Consulta: subjectFacets:"Metapopulation"
Registros recuperados: 14
Data/hora: 03/06/2024 09:15:51

Detecting Critical Scales in Fragmented Landscapes
Provedor de dados: 7
Autores: Keitt, Timothy; State University of New York at Stony Brook; Timothy.Keitt@StonyBrook.Edu; Urban, Dean L; Duke University; deanu@pinus.env.duke.edu; Milne, Bruce T; University of New Mexico; bmilne@sevilleta.unm.edu.
We develop methods for quantifying habitat connectivity at multiple scales and assigning conservation priority to habitat patches based on their contribution to connectivity. By representing the habitat mosaic as a mathematical "graph," we show that percolation theory can be used to quantify connectivity at multiple scales from empirical landscape data. Our results indicate that connectivity of landscapes is highly scale dependent, exhibiting a marked transition at a characteristic distance and varying significantly for organisms with different dispersal behavior. More importantly, we show that the sensitivity and importance of landscape pattern is also scale dependent, peaking at scales associated with the percolation transition. In addition, the...
Tipo: Peer-Reviewed Reports
Palavras-chave: Connectivity; Conservation in fragmented landscapes; Dispersal; Fragmentation; Habitat connectivity vs. dispersal distance; Landscape; Landscape graphs; Metapopulation; Percolation; Quantifying habitat connectivity at multiple scales; "stepping stone" patch; Strix occidentalis lucida.
Ano: 1997

Extinction Risk in Successional Landscapes Subject to Catastrophic Disturbances
Provedor de dados: 7
Autores: Boughton, David; Pacific Northwest Research Station, U.S. Forest Service; david.boughton@noaa.gov; Malvadkar, Urmila; Princeton University; malvadkr@princeton.edu.
We explore the thesis that stochasticity in successional-disturbance systems can be an agent of species extinction. The analysis uses a simple model of patch dynamics for seral stages in an idealized landscape; each seral stage is assumed to support a specialist biota. The landscape as a whole is characterized by a mean patch birth rate, mean patch size, and mean lifetime for each patch type. Stochasticity takes three forms: (1) patch stochasticity is randomness in the birth times and sizes of individual patches, (2) landscape stochasticity is variation in the annual means of birth rate and size, and (3) turnover mode is whether a patch is eliminated by disturbance or by successional change. Analytical and numerical analyses of the model suggest that...
Tipo: Peer-Reviewed Reports
Palavras-chave: Biodiversity; Catastrophe; Dispersal; Disturbance; Extinction; Landscape; Metapopulation; Patch dynamics; Patchy population; Succession.
Ano: 2002

Climate hindcasts: exploring the disjunct distribution of     Diopatra biscayensis
Provedor de dados: 5
Autores: Wethey, David S.; Woodin, Sarah A.; Berke, Sarah K.; Dubois, Stanislas.
The ecosystem engineer onuphid polychaete Diopatra biscayensis has a continuous population in the Bay of Biscay from the Cantabria coast in Spain to southern Brittany in France. A group of disjunct populations also are found in the English Channel, separated from the Biscay population by more than 400 coastal kilometers. It remains unclear whether D. biscayensis is native to the Bay of Biscay; it is also debated whether the disjunct populations in the English Channel are relics of a formerly continuous population, or the product of recent introductions through aquaculture. Here, we use climate hindcasts to explore hypotheses about the D. biscayensis historical distribution in Europe. If D. biscayensis is native, its range would have been restricted to...
Tipo: Text
Palavras-chave: Climate change; Biogeography; Metapopulation; Diopatra; Historical projections.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00356/46711/46974.pdf

Investigating spatial heterogeneity of von Bertalanffy growth parameters to inform the stock structuration of common sole, Solea solea, in the Eastern English Channel
Provedor de dados: 5
Autores: Du Pontavice, Hubert; Randon, Marine; Lehuta, Sigrid; Vermard, Youen; Savina-rolland, Marie.
In fisheries science, a mismatch between the delineation of a fish stock and the underlying biological population can lead to inaccurate assessment and management. Previous results suggested a potential spatial structuration of the Eastern English Channel (EEC) stock of common sole, Solea solea, in three sub-populations. In this article, we propose to investigate the spatial population structure of common sole in the EEC using the von Bertalanffy Growth Function parameters as indicators of population segregation. In order to test the sub-population hypothesis and evaluate its robustness to data sources, we developed three models, all including an area effect on growth parameters. The first model was aimed at testing a potential data source effect (in...
Tipo: Text
Palavras-chave: Key-words; Von Bertalanffy growth function; Stock structuration; Solea solea; Flatfish; Life-history traits; Metapopulation.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00445/55625/57301.pdf

Linking local retention, self-recruitment, and persistence in marine metapopulations
Provedor de dados: 5
Autores: Lett, Christophe; Tri Nguyen-huu,; Cuif, Marion; Saenz-agudelo, Pablo; Kaplan, David.
Three indices of larval retention have been used in the literature to assess the tendency for self-maintenance of local marine populations: local retention (LR), self-recruitment (SR), and relative local retention (RLR). Only one of these, LR, defined as the ratio of locally produced settlement to local egg production, has a clear relationship to self-persistence of individual sites. However, SR, the ratio of locally produced settlement to settlement of all origins at a site, is generally easier to measure experimentally. We use theoretical, simulation, and empirical approaches to bridge the gap between these different indices, and demonstrate that there is a proportional relationship between SR and LR for metapopulations close to a stable state and with...
Tipo: Text
Palavras-chave: Connectivity; Larval dispersal; Lifetime egg production; Local retention; Marine reserve; Metapopulation; Network persistence; Population persistence; Self-persistence; Self-recruitment.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00275/38628/81243.pdf

Large-scale population genetic structure in Bonelli's Eagle Aquila fasciata
Provedor de dados: 5
Autores: Mira, Sara; Arnaud-haond, Sophie; Palma, Luis; Cancela, Maria Leonor; Beja, Pedro.
In bird species that have a high movement capacity, dispersal may connect subpopulations over vast geographical regions, with important consequences for the design of conservation management strategies. Here we used a molecular approach to infer the patterns and rates of dispersal among eight Mediterranean subpopulations of the endangered Bonelli's Eagle, based on 245 individuals screened at 17 microsatellite loci. There was moderate genetic differentiation between subpopulations sampled in the western (Iberia and Morocco) and eastern (Cyprus) Mediterranean, whereas differentiation among subpopulations in the former region was weak to moderate and followed a pattern of isolation by distance. Within the western Mediterranean, the small, peripheral and...
Tipo: Text
Palavras-chave: Dispersal; Ecological divergence; Metapopulation; Philopatry; Population fragmentation.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00148/25924/24018.pdf

Using a spatially structured life cycle model to assess the influence of multiple stressors on an exploited coastal-nursery-dependent population
Provedor de dados: 5
Autores: Archambault, B.; Rivot, E.; Savina-rolland, Marie; Le Pape, Olivier.
Exploited coastal-nursery-dependent fish species are subject to various stressors occurring at specific stages of the life cycle: climate-driven variability in hydrography determines the success of the first eggs/larvae stages; coastal nursery habitat suitability controls juvenile growth and survival; and fisheries target mostly adults. A life cycle approach was used to quantify the relative influence of these stressors on the Eastern English Channel (EEC) population of the common sole (Solea solea), a coastal-nursery-dependent flatfish population which sustains important fisheries. The common sole has a complex life cycle: after eggs hatch, larvae spend several weeks drifting in open water. Survivors go on to metamorphose into benthic fish. Juveniles...
Tipo: Text
Palavras-chave: Life cycle model; Spatial processes; Metapopulation; Coastal nursery habitat degradation; Fishing; Solea; Multiple stressors; Scenarios.
Ano: 2018
URL: http://archimer.ifremer.fr/doc/00301/41213/40367.pdf

Sex, size and timing: Sampling design for reliable population genetics analyses using microsatellite data
Provedor de dados: 5
Autores: Dubois, Quentin; Lebigre, Christophe; Schtickzelle, Nicolas; Turlure, Camille.
Population genetics is used in a wide variety of fields such as ecology and biodiversity conservation. How estimated genetic characteristics of natural populations can be influenced by the sampling design has been a long-standing concern. Multiple simulation and empirical studies illustrated the influence of both sample size and polymorphism of markers. However, our review of studies on butterfly population genetics indicates no consensus on sample size for the estimation of genetic diversity or differentiation. Furthermore, other aspects of sampling design (sex ratio and timing of sampling) were not addressed and their potential impact on genetic parameter estimates rarely explored. Using a large empirical dataset (with spatial and temporal replicates)...
Tipo: Text
Palavras-chave: Butterfly; Conservation; Genetic diversity; Metapopulation; Number of samples; Period of sampling; Population structure; Sampling scheme optimization; Sex ratio.
Ano: 2018
URL: http://archimer.ifremer.fr/doc/00416/52783/53664.pdf

Variability and controls of otolith growth in the anchovy of the Bay of Biscay
Provedor de dados: 5
Autores: Petitgas, Pierre; Grellier, Patrick; Duhamel, Erwan; Masse, Jacques; Doray, Mathieu.
Individual fish growth depends on internal population factors such as phenotypic variability as well as external factors such as past environmental conditions (temperature, food) and selective mortality (predation or fishing). In the anchovy, growth in the first year is key to population dynamics as it determines the potential energy allocated to reproduction as well as the capacity to occupy off-shore habitats. Further, in the recent past, the anchovy in the bay of Biscay has experienced collapse and recovery and the role played by growth in this history is unknown. Since 2001 with the spring acoustic survey series PelGas, we have monitored individual fish growth by measuring in the otolith the increments between annual rings, in addition to age...
Tipo: Text
Palavras-chave: Anchovy; Biscay; Otoliths; Growth; Metapopulation.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00114/22550/20236.pdf

Adult-mediated connectivity and spatial population structure of sardine in the Bay of Biscay and Iberian coast
Provedor de dados: 5
Autores: Silva, Alexandra; Garrido, Susana; Ibaibarriaga, Leire; Pawlowski, Lionel; Riveiro, Isabel; Marques, Vitor; Ramos, Fernando; Duhamel, Erwan; Iglesias, Magdalena; Bryere, Philippe; Mangin, Antoine; Citores, Leire; Carrera, Pablo; Uriarte, Andres.
This work investigated adult-mediated connectivity and spatial population structure of sardine in the European Atlantic waters. The spatial and temporal progress of cohorts was modelled using abundance-at-age survey data by area in the period 2000 to 2016, covering the region from the northern Bay of Biscay to the eastern Gulf of Cadiz. A novel methodology was used to calculate indices of cohort movement between areas. Movement was relatively low between three large regions, the Bay of Biscay, the northern Spanish and Portuguese waters and the Gulf of Cadiz, each hosting a recruitment hotspot. On the other hand, one half of the sardines recruited in North Portugal and a quarter of those recruited in Southwest Portugal moved to northern Spanish waters and...
Tipo: Text
Palavras-chave: Metapopulation; Source-sink dynamics; Adult-mediated connectivity; Cohort dispersal; Small pelagic fishes; Stock identity; Fisheries management.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00465/57661/59856.pdf

The influence of variability in larval dispersal on the dynamics of a marine metapopulation in the eastern Channel
Provedor de dados: 5
Autores: Ellien, Celine; Thiebaut, Éric; Barnay, Anne-sophie; Dauvin, Jean-claude; Gentil, Franck; Salomon, Jean-claude.
In the English Channel, the polychaete Pectinaria in koreni forms isolated populations confined in bays and estuaries. To determine the influence of larval dispersal variability on the observed stock fluctuations of the three major Pectinaria koreni populations reported along the French coasts of the eastern Channel, larval dispersal was simulated using a 2D hydrodynamical lagrangian model integrating both the tidal residual and the wind-driven circulation. Year-to-year fluctuations of adult stocks were established from benthic surveys carried out between 1973 and 1998. Larval dispersal patterns vary between populations according to the relative importance of tidal advection and eddy diffusion so that local larval retention is maximal where tidal advection...
Tipo: Text
Palavras-chave: Pectinaria koreni; Metapopulation; Modelling; Recruitment; Larval dispersal; Pectinaria koreni; Métapopulation; Modélisation; Recrutement; Dispersion larvaire.
Ano: 2000
URL: https://archimer.ifremer.fr/doc/2000/publication-535.pdf

Sole larval supply to coastal nurseries: Interannual variability and connectivity at interregional and interpopulation scales
Provedor de dados: 5
Autores: Savina-, Marie; Lunghi, Mathias; Archambault, B.; Baulier, Loic; Huret, Martin; Le Pape, Olivier.
Simulating fish larval drift helps assess the sensitivity of recruitment variability to early life history. An individual-based model (IBM) coupled to a hydrodynamic model was used to simulate common sole larval supply from spawning areas to coastal and estuarine nursery grounds at the meta-population scale (4 assessed stocks), from the southern North Sea to the Bay of Biscay (Western Europe) on a 26-yr time series, from 1982 to 2007. The IBM allowed each particle released to be transported by currents, to grow depending on temperature, to migrate vertically depending on development stage, to die along pelagic stages or to settle successfully on a nursery, representing the life history from spawning to metamorphosis. The model outputs were analysed to...
Tipo: Text
Palavras-chave: Hydrodynamic model; Individual-based model; Larval supply; Nursery grounds; Recruitment variability; Solea solea; Metapopulation; English Channel; Bay of Biscay; Southern North Sea.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00297/40775/39782.pdf

Dynamics of Spatial Exploitation: A Metapopulation Approach
Provedor de dados: 31
Autores: Sanchirico,   James N.; Wilen,   James E.
We present a bioeconomic model of a harvesting industry operating over a heterogeneous environment comprised of discrete biological populations interconnected by dispersal processes. The model generalizes the H. S. Gordon [1954]/V. Smith [1968] model of open-access rent dissipation by accounting for intertemporal and spatial "Ricardian" patterns of exploitation. This model yields a simple, but insightful, framework from which one can investigate factors that contribute to the evolution of resource exploitation patterns over space and time. For example, we find that exploitation patterns are driven by biological and fleet dispersal and biological and economic heterogeneity. We conclude that one cannot really understand the biological processes operating in...
Tipo: Working or Discussion Paper
Palavras-chave: Renewable resources; Bioeconomics; Spatial modeling; Metapopulation; Environmental Economics and Policy; Q22; R19.
Ano: 2000
URL: http://purl.umn.edu/10513

Genetic consequences of population subdivision: the marsupial Micoureus paraguayanus (Mammalia: Didelphimorphia) as a case study
Provedor de dados: 103
Autores: Brito,Daniel.
Habitat fragmentation may cause population subdivision, affecting genetic variation, leading to heterozygosity loss and increased inbreeding, and contributing to population extinction. However, some genetic models have shown that under some conditions, population subdivision can favor heterozygosity and allelic diversity, and small populations may adapt to inbreeding. Here I investigate the relationship between population subdivision and genetic diversity for the marsupial Micoureus paraguayanus (Tate, 1931) using the program Vortex. Hypothetical populations of 100 and 2000 individuals were partitioned into 1, 2, 5 or 10 populations that were linked by varying rates of dispersal and also by sex-biased dispersal. Results suggested that heterozygosity and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Genetic drift; Genetic load; Habitat fragmentation; Inbreeding; Metapopulation; Population viability analysis.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702009000400013