| 1. |
- Gâteblé, Gildas, et al.
(författare)
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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
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Ingår i: Australian Systematic Botany. - 1030-1887 .- 1446-5701. ; 31, s. 448-480
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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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| 2. |
- Munzinger, Jérôme, et al.
(författare)
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Pycnandra longiflora (Sapotaceae) a species believed to be extinct, rediscovered in New Caledonia
- 2016
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Ingår i: Phytotaxa. - : Magnolia Press. - 1179-3155 .- 1179-3163. ; 278:2, s. 176-180
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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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| 3. |
- Munzinger, Jérôme, et al.
(författare)
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Revision of Pycnandra subgenus Leptostylis and description of subgenus Wagapensia (Sapotaceae), a genus endemic to New Caledonia
- 2015
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Ingår i: Australian Systematic Botany. - 1030-1887 .- 1446-5701. ; 28, s. 91-110
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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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| 4. |
- Swenson, Ulf, 1959-, et al.
(författare)
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Five new species and a systematic synopsis of Pycnandra (Sapotaceae), the largest endemic genus in New Caledonia
- 2016
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Ingår i: Australian Systematic Botany. - 1030-1887 .- 1446-5701. ; 29, s. 1-40
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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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| 5. |
- Swenson, Ulf, 1959-, et al.
(författare)
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Island life - classification and cryptic species of Pycnandra (Sapotaceae) in New Caledonia
- 2015
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Ingår i: Botanical journal of the Linnean Society. - 0024-4074 .- 1095-8339. ; 179, s. 57-77
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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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| 6. |
- Swenson, Ulf, 1959-, et al.
(författare)
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Metapopulation vicariance, age of island taxa and dispersal: A case study using the Pacific plant genus Planchonella (Sapotaceae)
- 2019
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Ingår i: Systematic Biology. - Oxford : Oxford University Press. - 1063-5157 .- 1076-836X. ; 68:6, s. 1020-1033
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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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| 7. |
- Swenson, Ulf, 1959-, et al.
(författare)
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Phylogeny, species delimitation and revision of Pleioluma (Sapotaceae) in New Caledonia, a frequently gynodioecious genus
- 2018
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Ingår i: Australian Systematic Botany. - 1030-1887 .- 1446-5701. ; 31, s. 120-165
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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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| 8. |
- Swenson, Ulf, 1959-, et al.
(författare)
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Sapotaceae biogeography supports New Caledonia being an old Darwinian island
- 2014
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Ingår i: Journal of Biogeography. - : Wiley. - 0305-0270 .- 1365-2699. ; 41, s. 797-809
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Tidskriftsartikel (refereegranskat)abstract
- Aim Panbiogeographers suggest that the biome in New Caledonia is of vicariant origin, dating from the Cretaceous – rather than being the result of repeated dispersal since c. 37 Ma, when the area is postulated to have re-emerged after c. 15 Ma of submergence. Distributions of the plant family Sapotaceae were used as a model system to test this, and to elucidate the probabilities of ancestral areas, all phrased in six hypotheses.Location Australasia and the Pacific.Methods We used a recently published dataset with extensive sampling (168 terminals) from the subfamily Chrysophylloideae and three nuclear ribosomal DNA markers. Phylogenetic divergence times and ancestral areas were estimated in a Bayesian framework using beast, a relaxed clock method, and with fossil calibration points. Area transition probabilities were modelled using a reversible rate matrix, assigning equal prior probability to each transition between two areas.Results Our analyses suggest that Sapotaceae arrived and diversified in New Caledonia nine times during the period 4.2–33.1 Ma. All crown-node radiations occurred in the Miocene or Pliocene, with stem splits reaching back into the Oligocene. Australia and New Guinea are the most likely source areas for Sapotaceae in New Caledonia, but this archipelago has never acted as a stepping stone for Sapotaceae to disperse into the Pacific.Main conclusions Repeated dispersal is the only mechanism able to explain the range expansion of Sapotaceae into New Caledonia. The family has successfully colonized the main island nine times since its re-emergence in the Eocene. We reject the panbiogeographical hypotheses that representatives of Sapotaceae in New Caledonia originated in the Cretaceous, differentiated due to vicariance, and were of Pacific origin. We therefore argue that New Caledonia is an old Darwinian island. The Pacific has been colonized repeatedly and terminal lineages are never older than the islands they inhabit (except for Hawaii). Chrysophylloideae extended across Wallace’s Line into Southeast Asia around 20 Ma, when the Australian continent came into juxtaposition with Eurasia.
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| 9. |
- Swenson, Ulf, 1959-, et al.
(författare)
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The largest endemic genus in New Caledonia grows: Three new species of Pycnandra (Sapotaceae) restricted to ultramafic substrate with updated subgeneric keys
- 2021
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Ingår i: Australian Systematic Botany. - 1030-1887 .- 1446-5701. ; 34, s. 510-525
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Tidskriftsartikel (refereegranskat)abstract
- Pycnandra Benth., a member of subfamily Chrysophylloideae (Sapotaceae), is the largest endemic genus in New Caledonia and is subdivided into six subgenera. It circumscribes 59 species, plus an additional three described here, and nine additional species that remain undescribed for various reasons. We here use nrDNA data of ETS, ITS, and RPB2, analyse it within a Bayesian framework using BEAST, and place the new species in their respective subgenera. Pycnandra perplexaSwenson & Gâteblé is placed in subgenus Achradotypus and given a preliminary IUCN Red List assessment of Near Threatened (NT). It is confined to the ultramafic massif of southern Grande Terre and separated from the similar species P. griseosepala Vink, which is confined to non-ultramafic mountains north of the large southern ultramafic plateau. Pycnandra kopetoensis Munzinger & Swenson and P. margueriteae Munzinger & Swenson are two new micro-endemic species known only from their type localities, where habitats have been destroyed by deforestation, deliberate fires and mining activities. Pycnandra kopetoensis is named after Mount Kopéto, placed in subgenus Leptostylis, and given a preliminary assessment as Critically Endangered (CR). Pycnandra margueriteae is from a small remnant forest near Bourail and categorised as Critically Endangered (CR). Revised identification keys for subgenus Achradotypus, Leptostylis and Pycnandra are provided.
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| 10. |
- Swenson, Ulf, 1959-, et al.
(författare)
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Towards a natural classification of Sapotaceae subfamily Chrysophylloideae in Oceania and Southeast Asia based on nuclear sequence data
- 2013
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Ingår i: Taxon. - : Wiley. - 0040-0262 .- 1996-8175. ; 63, s. 746-770
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Tidskriftsartikel (refereegranskat)abstract
- Generic limits within subfamily Chrysophylloideae (Sapotaceae) from Oceania and Southeast Asia are reconciled based on a molecular phylogeny. We analysed sequences of nuclear ribosomal DNA (ETS, ITS) and the nuclear gene RPB2 with BEAST and parsimony jackknifing, using a sample of 168 terminals. Eight morphological characters were traced on a condensed majority-rule consensus tree to identify diagnostic character combinations for the genera. Accepted genera with character support are Magodendron, Pichonia, Planchonella, Pycnandra, Sersalisia, and Van-royena, while Beccariella and Niemeyera require amendment. Beccariella, a widely distributed group, is an illegitimate later homonym and we propose that the genus Pleioluma is resurrected in its place. The Australian genus Niemeyera is paraphyletic, but it is rendered monophyletic by reinstating Amorphospermum for N. antiloga. Beauvisagea, Blabeia, Fontbrunea, and Krausella are all segregates of Planchonella and rejected, while Wokoia is a later synonym of Pichonia. Planchonella baillonii, an endemic species of New Caledonia, is the sole member of an old lineage and firmly placed as the sister to a clade comprising the other congeners. Planchonella sandwicensis, a Hawaiian species, previously proposed to be a distinct genus, is a member of Planchonella. In the Pacific, P. tahitensis (including P. grayana) is a polymorphic species, widely distributed and adapted to a wide range of habitats. We provide a generic key (excluding Xantolis), diagnostic character combinations for all genera, and the necessary taxonomic combinations for Pichonia, Planchonella, Pleioluma, and Sersalisia to render each genus monophyletic.
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