scholarly journals An investigation of long-distance dispersal based on species native to both Tasmania and New Zealand

2001 ◽  
Vol 49 (3) ◽  
pp. 333 ◽  
Author(s):  
Gregory J. Jordan

Some 200 species of plants are currently recognised as being native to both Tasmania and New Zealand. It is argued that dispersal across the 1500–2000-km Tasman Sea has occurred in all of these species. Almost all (187) are herbs and constitute over 20% of the herbaceous flora of Tasmania. Common species, non-dioecious species, species with very small seeds, species from aquatic, coastal or wet habitats and possibly species with hooked fruit are all over-represented among the disjunct species of herbs. The incidence of disjunct species also varies significantly among families. In contrast, fleshy fruited species, or species with plumes or very hairy disseminules, are not over-represented among the herbaceous disjunct species. These data are used to model the probability that a species (past or present) with given traits would show a within-species trans-Tasman disjunction, and it is inferred that this can be used to give a crude approximation of the rates of long-distance dispersal for different types of species. The model can be tested by using molecular clock methods and could be made more robust by incorporating equivalent data from other disjunct regions.

2006 ◽  
Vol 84 (8) ◽  
pp. 1266-1281 ◽  
Author(s):  
Gabriel Bernardello ◽  
Gregory J. Anderson ◽  
Tod F. Stuessy ◽  
Daniel J. Crawford

We review the hypothesized origin and the methods of arrival of the angiosperm colonists to the Juan Fernandez Islands. We also summarize the dispersal capabilities of the current flora, including data on fruit type, fruit length, and dispersal unit length, correlating these features with dispersal and establishment. Most species originated from South America, followed by Pantropical, Australian, New Zealand, and Pacific colonizers. Sea and land birds were the most important initial long-distance dispersal agents. Most colonizing species are hermaphroditic flowered, and thus all dispersal methods are represented among them. Monoecious, andromonoecious and gynomonoecious, dioecious, and polygamous species were mainly carried by birds. Most wind- and bird-pollinated colonizing genera arrived with birds as did most annual herbs and species with bright-colored flowers. In the current flora, the majority of the species have dry fruits. In monoecious, andromonoecious and gynomonoecious, and dioecious species, achenes predominate. Fleshy fruits are limited to perennials. Most species have medium to small dispersal units, and generally, the larger the flower, the larger the fruit. Large- and medium-sized dispersal units are common in shrubs and trees. Abiotic dispersal is common in the current flora, which may reflect the ancestral dispersal capability of the colonizers, or adaptation to the absence of a fauna to disperse seeds and fruits. Anemochorous and autochorous species are mainly perennial and have medium to large, unisexual flowers. Anemochorous species have small dispersal units and dull-colored flowers, whereas large dispersal units and brightly colored flowers are frequent in autochorous species. Medium-sized dispersal units are represented in autochorous or ornithochorous species. The establishment and evolution of this flora was previously discussed to have occurred with very few pollination and (or) reproductive options. This study suggests that elements associated with dispersal are also analogously limited.


Author(s):  
E. Punithalingam

Abstract A description is provided for Scirrhia pini[Mycosphaerella pini]. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On pines including Pinus radiata and its hybrids, P. halepensis, P. canariensis, P. carbaea, P. ponderosa, P. nigra and others, Pseudotsuga menziesii (46, 2860), Larix decidua (49, 273). DISEASE: Dothistroma blight; red band. GEOGRAPHICAL DISTRIBUTION: North America (Canada, USA including Alaska), South America (Argentina, Brazil, Chile, Uruguay), Australasia and Oceania (New Zealand), Asia (Brunei, India, Japan), Africa (Ethiopia, Kenya, Malawi, Rhodesia, Swaziland, Tanzania, Uganda), Europe (Austria, France, Rumania, UK, USSR (Republic of Georgia), Yugoslavia) (CMI Map 419, ed. 2, 1970; record in CMI Herbarium). TRANSMISSION: By airborne conidia released and dispersed by a splash take-off mechanism for short distances. Long distance dispersal may be by transport of infected material, such as nursery stock and, under special conditions, clouds may carry sporal inoculum (43, 2100). Survival time of inoculum in the form of cast, infected foliage on the forest floor is limited to 2-6 months under moist conditions (50, 2003).


2017 ◽  
Vol 4 (7) ◽  
pp. 170147 ◽  
Author(s):  
E. M. Biersma ◽  
J. A. Jackson ◽  
J. Hyvönen ◽  
S. Koskinen ◽  
K. Linse ◽  
...  

A bipolar disjunction is an extreme, yet common, biogeographic pattern in non-vascular plants, yet its underlying mechanisms (vicariance or long-distance dispersal), origin and timing remain poorly understood. Here, combining a large-scale population dataset and multiple dating analyses, we examine the biogeography of four bipolar Polytrichales mosses, common to the Holarctic (temperate and polar Northern Hemisphere regions) and the Antarctic region (Antarctic, sub-Antarctic, southern South America) and other Southern Hemisphere (SH) regions. Our data reveal contrasting patterns, for three species were of Holarctic origin, with subsequent dispersal to the SH, while one, currently a particularly common species in the Holarctic ( Polytrichum juniperinum ), diversified in the Antarctic region and from here colonized both the Holarctic and other SH regions. Our findings suggest long-distance dispersal as the driver of bipolar disjunctions. We find such inter-hemispheric dispersals are rare, occurring on multi-million-year timescales. High-altitude tropical populations did not act as trans-equatorial ‘stepping-stones’, but rather were derived from later dispersal events. All arrivals to the Antarctic region occurred well before the Last Glacial Maximum and previous glaciations, suggesting that, despite the harsh climate during these past glacial maxima, plants have had a much longer presence in this southern region than previously thought.


2012 ◽  
Vol 44 (2) ◽  
pp. 189-246 ◽  
Author(s):  
Gintaras KANTVILAS

AbstractWith 30 species, Tasmania is a major area of species diversity in the genus Menegazzia. Seven of these are new to science: M. abscondita Kantvilas, known from Tasmania and New Zealand, and M. athrotaxidis Kantvilas, M. hypogymnioides Kantvilas, M. petraea Kantvilas, M. ramulicola Kantvilas, M. subtestacea Kantvilas and M. tarkinea Kantvilas, all endemic to Tasmania. An identification key, descriptions based exclusively on Tasmanian collections, and detailed discussion of distribution, ecology, chemical composition and inter-species relationships are provided. All literature records of Menegazzia species pertaining to Tasmania are accounted for. New synonyms include: Menegazzia prototypica P. James and Parmelia pertusa var. coskinodes F. Wilson [synonyms of M. myriotrema (Müll. Arg.) R. Sant.], M. fertilis P. James [a synonym of M. platytrema (Müll. Arg.) R. Sant.] and Parmelia pertusa var. montana F. Wilson (a synonym of M. subtestacea). Incorrectly recorded species that should be deleted from the Tasmanian census include M. castanea P. James & D. J. Galloway (present on Macquarie Island) and M. testacea P. James & D. J. Galloway (endemic to New Zealand). The South American species, M. sanguinascens (Räs.) R. Sant., is recorded in Australasia (Tasmania) for the first time, whereas the widespread south-eastern Australian M. norstictica P. James is recorded for Western Australia. Salient features of the genus are discussed, including morphology, anatomy and chemistry. The biogeography of the genus is explored briefly. Twelve species (40%) are endemic to Tasmania, a level of endemism unmatched by any other species-rich genus on the island. Twelve species are shared with mainland Australia, eleven are shared with New Zealand, and only four species are shared with southern South America, all of which are sorediate, suggesting they are products of long-distance dispersal.


2013 ◽  
Author(s):  
Geoffrey Zahn ◽  
Stephen L. Stevenson ◽  
Frederick W. Spiegel

During the period of March 2004 to December 2007, samples of aerial litter (dead but still attached plant parts) and ground litter were collected from study sites representing a wide range of latitudes (34° S to 50° S) and a variety of different types of habitats throughout New Zealand (including Stewart Island and the Auckland Islands). The objective was to survey the assemblages of protosteloid amoebae present in this region of the world. Twenty-nine described species of protosteloid amoebae were recorded, along with the heterolobesean acrasid, Acrasis rosea. Of the species recovered, Protostelium mycophaga was by far the most abundant and was found in more than half of all samples. Most species were found in fewer than 10% of the samples collected. Seven abundant or common species were found to display significant preferences for aerial litter or ground litter microhabitats. There was some evidence of a general pattern of a decrease in species richness and diversity with increasing latitude and precipitation and elevation.


Zootaxa ◽  
2010 ◽  
Vol 2650 (1) ◽  
pp. 1
Author(s):  
MATTHEW J. COLLOFF

Three new species of oribatid mite belonging to the genus Crotonia are described: one from Lord Howe Island (C. gorgonia sp. nov.) and two (C. norfolkensis sp. nov. and C. utricularia sp. nov.) from Norfolk Island, South-west Pacific. Crotonia gorgonia sp. nov. belongs to the Capistrata species group which reaches its highest diversity in Australia but is absent from New Zealand. Crotonia norfolkensis sp. nov. is a member of the Cophinaria group, recorded from Australia, New Zealand and New Caledonia, but with closest morphological similarity to C. brachyrostrum (Hammer, 1966) from New Zealand. Crotonia utricularia sp. nov. belongs to the Unguifera group, which reaches its highest diversity in New Zealand, is absent from Australia, and is present on Vanuatu and the Marquesas. The distribution of members of the species-groups of Crotonia in the south-western Pacific indicates that the species from Lord Howe Island has affinities with species from Australia, while the species from Norfolk Island are both most similar to species from New Zealand, and represents further evidence of the capacity of Crotonia spp. for long-distance dispersal to oceanic islands.


2002 ◽  
Vol 50 (1) ◽  
pp. 127 ◽  
Author(s):  
Kitty Vijverberg ◽  
Louis Lie ◽  
Konrad Bachmann

The Australian and New Zealand Microseris is supposed to have evolved from one or a few diaspores after a unique event of long-distance dispersal from western North America. At present, the plant group includes two species, M. lanceolata (Walp.) Sch.-Bip. and M. scapigera (Forst.) Sch.-Bip., each with two morphologically and ecologically divergent ecotypes. In spite of this classification, the morphological variation within and among ecotypes is not entirely consistent, and molecular investigations show evidence for the, possibly recent, occurrence of hybridisations between plants of different ecotypes. The present study investigates the overall morphological similarities among 1–4 plants of each of 54 Australian and New Zealand Microseris populations. The aim of the study was to gain further insights into the delimitation of species and ecotypes, the placement of populations that could thus far not be assigned to an ecotype and the adaptive radiation of the plant group. The results confirm the previously defined ecotypes and assign all but two of the questionable populations to ecotypes. They show that a broad range of character states rather than a few 'diagnostic' ones are specific for the ecotypes. The data confirm our earlier conclusion from molecular results, indicating that ecotype characteristics are maintained or reestablished by selection or adaptation, after dispersal or hybridisation between ecotypes. Despite (incidental) genetic exchange among populations of different ecotypes, the process of adaptive radiation is progressing. The combined morphological and molecular results are not incongruent with the present species delimitation. However, they also may support the split up of M. scapigera into two species and other phylogenetic solutions.


1995 ◽  
Vol 73 (S1) ◽  
pp. 731-737 ◽  
Author(s):  
Robert W. Lichtwardt

Almost all mycogeographic studies to date have dealt with fungi that are directly or indirectly associated with plants; very few have been concerned with fungal associates of insects or other animals. Some widespread species of Trichomycetes (Zygomycota), all of which live in arthropod guts, are useful subjects for biogeographic studies, and such an approach can be used in some instances to distinguish between long-distance dispersal and vicariance events. Evidence for the presumed antiquity of certain trichomycete species is provided using specific examples of Eccrinales and Asellariales in marine Isopoda, and Harpellales in lotic larvae of Chironomidae and Plecoptera. These examples indicate that speciation of the fungi is more conservative than that of their hosts. Thirty-two isolates of Smittium culisetae cultured from different continents and from several families of dipteran hosts had almost no variation in their isozyme patterns, which suggests a degree of evolutionary stasis in that species. Historical mycogeography, though it requires some basic knowledge of the taxonomy of fungal groups, adds a spacial component to phylogenetic systematics as well as a more realistic time scale than phylogeny alone can provide. Mycogeography can also be used to reassess and develop new phylogenies for some fungal species. Key words: biogeography, fungi, Harpellales, insects, isopods, Trichomycetes.


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