An isolated population of the southern scrub-robin (Drymodes brunneopygia) in the Great Victoria Desert

2017 ◽  
Vol 23 (1) ◽  
pp. 95 ◽  
Author(s):  
J. M. Turpin ◽  
R. E. Johnstone
Keyword(s):  
Environmental Changes ◽  
Reproductive Rate ◽  
Species Range ◽  
Isolated Population ◽  
Arid Shrublands ◽  
Limited Dispersal ◽  
Dispersal Capability ◽  
Semiarid Shrublands

From 2013 to 2015 we recorded an isolated, highly fragmented and previously undocumented population of the southern scrub-robin within the arid shrublands of the Great Victoria Desert. In this region, the southern scrub-robin persists in scattered and intermittent areas of long-unburnt mulga (Acacia spp.) shrubland, with a dense shrubby understorey dominated by Aluta maisonneuvei and Eremophila shrubs. The Great Victoria Desert supports the only known desert population as the southern scrub-robin otherwise occurs in the temperate and semiarid shrublands of southern Australia and occurs in the desert at the arid extreme of its range. Fire is highlighted as a significant threatening process due to the species’ restricted occurrence (less than 5% of the landscape in the region), low reproductive rate, limited dispersal capability and persistence within long-unburnt and fire-sensitive habitats. As forecast environmental changes are likely to render the arid extremes of the species’ range unsuitable, this outlying, desert population is potentially declining and of conservation significance.

scholarly journals Habitat choice meets thermal specialization: Competition with specialists may drive suboptimal habitat preferences in generalists

2018 ◽  
Vol 115 (47) ◽  
pp. 11988-11993 ◽  
Author(s):  
Staffan Jacob ◽  
Estelle Laurent ◽  
Bart Haegeman ◽  
Romain Bertrand ◽  
Jérôme G. Prunier ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Environmental Variability ◽  
Habitat Preferences ◽  
Habitat Choice ◽  
Current Theory ◽  
Ecological Specialization ◽  
Metapopulation Model ◽  
Niche Specialization ◽  
Random Dispersal ◽  
Limited Dispersal

Limited dispersal is classically considered as a prerequisite for ecological specialization to evolve, such that generalists are expected to show greater dispersal propensity compared with specialists. However, when individuals choose habitats that maximize their performance instead of dispersing randomly, theory predicts dispersal with habitat choice to evolve in specialists, while generalists should disperse more randomly. We tested whether habitat choice is associated with thermal niche specialization using microcosms of the ciliate Tetrahymena thermophila, a species that performs active dispersal. We found that thermal specialists preferred optimal habitats as predicted by theory, a link that should make specialists more likely to track suitable conditions under environmental changes than expected under the random dispersal assumption. Surprisingly, generalists also performed habitat choice but with a preference for suboptimal habitats. Since this result challenges current theory, we developed a metapopulation model to understand under which circumstances such a preference for suboptimal habitats should evolve. We showed that competition between generalists and specialists may favor a preference for niche margins in generalists under environmental variability. Our results demonstrate that the behavioral dimension of dispersal—here, habitat choice—fundamentally alters our predictions of how dispersal evolve with niche specialization, making dispersal behaviors crucial for ecological forecasting facing environmental changes.

Fire Ecology, Animal Populations and Man: a Study of some Ecological Relationships in Prehistory

1976 ◽  
Vol 42 ◽  
pp. 15-45 ◽  
Author(s):  
Paul Mellars
Keyword(s):  
Fire Ecology ◽  
Environmental Changes ◽  
Reproductive Rate ◽  
Human Populations ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Ecological Relationships ◽  
Animal Populations ◽  
Hunting And Gathering

SummaryThe occurrence of fires in many types of woodland and forested environments would have benefited human populations in several different ways. In addition to greatly increasing the mobility of the human groups, the occurrence of fire in many types of forest would have led to substantial improvements in the economic potential of the environment. Improvements in both the quantity and nutritional quality of the food supplies available to herbivorous animals would have increased not only the total carrying capacity of the environment for these species, but also the relative growth-rates and reproductive rate of the animals. In certain cases it is likely that burning would have increased the overall ‘productivity’ of ungulate populations by a factor of × 10. Similar improvements may have been achieved in the yields of certain vegetable food resources. The potential impact of these environmental changes on the population numbers and settlement patterns of human communities is discussed, and it is suggested that the adoption of systematic policies of forest burning by hunting and gathering populations may have led in certain situations to the emergence of more complex patterns of man-animal relationships which were closely similar to those of traditional ‘herding’ or ‘pastoralist’ economies.

Species range shifts due to environmental changes in scaled squid, Pholidoteuthis massyae and bathyal octopus, Muusoctopus eureka

2011 ◽  
Vol 4 ◽  
Author(s):  
Vladimir Laptikhovsky ◽  
Alexander Arkhipkin ◽  
Paul Brickle ◽  
Sarah Hearne ◽  
Karen Neely
Keyword(s):  
Environmental Changes ◽  
Species Range ◽  
Range Shifts

The Benthic Amphipod Fauna of the Azores (Portugal): an Up-To-Date Annotated List of Species, and Some Biogeographic Considerations

Crustaceana ◽  
1993 ◽  
Vol 65 (2) ◽  
pp. 204-217 ◽  
Author(s):  
Denise BELLAN-SANTINI ◽  
Joao Carlos Marques ◽  
M. Fatima Rosa Lopes
Keyword(s):  
North Atlantic ◽  
Biological Material ◽  
New Records ◽  
North Atlantic Region ◽  
Ecological Data ◽  
Atlantic Region ◽  
Azores Archipelago ◽  
Annotated List ◽  
Limited Dispersal ◽  
Dispersal Capability

AbstractThe Azores archipelago, located in the middle north Atlantic region, is biogeographically very interesting. With regard to the benthic amphipod fauna there are only few studies that concern the Azores, although species inventory and distributional ecology are relatively well known for the Portuguese continental coast (0 to 700 m). Actually, the knowledge of benthic amphipods from the Azores is limited to the results of two oceanographical expeditions, that took place in the first half of this century, and to data provided by some relatively recent papers and several other sporadic references. Moreover, this knowledge is mainly or exclusively taxonomic. Benthic amphipod dispersal capability is small compared to that of molluscs, decapods or fishes. They have direct development and a reduced swimming capability, and their migrations, both nictemeral and horizontal, cannot compensate these features. This limited dispersal capability determines a clear endemic tendency, and a reduced probability of global fauna mixtures. Therefore, amphipods constitute a fine biological material for biogeographic studies. In order to provide a tool for biogeographical comparisons, the available data on the Azores amphipod fauna were compiled. A review of the available literature and the study of several collections from the Azores, sampled during 1988 and 1989 at the islands of S. Miguel and Faial, provided a list of 122 species from 29 families. Thirty species were identified from the study of the S. Miguel and Faial collections, of which 15 (50%) are new records for the Azores, which emphasizes the existing lack of knowledge. One Ampithoe species might be new, and will be further studied, although it will be necessary to collect more specimens. Additionally, some available ecological data for each species arc given in the present paper.

Distribution and ecology of chironomids (Diptera, Chironomidae) on Byers Peninsula, Maritime Antarctica

2013 ◽  
Vol 25 (2) ◽  
pp. 288-291 ◽  
Author(s):  
Eugenio Rico ◽  
Antonio Quesada
Keyword(s):  
Microbial Mats ◽  
Carbon Sources ◽  
South Shetland Islands ◽  
The South ◽  
Central Plateau ◽  
Aquatic Mosses ◽  
Belgica Antarctica ◽  
Limited Dispersal ◽  
Dispersal Capability ◽  
Distribution And Ecology

AbstractThis study describes the ecology and distribution of the only two native Antarctic insects, the chironomid species Parochlus steinenii and Belgica antarctica, both found on Byers Peninsula (Livingston Island, South Shetland Islands). Parochlus steinenii inhabits lakes of the central plateau of Byers Peninsula associated with aquatic mosses on the bottom of lakes and in some streams of the South Beach area. Some streams have stable populations which are able to complete their life cycle while other streams have temporary, unstable populations. Belgica antarctica also inhabits streams running through mosses located in the South Beach area. Our data indicate that this species has a limited dispersal capability which is positively light activated for both adults and pupae. Both Antarctic midge species coexists on Byers Peninsula and share some stretches of streams. Isotopic studies show a non-selective feeding regime for both species with mixed carbon sources associated with both biofilm/microbial mats and mosses.

Phylogeographic pattern and glacial refugia of a rocky shore species with limited dispersal capability: the case of Montagu’s blenny (Coryphoblennius galerita, Blenniidae)

2014 ◽  
Vol 161 (11) ◽  
pp. 2509-2520 ◽  
Author(s):  
S. M. Francisco ◽  
V. C. Almada ◽  
C. Faria ◽  
E. M. Velasco ◽  
J. I. Robalo
Keyword(s):  
Rocky Shore ◽  
Glacial Refugia ◽  
Phylogeographic Pattern ◽  
Limited Dispersal ◽  
Dispersal Capability

scholarly journals Species’ range dynamics affect the evolution of spatial variation in plasticity under environmental change

2018 ◽  
Author(s):  
Max Schmid ◽  
Ramon Dallo ◽  
Frédéric Guillaume
Keyword(s):  
Phenotypic Plasticity ◽  
Environmental Change ◽  
Range Expansion ◽  
Evolutionary Dynamics ◽  
Environmental Changes ◽  
Species Range ◽  
Range Shifts ◽  
Environmental Tolerance ◽  
Spatial Differences ◽  
Range Dynamics

AbstractWhile clines in environmental tolerance and phenotypic plasticity along a single species’ range are widespread and of special interest in the context of adaptation to environmental changes, we know little about their evolution. Recent empirical findings in ectotherms suggest that processes underlying dynamic species’ ranges can give rise to spatial differences in environmental tolerance and phenotypic plasticity within species. We used individual-based simulations to investigate how plasticity and tolerance evolve in the course of three scenarios of species’ range shifts and range expansions on environmental gradients. We found that regions of a species’ range which experienced a longer history or larger extent of environmental change generally exhibited increased plasticity or tolerance. Such regions may be at the trailing edge when a species is tracking its ecological niche in space (e.g., in a climate change scenario) or at the front edge when a species expands into a new habitat (e.g., in an expansion/invasion scenario). Elevated tolerance and plasticity in the distribution center was detected when asymmetric environmental change (e.g., polar amplification) led to a range expansion. Greater gene flow across the range had a dual effect on plasticity and tolerance clines, with an amplifying effect in niche expansion scenarios (allowing for faster colonization into novel environments), but with a dampening effect in range shift scenarios (favoring spatial translocation of adapted genotypes). However, tolerance and plasticity clines were transient and slowly flattened out after range dynamics because of genetic assimilation. In general, our approach allowed us to investigate the evolution of environmental tolerance and phenotypic plasticity under transient evolutionary dynamics in non-equilibrium situations, which contributes to a better understanding of observed patterns and of how species may respond to future environmental changes.Impact SummaryIn a variable and changing environment, the ability of a species to cope with a range of selection pressures and a multitude of environmental conditions is critical, both for its’ spatial distribution and its’ long-term persistence. Striking examples of spatial differences in environmental tolerance have been found within species, when single populations differed from each other in their environmental optimum and tolerance breadth, a characteristic that might strongly modify a species’ response to future environmental change. However, we still know little about the evolutionary processes causing these tolerance differences between populations, especially when the differences result from transient evolutionary dynamics in non-equilibrium situations. We demonstrate with individual-based simulations, how spatial differences in environmental tolerance and phenotypic plasticity evolved across a species’ range during three scenarios of range shifts and range expansion. Range dynamics were either driven by environmental change or by the expansion of the ecological niche. The outcome strongly differed between scenarios as tolerance and plasticity were maximized either at the leading edge, at the trailing edge, or in the middle of the species’ range. Spatial tolerance variation resulted from colonization chronologies and histories of environmental change that varied along the range. Subsequent to the range dynamics, the tolerance and plasticity clines slowly leveled out again as result of genetic assimilation such that the described responses are long-lasting, but in the end temporary. These findings help us better understand species’ evolutionary responses during range shifts and range expansion, especially when facing environmental change.

scholarly journals Genetic hypervariability of a Northeastern Atlantic venomous rockfish

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11730
Author(s):  
Sara M. Francisco ◽  
Rita Castilho ◽  
Cristina S. Lima ◽  
Frederico Almada ◽  
Francisca Rodrigues ◽  
...  
Keyword(s):  
Mitochondrial Control Region ◽  
Marine Species ◽  
Intraspecific Diversity ◽  
Historical Factors ◽  
Coastal Species ◽  
Large Numbers ◽  
Sampling Locations ◽  
Limited Dispersal ◽  
Dispersal Capability ◽  
Northeastern Atlantic

Background Understanding the interplay between climate and current and historical factors shaping genetic diversity is pivotal to infer changes in marine species range and communities’ composition. A phylogeographical break between the Atlantic and the Mediterranean has been documented for several marine organisms, translating into limited dispersal between the two basins. Methods In this study, we screened the intraspecific diversity of 150 individuals of the Madeira rockfish (Scorpaena maderensis) across its distributional range (seven sampling locations in the Atlantic and Mediterranean basins) using the mitochondrial control region and the nuclear S7 first intron. Results The present work is the most comprehensive study done for this species, yielding no genetic structure across sampled locations and no detectable Atlantic-Mediterranean break in connectivity. Our results reveal deep and hyper-diverse bush-like genealogies with large numbers of singletons and very few shared haplotypes. The genetic hyper-diversity found for the Madeira rockfish is relatively uncommon in rocky coastal species, whose dispersal capability is limited by local oceanographic patterns. The effect of climate warming on the distribution of the species is discussed.

scholarly journals Going Deeper into High and Low Phylogenetic Relationships of Protura

Genes ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 292 ◽  
Author(s):  
Carapelli ◽  
Bu ◽  
Chen ◽  
Nardi ◽  
Leo ◽  
...  
Keyword(s):  
Species Level ◽  
Nuclear Markers ◽  
Early Diversification ◽  
Open Questions ◽  
Limited Dispersal ◽  
Dispersal Capability ◽  
History Of ◽  
Nuclear Loci ◽  
Different Sources ◽  
Level Identification

Proturans are small, wingless, soil-dwelling arthropods, generally associated with the early diversification of Hexapoda. Their bizarre morphology, together with conflicting results of molecular studies, has nevertheless made their classification ambiguous. Furthermore, their limited dispersal capability (due to the primarily absence of wings) and their euedaphic lifestyle have greatly complicated species-level identification. Mitochondrial and nuclear markers have been applied herein to investigate and summarize proturan systematics at different hierarchical levels. Two new mitochondrial genomes are described and included in a phylum-level phylogenetic analysis, but the position of Protura could not be resolved with confidence due to an accelerated rate of substitution and extensive gene rearrangements. Mitochondrial and nuclear loci were also applied in order to revise the intra-class systematics, recovering three proturan orders and most of the families/subfamilies included as monophyletic, with the exception of the subfamily Acerentominae. At the species level, most morphologically described species were confirmed using molecular markers, with some exceptions, and the advantages of including nuclear, as well as mitochondrial, markers and morphology are discussed. At all levels, an enlarged taxon sampling and the integration of data from different sources may be of significant help in solving open questions that still persist on the evolutionary history of Protura.

Decadal changes in the productivity of New England fish populations

2019 ◽  
Vol 76 (9) ◽  
pp. 1528-1540 ◽  
Author(s):  
Adrien Tableau ◽  
Jeremy S. Collie ◽  
Richard J. Bell ◽  
Cóilín Minto
Keyword(s):  
New England ◽  
State Space ◽  
Environmental Changes ◽  
Reproductive Rate ◽  
Short Term ◽  
State Space Approach ◽  
Linear State ◽  
Northeast Us ◽  
Time Invariant ◽  
Space Approach

The Northwest Atlantic continental shelf is a large ecosystem undergoing rapid environmental changes, which are expected to modify the productivity of natural marine resources. Current management of most fished species assumes stationary production relationships or time-invariant recruitment rates. With linear state-space models, we examined the evidence of dynamic productivity for 25 stocks of the Northeast US shelf. We expanded the suite of options available within the state-space approach to produce robust estimates. Fifteen of the stocks exhibited time-varying productivity or changes in their maximum reproductive rate. Few productivity time series are related across the whole region, though adjacent stocks of the same species exhibited similar trends. Some links to region-wide environmental variables were observed. We demonstrate that fish recruitment can often be better predicted over a short-term horizon by accounting for dynamic productivity, which could be valuable for fisheries management. Improving predictions by incorporating environmental covariates or covariance among the stocks must be considered case by case and with caution, as their relationships may change over time.

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