The Biota of Long-Distance Dispersal. V. Plant Dispersal to Pacific Islands

1967 ◽  
Vol 94 (3) ◽  
pp. 129 ◽  
Author(s):  
Sherwin Carlquist
Keyword(s):  
Pacific Islands ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Plant Dispersal

Buoyancy, salt tolerance and germination of coastal seeds: implications for oceanic hydrochorous dispersal

2010 ◽  
Vol 37 (12) ◽  
pp. 1175 ◽  
Author(s):  
Lydia K. Guja ◽  
David J. Merritt ◽  
Kingsley W. Dixon
Keyword(s):  
Salt Tolerance ◽  
Saline Water ◽  
Long Distance Dispersal ◽  
Single Factor ◽  
Long Distance ◽  
Plant Dispersal ◽  
Salt Response ◽  
Coastal Plant ◽  
Dispersal Unit ◽  
Adverse Environmental Conditions

Many coastal plant species are widely distributed, including several pan-global species. Long-distance dispersal and physiological resilience of diaspores (i.e. the plant dispersal unit encompassing the seed and any additional surrounding or attached tissues at dispersal) to adverse environmental conditions are possible contributors to the presence of species over hundreds of kilometres of coastline. Dispersal by water (hydrochory) may occur in coastal habitats. This study investigated diaspore traits considered important for oceanic hydrochorous dispersal, including morphology, buoyancy and survival in seawater, and germination under saline conditions for 13 species common to Holocene dune communities in Western Australia. Of the diaspores of 13 species dominant in this coastal community, 11 floated in seawater, with 7 having >50% of diaspores buoyant after 14 days and some diaspores remaining buoyant for 70 days. Of the 10 species that germinated, diaspores of 9 survived exposure to seawater for up to 70 days. Germination of physiologically dormant seeds contained within indehiscent woody fruits and physically dormant seeds was least affected by time in seawater. The effects of varying concentrations of NaCl (0–500 mM) on germination differed between species, but most were able to recover and germinate when transferred to non-saline water. Three different patterns of salt response were observed. It appears likely a combination of diaspore traits, rather than a single factor, facilitate oceanic hydrochorous dispersal.

Chapter 8 Palaeobiogeography of New Caledonia

2020 ◽  
Vol 51 (1) ◽  
pp. 189-213 ◽  
Author(s):  
P. Maurizot ◽  
H. J. Campbell
Keyword(s):  
Fossil Record ◽  
Pacific Islands ◽  
New Caledonia ◽  
Biodiversity Hotspot ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Main Island ◽  
Geological Record ◽  
Terrestrial Environments ◽  
Global Biodiversity

AbstractNew Caledonia is known as a global biodiversity hotspot. Like most Pacific islands, its modern biota is characterized by high levels of endemism and is notably lacking in some functional groups of biota. This is the result of its distinctive palaeobiogeographical history, which can be described in terms of three major episodes relating to Gondwana, Zealandia and New Caledonia. The geological record, the fossil record and the modern biota of the archipelago are all reviewed here. The geological record shows that the main island, Grande Terre, was submerged between 75 and 60 Ma. There is a 9 myr interval without any geological record between 34 and 25 Ma, immediately after the obduction of the Peridotite Nappe. Grande Terre may or may not have been submerged during this 9 myr interval. The ages given by molecular biology, independent of any geological calibration points, form a continuous spectrum from 60 Ma up to the present day. The derived lineage ages from molecular phylogenies all post-date 60 Ma, supporting the idea of the continuous availability of terrestrial environments since 60 Ma. Of the three common scenarios for the origin of the New Caledonia biota, long-distance dispersal is the most plausible, rather than vicariance or dispersal over short distances.

scholarly journals Spatial structure of natural boxwood and the invasive box tree moth can promote coexistence

2020 ◽  
Author(s):  
Léo Ledru ◽  
Jimmy Garnier ◽  
Christiane Gallet ◽  
Camille Noûs ◽  
Sébastien Ibanez
Keyword(s):  
Spatial Structure ◽  
Spatial Dynamics ◽  
Field Measurements ◽  
Global Scale ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Moth Population ◽  
Plant Dispersal ◽  
Local Plant ◽  
Parameter Values

AbstractIn the absence of top-down and bottom-up controls, herbivores eventually exhaust their host plants driving them-selves to extinction. Poorly mobile herbivores may nevertheless go extinct only locally; then recolonize intact plant patches elsewhere, leaving time to previously over-exploited patches to regrow. However most herbivores such as winged insects are highly mobile, which may prevent the formation of spatial heterogeneity.We test if long-distance dispersal can preclude coexistence using the invasion of box tree moth (Cydalima perspectalis) in Europe as a model system. We build a lattice model and estimate the parameters with a combination of field measurements, experimental data and literature sources. Space corresponds either to a realistic boxwood landscape in the Alps, or to theoretical landscapes of various sizes.We find that both species persist under a large range of realistic parameter values, despite a severe reduction in boxwood biomass, with an alternation of outbreaks and near-to-extinction moth densities. Large landscapes are necessary for coexistence, allowing the formation of spatial structure. Low plant regrowth combined with long-distance dispersal could drive moths to extinction, because of resources depletion at the global scale even without a complete synchronization of the local dynamics. The spatial dynamics leads to formation of small plant patches evenly distributed in the landscape, because of a combination of local plant dispersal and global indirect competition between plants through their positive effect on moth population size. Coexistence is favored by such heterogeneous landscapes, because empty patches increase moth mortality during dispersal: the system thus creates its own stability conditions.

Systematics, Biogeography, and Morphological Character Evolution of the Hemiepiphytic Subfamily Monsteroideae (Araceae)

2019 ◽  
Vol 104 (1) ◽  
pp. 33-48 ◽  
Author(s):  
Alejandro Zuluaga ◽  
Martin Llano ◽  
Ken Cameron
Keyword(s):  
Dna Sequences ◽  
Pacific Islands ◽  
R Package ◽  
Morphological Characters ◽  
Ancestral State ◽  
Seed Shape ◽  
Long Distance ◽  
The Pacific ◽  
And Migration ◽  
The Tropics

The subfamily Monsteroideae (Araceae) is the third richest clade in the family, with ca. 369 described species and ca. 700 estimated. It comprises mostly hemiepiphytic or epiphytic plants restricted to the tropics, with three intercontinental disjunctions. Using a dataset representing all 12 genera in Monsteroideae (126 taxa), and five plastid and two nuclear markers, we studied the systematics and historical biogeography of the group. We found high support for the monophyly of the three major clades (Spathiphylleae sister to Heteropsis Kunth and Rhaphidophora Hassk. clades), and for six of the genera within Monsteroideae. However, we found low rates of variation in the DNA sequences used and a lack of molecular markers suitable for species-level phylogenies in the group. We also performed ancestral state reconstruction of some morphological characters traditionally used for genera delimitation. Only seed shape and size, number of seeds, number of locules, and presence of endosperm showed utility in the classification of genera in Monsteroideae. We estimated ancestral ranges using a dispersal-extinction-cladogenesis model as implemented in the R package BioGeoBEARS and found evidence for a Gondwanan origin of the clade. One tropical disjunction (Monstera Adans. sister to Amydrium Schott–Epipremnum Schott) was found to be the product of a previous Boreotropical distribution. Two other disjunctions are more recent and likely due to long-distance dispersal: Spathiphyllum Schott (with Holochlamys Engl. nested within) represents a dispersal from South America to the Pacific Islands in Southeast Asia, and Rhaphidophora represents a dispersal from Asia to Africa. Future studies based on stronger phylogenetic reconstructions and complete morphological datasets are needed to explore the details of speciation and migration within and among areas in Asia.

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