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Sökning: WFRF:(Swenson Ulf) > (2015-2019)

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1.
  • de Faria, Aparecida Donisete, et al. (författare)
  • Towards a natural classification of Sapotaceae subfamily Chrysophylloideae in the Neotropics
  • 2017
  • Ingår i: Botanical journal of the Linnean Society. - : Oxford University Press (OUP). - 0024-4074 .- 1095-8339. ; 185, s. 27-55
  • Tidskriftsartikel (refereegranskat)abstract
    • Generic limits of Chrysophyllum and Pouteria (Chrysophylloideae, Sapotaceae) have been found to be untenable. We here search for natural lineages in Neotropical Chrysophylloideae by sampling 101 terminals for molecular sequences of nuclear ribosomal DNA (external and internal transcribed spacer), the nuclear gene RPB2 and 17 morphological characters. Data were analysed with Bayesian inference and parsimony jackknifing. Morphological traits were finally optimized onto the tree to identify the most coherent characters. The resulting phylogenetic tree suggests that the limits of the well-known genera Chrysophyllum and Pouteria must be amended. Diploon, Ecclinusa and Elaeoluma can be maintained and Chrysophyllum sections Ragala section Prieurella and the satellite gen- era Achrouteria, Cornuella, Martiusella and Nemaluma merit generic resurrection. Lucuma may be restored if the type species belongs to the clade. The accepted genera Chromolucuma, Pradosia and Sarcaulus gain strong clade support, but are embedded in a core clade of Pouteria and may be relegated to the subgeneric level if morphologi- cal studies cannot provide evidence concurring with narrow generic concepts. Circumscriptions of Micropholis and Chrysophyllum sections Chrysophyllum and Villocuspis remain unclear and must be explored by using an extended taxon sampling. We predict that yet-to-be-analysed species of Pouteria sections Franchetella, Gayella, Oxythece and Pouteria and members of the currently accepted genera Chromolucuma, Pradosia and Sarcaulus will fall inside the core clade of Pouteria when analysed. 
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2.
  • Gâteblé, Gildas, et al. (författare)
  • One endemic plant species on average per month in New Caledonia, including eight more new species from Île Art (Belep Islands), a major micro-hotspot in need of protection
  • 2018
  • Ingår i: Australian Systematic Botany. - 1030-1887 .- 1446-5701. ; 31, s. 448-480
  • Tidskriftsartikel (refereegranskat)abstract
    • The New Caledonian biodiversity hotspot contains many micro-hotspots that exhibit high plant micro- endemism, and that are facing different types and intensities of threats. The Belep archipelago, and especially Île Art, with 24 and 21 respective narrowly endemic species (1 Extinct, 21 Critically Endangered and 2 Endangered), should be considered as the most sensitive micro-hotspot of plant diversity in New Caledonia because of the high anthropogenic threat of fire. Nano-hotspots could also be defined for the low forest remnants of the southern and northern plateaus of Île Art. With an average rate of more than one new species described for New Caledonia each month since January 2000 and five new endemics for the Belep archipelago since 2009, the state of knowledge of the flora is steadily improving. The present account of eight new species from Île Art (Bocquillonia montrouzieri Gâteblé & McPherson, Cleidion artense Gâteblé & McPherson, Endiandra artensis Munzinger & McPherson, Eugenia belepiana J.W.Dawson ex N.Snow, Eugenia insulartensis J.W.Dawson ex N.Snow, Macaranga latebrosa Gâteblé & McPherson, Planchonella serpentinicola Swenson & Munzinger and Psychotria neodouarrei Barrabé & A.Martini) further demonstrates the need both to recognise the Belep Islands as a major New Caledonian micro-hotspot and to formulate concrete conservation programs for the archipelago. 
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3.
  • Gâteblé, Gildas, et al. (författare)
  • Pichonia munzingeri (Sapotaceae), a new and rare micro-endemic species from New Caledonia
  • 2019
  • Ingår i: Candollea. - : Society of Conservatoire at Jardin Botaniques de la Ville de Geneve. - 0373-2967 .- 2235-3658. ; 74, s. 1-7
  • Tidskriftsartikel (refereegranskat)abstract
    • Pichonia munzingeri Gâteblé & Swenson (Sapotaceae, Chrysophylloideae) is here described from the southern ultrama c massif of Grande Terre, New Caledonia. It is a micro-endemic species con ned to a small area along Oumbéa Creek in La Coulée Valley of Mont-Dore. Based on nuclear ribosomal sequence data, areolate higher leaf venation, staminodes, stamens in corolla tube ori ce, and seeds having plano-convex cotyledons, no endosperm, and no radicle, this new species is placed in Pichonia Pierre. Preliminary phylogenetic analysis places Pichonia munzingeri as the sister species to all other congeners in New Caledonia, which justi es a high conservation status from the authorities for protecting the species. Less than 50 individuals have been counted in an area a ected by the major “Montagne des Sources” anthropogenic re in late 2005. Hence, repeated res form the main threat to the existence of this new species, and it is assigned an IUCN Red List preliminary status as “Critically Endangered”. 
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4.
  • Greimler, Josef, et al. (författare)
  • Invasive species
  • 2017
  • Ingår i: Plants of Oceanic Islands. - New York : Cambridge University Press. ; , s. 134-148
  • Bokkapitel (övrigt vetenskapligt/konstnärligt)
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5.
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6.
  • Munzinger, Jérôme, et al. (författare)
  • Pycnandra longiflora (Sapotaceae) a species believed to be extinct, rediscovered in New Caledonia
  • 2016
  • Ingår i: Phytotaxa. - : Magnolia Press. - 1179-3155 .- 1179-3163. ; 278:2, s. 176-180
  • Tidskriftsartikel (refereegranskat)abstract
    • Pycnandra longiflora (Sapotaceae) belongs to the largest endemic genus in New Caledonia. It is only known from the type collection made in 1861–67 at the obscure locality “Gatope”. Relocation of this species has been of high priority for more than a decade, but without success. Pycnandra longiflora was therefore recently declared extinct. However, a population was recently discovered near a mining site at Onajiele, in the Ouazangou-Taom massif, and it is revealed that P. longiflora has the most spectacular flowers in the entire genus, being large and bicoloured in red and yellow. A thorough description is here outlined and we propose a preliminary IUCN status as Critically Endangered.
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7.
  • Munzinger, Jérôme, et al. (författare)
  • Revision of Pycnandra subgenus Leptostylis and description of subgenus Wagapensia (Sapotaceae), a genus endemic to New Caledonia
  • 2015
  • Ingår i: Australian Systematic Botany. - 1030-1887 .- 1446-5701. ; 28, s. 91-110
  • Tidskriftsartikel (refereegranskat)abstract
    • The genus Pycnandra Benth. (Sapotaceae, Chrysophylloideae) is endemic to New Caledonia with 66 known species and is subdivided in six subgenera. We have earlier revised four of these subgenera and here continue with P. subgenus Leptostylis and describe P. subgenus Wagapensia. Subgenus Leptostylis is distinguished mainly by its opposite leaves and four sepals, and includes eight species, of which two are described as new (P. amplexicaulis and P. sclerophylla). Two species, P. longiflora and P. micrantha, are assumed extinct because extensive fieldwork has not been able to relocate the plants. Variation in leaf morphology was observed in Leptostylis gatopensis, which is by consequence considered as synonym of Pycnandra filipes. Two additional taxa belong to this subgenus, but cannot presently be described because sufficient fertile material is unavailable. Subgenus Wagapensia is monotypic and readily distinguished on the basis of its subverticillate leaves and leafy shoots usually borne beneath apical clusters of leaves, a character common in Sapotaceae but unique in Pycnandra. The members of P. subgenus Leptostylis occur mainly in maquis vegetation or sclerophyllous forests on ultramafic soil, but three taxa are confined to calcareous areas. Mining activities in New Caledonian ultramafic areas are extensive and because some of these species are naturally rare, IUCN Red List assessments are provided to all species. Pycnandra grandifolia and P. wagapensis are assigned the IUCN status Vulnerable, P. amplexicaulis and P. sclerophylla are considered Endangered, P. filipes subspecies multiflora and P. goroensis are considered to be Critically Endangered, whereas P. micrantha and P. longiflora appear to be extinct.
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8.
  • Popovkin, Alex, et al. (författare)
  • Pouteria synsepala (Sapotaceae: Chrysophylloideae) a new species from the northern littoral of Bahia, Brazil
  • 2016
  • Ingår i: Phytotaxa. - : Magnolia Press. - 1179-3155 .- 1179-3163. ; 286, s. 039-046
  • Tidskriftsartikel (refereegranskat)abstract
    • A new species of Pouteria from the Atlantic Forest area of the northern littoral of Bahia State, Brazil, is described and illus- trated. Pouteria synsepala, whose epithet refers to the basally united sepals, a feature rare in the genus, resembles P. salicifo- lia in its narrowly elliptic leaves, but differs by the angle of secondary veins in relation to the midrib, pentamerous flowers, and stamens adnate to the corolla tube from the base to the tube orifice. Micromorphological studies revealed different pat- terns of stomate and wax morphology in the two species, providing further justification for the recognition of P. synsepala.
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9.
  • Sontag, Walter A., et al. (författare)
  • Modeling species diversity
  • 2017
  • Ingår i: Plants of Oceanic Islands. - New York : Cambridge University Press. ; , s. 354-366
  • Bokkapitel (övrigt vetenskapligt/konstnärligt)
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10.
  • Stuessy, Tod F., et al. (författare)
  • Conservation of native and endemic species
  • 2017
  • Ingår i: Plants of Oceanic Islands. - New York : Cambridge University Press. ; , s. 149-162
  • Bokkapitel (övrigt vetenskapligt/konstnärligt)
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11.
  • Stuessy, Tod, et al. (författare)
  • Impacts on the vegetation
  • 2017
  • Ingår i: Plants of Oceanic Islands. - New York : Cambridge University Press. ; , s. 115-133
  • Bokkapitel (övrigt vetenskapligt/konstnärligt)
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12.
  • Swenson, Ulf, 1959-, et al. (författare)
  • Five new species and a systematic synopsis of Pycnandra (Sapotaceae), the largest endemic genus in New Caledonia
  • 2016
  • Ingår i: Australian Systematic Botany. - 1030-1887 .- 1446-5701. ; 29, s. 1-40
  • Tidskriftsartikel (refereegranskat)abstract
    • Pycnandra Benth. (Sapotaceae) is the largest endemic genus in New Caledonia and is subdivided into six subgenera. An addition of five species are here described in four subgenera, viz. P. comptonioides Swenson & Munzinger, P. kouakouensis Swenson & Munzinger, P. montana Swenson & Munzinger, P. poindimiensis Swenson & Munzinger and P. versicolor Swenson & Munzinger. Another seven to nine taxa are discussed but remain undescribed owing to the lack of adequate collections (and may remain undescribed pending the interpretation of the Nagoya Protocol). Pycnandra is characterised by a non-areolate higher leaf venation, sepals glabrous on the inner surface, no staminodes, and a single-seeded fruit. The members occur in a wide range of habitats and most species have very specific substrate requirements, growing on ultramafic, non-ultramafic or calcareous substrates. Almost 40 species are restricted to ultramafic substrates and many are now at risk of extinction because of deforestation, deliberately set fires and mining. We provide a systematic synopsis with keys to subgenera and species, phenology, substrate preferences, altitudinal ranges and preliminary IUCN Red List assessments for all described taxa. Four of the five new species are assessed as Critically Endangered. Pycnandra versicolor is in urgent need of conservation management beacuse its entire distribution is inside an active mine on the Koniambo massif.
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13.
  • Swenson, Ulf, 1959-, et al. (författare)
  • Hawaiiöarna - en flora på fallrepet
  • 2016
  • Ingår i: Svensk Botanisk Tidskrift. - 0039-646X. ; 110:2, s. 80-107
  • Tidskriftsartikel (refereegranskat)
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14.
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15.
  • Swenson, Ulf, 1959-, et al. (författare)
  • Island life - classification and cryptic species of Pycnandra (Sapotaceae) in New Caledonia
  • 2015
  • Ingår i: Botanical journal of the Linnean Society. - 0024-4074 .- 1095-8339. ; 179, s. 57-77
  • Tidskriftsartikel (refereegranskat)abstract
    • Pycnandra (Sapotaceae), the largest endemic genus in New Caledonia, comprises 66 species classified in six subgenera. We tested phylogenetic relationships and a proposed infrageneric classification by sampling 60 species for sequences of nuclear ribosomal DNA (ETS, ITS, RPB2) and plastid DNA (trnH–psbA) and nine morphological characters. Data were analysed with Bayesian inference, parsimony jackknifing and lineage through time. We recovered a phylogenetic tree supporting the recognition of six proposed subgenera (Achradotypus, Leptostylis, Pycnandra, Sebertia, Trouettia and Wagapensia). Because a subgeneric classification is used, the nomenclature will be stable when the members are transferred to Pycnandra. Morphological traits were optimized in the BEAST analysis, adding evidence to earlier work that morphology has limited value for successfully diagnosing groups in Sapotaceae. We confirm a previously suspected case of cryptic species that exhibit the same morphological features and require the same abiotic conditions, but are distantly related in the phylogenetic tree. We detected two possible new cases of cryptic sibling species that might warrant recognition. A slowdown in speciation rate in several genera has been suggested as evidence that New Caledonia was once submerged after rifting from Australia. Plotting lineages through time reveals two important intervals at 7.5–8.6 Ma and present to 1.5 Ma, when net molecular diversification within the genus was zero. This indicates that the genus presently has reached a dynamic equilibrium, providing additional evidence that New Caledonia is an old Darwinian island, being submerged during the Eocene and colonized after re-emergence c. 37 Ma.
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16.
  • Swenson, Ulf, 1959-, et al. (författare)
  • Metapopulation vicariance, age of island taxa and dispersal: A case study using the Pacific plant genus Planchonella (Sapotaceae)
  • 2019
  • Ingår i: Systematic Biology. - Oxford : Oxford University Press. - 1063-5157 .- 1076-836X. ; 68:6, s. 1020-1033
  • Tidskriftsartikel (refereegranskat)abstract
    • Oceanic islands originate fromvolcanism or tectonic activity without connections to continental landmasses, are colonized by organisms, and eventually vanish due to erosion and subsidence. Colonization of oceanic islands occurs through long-distance dispersals (LDDs) or metapopulation vicariance, the latter resulting in lineages being older than the islands they inhabit. If metapopulation vicariance is valid, island ages cannot be reliably used to provide maximum age constraints for molecular dating.We explore the relationships between the ages of members of a widespread plant genus (Planchonella, Sapotaceae) and their host islands across the Pacific to test various assumptions of dispersal and metapopulation vicariance. We sampled three nuclear DNA markers from 156 accessions representing some 100 Sapotaceae taxa, and analyzed these in BEAST with a relaxed clock to estimate divergence times and with a phylogeographic diffusion model to estimate range expansions over time. The phylogeny was calibrated with a secondary point (the root) and fossils from New Zealand. The dated phylogeny reveals that the ages of Planchonella species are, in most cases, consistent with the ages of the islands they inhabit. Planchonella is inferred to have originated in the Sahul Shelf region, to which it back-dispersed multiple times. Fiji has been an important source for range expansion in the Pacific for the past 23 myr. Our analyses reject metapopulation vicariance in all cases tested, including between oceanic islands, evolution of an endemic Fiji–Vanuatu flora, and westward rollback vicariance between Vanuatu and the Loyalty Islands. Repeated dispersal is the only mechanism able to explain the empirical data. The longest (8900 km) identified dispersal is between Palau in the Pacific and the Seychelles in the Indian Ocean, estimated at 2.2 Ma (0.4–4.8 Ma). The first split in a Hawaiian lineage (P. sandwicensis) matches the age of Necker Island (11.0Ma), when its ancestor diverged into two species that are distinguished by purple and yellowfruits. Subsequent establishment across the Hawaiian archipelago supports, in part, progression rule colonization. In summary, we found no explanatory power in metapopulation vicariance and conclude that Planchonella has expanded its range across the Pacific by LDD.We contend that this will be seen in many other groups when analyzed in detail.
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17.
  • Swenson, Ulf, 1959-, et al. (författare)
  • Phylogeny, species delimitation and revision of Pleioluma (Sapotaceae) in New Caledonia, a frequently gynodioecious genus
  • 2018
  • Ingår i: Australian Systematic Botany. - 1030-1887 .- 1446-5701. ; 31, s. 120-165
  • Tidskriftsartikel (refereegranskat)abstract
    • Pleioluma (Baill.) Baehni (Sapotaceae) circumscribes some 40 medium-sized trees and shrubs, many gynodioecious, in Australia, Malesia and New Caledonia. Systematics of the group is unclear and delimitations of species are notoriously difficult. We explore species boundaries in New Caledonia by multiple accessions of ‘species’, molecules and morphology in a Bayesian framework. The molecular phylogenetic signal is weak, but morphology provides enough information to support groups, species and recognition of one cryptic species. Pleioluma is then revised for New Caledonia, a genus distinguished by areolate higher leaf venation, sepals being pubescent on both surfaces, stamens inserted in or below the middle of the corolla tube, presence of staminodes, foliaceous cotyledons and endosperm. Seventeen endemic species are recognised with descriptions, recognition notes, distributions, etymologies and conservation assessments. Six species are described as new, of which four are assigned IUCN preliminary status as Critically Endangered and in urgent need of protection (Pleioluma acutifolia Swenson & Munzinger, P. belepensis Swenson & Munzinger, P. butinii Swenson & Munzinger and P. tchingouensis Swenson & Munzinger). The new species, P. dioica Swenson & Munzinger and P. tenuipedicellata Swenson & Munzinger are respectively assessed as Data Deficient and Vulnerable. The micro-endemic species P. vieillardii (Baill.) Swenson & Munzinger, confined to the Koniambo massif, is also critically endangered and needs urgent conservation management. 
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18.
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19.
  • Terra-Araujo, Mário H., et al. (författare)
  • A taxonomic update of Neotropical Pradosia (Sapotaceae, Chrysophylloideae)
  • 2016
  • Ingår i: Systematic Botany. - 0363-6445 .- 1548-2324. ; 41, s. 634-650
  • Tidskriftsartikel (refereegranskat)abstract
    • We provide a systematic update of Pradosia (Sapotaceae, Chrysophylloideae), including overall morphology, a key to all species, comprehensive morphological descriptions, geographic distributions, and important characteristics for each species. Phyloge- netic analyses based on molecular data demonstrated that the genus is monophyletic and includes three main clades. Twenty-three species of Pradosia are accepted, which are mostly distributed in lowland rainforests on either white-sand or clayish soils in tropical South America. A rotate corolla with a short tube, lack of staminodes, a drupaceous fruit with plano-convex cotyledons, an exserted radicle below the cotyledons, and the absence of endosperm are diagnostic for the genus. Two names are reduced into synonymy, viz. Pradosia atroviolacea Ducke, syn. of P. grisebachii (Pierre) T. D. Penn., and Pradosia verrucosa Ducke, syn. of P. glaziovii (Pierre) T. D. Penn. The affinity of P. argentea (Kunth) T. D. Penn., a species known only from the type collection, remains uncertain and for now excluded from the genus.
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20.
  • Terra-Araujo, Mario, et al. (författare)
  • Species tree phylogeny and biogeography of the Neotropical genus Pradosia (Sapotaceae, Chrysophylloideae).
  • 2015
  • Ingår i: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903 .- 1095-9513. ; 87, s. 1-13
  • Tidskriftsartikel (refereegranskat)abstract
    • Recent phylogenetic studies in Sapotaceae have demonstrated that many genera need to be redefined to better correspond to natural groups. The Neotropical genus Pradosia is believed to be monophyletic and includes 26 recognized species. Here we reconstruct the generic phylogeny by a species-tree approach using ∗BEAST, 21 recognized species (36 accessions), sequence data from three nuclear markers (ITS, ETS, and RPB2), a relaxed lognormal clock model, and a fossil calibration. We explore the evolution of five selected morphological characters, reconstruct the evolution of habitat (white-sand vs. clayish soils) preference, as well as space and time by using a recently developed continuous diffusion model in biogeography. We find Pradosia to be monophyletic in its current circumscription and to have originated in the Amazon basin at ∼ 47.5 Ma. Selected morphological characters are useful to readily distinguish three clades. Preferences to white-sand and/or clay are somewhat important for the majority of species, but speciation has not been powered by habitat shifts. Pradosia brevipes is a relative young species (∼ 1.3 Ma) that has evolved a unique geoxylic life strategy within Pradosia and is restricted to savannahs. Molecular dating and phylogenetic pattern indicate that Pradosia reached the Brazilian Atlantic coast at least three times: at 34.4 Ma (P. longipedicellata), at 11.7 Ma (P. kuhlmannii), and at 3.9 Ma (weakly supported node within the red-flowered clade).
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21.
  • Zhao, Wan-Yi, et al. (författare)
  • Rehderodendron truongsonense (Styracaceae), a new species from Vietnam
  • 2019
  • Ingår i: Journal of the Botanical Research Institute of Texas. - 1934-5259. ; 13:1, s. 157-171
  • Tidskriftsartikel (refereegranskat)abstract
    • Rehderodendron truongsonense, a new species from Vietnam, is described and illustrated. In the treatment of the Styracaceae for the Flore du Cambodge, du Laos, et du Viêtnam, specimens of this species were recognized as R. macrocarpum Hu. These specimens clearly differ from R. macrocarpum, however, as well as from all other species of Rehderodendron (where these characters are known) by, e.g., an evergreen ver- sus deciduous habit, fewer secondary veins of the leaf blade, shorter inflorescences and corolla lobes, large and conspicuous lowermost bracteoles, the presence of eight ovules per carpel, and a fruit with ca. 10 to 20 ribs that are indistinct. Phylogenetic analysis based on five chloroplast DNA regions (clpP-psbB, ndhD-psaC-ndhE-ndhG, rpl22-rps19, rps18-rpl20, and psbI-trnS-GCU) placed the new species as nested within Rehderodendron and sister to R. gongshanense. This new species is endemic to the Truong Son Mountain Range, from which the epi- thet is derived, and we assign it an IUCN Red List preliminary status as Near Threatened. 
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