Plant dispersal syndromes are unreliable, especially for predicting zoochory and long‐distance dispersal

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.

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Are long-distance dispersal syndromes associated with the conservation status of plant species? The Canary Islands as a case study

Mediterranean Botany ◽

10.5209/mbot.60071 ◽

2018 ◽

Vol 39 (2) ◽

Cited By ~ 1

Author(s):

Alberto J. Coello ◽

María Leo ◽

Yurena Arjona ◽

Pablo Vargas

Keyword(s):

Plant Species ◽

Canary Islands ◽

Conservation Status ◽

Long Distance Dispersal ◽

Long Distance ◽

Dispersal Syndromes

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

Bulletin of the Torrey Botanical Club ◽

10.2307/2484044 ◽

1967 ◽

Vol 94 (3) ◽

pp. 129 ◽

Cited By ~ 120

Author(s):

Sherwin Carlquist

Keyword(s):

Pacific Islands ◽

Long Distance Dispersal ◽

Long Distance ◽

Plant Dispersal

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The diversification of Pterocarpus (Leguminosae: Papilionoideae) was influenced by biome-switching and infrequent long-distance dispersal

10.1101/2021.05.14.444160 ◽

2021 ◽

Author(s):

Rowan J Schley ◽

Qin Ming ◽

Mohammad Vatanparast ◽

Panagotia Malakasi ◽

Manuel de la Estrella ◽

...

Keyword(s):

Dry Forest ◽

Distribution Data ◽

Arid Environments ◽

Long Distance Dispersal ◽

Sequencing Data ◽

Long Distance ◽

Dispersal Syndromes ◽

Moist Forest ◽

Spatio Temporal ◽

Fruit Dispersal

Aim: Phenotypes which evolved for dispersal over ecological timescales may lead to significant macroevolutionary consequences, such as infrequent long-distance dispersal and diversification in novel environments. We aimed to reconstruct the phylogenetic history of Pterocarpus (Leguminosae/ Fabaceae) to assess whether seed dispersal phenotypes help to explain the current biogeographical patterns of this group. Location: Pantropical. Taxon: The Pterocarpus clade, particularly Pterocarpus (Leguminosae/Fabaceae). Methods: We sequenced ~300 nuclear loci captured using Angiosperms-353, a genomic 'bait set' for flowering plants, from which we generated a time-calibrated phylogenomic tree. To corroborate this, we also generated a time-calibrated phylogenetic tree from data-mined Sanger-sequencing data. We then collated distribution data and fruit dispersal morphology traits to compare trait-dependent and trait-independent biogeographical models, allowing us to assess whether dispersal traits influenced the spatio-temporal evolution of Pterocarpus. Finally, using the results of these model tests, we estimated the ancestral ranges and biomes of Pterocarpus species to better understand their biogeographical history. Results: We recovered well-supported phylogenetic relationships within Pterocarpus, within which there were two subclades - one Neotropical and the other Palaeotropical. Our divergence date estimates suggested that Pterocarpus largely diversified from around 12 Ma, during the Miocene. Trait-dependent biogeographical models were rejected for both range and biome evolution within Pterocarpus, but models parameterising dispersal were supported. Pterocarpus largely diversified in the Neotropics, followed by dispersal and diversification into Africa and Asia, with later dispersal into Australasia/Oceania. The neotropical subclade of Pterocarpus underwent multiple biome switches between moist forest and dry forest, while in palaeotropical Pterocarpus we reconstructed multiple switches between moist forest and grassland. Main conclusions: Overall, our analyses suggest that Pterocarpus underwent infrequent cross-continental dispersal and adaptation to novel biomes. While this was minimally impacted by fruit dispersal syndromes, shifts between moist and arid environments precipitated by long-distance dispersal and environmental change have played an important role in diversification within Pterocarpus since the Miocene.

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Seed dispersal

The Biology of Coastal Sand Dunes ◽

10.1093/oso/9780198570356.003.0008 ◽

2009 ◽

Author(s):

M. Anwar Maun

Keyword(s):

Point Of View ◽

Clear Correlation ◽

Long Distance ◽

Plant Dispersal ◽

Sand Surface ◽

Dispersal Syndromes ◽

Dispersal Agent ◽

Cakile Maritima ◽

Whole Plants ◽

Evolutionary Point

Dispersal is a term used for the dissemination of detached reproductive structures from parent plants to a new site. Disseminules include spores, seeds, fruits, whole inflorescences, whole plants, fragments of the parent plant, bulbs and bulbils. Fruit attributes related to a particular dispersal agent or dispersal syndromes are complex and have resulted from millions of years of evolution. In practice, dispersal is mainly local, although some species of sea coasts are well adapted for long-distance dispersal. Knowledge of the modes of plant dispersal is vital to the study of coastal dune ecology because of the clear correlation between diversity and dispersal mechanisms. From the evolutionary point of view, dispersal improves fitness of species: the progeny is able to colonize a new site and extend the range of the species. The fitness here will be defined as getting to a coastal site by using any vector for dispersal, colonization of the new site (germination, establishment and reproduction) and dispersal of the propagules of the immigrant from the new site. Dispersal confers many benefits to the populations of plant species. It reduces competition for limited space and resources in the parental location and the more widely dispersed the propagules, the greater are the chances for the offspring to colonize elsewhere. Dispersal increases the chances of survival and evolution of more fit strains of a species by occupying more diverse habitats than the parents, and speciation may eventually occur in response to new selective pressures. For species adapted to live along sea coasts, dispersal by sea is primarily directed for dissemination to another site by the sea coast. During dispersal several physiological changes may occur in the disseminules that facilitate colonization of the species at the new habitat. For example, Barbour (1972) reported that immersion of upper fruits of Cakile maritima in seawater stimulated their subsequent germination under controlled conditions. Seed coat dormancy may also be broken by abrasion of seeds in sand while being rolled along the sand surface. Considering the large number of species along coasts and on islands, only a very few species may be successfully disseminated in seawater.

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

10.1101/2020.11.18.388322 ◽

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.

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