in the zone of persistent cloud and has a discontinuous,island-like,distribution.It is diverse,rich in endemic species,and likely to be sensitive to climate change.Six 1-ha sampling plots were established across the main distribution area of the upper montane evergreen broad-leaved forest in Yunnan.All trees with d.b.h.>1 cm in each plot were identified.Patterns of seed plant distributions were quantified at the specific,generic and family levels.The forests are dominated by the families Fagaceae,Lauraceae,Theaceae and Magnoliaceae,but are very diverse with only a few species shared between sites.Floristic similarities at the family and generic level were high,but they were low at the specific level,with species complementarity between plots.Diversity varied greatly among sites,with greater species richness and more rare species in western Yunnan than central Yunnan.The flora is dominated by tropical biogeographical elements,mainly the pantropic and the tropical Asian distributions at the family and genus levels.In contrast,at the species level,the flora is dominated by the southwest or the southeast China distributions,including Yunnan endemics.This suggests that the flora of the upper montane forest in Yunnan could have a tropical floristic origin,and has adapted to cooler temperatures with the uplift of the Himalayas.Due to great sensitivity to climate,high endemism and species complementarity,as well as the discontinuous,island-like,distribution patterns of the upper montane forest in Yunnan,the regional conservation of the forest is especially needed.展开更多
In 1998, a revolutionary system of angiosperm classification, the Angiosperm Phylogeny Group system was published. Meanwhile, another new system of classification of angiosperms, the eight-class system was proposed by...In 1998, a revolutionary system of angiosperm classification, the Angiosperm Phylogeny Group system was published. Meanwhile, another new system of classification of angiosperms, the eight-class system was proposed by C.Y. Wu and colleagues based on long term work on the flora of China. The Flora Reipublicae Popularis Sinicae project was initiated in 1959 and completed by 2004. It is the largest Flora so far completed in the world, including 31 228 species of vascular plants, or one-eighth of the global plant diversity. The English-language and updated Flora of China （FOC） is an international joint effort initiated in 1988 and accelerated in 1998. Up to now, 15 of the 24 volumes of the FOC have been published. Based on the floristic data, the composition, characteristics, floristic divisions and affinities of the flora of China have been studied by Wu and colleagues since 1965. In the past 10 years, analyses of the available floristic data have been very productive. The East Asiatic Floristic Kingdom was proposed in 1998. All 346 families of angiosperms in China, according to the eight-class system of classification, were comprehensively discussed by using knowledge of current and historical distribution of seed plants in the world, together with some morphological and molecular data. A scheme of distribution patterns or areal-types of families and genera of seed plants in China was modified and elucidated, together with a proposed scheme of areal-types of the world. Molecular phylogenetic and biogeographical studies of angiosperms in China in the past 10 years also witnessed a progressive development. Integration of morphological and molecular data and fossil evidence revealed some significant results. Eastern Asia, which used to be regarded as an important center of survival during the ice age, is likely an important center of diversification of angiosperms.展开更多
Treelines are ecologically unique,fragile,and rich in natural resources.They harbour high species diversity and at the same time are under threat due to anthropogenic activities.Recognizing this,the present study has ...Treelines are ecologically unique,fragile,and rich in natural resources.They harbour high species diversity and at the same time are under threat due to anthropogenic activities.Recognizing this,the present study has been framed to document the patterns of species richness and diversity in the state of Himachal Pradesh,western Himalaya.A total of six treeline sites(three disturbed and three undisturbed)were identified for vegetation sampling.Trees,shrubs,and herbs were sampled at each site using nested plots of 10 m^(2),5 m^(2),and 1 m^(2),respectively.The study exhibits the rich diversity of treeline communities,the patterns of which varied between treeline sites.Altogether,221 species of vascular plants belonging to 47 families and 140 genera were recorded from the area.Amongst families,Asteraceae was the dominant family followed by Apiaceae and Ranunculaceae.The study also revealed the presence of threatened species like Aconitum heterophyllum,Angelica glauca,Bergenia stracheyi,Dactylorhiza hatagirea,Picrorhiza kurroa,and Trillium govanianum etc.at treeline.Moreover,species composition revealed high densities of Betula utilis followed by the under canopy of Rhododendron campanulatum and R.anthopogon at treeline sites.Overall,species richness of herbs,shrubs,and trees were higher at undisturbed site as compared to disturbed one.The diversity indices of herbs and shrubs varied significantly between treeline sites while that of trees was non-significant.At the same time,soil properties showed distinct patterns wherein pH and available nitrogen significantly varied between treeline sites.Present study provides detailed insights into the floristic and ecological aspects of treeline communities from the unexplored ecoregion of western Himalaya.The treelines in the area are anthropogenically depressed and continued land-use activities might result in habitat fragmentation and displacement of plant communities in the near future.展开更多
Potential interactive effects and trade-offs between drivers can regulate species diversity,affecting distributions by several orders of magnitude and distribution.The decomposition ofβ-diversity into turnover and ne...Potential interactive effects and trade-offs between drivers can regulate species diversity,affecting distributions by several orders of magnitude and distribution.The decomposition ofβ-diversity into turnover and nestedness could disentangle community assembly rules and offer the opportunity to encompass the processes that structure the communities and maintain theβ-diversity on the campo rupestre.We evaluatedα-andβ-diversity and species conservation status of rocky outcrop communities in the Parque Nacional da Serra do Cipó,as well as the decomposed component of theβ-diversity index.Due to the isolation characteristics of rocky outcrops,we expect to find high taxonomic turnover among the communities.The study was performed on five quartzitic rocky outcrops divided into two sampling stations.We used field expeditions and plant inventory data of shrubs and herbaceous layers.We recorded 286 angiosperms taxa among rocky outcrops of campo rupestre of Serra do Cipó.The structure andα-diversity showed significant differences among rocky outcrops and an evident oligarchic structure in the plant communities analyzed.Taxonomicβ-diversity showed high turnover with a significant contribution of the turnover component to this index.This pattern reflects the interplay between regional and local scale processes.Therefore,we believe this approach becomes a unified framework,which allows the comparison of diversity patterns and ecological processes in rocky outcrops ecosystems.We highlight the high percentage of not evaluated species for threats and the need to fill this lack.展开更多
Two protected sites located on the outskirts of the Sena Oura National Park (PNSO) in West Mayo-Kebbi cover an area of 1800 m2 is pattern choose in pastoral enclave in both village. This study was undertaken to highli...Two protected sites located on the outskirts of the Sena Oura National Park (PNSO) in West Mayo-Kebbi cover an area of 1800 m2 is pattern choose in pastoral enclave in both village. This study was undertaken to highlight the floristic diversity of the herbaceous and woody vegetation on these sites in the offing to know the ability of charge into UBT that most support the park peripheral. It took place on two experimental sites on a natural course in two villages: Wazetelan and Massang. The approach used for the study was a survey using the systematic sampling method and a 30 m × 30 m plot. The survey consisted in listing all the taxa in a floristically homogeneous plot, each assigned the Braun-Blanquet dominance abundance coefficient. These surveys revealed a floristic richness of 73 species, 58 genera, including 46 herbaceous and 26 woody species. The Shannon result gives H1' = 0.12 bit for herbaceous species and H2' = 0.44 bit for woody species, meaning that the herbaceous and woody populations of all the surveys have a very low species diversity, as H' < 3 according to the Shannon index assessment threshold. Herbaceous species are divided into 13 families and 33 genera. The most represented families are Fabaceae (27.3%) and Poaceae (21.9%). Most of the other families (1.3%) have only one species, if any. Herbaceous species are divided into 33 genera grouped into 13 families. The most represented families are Fabaces (16 species), 34%, and Poaceae (12 species), 26%. The 26 woody species, most of which come from itinerant surveys, are distributed across 24 genera and 12 families, the most important of which is Fabaceae with 09 species (34.6%). This floristic assessment, in terms of quantity and quality, has enabled us to estimate the carrying capacity of the two pastoral enclaves in Dari and Goumadji cantons, and to guide the government’s actions with regard to rangeland management.展开更多
Based on the thorough investigation of the components of urban forest in Nanjing and the collection of samples,it is concluded that there are 1 500 species(including subspecies) of vascular plants belonging to 572 gen...Based on the thorough investigation of the components of urban forest in Nanjing and the collection of samples,it is concluded that there are 1 500 species(including subspecies) of vascular plants belonging to 572 genera of 172 families,among which there are 63 species of ferns belonging to 36 genera of 25 families,1 437 species of seed plants belonging to 536 genera of 147 families.The characteristics are that the flora is rich in species,complex in geographic composition,and possess the distinct transferring quality from tropical to temperate zone.Besides,it is characterized with certain ancient nature,and the peculiar elements are comparatively simple.展开更多
The tropical flora in southern China is represented mainly by three regional flora, i.e. southern Yunnan (southwestern China), southwestern Guangxi (southwestern China) and Hainan Island (southern China). The floristi...The tropical flora in southern China is represented mainly by three regional flora, i.e. southern Yunnan (southwestern China), southwestern Guangxi (southwestern China) and Hainan Island (southern China). The floristic composition of each is concisely enumerated. Their geographical elements at generic level are analyzed. Furthermore, a comparison of floristic similarities between southern Yunnan and Hainan Island and Malay Peninsula and Brunei of western Malesia is made, based on existing regional flora treatments. The following is concluded: (1) The flora of southern China consists mainly of tropical floristic elements which contribute about 60% at the family level and more than 80 % at the generic level of its total flora. The dominant distribution type of the flora of southern China at the generic level is the tropical Asian distribution pattern. This reveals that the flora of southern China is of tropical nature with a strong tropical Asian affinity; (2) Most of the dominant families from the flora of southern China are also dominant in the Malesian flora. The floristic similarities between the regional flora of southern China and the regional flora of western Malesia are over 70% at the family level and more than 50% at the generic level. This suggests that the tropical flora of southern China belongs to the Malesian floristic region; (3) Situated at the northern margin of tropical Asia, on the other hand it is also obvious that the flora of southern China comprises less strictly tropical elements compared to the Malesian flora, and is consequently only a marginal type of the latter; (4) The close affinity of the flora of southern China to the Malesian flora can be explained by the geological history of southeast Asia.展开更多
Background： The ＇Khasi hill sal＇ forest ecosystem in Meghalaya, India represents the easternmost limit of sal distribution. We tested if tree diversity and compositional heterogeneity of this ecosystem was higher t...Background： The ＇Khasi hill sal＇ forest ecosystem in Meghalaya, India represents the easternmost limit of sal distribution. We tested if tree diversity and compositional heterogeneity of this ecosystem was higher than other sal-dominated forests due to moister environment. Methods： Vegetation was sampled in 11 transects of 10 m width and up to 500 m length covering 5.2 ha area. All stems ≥10 cm girth at breast height were enumerated. Results： We found a pattern of mixed dominance of Shored robusta （sal） and Schima wollichii and co-dominance of Pinus kesiyo and Careya arborea. The Shannon＇s diversity index （H＇） was 3.395 nats. This value is remarkably high and competitive to that of moist sal forests of eastern Himalayan foothills and sal-dominated forests of Tripura. A high value of H＇ was manifested by： a） high species richness （S = 123）, b） good equitability （70.6%）, c） ＇fair＇ resource apportionment, and d） abundance of rare species （84% species with less than one per cent of total individuals, 67% species with two or less individuals ha-1 and 59% species with one or less individuals ha-1）. The compositional heterogeneity was ＇fair＇ （Whittaker＇sβw = 3.15）. The presence of Fagaceae with six species commanding 4.3% of importance value （IVl） and of a pine （P. kesiya） in sal forest was remarkable. As many as 58 species showed ＇low density （〈 10 individuals ha-1）, uniform dispersion＇, five species achieved ＇higher density （〉 10 individuals ha-l）, uniform dispersion＇ and six of the top 10 species were ＇clumped＇. The forest showed an exponential demographic curve illustrating ＇good＇ regeneration of an expanding community. Vertical stratification was simple with a poor canopy and fair subcanopy, which together with low basal area （15.65 m2 . ha-1 for individuals ≥ 10 cm gbh） indicated logging of mature sal trees in the past. Conclusions： The ＇Khasi hill sal＇ forest ecosystem is richer in alpha and beta diversity than most sal-dominated forests, but past logging has reduced basal area. Selective removal of small timber and firewood, slash-and-burn agriculture and recurrent burning of forest floor are the principal anthropogenic factors controlling forest structure and regeneration of species.展开更多
In this study, Liriomyza sativaes was raised on Florist cinerarias in greenhouse with different temperatures at 15, 20, 25, 30 and 35 ℃, and their corresponding development duration of entire generation were 47.0, 25...In this study, Liriomyza sativaes was raised on Florist cinerarias in greenhouse with different temperatures at 15, 20, 25, 30 and 35 ℃, and their corresponding development duration of entire generation were 47.0, 25.0, 15.5, 12.5 and 12.0 d. The beginning growth temperatures of egg, larva, pupa and entire generation of Liriomyza sativae were 8.5, 9.8, 10.2 and 10.4 ℃, and their effective accumulated temperatures were 52.7, 75.8, 158.5 and 262.2 d ·℃, respectively. Liriomyza sativae had 7 generations on Florist cinerarias in Ningxia each year. However, it occurred in the whole year in greenhouse. The length of its development duration in greenhouse decreased in order from cucumber, Callestephus chinensis, Florist cinerarias to pea, but the eclosion rate of its pupa was in the eentrary order. Under the temperature of 10, 0, - 15 and 20 ℃ ,the longer the storage of pupa was,the higher the mortality rate would be. Liriomyza sativae couldn＇t survive in the winter in Ningxia Province in the natural environment.展开更多
The survey of new benthic substrata is expected to yield new records of diatom taxa. A particular type of substratum is the skin of the Stone scorpionfish Scorpaena mystes Jordan & Starks, 1895 that, because of it...The survey of new benthic substrata is expected to yield new records of diatom taxa. A particular type of substratum is the skin of the Stone scorpionfish Scorpaena mystes Jordan & Starks, 1895 that, because of its benthic form of life, represents a potential colonizing surface for various organisms, including epizoic and opportunistic diatom taxa (epibiotic community). Thus, a floristic survey of diatoms was carried out by sampling the epibiotic community from S. mystes specimens collected in the east coast of Baja California Sur (Gulf of California). Thirty diatoms are new records for Mexican littorals. Twelve of these taxa had not been hitherto recorded for American coasts. Micrographs, and morphometric and distribution data on these taxa are provided.展开更多
The shrub-tree floristic composition of the natural regeneration stratum of a bauxite mine in the process of restoration and in a reference ecosystem(remnant of a preserved secondary Seasonal Semi-Deciduous Forest)wer...The shrub-tree floristic composition of the natural regeneration stratum of a bauxite mine in the process of restoration and in a reference ecosystem(remnant of a preserved secondary Seasonal Semi-Deciduous Forest)were analysed to evaluate forest restoration conditions after five years of planting.The influence of canopy openness,accumulated leaf litter and soil attributes in the regeneration stratum were also investigated in both the forests.The floristic composition of the regeneration stratum in the forest under restoration(16 species and 5,083 individuals ha-1)and in the reference ecosystem(58 species and 26,250 individuals ha-1)are distinct due to the difference in the environmental variables.Results showed that the reference ecosystem favours the presence of species that tolerate environments with greater shading and higher aluminium and organic matter content in the soil like Psychotria carthagenensis Jacq.,while the forest under restoration favours the presence of species adapted to fertile soils and those that tolerate greater luminosity like Vernonanthura phosphorica(Vell.)H.Rob.展开更多
Yunnan in southwestern China is renowned for its high plant diversity.To understand how this modern botanical richness formed,it is critical to investigate the past biodiversity throughout the geological time.In this ...Yunnan in southwestern China is renowned for its high plant diversity.To understand how this modern botanical richness formed,it is critical to investigate the past biodiversity throughout the geological time.In this review,we present a summary on plant diversity,floristics and climates in the Cenozoic of Yunnan and document their changes,by compiling published palaeobotanical sources.Our review demonstrates that thus far a total of 386 fossil species of ferns,gymnosperms and angiosperms belonging to 170 genera within 66 families have been reported from the Cenozoic,particularly the Neogene,of Yunnan.Angiosperms display the highest richness represented by 353 species grouped into 155 genera within 60 families,with Fagaceae,Fabaceae,Lauraceae and Juglandaceae being the most diversified.Most of the families and genera recorded as fossils still occur in Yunnan,but seven genera have disappeared,including Berryophyllum,Cedrelospermum,Cedrus,Palaeocarya,Podocarpium,Sequoia and Wataria.The regional extinction of these genera is commonly referred to an aridification of the dry season associated with Asian monsoon development.Floristic analyses indicate that in the late Miocene,Yunnan had three floristic regions:a northern subtropical floristic region in the northeast,a subtropical floristic region in the east,and a tropical floristic region in the southwest.In the late Pliocene,Yunnan saw two kinds of floristic regions:a subalpine floristic region in the northwest,and two subtropical floristic regions separately in the southwest and the eastern center.These floristic concepts are verified by results from our areal type analyses which suggest that in the Miocene southwestern Yunnan supported the most Pantropic elements,while in the Pliocene southwestern Yunnan had abundant Tropical Asia(Indo e Malaysia)type and East Asia and North America disjunct type that were absent from northwestern Yunnan.From the late Miocene to late Pliocene through to the present,floristic composition and vegetation types changed markedly,presumably in response to altitude changes and coeval global cooling.An integration of palaeoclimate data suggests that during the Neogene Yunnan was warmer and wetter than today.Moreover,northern Yunnan witnessed a pronounced temperature decline,while southern Yunnan experienced only moderate temperature changes.Summer precipitation was consistently higher than winter precipitation,suggesting a rainfall seasonality.This summary on palaeoclimates helps us to understand under what conditions plant diversity occurred and evolved in Yunnan throughout the Cenozoic.展开更多
Although the high diversity of plant species in the rupestrian fields has been primarily attributed to the existence of a set of distinct habitats, few studies support this assertion. The present study aimed to furthe...Although the high diversity of plant species in the rupestrian fields has been primarily attributed to the existence of a set of distinct habitats, few studies support this assertion. The present study aimed to further investigate the relationship between physical and chemical attributes of soils with the diversity of plant species in this unique ecosystem. The rupestrian field is a unique vegetation formation that covers some of the southeastern Brazilian mountains in the transition of the Atlantic rain forest and the Cerrado(savanna). Different habitats occur according to soil characteristics(e.g., presence of rocks, sand, fertility, hydrology, etc.). These attributes ultimately influence the vegetation that is highly adapted to the harsh edaphic and climatic mountain conditions. Five distinct habitats were studied by us: rocky outcrops, peat bogs, sandy bogs, quartz gravel fields, and "cerrado"(savanna). A floristic survey indicated that four families are found at greater frequency: Poaceae, Asteraceae, Cyperaceae, and Leguminosae. The greatest diversity of plant species was found in the rocky outcrops habitat, followed by cerrado, peat bog, quartz gravel grassland, and sandy bogs, respectively. The main difference in the floristic composition among these habitats was related to the dominant species. Trachypogon spicatus(Poaceae) was the most dominant species in the rocky outcrops, Axonopus siccus(Poaceae) in the peat bogs, Lagenocarpus rigidus(Cyperaceae) in the sandy bogs, Schizachyrium tenerum(Poaceae) in the cerrado, while Vellozia sp. 8(Velloziaceae) dominated the vegetation in the quartz gravel grassland. This study demonstrated that physical and chemical soil properties strongly related the diversity of plant species occurring in the different habitats of rupestrian fields.展开更多
Understanding the factors that drive variation in species distribution is a central theme of ecological research. Although several studies focused on alpine vegetation, few efforts have been made to identify the envir...Understanding the factors that drive variation in species distribution is a central theme of ecological research. Although several studies focused on alpine vegetation, few efforts have been made to identify the environmental factors that are responsible for the variations in species composition and richness of alpine shrublands using numerical methods. In the present study, we investigated vegetation and associated environmental variables from 45 sample plots in the middle Qilian Mountains of the northwestern China to classify different community types and to elucidate the species- environment relationships. We also estimated the relative contributions of topography and site conditions to spatial distribution patterns of the shrub communities using the variation partitioning. The results showed that four shrub community types were identified and striking differences in fioristic composition were found among them. Species composition greatly depended on elevation, slope, shrub cover, soil pH and organic carbon. The important determinants of species richness were soil bulk density and slope. No significant differences in species richness were detected among the community types. Topography and site conditions had almost equal effects on compositional variation. Nonetheless,a large amount of the variation in species composition remained unexplained.展开更多
基金The Department of Biotechnology,New Delhi provided principal funding through a grant to US(BT/PR7928/NDB/52/9/2006)
文摘The lowland rainforests of Meghalaya, India represent the westernmost limit of the rainforests north of the Tropic of Cancer. These forests, on the Shillong plateau, are akin to Whitmore's ‘tropical lowland evergreen rainforest' formation and exhibit striking similarities and conspicuous differences with the equatorial rainforests in Asia-Pacific as well as tropical seasonal rainforests in southwestern China near the Tropic of Cancer. We found these common attributes of the rainforests in Meghalaya: familial composition with predominance of Euphorbiaceae, Lauraceae, Meliaceae, Moraceae, Myrsiticaceae,Myrtaceae and Rubiaceae; deciduousness in evergreen physiognomy; dominance of mega-and mesophanerophytic life-forms; abundance of species with low frequency of occurrence(rare and aggregated species); low proportional abundance of the abundant species; and truncated lognormal abundance distribution. The levels of stand density and stand basal area were comparable with seasonal rainforests in southwestern China, but were lower than equatorial rainforests. Tropical Asian species predominated flora, commanding 95% of the abundance. The differences include overall low stature(height) of the forest, inconspicuous stratification in canopy, fewer species and individuals of liana, thicker understory,higher proportion of rare species, absence of locally endemic species and relatively greater dominance of Fagaceae and Theaceae. The richness of species per hectare(S) was considerably lower at higher latitudes in Meghalaya than in equatorial rainforests, but was comparable with seasonal rainforests. Shannon's diversity index(H’=4.40 nats for ≥10 cm gbh and 4.25 nats for ≥30 cm gbh) was lower on higher latitudes in Meghalaya in comparison to species-rich equatorial rainforests, but it was the highest among all lowland rainforests near the Tropic of Cancer.
基金supported by the National Natural Science Foundation of China,No.41471051,41071040,31170195
文摘The upper montane evergreen broad-leaved forest in Yunnan occurs mainly in the zone of persistent cloud and has a discontinuous,island-like,distribution.It is diverse,rich in endemic species,and likely to be sensitive to climate change.Six 1-ha sampling plots were established across the main distribution area of the upper montane evergreen broad-leaved forest in Yunnan.All trees with d.b.h.>1 cm in each plot were identified.Patterns of seed plant distributions were quantified at the specific,generic and family levels.The forests are dominated by the families Fagaceae,Lauraceae,Theaceae and Magnoliaceae,but are very diverse with only a few species shared between sites.Floristic similarities at the family and generic level were high,but they were low at the specific level,with species complementarity between plots.Diversity varied greatly among sites,with greater species richness and more rare species in western Yunnan than central Yunnan.The flora is dominated by tropical biogeographical elements,mainly the pantropic and the tropical Asian distributions at the family and genus levels.In contrast,at the species level,the flora is dominated by the southwest or the southeast China distributions,including Yunnan endemics.This suggests that the flora of the upper montane forest in Yunnan could have a tropical floristic origin,and has adapted to cooler temperatures with the uplift of the Himalayas.Due to great sensitivity to climate,high endemism and species complementarity,as well as the discontinuous,island-like,distribution patterns of the upper montane forest in Yunnan,the regional conservation of the forest is especially needed.
基金the State Key Basic Research and Development Plan of China (973 Program 2007CB411601) and the Yunnan Provincial Government through an Award for Prominent Contributions in Science and Technology to Professor Wu Zheng-Yi in 2001
文摘In 1998, a revolutionary system of angiosperm classification, the Angiosperm Phylogeny Group system was published. Meanwhile, another new system of classification of angiosperms, the eight-class system was proposed by C.Y. Wu and colleagues based on long term work on the flora of China. The Flora Reipublicae Popularis Sinicae project was initiated in 1959 and completed by 2004. It is the largest Flora so far completed in the world, including 31 228 species of vascular plants, or one-eighth of the global plant diversity. The English-language and updated Flora of China （FOC） is an international joint effort initiated in 1988 and accelerated in 1998. Up to now, 15 of the 24 volumes of the FOC have been published. Based on the floristic data, the composition, characteristics, floristic divisions and affinities of the flora of China have been studied by Wu and colleagues since 1965. In the past 10 years, analyses of the available floristic data have been very productive. The East Asiatic Floristic Kingdom was proposed in 1998. All 346 families of angiosperms in China, according to the eight-class system of classification, were comprehensively discussed by using knowledge of current and historical distribution of seed plants in the world, together with some morphological and molecular data. A scheme of distribution patterns or areal-types of families and genera of seed plants in China was modified and elucidated, together with a proposed scheme of areal-types of the world. Molecular phylogenetic and biogeographical studies of angiosperms in China in the past 10 years also witnessed a progressive development. Integration of morphological and molecular data and fossil evidence revealed some significant results. Eastern Asia, which used to be regarded as an important center of survival during the ice age, is likely an important center of diversification of angiosperms.
基金the Ministry of Environment Forest and Climate Change and GB Pant National Institute of Himalayan Environment for providing financial assistance through the National Mission on Himalayan Studies (GAP-0199)
文摘Treelines are ecologically unique,fragile,and rich in natural resources.They harbour high species diversity and at the same time are under threat due to anthropogenic activities.Recognizing this,the present study has been framed to document the patterns of species richness and diversity in the state of Himachal Pradesh,western Himalaya.A total of six treeline sites(three disturbed and three undisturbed)were identified for vegetation sampling.Trees,shrubs,and herbs were sampled at each site using nested plots of 10 m^(2),5 m^(2),and 1 m^(2),respectively.The study exhibits the rich diversity of treeline communities,the patterns of which varied between treeline sites.Altogether,221 species of vascular plants belonging to 47 families and 140 genera were recorded from the area.Amongst families,Asteraceae was the dominant family followed by Apiaceae and Ranunculaceae.The study also revealed the presence of threatened species like Aconitum heterophyllum,Angelica glauca,Bergenia stracheyi,Dactylorhiza hatagirea,Picrorhiza kurroa,and Trillium govanianum etc.at treeline.Moreover,species composition revealed high densities of Betula utilis followed by the under canopy of Rhododendron campanulatum and R.anthopogon at treeline sites.Overall,species richness of herbs,shrubs,and trees were higher at undisturbed site as compared to disturbed one.The diversity indices of herbs and shrubs varied significantly between treeline sites while that of trees was non-significant.At the same time,soil properties showed distinct patterns wherein pH and available nitrogen significantly varied between treeline sites.Present study provides detailed insights into the floristic and ecological aspects of treeline communities from the unexplored ecoregion of western Himalaya.The treelines in the area are anthropogenically depressed and continued land-use activities might result in habitat fragmentation and displacement of plant communities in the near future.
基金the Graduate Program in Ecology, Conservation and Wildlife Management (ECMVS)Institute of Biological Sciences (ICB)+1 种基金Department of Botany, Biodiversitas Foundation, Universidade Federal de Minas GeraisCoordenacao de Aperfeicoamento de Pessoal de Nível Superior (CAPES) for supporting this study
文摘Potential interactive effects and trade-offs between drivers can regulate species diversity,affecting distributions by several orders of magnitude and distribution.The decomposition ofβ-diversity into turnover and nestedness could disentangle community assembly rules and offer the opportunity to encompass the processes that structure the communities and maintain theβ-diversity on the campo rupestre.We evaluatedα-andβ-diversity and species conservation status of rocky outcrop communities in the Parque Nacional da Serra do Cipó,as well as the decomposed component of theβ-diversity index.Due to the isolation characteristics of rocky outcrops,we expect to find high taxonomic turnover among the communities.The study was performed on five quartzitic rocky outcrops divided into two sampling stations.We used field expeditions and plant inventory data of shrubs and herbaceous layers.We recorded 286 angiosperms taxa among rocky outcrops of campo rupestre of Serra do Cipó.The structure andα-diversity showed significant differences among rocky outcrops and an evident oligarchic structure in the plant communities analyzed.Taxonomicβ-diversity showed high turnover with a significant contribution of the turnover component to this index.This pattern reflects the interplay between regional and local scale processes.Therefore,we believe this approach becomes a unified framework,which allows the comparison of diversity patterns and ecological processes in rocky outcrops ecosystems.We highlight the high percentage of not evaluated species for threats and the need to fill this lack.
文摘Two protected sites located on the outskirts of the Sena Oura National Park (PNSO) in West Mayo-Kebbi cover an area of 1800 m2 is pattern choose in pastoral enclave in both village. This study was undertaken to highlight the floristic diversity of the herbaceous and woody vegetation on these sites in the offing to know the ability of charge into UBT that most support the park peripheral. It took place on two experimental sites on a natural course in two villages: Wazetelan and Massang. The approach used for the study was a survey using the systematic sampling method and a 30 m × 30 m plot. The survey consisted in listing all the taxa in a floristically homogeneous plot, each assigned the Braun-Blanquet dominance abundance coefficient. These surveys revealed a floristic richness of 73 species, 58 genera, including 46 herbaceous and 26 woody species. The Shannon result gives H1' = 0.12 bit for herbaceous species and H2' = 0.44 bit for woody species, meaning that the herbaceous and woody populations of all the surveys have a very low species diversity, as H' < 3 according to the Shannon index assessment threshold. Herbaceous species are divided into 13 families and 33 genera. The most represented families are Fabaceae (27.3%) and Poaceae (21.9%). Most of the other families (1.3%) have only one species, if any. Herbaceous species are divided into 33 genera grouped into 13 families. The most represented families are Fabaces (16 species), 34%, and Poaceae (12 species), 26%. The 26 woody species, most of which come from itinerant surveys, are distributed across 24 genera and 12 families, the most important of which is Fabaceae with 09 species (34.6%). This floristic assessment, in terms of quantity and quality, has enabled us to estimate the carrying capacity of the two pastoral enclaves in Dari and Goumadji cantons, and to guide the government’s actions with regard to rangeland management.
文摘Based on the thorough investigation of the components of urban forest in Nanjing and the collection of samples,it is concluded that there are 1 500 species(including subspecies) of vascular plants belonging to 572 genera of 172 families,among which there are 63 species of ferns belonging to 36 genera of 25 families,1 437 species of seed plants belonging to 536 genera of 147 families.The characteristics are that the flora is rich in species,complex in geographic composition,and possess the distinct transferring quality from tropical to temperate zone.Besides,it is characterized with certain ancient nature,and the peculiar elements are comparatively simple.
文摘The tropical flora in southern China is represented mainly by three regional flora, i.e. southern Yunnan (southwestern China), southwestern Guangxi (southwestern China) and Hainan Island (southern China). The floristic composition of each is concisely enumerated. Their geographical elements at generic level are analyzed. Furthermore, a comparison of floristic similarities between southern Yunnan and Hainan Island and Malay Peninsula and Brunei of western Malesia is made, based on existing regional flora treatments. The following is concluded: (1) The flora of southern China consists mainly of tropical floristic elements which contribute about 60% at the family level and more than 80 % at the generic level of its total flora. The dominant distribution type of the flora of southern China at the generic level is the tropical Asian distribution pattern. This reveals that the flora of southern China is of tropical nature with a strong tropical Asian affinity; (2) Most of the dominant families from the flora of southern China are also dominant in the Malesian flora. The floristic similarities between the regional flora of southern China and the regional flora of western Malesia are over 70% at the family level and more than 50% at the generic level. This suggests that the tropical flora of southern China belongs to the Malesian floristic region; (3) Situated at the northern margin of tropical Asia, on the other hand it is also obvious that the flora of southern China comprises less strictly tropical elements compared to the Malesian flora, and is consequently only a marginal type of the latter; (4) The close affinity of the flora of southern China to the Malesian flora can be explained by the geological history of southeast Asia.
基金Department of Biotechnology (DBT), Government of India, New Delhi provided principal funding for this work through a project grant to US (grant number BT/PR7928/NDB/52/9/2006)
文摘Background： The ＇Khasi hill sal＇ forest ecosystem in Meghalaya, India represents the easternmost limit of sal distribution. We tested if tree diversity and compositional heterogeneity of this ecosystem was higher than other sal-dominated forests due to moister environment. Methods： Vegetation was sampled in 11 transects of 10 m width and up to 500 m length covering 5.2 ha area. All stems ≥10 cm girth at breast height were enumerated. Results： We found a pattern of mixed dominance of Shored robusta （sal） and Schima wollichii and co-dominance of Pinus kesiyo and Careya arborea. The Shannon＇s diversity index （H＇） was 3.395 nats. This value is remarkably high and competitive to that of moist sal forests of eastern Himalayan foothills and sal-dominated forests of Tripura. A high value of H＇ was manifested by： a） high species richness （S = 123）, b） good equitability （70.6%）, c） ＇fair＇ resource apportionment, and d） abundance of rare species （84% species with less than one per cent of total individuals, 67% species with two or less individuals ha-1 and 59% species with one or less individuals ha-1）. The compositional heterogeneity was ＇fair＇ （Whittaker＇sβw = 3.15）. The presence of Fagaceae with six species commanding 4.3% of importance value （IVl） and of a pine （P. kesiya） in sal forest was remarkable. As many as 58 species showed ＇low density （〈 10 individuals ha-1）, uniform dispersion＇, five species achieved ＇higher density （〉 10 individuals ha-l）, uniform dispersion＇ and six of the top 10 species were ＇clumped＇. The forest showed an exponential demographic curve illustrating ＇good＇ regeneration of an expanding community. Vertical stratification was simple with a poor canopy and fair subcanopy, which together with low basal area （15.65 m2 . ha-1 for individuals ≥ 10 cm gbh） indicated logging of mature sal trees in the past. Conclusions： The ＇Khasi hill sal＇ forest ecosystem is richer in alpha and beta diversity than most sal-dominated forests, but past logging has reduced basal area. Selective removal of small timber and firewood, slash-and-burn agriculture and recurrent burning of forest floor are the principal anthropogenic factors controlling forest structure and regeneration of species.
基金Supported by the Ningxia Natural Foundation Program(NZ0501)~~
文摘In this study, Liriomyza sativaes was raised on Florist cinerarias in greenhouse with different temperatures at 15, 20, 25, 30 and 35 ℃, and their corresponding development duration of entire generation were 47.0, 25.0, 15.5, 12.5 and 12.0 d. The beginning growth temperatures of egg, larva, pupa and entire generation of Liriomyza sativae were 8.5, 9.8, 10.2 and 10.4 ℃, and their effective accumulated temperatures were 52.7, 75.8, 158.5 and 262.2 d ·℃, respectively. Liriomyza sativae had 7 generations on Florist cinerarias in Ningxia each year. However, it occurred in the whole year in greenhouse. The length of its development duration in greenhouse decreased in order from cucumber, Callestephus chinensis, Florist cinerarias to pea, but the eclosion rate of its pupa was in the eentrary order. Under the temperature of 10, 0, - 15 and 20 ℃ ,the longer the storage of pupa was,the higher the mortality rate would be. Liriomyza sativae couldn＇t survive in the winter in Ningxia Province in the natural environment.
文摘The survey of new benthic substrata is expected to yield new records of diatom taxa. A particular type of substratum is the skin of the Stone scorpionfish Scorpaena mystes Jordan & Starks, 1895 that, because of its benthic form of life, represents a potential colonizing surface for various organisms, including epizoic and opportunistic diatom taxa (epibiotic community). Thus, a floristic survey of diatoms was carried out by sampling the epibiotic community from S. mystes specimens collected in the east coast of Baja California Sur (Gulf of California). Thirty diatoms are new records for Mexican littorals. Twelve of these taxa had not been hitherto recorded for American coasts. Micrographs, and morphometric and distribution data on these taxa are provided.
基金To the National Council of Scientific and Technological Development of Brazil(CNPq),provided fellowships for K.A.Silva(CNPq 142415/2013-8)research fellowships for S.V.Martins.The Companhia Brasileira de Alumínio(CBA)for provided infrastructure and financial support for the project.
文摘The shrub-tree floristic composition of the natural regeneration stratum of a bauxite mine in the process of restoration and in a reference ecosystem(remnant of a preserved secondary Seasonal Semi-Deciduous Forest)were analysed to evaluate forest restoration conditions after five years of planting.The influence of canopy openness,accumulated leaf litter and soil attributes in the regeneration stratum were also investigated in both the forests.The floristic composition of the regeneration stratum in the forest under restoration(16 species and 5,083 individuals ha-1)and in the reference ecosystem(58 species and 26,250 individuals ha-1)are distinct due to the difference in the environmental variables.Results showed that the reference ecosystem favours the presence of species that tolerate environments with greater shading and higher aluminium and organic matter content in the soil like Psychotria carthagenensis Jacq.,while the forest under restoration favours the presence of species adapted to fertile soils and those that tolerate greater luminosity like Vernonanthura phosphorica(Vell.)H.Rob.
基金supported by the National Natural Science Foundation of China (No. U1502231)the Foundation of the State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (No. 163108)the foundation of the Yunnan Key Laboratory for Palaeobiology, Yunnan University (No. 2015DG007-KF01)
文摘Yunnan in southwestern China is renowned for its high plant diversity.To understand how this modern botanical richness formed,it is critical to investigate the past biodiversity throughout the geological time.In this review,we present a summary on plant diversity,floristics and climates in the Cenozoic of Yunnan and document their changes,by compiling published palaeobotanical sources.Our review demonstrates that thus far a total of 386 fossil species of ferns,gymnosperms and angiosperms belonging to 170 genera within 66 families have been reported from the Cenozoic,particularly the Neogene,of Yunnan.Angiosperms display the highest richness represented by 353 species grouped into 155 genera within 60 families,with Fagaceae,Fabaceae,Lauraceae and Juglandaceae being the most diversified.Most of the families and genera recorded as fossils still occur in Yunnan,but seven genera have disappeared,including Berryophyllum,Cedrelospermum,Cedrus,Palaeocarya,Podocarpium,Sequoia and Wataria.The regional extinction of these genera is commonly referred to an aridification of the dry season associated with Asian monsoon development.Floristic analyses indicate that in the late Miocene,Yunnan had three floristic regions:a northern subtropical floristic region in the northeast,a subtropical floristic region in the east,and a tropical floristic region in the southwest.In the late Pliocene,Yunnan saw two kinds of floristic regions:a subalpine floristic region in the northwest,and two subtropical floristic regions separately in the southwest and the eastern center.These floristic concepts are verified by results from our areal type analyses which suggest that in the Miocene southwestern Yunnan supported the most Pantropic elements,while in the Pliocene southwestern Yunnan had abundant Tropical Asia(Indo e Malaysia)type and East Asia and North America disjunct type that were absent from northwestern Yunnan.From the late Miocene to late Pliocene through to the present,floristic composition and vegetation types changed markedly,presumably in response to altitude changes and coeval global cooling.An integration of palaeoclimate data suggests that during the Neogene Yunnan was warmer and wetter than today.Moreover,northern Yunnan witnessed a pronounced temperature decline,while southern Yunnan experienced only moderate temperature changes.Summer precipitation was consistently higher than winter precipitation,suggesting a rainfall seasonality.This summary on palaeoclimates helps us to understand under what conditions plant diversity occurred and evolved in Yunnan throughout the Cenozoic.
文摘Although the high diversity of plant species in the rupestrian fields has been primarily attributed to the existence of a set of distinct habitats, few studies support this assertion. The present study aimed to further investigate the relationship between physical and chemical attributes of soils with the diversity of plant species in this unique ecosystem. The rupestrian field is a unique vegetation formation that covers some of the southeastern Brazilian mountains in the transition of the Atlantic rain forest and the Cerrado(savanna). Different habitats occur according to soil characteristics(e.g., presence of rocks, sand, fertility, hydrology, etc.). These attributes ultimately influence the vegetation that is highly adapted to the harsh edaphic and climatic mountain conditions. Five distinct habitats were studied by us: rocky outcrops, peat bogs, sandy bogs, quartz gravel fields, and "cerrado"(savanna). A floristic survey indicated that four families are found at greater frequency: Poaceae, Asteraceae, Cyperaceae, and Leguminosae. The greatest diversity of plant species was found in the rocky outcrops habitat, followed by cerrado, peat bog, quartz gravel grassland, and sandy bogs, respectively. The main difference in the floristic composition among these habitats was related to the dominant species. Trachypogon spicatus(Poaceae) was the most dominant species in the rocky outcrops, Axonopus siccus(Poaceae) in the peat bogs, Lagenocarpus rigidus(Cyperaceae) in the sandy bogs, Schizachyrium tenerum(Poaceae) in the cerrado, while Vellozia sp. 8(Velloziaceae) dominated the vegetation in the quartz gravel grassland. This study demonstrated that physical and chemical soil properties strongly related the diversity of plant species occurring in the different habitats of rupestrian fields.
基金supported by the National Natural Science Foundation of China (Grant No. 91025002)
文摘Understanding the factors that drive variation in species distribution is a central theme of ecological research. Although several studies focused on alpine vegetation, few efforts have been made to identify the environmental factors that are responsible for the variations in species composition and richness of alpine shrublands using numerical methods. In the present study, we investigated vegetation and associated environmental variables from 45 sample plots in the middle Qilian Mountains of the northwestern China to classify different community types and to elucidate the species- environment relationships. We also estimated the relative contributions of topography and site conditions to spatial distribution patterns of the shrub communities using the variation partitioning. The results showed that four shrub community types were identified and striking differences in fioristic composition were found among them. Species composition greatly depended on elevation, slope, shrub cover, soil pH and organic carbon. The important determinants of species richness were soil bulk density and slope. No significant differences in species richness were detected among the community types. Topography and site conditions had almost equal effects on compositional variation. Nonetheless,a large amount of the variation in species composition remained unexplained.
