scholarly journals The impacts of historical barriers on floristic patterns of plant groups with different dispersal abilities in the Ryukyu Archipelago, Japan

2014 ◽  
Author(s):  
Koh Nakamura ◽  
Rempei Suwa ◽  
Tetsuo Denda ◽  
Masatsugu Yokota
Keyword(s):  
Geographic Distance ◽  
Randomization Test ◽  
Dispersal Ability ◽  
Data Sets ◽  
Ryukyu Archipelago ◽  
Landscape Resistance ◽  
Plant Dispersal ◽  
Plant Groups ◽  
Floristic Patterns ◽  
Dispersal Abilities

The effects of historical barriers in biogeographical patterns are expected to persist differently depending on dispersal abilities of organisms. We tested two hypotheses that plant groups with different dispersal abilities display different floristic patterns, and that historical barriers can explain floristic differentiation patterns in plants with low dispersal ability but not in plants with higher dispersal ability, in the seed plant flora of the Ryukyu Archipelago. This area is biogeographically interesting because several similar floristic differentiation patterns have been proposed, all of which are primarily explained by two historical barriers, the Tokara Tectonic Strait (Tokara Gap) and the Kerama Gap, which arose during the formation of the islands. We calculated floristic dissimilarity distance among 26 islands based on data sets for three dispersal-ability classes. Clustering analyses based on the floristic dissimilarity distance generated similar floristic patterns regardless of dispersal-ability class. We propose that because the landscape resistance is so strong that migration of plants is severely restricted regardless of their dispersal abilities, the similar floristic differentiation patterns are generated. Multivariate regression analyses using Mantel's randomization test indicated that floristic differentiations among islands were explained by the both effects of the historical barriers and geographic distance in all dispersal-ability classes. Significance of the historical barriers is not determined by the plant dispersal abilities but presumably by the spatial distribution of the islands, stochastic dispersals, and time since the formation of the barriers.

scholarly journals Life history, climate and biogeography interactively affect worldwide genetic diversity of plant and animal populations

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
H. De Kort ◽  
J. G. Prunier ◽  
S. Ducatez ◽  
O. Honnay ◽  
M. Baguette ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Life History ◽  
Evolutionary Dynamics ◽  
Environmental Changes ◽  
Peripheral Populations ◽  
Plant Dispersal ◽  
Weak Support ◽  
Animal Populations ◽  
Plant Groups ◽  
Conservation Genetic

AbstractUnderstanding how biological and environmental factors interactively shape the global distribution of plant and animal genetic diversity is fundamental to biodiversity conservation. Genetic diversity measured in local populations (GDP) is correspondingly assumed representative for population fitness and eco-evolutionary dynamics. For 8356 populations across the globe, we report that plants systematically display much lower GDP than animals, and that life history traits shape GDP patterns both directly (animal longevity and size), and indirectly by mediating core-periphery patterns (animal fecundity and plant dispersal). Particularly in some plant groups, peripheral populations can sustain similar GDP as core populations, emphasizing their potential conservation value. We further find surprisingly weak support for general latitudinal GDP trends. Finally, contemporary rather than past climate contributes to the spatial distribution of GDP, suggesting that contemporary environmental changes affect global patterns of GDP. Our findings generate new perspectives for the conservation of genetic resources at worldwide and taxonomic-wide scales.

scholarly journals Host–parasitoid evolution in a metacommunity

2016 ◽  
Vol 283 (1831) ◽  
pp. 20160477 ◽  
Author(s):  
Denon Start ◽  
Benjamin Gilbert
Keyword(s):  
Natural Enemies ◽  
Patch Size ◽  
Common Garden ◽  
Species Traits ◽  
Dispersal Ability ◽  
Isolated Populations ◽  
Selection Gradient ◽  
Phenotypic Differences ◽  
Dispersal Abilities ◽  
Phenotypic Shift

Patch size and isolation are predicted to alter both species diversity and evolution; yet, there are few empirical examples of eco-evolutionary feedback in metacommunities. We tested three hypotheses about eco-evolutionary feedback in a gall-forming fly, Eurosta solidaginis and two of its natural enemies that select for opposite traits: (i) specialization and poor dispersal ability constrain a subset of natural enemies from occupying small and isolated patches, (ii) this constraint alters selection on the gall fly, causing phenotypic shifts towards traits resistant to generalist and dispersive enemies in small and isolated patches, and (iii) reduced dispersal evolves in small, isolated populations. We sampled patches in a natural metacommunity and found support for all hypotheses; Eurosta 's specialist wasp parasitoid attacked fewer galls in small and isolated patches, generating a selection gradient that favoured small galls resistant to predation by a dispersive and generalist bird predator. Phenotype distributions matched this selection gradient, and these phenotypic differences were maintained in a common garden experiment. Finally, we found lower dispersal abilities in small and isolated patches, a phenotypic shift that aids in the maintenance of local adaptation. We suggest that the trophic rank and the species traits of consumers are central to evolution in metacommunities.

scholarly journals Carnivores, competition and genetic connectivity in the Anthropocene

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Scott Creel ◽  
Göran Spong ◽  
Matthew Becker ◽  
Chuma Simukonda ◽  
Anita Norman ◽  
...  
Keyword(s):  
Genetic Distance ◽  
Human Activity ◽  
High Throughput Sequencing ◽  
Geographic Distance ◽  
Genetic Connectivity ◽  
Large Carnivores ◽  
Mass Extinctions ◽  
Landscape Resistance ◽  
African Wild Dogs ◽  
Wild Dogs

Abstract Current extinction rates are comparable to five prior mass extinctions in the earth’s history, and are strongly affected by human activities that have modified more than half of the earth’s terrestrial surface. Increasing human activity restricts animal movements and isolates formerly connected populations, a particular concern for the conservation of large carnivores, but no prior research has used high throughput sequencing in a standardized manner to examine genetic connectivity for multiple species of large carnivores and multiple ecosystems. Here, we used RAD SNP genotypes to test for differences in connectivity between multiple ecosystems for African wild dogs (Lycaon pictus) and lions (Panthera leo), and to test correlations between genetic distance, geographic distance and landscape resistance due to human activity. We found weaker connectivity, a stronger correlation between genetic distance and geographic distance, and a stronger correlation between genetic distance and landscape resistance for lions than for wild dogs, and propose a new hypothesis that adaptations to interspecific competition may help to explain differences in vulnerability to isolation by humans.

scholarly journals Dispersal limitations of early life stages and sibling aggregations in a broadcastingMilleporahydrocoral, as revealed by parentage analysis

2018 ◽  
Author(s):  
Caroline E. Dubé ◽  
Emilie Boissin ◽  
Alexandre Mercière ◽  
Serge Planes
Keyword(s):  
Geographic Distance ◽  
French Polynesia ◽  
Parentage Analysis ◽  
Dispersal Ability ◽  
Dispersal Patterns ◽  
High Dispersal ◽  
Local Sustainability ◽  
Limited Dispersal ◽  
Dispersal Events ◽  
Critical Process

AbstractDispersal is a critical process for the persistence and productivity of marine populations. For many reef species, there is increasing evidence that local demography and self-recruitment have major consequences on their genetic diversity and adaptation to environmental change. Yet empirical data of dispersal patterns in reef-building species remain scarce. Here, we document the first genetic estimates of local dispersal and self-recruitment in a broadcasting reef-builder, the hydrocoralMillepora platyphylla. Using microsatellite markers, we gathered genotypic information from 3160 georeferenced colonies collected over 9000 m2of reef in three adjacent habitats in Moorea, French Polynesia; the mid slope, upper slope and back reef. Our parentage analysis revealed a predominance of self-recruitment with 58% of sexual propagules produced locally. Sexual propagules often settled at less than 10 meters from their parents and dispersal events decrease with increasing geographic distance. Limited dispersal among adjacent habitats via cross-reef transport was also detected. Sibship analysis showed that both full and half siblings recruit together on the reef, resulting in sibling aggregations. The identification of local families revealed discrepancies between dispersal patterns of sexual and asexual propagules. Self-recruits are dispersed with along-reef currents and settled in alignment with the location of their parents, while the dispersal of asexual fragments is heavily influenced by wave-driven cross-reef currents. Our findings highlight the importance of self-recruitment together with clonality in stabilising population dynamics, as it can enhance local sustainability and resilience to disturbance, but also raise uncertainties on the widely accepted high dispersal ability of broadcasting reef species.

scholarly journals Fungi are more dispersal-limited than bacteria among flowers

2020 ◽  
Author(s):  
Rachel Vannette ◽  
Griffin Hall ◽  
Ivan Munkres
Keyword(s):  
Community Assembly ◽  
Dispersal Ability ◽  
Numerical Abundance ◽  
Flower Traits ◽  
Biodiversity Maintenance ◽  
Dispersal Abilities ◽  
Dispersal Routes ◽  
The Difference ◽  
Bacteria And Fungi ◽  
Plant Pollinator

AbstractDispersal, particularly variation in dispersal ability among taxa, affects community assembly in individual communities and biodiversity maintenance within metacommunities. Although fungi and bacteria frequently coexist, their relative dispersal abilities are poorly understood. Here, we compare the incidence and abundance of culturable flower-inhabiting bacteria and fungi among individual flowers. Using collections that span two coflowering communities across two years, we assess viable bacterial and fungal incidence and abundance within individual flower samples, and examine patterns across plant species that differ in flower traits. Our results demonstrate that bacteria can be detected in more flowers and in greater numerical abundance than fungi, particularly in flowers with more exposed corollas. For fungi, however, flowers with long corollas were equally likely as exposed flowers to contain cells, and hosted higher numbers of fungal cells, primarily yeasts. Across all flowers, bacteria and fungal incidence was positively related, but within flowers containing microbes, bacterial and fungal incidence was negatively related, suggesting shared dispersal routes but competition among microbes within flowers. The difference in dispersal abilities of bacteria and fungi identified here may have broad relevance for community assembly of microbes and plant-pollinator interactions.

Plant composition patterns inside an endemic birds’ nest fern (Asplenium goudeyi) on Lord Howe Island: effects of fern size, fern isolation and plant dispersal abilities

2015 ◽  
Vol 31 (5) ◽  
pp. 413-421 ◽  
Author(s):  
Amanda Taylor ◽  
Kevin Burns
Keyword(s):  
Species Interactions ◽  
Individual Species ◽  
Ecological Communities ◽  
Plant Composition ◽  
Plant Dispersal ◽  
Lord Howe Island ◽  
Endemic Birds ◽  
Chance Events ◽  
Dispersal Abilities ◽  
Species Occurrences

Abstract:The importance of deterministic and stochastic processes in structuring ecological communities is an enduring debate. Although this debate is nearly a century old, the extent to which communities are structured by species interactions or chance events is a central issue in ecology. We examined the assemblages of plants living inside 119 birds’ nest ferns (Asplenium goudeyi), which are endemic to Lord Howe Island. Specifically, we investigated whether patterns of species richness and community composition were influenced by fern size, fern isolation and plant dispersal abilities. Fern size and fern isolation significantly predicted plant community richness. At the community level, plant composition patterns did not deviate from randomized expectations. Individual species occurrences increased with increasing community richness, and no species exclusions were observed. Wind-dispersed taxa, which accounted for 29% of all species, were well represented in isolated ferns. Comparatively, poorer dispersers were confined to ferns nearest the forest at the base of the cliffs. We suggest that dispersal plays a key role in structuring plant communities living within birds’ nest ferns, and that species interactions are less important. Our study emphasizes the importance of epiphytes with a nest-like growth form as habitat for plants in a harsh environment.

scholarly journals How Important Are Resistance, Dispersal Ability, Population Density and Mortality in Temporally Dynamic Simulations of Population Connectivity? A Case Study of Tigers in Southeast Asia

Land ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 415
Author(s):  
Eric Ash ◽  
Samuel A. Cushman ◽  
David W. Macdonald ◽  
Tim Redford ◽  
Żaneta Kaszta
Keyword(s):  
Population Density ◽  
Southeast Asia ◽  
Population Distribution ◽  
Landscape Connectivity ◽  
Relative Effect ◽  
Relative Strength ◽  
Population Connectivity ◽  
Dispersal Ability ◽  
Landscape Resistance ◽  
Kernel Approach

Development of landscape connectivity and spatial population models is challenging, given the uncertainty of parameters and the sensitivity of models to factors and their interactions over time. Using spatially and temporally explicit simulations, we evaluate the sensitivity of population distribution, abundance and connectivity of tigers in Southeast Asia to variations of resistance surface, dispersal ability, population density and mortality. Utilizing a temporally dynamic cumulative resistant kernel approach, we tested (1) effects and interactions of parameters on predicted population size, distribution and connectivity, and (2) displacement and divergence in scenarios across timesteps. We evaluated the effect of varying levels of factors on simulated population, cumulative resistance kernel extent, and kernel sum across nine timesteps, producing 24,300 simulations. We demonstrate that predicted population, range shifts, and landscape connectivity are highly sensitive to parameter values with significant interactions and relative strength of effects varying by timestep. Dispersal ability, mortality risk and their interaction dominated predictions. Further, population density had intermediate effects, landscape resistance had relatively low impacts, and mitigation of linear barriers (highways) via lowered resistance had little relative effect. Results are relevant to regional, long-term tiger population management, providing insight into potential population growth and range expansion across a landscape of global conservation priority.

Reproductive-Biology of Megascolides Australis Mccoy (Oligochaeta, Megascolecidae)

1995 ◽  
Vol 43 (5) ◽  
pp. 489 ◽  
Author(s):  
BD Vanpraagh
Keyword(s):  
Life History ◽  
Reproductive Biology ◽  
Reproductive Strategies ◽  
Egg Laying ◽  
Dispersal Ability ◽  
Low Density ◽  
Spermathecal Duct ◽  
Dispersal Abilities ◽  
Reproductive Processes

Observations of gametogenesis facilitated understanding life history and reproductive processes in Megascolides australis, whose reproductive strategies are correlated with longevity, low density and poor dispersal ability. Worms are biparental and have a discrete breeding (egg laying) season in spring and summer. This coincides with the greatest number of mature ova and the glandular epidermis of the clitellar region being thickest. Gametogenesis occurs throughout the year, with sperm present in the spermathecae and available on male funnels ail year. Non-seasonal copulation may occur when two worms meet and conditions are favourable; this trait is advantageous for species in low densities with poor dispersal abilities. The spermathecal structure of M. australis differs from that of other megascolecids recorded in that the structure of the diverticulum includes many multiloculate chambers that do not connect directly with the spermathecal duct. The sperm form orientated bundles (spermatozeugmata) not previously described for Megascolecidae and are stored in the ampulla rather than the diverticula.

Genetic estimates of dispersal ability in the leucaena psyllid predator Curinus coeruleus (Coleoptera: Coccinellidae): implications for biological control

1996 ◽  
Vol 86 (4) ◽  
pp. 355-361 ◽  
Author(s):  
Peter A. Follett ◽  
George K. Roderick
Keyword(s):  
Biological Control ◽  
Gene Flow ◽  
Pacific Islands ◽  
Isolation By Distance ◽  
Geographic Distance ◽  
Population Subdivision ◽  
Dispersal Ability ◽  
The Pacific ◽  
The Individual ◽  
Curinus Coeruleus

AbstractThe leucaena psyllid, Heteropsylla cubana Crawford, can devastate plantings of Leucaena leucocephala (Leguminosae), an economically important tree species in the Pacific Islands, Southeast Asia, Australia, India, Africa, and elsewhere. The predatory beetle, Curinus coeruleus Mulsant (Coleoptera: Coccinellidae), has been introduced into many of these areas from Hawaii for biological control of the psyllid. In this study, collections of C. coeruleus were made from 11 populations on four islands in the Hawaiian archipelago to determine population structure and estimate levels of gene flow. Over all populations, a measure of population subdivision, θ was 0.095, and the estimate of Nem, the average migration rate, was 2.4. θ values for the individual islands were 0.02, 0.12, 0.24 and 0.05 for Kauai, Hawaii, Maui, and Oahu, respectively. Estimated levels of gene flow between populations were not correlated with geographic distance, therefore isolation by distance does not appear to be an important process structuring C. coeruleus populations. Gene flow estimates can be used to characterize dispersal capabilities in insects or other organisms released for biological control. In this case, the inferior dispersal ability of C. coeruleus likely limits its rapid widespread establishment during release programmes.

scholarly journals Habitat Fragmentation Reduces Genetic Diversity and Connectivity of the Mexican Spotted Owl: A Simulation Study Using Empirical Resistance Models

Genes ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 403 ◽  
Author(s):  
Ho Wan ◽  
Samuel Cushman ◽  
Joseph Ganey
Keyword(s):  
Genetic Diversity ◽  
Isolation By Distance ◽  
Geographic Distance ◽  
Geographic Area ◽  
Negative Influence ◽  
Landscape Resistance ◽  
Effective Population ◽  
Habitat Amount ◽  
Spotted Owl ◽  
Habitat Patches

We evaluated how differences between two empirical resistance models for the same geographic area affected predictions of gene flow processes and genetic diversity for the Mexican spotted owl (Strix occidentalis lucida). The two resistance models represented the landscape under low- and high-fragmentation parameters. Under low fragmentation, the landscape had larger but highly concentrated habitat patches, whereas under high fragmentation, the landscape had smaller habitat patches that scattered across a broader area. Overall habitat amount differed little between resistance models. We tested eight scenarios reflecting a factorial design of three factors: resistance model (low vs. high fragmentation), isolation hypothesis (isolation-by-distance, IBD, vs. isolation-by-resistance, IBR), and dispersal limit of species (200 km vs. 300 km). Higher dispersal limit generally had a positive but small influence on genetic diversity. Genetic distance increased with both geographic distance and landscape resistance, but landscape resistance displayed a stronger influence. Connectivity was positively related to genetic diversity under IBR but was less important under IBD. Fragmentation had a strong negative influence on the spatial patterns of genetic diversity and effective population size (Ns). Despite habitats being more concentrated and less widely distributed, the low-fragmentation landscape had greater genetic diversity than the high-fragmentation landscape, suggesting that highly concentrated but larger habitat patches may provide a genetic refuge for the Mexican spotted owl.

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