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Letteratura scientifica selezionata sul tema "Dispersal"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 29 luglio 2024

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Articoli di riviste sul tema "Dispersal"

Roxburgh, Lizanne. "The effect of gut processing on the quality of mistletoe seed dispersal". Journal of Tropical Ecology 23, n. 3 (24 aprile 2007): 377–80. http://dx.doi.org/10.1017/s0266467407004014.

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Disperser effectiveness is the contribution that a disperser makes to the future reproduction of a plant (Schupp 1993), and it has two components: quality and quantity of dispersal. Quantity of dispersal is a function of the number of visits that a disperser makes to a fruiting plant and the number of seeds that are dispersed during each visit. Quality of dispersal is a function of the treatment that a seed receives from its disperser and the site that the seed is finally deposited in. The quality of seed dispersal of the mistletoe Phragmanthera dschallensis (Engl.) M.G. Gilbert (Loranthaceae) by frugivorous birds was examined in this study.

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Kamler, Jan F., Warren B. Ballard, Eric M. Gese, Robert L. Harrison e Seija M. Karki. "Dispersal characteristics of swift foxes". Canadian Journal of Zoology 82, n. 12 (1 dicembre 2004): 1837–42. http://dx.doi.org/10.1139/z04-187.

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From 1997 to 2001, we monitored movements of 109 adult and 114 juvenile swift foxes, Vulpes velox (Say, 1823), at study sites in Colorado, New Mexico, and Texas to determine patterns of dispersal. Significantly more male (93%) than female (58%) juveniles dispersed, and both sexes had similar bimodal dispersal patterns with peaks in September–October and January–February. Adult dispersal occurred more evenly throughout the year, and significantly more male (32%) than female (5%) adults dispersed. Adult males tended to disperse after the death of their mate. Of dispersing foxes with known fates, settlement percentages in new territories were similar between juvenile males and females (40% overall), but they were significantly lower than for adults (89%). All other dispersing foxes with known fates died. Among juvenile females with known fates, similar percentages of philopatric and dispersing foxes reproduced as yearlings (50% overall), so the benefits of dispersal versus philopatry were not clear. Although rarely reported for other species, adult males were an important dispersal cohort in swift foxes (43% of male dispersals and 25% of all dispersals). Because of the female-biased philopatry among swift foxes, dispersal of adult males likely decreased the chances for inbreeding (e.g., father–daughter breeding).

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Lei, Boyu, Jifa Cui, Chris Newman, Christina D. Buesching, Zongqiang Xie, David W. Macdonald e Youbing Zhou. "Seed dispersers shape the pulp nutrients of fleshy-fruited plants". Proceedings of the Royal Society B: Biological Sciences 288, n. 1953 (23 giugno 2021): 20210817. http://dx.doi.org/10.1098/rspb.2021.0817.

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The dispersal-syndrome hypothesis posits that fruit traits are a product of selection by frugivores. Although criticized as adaptationist, recent studies have suggested that traits such as fruit or seed size, colour and odour exhibit signatures that imply selection by animal mutualists. These traits imply nutritional rewards (e.g. lipid, carbohydrate), attracting frugivores; however, this remains incompletely resolved. Here, we investigated whether fruit nutrients (lipid, sugar, protein, vitamin C, water content) moderate the co-adaptation of key disperser-group mutualisms. Multivariate techniques revealed that fruit nutrients assembled non-randomly and grouped according to key dispersal modes. Bird-dispersed fruits were richer in lipids than mammal-dispersed fruits. Mixed-dispersed fruits had significantly higher vitamin C than did mammal- or bird-dispersed fruits separately. Sugar and water content were consistently high irrespective of dispersal modes, suggesting that these traits appeal to both avian and mammalian frugivores to match high-energy requirements. Similarly, protein content was low irrespective of dispersal modes, corroborating that birds and mammals avoid protein-rich fruits, which are often associated with toxic levels of nitrogenous secondary compounds. Our results provide substantial over-arching evidence that seed disperser assemblages co-exert fundamental selection pressures on fruit nutrient trait adaptation, with broad implications for structuring fruit–frugivore mutualism and maintaining fruit trait diversity.

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Just, Michael G., Wade A. Wall, Stacy D. Huskins e Matthew G. Hohmann. "Effects of Landscape Heterogeneity and Disperser Movement on Seed Dispersal". Ecologies 5, n. 2 (11 aprile 2024): 198–217. http://dx.doi.org/10.3390/ecologies5020013.

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The primacy of endozoochory for the maintenance and expansion of many woody plant populations is well known, but seed dispersal is not well understood for most species. This is especially true for rare species, where small population size and low fruit production can limit field- or observation-based experiments. Additionally, the effect of environmental heterogeneity on disperser movement is rarely investigated but has been shown to improve estimates of plant population spatial patterns and dynamics. We used simulation experiments to explore the effects of environmental heterogeneity and disperser movement on Lindera subcoriacea seed dispersal, a rare shrub from the southeastern United States with avian-dispersed seeds. Our experiments incorporated environmental heterogeneity and simulated disperser movement for five bird species, based on either landscape permeability or straight path rules. We anticipated that permeability-based movement would result in greater dispersal distances and seed dispersal effectiveness, which characterizes both quantity and quality. Generally, we did not find differences in seed dispersal between permeability and straight path experiments. However, we did find that permeability-based experiments had greater deposition into suitable habitat during flight (23 vs. 1%). These rare but longer distance depositions may be especially important for plants that are influenced by gap or interpopulation dynamics. We also found consistently greater dispersal into high quality habitats regardless of disperser species in permeability experiments, implying that incorporating species-specific assessments of landscape utilization (occupancy) could influence the effectiveness of seed dispersal. Our study suggests that including environmental heterogeneity in seed dispersal models can provide additional insights not provided by avian parameters (e.g., gut capacity, seed retention time, and flight speed) commonly used to inform dispersal models.

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McLellan, Bruce N., e Frederick W. Hovey. "Natal dispersal of grizzly bears". Canadian Journal of Zoology 79, n. 5 (1 maggio 2001): 838–44. http://dx.doi.org/10.1139/z01-051.

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We studied natal dispersal of grizzly bears (Ursus arctos), a solitary nonterritorial carnivore with a promiscuous mating system, between 1979 and 1998. Dispersal distances for 2-year-olds did not differ between males and females, but by 3 years of age, males had dispersed farther than females, and farther still by 4 years of age. Dispersal of both sexes was a gradual process, occurring over 14 years. From the locations of death, or last annual ranges, it was estimated that 18 males dispersed 29.9 ± 3.5 km (mean ± SE) and 12 females dispersed 9.8 ± 1.6 km. Eleven of these males dispersed the equivalent of at least the diameter of 1 adult male home range, whereas only 3 of the females dispersed at least the diameter of 1 adult female home range. The longest dispersals recorded were 67 km for a male and 20 km for a female. Because the social system consists of numerous overlapping home ranges of both sexes, long dispersal distances may not be required to avoid inbreeding or competition with relatives. Simple models suggest that 61% of the ranges of brother and sister pairs would not overlap, but the home range of every daughter would overlap her father's range. The home range of an estimated 19 ± 4 (mean ± SD) adult males, however, would overlap at least a portion of each female's range, thereby reducing the chance of a female mating with her brother or father. Understanding the dispersal behaviour of grizzly bears is essential for developing conservation strategies. Our results suggest that meta-population reserve designs must provide corridors wide enough for male grizzly bears to live in with little risk of being killed.

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Rehm, E., E. Fricke, J. Bender, J. Savidge e H. Rogers. "Animal movement drives variation in seed dispersal distance in a plant–animal network". Proceedings of the Royal Society B: Biological Sciences 286, n. 1894 (16 gennaio 2019): 20182007. http://dx.doi.org/10.1098/rspb.2018.2007.

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Frugivores play differing roles in shaping dispersal patterns yet seed dispersal distance is rarely quantified across entire communities. We model seed dispersal distance using gut passage times and bird movement for the majority (39 interactions) of known bird–tree interactions on the island of Saipan to highlight differences in seed dispersal distances provided by the five avian frugivores. One bird species was found to be a seed predator rather than a disperser. The remaining four avian species dispersed seeds but differences in seed dispersal distance were largely driven by interspecific variation in bird movement rather than intraspecific variation in gut passage times. The median dispersal distance was at least 56 m for all species-specific combinations, indicating all species play a role in reducing high seed mortality under the parent tree. However, one species—the Micronesian Starling—performed 94% of dispersal events greater than 500 m, suggesting this species could be a key driver of long-distance dispersal services (e.g. linking populations, colonizing new areas). Assessing variation in dispersal patterns across this network highlights key sources of variation in seed dispersal distances and suggests which empirical approaches are sufficient for modelling how seed dispersal mutualisms affect populations and communities.

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van de Meutter, Frank, Robby Stoks e Luc de Meester. "Size-selective dispersal of Daphnia resting eggs by backswimmers ( Notonecta maculata )". Biology Letters 4, n. 5 (15 luglio 2008): 494–96. http://dx.doi.org/10.1098/rsbl.2008.0323.

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Freshwater zooplankton is increasingly used to study effects of dispersal on community and metacommunity structure. Yet, it remains unclear how zooplankton disperses. Clearly, birds and wind play a significant role as zooplankton dispersal agents, but they may not always be the main vectors. This experimental study shows that a cosmopolitan aquatic insect, Notonecta , can be an important vector of cladoceran resting eggs (ephippia). Dispersing Notonecta frequently transported ephippia during flight, with a bias towards smaller ephippia in two species. A similar trend was present at the species level: Daphnia species with smaller ephippia were more often dispersed, suggesting that Notonecta could generate specific colonist communities. In addition, buoyancy appeared a critical trait, as non-floating ephippia of Daphnia magna were never dispersed. Our data suggest that Notonecta could be important dispersers of Daphnia , and that knowledge of dispersal dynamics of Notonecta may be used to predict Daphnia dispersal, colonization and resilience to disturbance.

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Moses, Kara L., e Stuart Semple. "Primary seed dispersal by the black-and-white ruffed lemur (Varecia variegata) in the Manombo forest, south-east Madagascar". Journal of Tropical Ecology 27, n. 5 (2 agosto 2011): 529–38. http://dx.doi.org/10.1017/s0266467411000198.

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Abstract:Seed dispersal is a pivotal ecological process but remains poorly understood on Madagascar, where lemurs are key dispersers. The black-and-white ruffed lemur (Varecia variegata) possesses many behavioural and ecological attributes potentially conducive to effective seed dispersal, but no studies have investigated dispersal patterns in this species. This 3-mo study quantified aspects of the primary seed dispersal patterns generated by two Varecia variegata groups (7 individuals). Feeding and ranging behaviour was quantified using behavioural observation (345.6 h), dispersal quantity and seed identity was determined by faecal analysis, and 10-wk germination trials tested effects of gut passage on germination of four species. Individual lemurs dispersed an estimated 104 seeds d−1, of 40 species. Most seeds were large (>10 mm); the largest was 42 mm long. Gut passage was rapid (mean 4.4 h) and generally increased germination speed and success. Mean and maximum inferred dispersal distances were 180 and 506 m respectively; low compared with many anthropoids, but possibly typical of lemurs. Though limited by a short study period, results suggest that the ruffed lemur is an effective disperser of seeds and possibly a critical disperser of large-seeded species which other frugivores cannot swallow. Loss of large-bodied seed dispersers such as Varecia variegata may have far-reaching ecological consequences including impacts on forest structure and dynamics.

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Caughlin, T. Trevor, Jake M. Ferguson, Jeremy W. Lichstein, Pieter A. Zuidema, Sarayudh Bunyavejchewin e Douglas J. Levey. "Loss of animal seed dispersal increases extinction risk in a tropical tree species due to pervasive negative density dependence across life stages". Proceedings of the Royal Society B: Biological Sciences 282, n. 1798 (7 gennaio 2015): 20142095. http://dx.doi.org/10.1098/rspb.2014.2095.

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Overhunting in tropical forests reduces populations of vertebrate seed dispersers. If reduced seed dispersal has a negative impact on tree population viability, overhunting could lead to altered forest structure and dynamics, including decreased biodiversity. However, empirical data showing decreased animal-dispersed tree abundance in overhunted forests contradict demographic models which predict minimal sensitivity of tree population growth rate to early life stages. One resolution to this discrepancy is that seed dispersal determines spatial aggregation, which could have demographic consequences for all life stages. We tested the impact of dispersal loss on population viability of a tropical tree species, Miliusa horsfieldii, currently dispersed by an intact community of large mammals in a Thai forest. We evaluated the effect of spatial aggregation for all tree life stages, from seeds to adult trees, and constructed simulation models to compare population viability with and without animal-mediated seed dispersal. In simulated populations, disperser loss increased spatial aggregation by fourfold, leading to increased negative density dependence across the life cycle and a 10-fold increase in the probability of extinction. Given that the majority of tree species in tropical forests are animal-dispersed, overhunting will potentially result in forests that are fundamentally different from those existing now.

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Stevenson, Pablo, e Adriana Guzmán. "Seed dispersal, habitat selection and movement patterns in the Amazonian tortoise, Geochelone denticulata". Amphibia-Reptilia 29, n. 4 (2008): 463–72. http://dx.doi.org/10.1163/156853808786230442.

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AbstractThe Amazonian tortoise Geochelone denticulata may play an important role in forest dynamics due to its highly frugivorous diet, ability to disperse viable seeds, and predilection for resting in forest gaps for thermoregulation. The purpose of our study was to evaluate the species' effectiveness as a seed disperser. We measured dispersal quantity (abundance of seeds in feces, frequency of droppings, and population density of the disperser) and dispersal quality (movement patterns, habitat use, germination rates of dispersed seeds, and recruitment probabilities of seedlings) in a SW Amazonian forest, in Peru. Population density was calculated by mark-recapture and line-transect methods. Eight individuals were radio-tracked to monitor habitat use. Diet was described from fecal samples, which were washed to count seeds and for germination experiments. Seedling survival in different environmental conditions was monitored for three plant species. Population densities with mark-recapture estimates (0.15-0.31 individuals/ha) were much higher than with line transects estimates (0.0025 individuals/ha). Diet included fruit of 55 different plant species. Dispersed seeds had high germination rates (average 76%). In spite of their low activity, we documented long seed dispersal distances (average 89.6 m). Tortoises showed a marked preference for the open-canopy swampy forest, where long term recruitment was not favorable for seedlings of the species examined. However, the high solar radiation in this forest type promoted survival of pioneer seedlings in the short term. In conclusion, while G. denticulata did not perform a very efficient role in terms of the quantity of seed dispersal, the species can be considered efficient in many aspects of dispersal quality.

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Più fonti

Tesi sul tema "Dispersal"

Lou, Vega Salvador 1972. "Modelo matemático para o estudo do efeito Allee sobre a dispersão de plantas por agentes e em meios heterogêneos". [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/306712.

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Orientador: Wilson Castro Ferreira Junior
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Matemática Estatística e Computação Científica
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Resumo: Apresentamos um modelo integro - recursivo para a dispersão de uma planta que acopla uma dinâmica de reprodução, com efeito, Allee e uma dinâmica de dispersão em um meio heterogêneo. Propomos um modelo de difusão e sedimentação para derivar núcleos de dispersão teóricos, que representem o padrão de dispersão de sementes gerado por pássaros frugívoros em um meio heterogêneo. O núcleo gerado através do modelo _e capaz de reproduzir o padrão espacial de agregação de sementes gerado pelos pássaros frugívoros sob condições naturais. Enquanto _a dinâmica de reprodução, consideramos um efeito Allee devido à limitação de pólen, que reduz a produção de sementes. Introduzimos o efeito Allee através de uma função de probabilidade que depende da densidade local de plantas. Analisa-se o comportamento da expansão da planta, e estima-se a velocidade média de expansão. O modelo mostra uma invasão através de pulsos, que atribuímos ao efeito Allee e ao comportamento de dispersão da planta
Abstract: We present an integro-difference model for a plant dispersal, which couples a reproductive dynamic with Allee effect and dispersal dynamic in a heterogeneous environment. We propose diffusion and settling model to derive theoretical dispersal kernels that represent the seed dispersal pattern generated by frugivores birds in a heterogeneous environment. The dispersal kernel derived through the model is able to reproduce the aggregate seed dispersal pattern generated by the frugivores birds under field conditions. As for the reproductive dynamic, we consider an Allee effect due to pollen limitation, which reduces seed production. We introduce the Allee effect through a probability function, which depends on the local plant density. The plant expansion behavior is analyzed, and the average expansion speed is estimated. The model shows a pulsed invasion, which we attribute to the Allee effect and the plant dispersal behavior
Doutorado
Matematica Aplicada
Doutor em Matemática Aplicada

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Newell, Simon C. "Dispersal in carabids". Thesis, University of Plymouth, 1986. http://hdl.handle.net/10026.1/2725.

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The study consisted primarily of a number of surveys in brassica fields, using pitfall and gutter traps. At all sites a number of different species of carabids were marked and released. From the pitfall trapping it was found that different carabid species inhabitated different parts of the field, particularly in relation to the field boundaries. Two common species, Nebria brevicollis and Bembidion lampros, over-wintered in the hedgebanks, moving out into the fields in the spring. Two other common species, Pterostichus melanarius and Harpalus rufipes, were primarily associated with the field, but activity in the field boundaries continued later into the year. Marking concentrated on four species; P. cupreus, P. melanarius, H. rufipes and N. brevicollis. At all sites the recapture rate of rufipes was much lower than that of P. melanarius, though they are of similar size. Using this data, mean displacement/day was calculated for each species. To identify the causes for the differences in recapture rate between the species, two species were individually tracked at night, in the field. Positions every two minutes were recorded and the distance and turn between each point measured. The results showed that H. rufipes had a higher turn rate and moved less than melanarius. The data from tracking was incorporated into a computer simulation model which recreated the beetles' tracks, using the same time interval. Traps were added and the model used to simulate the recapture experiments in the field. Changes in dispersal patterns were used to create differences in the catch in different patches. It was found that changes in turning behaviour could not produce changes in density, because of behaviour at the boundaries. Delaying the change in behaviour produces differences in numbers, but orientation is the most likely mechanism. The relationship between step length, turn and catch was also evaluated.

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Heinz, Simone K. "Dispersal in fragmented landscapes : from individual dispersal behaviour to metapopulation dynamics /". Leipzig-Halle : UFZ-Umweltforschungszentrum Leipzig-Halle, 2004. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=015383379&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.

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Ansong, Michael. "Unintentional Human Dispersal of Weed Seed". Thesis, Griffith University, 2016. http://hdl.handle.net/10072/365736.

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Seed dispersal is an important biological process as propagule pressure affects the success of plant invasions. The role and importance of humans in this process is increasingly recognised, particularly in relation to long distance seed dispersal. There is still comparatively limited research on unintentional human-mediated seed dispersal, including for seed dispersed from clothing, compared to other dispersal mechanisms such as wind or seed attached to fur. With more people travelling globally, including to remote locations, humans can unintentionally transport seeds over long distances. This can facilitate biological invasions in urban, rural and remote natural areas when it involves the dispersal of weed seed. Weeds, which are often defined as plants growing in sites where they are not wanted, are a major problem in both natural and agricultural systems. They can reduce biodiversity in natural ecosystems and productivity in agricultural regions, and once established, they are expensive to control or eradicate. Therefore, limiting weed seed dispersal, including over long distances, is important in controlling their spread globally. This thesis examines aspects of unintentional human-mediated weed seed dispersal, using data mining, experimental, modelling and social methods.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Environment
Science, Environment, Engineering and Technology
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Meister, Gerald Alan. "Dispersal of transposable elements". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0019/NQ46389.pdf.

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Clarke, S. A. "Dispersal of Satyrid butterflies". Thesis, Oxford Brookes University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383645.

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Paulson, Matthew David. "Seasonal dispersal of pests". Thesis, University of Bristol, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.529837.

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Bonadonna, Costanza. "Models of tephra dispersal". Thesis, University of Bristol, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367665.

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Lou, Vega Salvador 1972. "Dispersão de longo alcance e efeito Allee em um processo invasivo". [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/306718.

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Orientador: Wilson Castro Ferreira Junior
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica
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Resumo: Proponemos um modelo matemático para uma planta invasora, que acopla a dinâmica de reproduão com Efeito Allee e a dispersão de longa distância de uma planta invasora. Consideramos um efeito Allee devido à limitação de pólen, que reduz a produção de sementes. Introduzimos o efeito Allee através de uma função de probabilidade de encontro pólen-estigma que depende da densidade de plantas. Para a modelagem do processo de dispersão utilizamos equações íntegrorecursiva (IRE) tomando um núcleo de dispersão misto, que representa a dispesão local e a longa distância. Analisamos a dinâmica local do modelo determinando os pontos de equilíbrio e as suas estabilidades, para então analisar o processo de dispersão. Analisamos o modelo de dispersão por meio de simulação numérica, o que permitiu observar o deslocamento espacial da frente da invasão. Isto permitiu calcular a velocidade de expansão. Determinamos a inuência do efeito Allee, da capacidade reprodutiva e da dispersão de longa distância sobre a velocidade de expansão. Observamos que o efeito Allee torna velocidades aceleradas em velocidades constantes de expansão. A velocidade de expansão decresce com o aumento na intensidade do efeito Allee, mas aumenta com a capacidade reprodutiva. A dispersão de longa distância gera maiores velocidades de expansão, embora para fortes intensidades do efeito Allee o acréscimo na velocidade não é signifícativo em relação à velocidade gerada pela dispersão local. Os resultados mostram que apesar da dispersão contribuir ao aumento na velocidade de expansão, a dispersão também torna a população mais suscetável á extinção.
Abstract: We present a mathematical model which couples the reproductive dynamic with an Allee effect and a long distance diseprsal of an invasive plant. We consider an Allee effect due to pollen limitation, which reduces seed production. We introduce the Allee effect through a probability function that describes pollen-stigma encounters as function of the population density. To model the dispersal process we used integro-diference equations (IDE) and employed a mixed kernel which represents the local and long distance dispersal processes. We analyzed the local dynamic through the stability of their equilibrium points. For the spatial dynamic we used numerical simulations, that allowed us to observe the spatial displacement of the invasion front. This permitted us to compute the expansion speeds. We determined the inuence of the Allee effect, reproductive capacity and the long distance diseprsal on the invasion speeds. We observed than an Allee effect turns accelerating expansion speeds into constant speeds. Expansion speeds decreases with Allee effect intensity but increases with the reproductive capacity of the population. Long distance dispersal produces higher invasion speeds, but for strong intensities of the Allee effect, the increase is not significant in relation to the speeds generated by the local dispersal. Our results show that while dispersal contributes to expansion speeds, it also turns the population more susceptible to extinction.
Mestrado
Biomatematica
Mestre em Matemática Aplicada

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Gwynne-Evans, David. "The dispersal paradox : can lowland granivorous mice also disperse the seeds they devour?" Bachelor's thesis, University of Cape Town, 2003. http://hdl.handle.net/11427/24830.

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The relationship between two rodent species and the Cape Reed (Willdenowia incurvata) were examined. Many studies have focussed on the role of rodents as predators of plant seeds. However, it seems that certain rodents may actually perform a crucial role in the dispersal of plants. Experiments to uncover the dispersal mechanism were carried out. Also examined is the role of the appendages present on the Restio seeds, possibly as energy-rich rewards for dispersal for the rodents. It was found that the Restio may be dependent on seed-dispersing rodents, although this mutualism is not so important in fragmented habitats.

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Più fonti

Libri sul tema "Dispersal"

Jean, Clobert, a cura di. Dispersal. Oxford: Oxford University Press, 2001.

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Stenseth, Nils Chr, e William Z. Lidicker, a cura di. Animal Dispersal. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2338-9.

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R, Murray David, a cura di. Seed dispersal. Sydney: Academic Press, 1986.

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Estrada, Alejandro, e Theodore H. Fleming, a cura di. Frugivores and seed dispersal. Dordrecht: Springer Netherlands, 1986. http://dx.doi.org/10.1007/978-94-009-4812-9.

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Robbeets, Martine, e Alexander Savelyev, a cura di. Language Dispersal Beyond Farming. Amsterdam: John Benjamins Publishing Company, 2017. http://dx.doi.org/10.1075/z.215.

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Schroeder, M. A. Dispersal in spruce grouse. [s.l: s.n.], 1985.

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Alejandro, Estrada, e Fleming Theodore H, a cura di. Frugivores and seed dispersal. Dordrecht: W. Junk, 1986.

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K, Geiselman Cullen, Mori Scott A. 1941- e New York Botanical Garden, a cura di. Seed dispersal by bats in the neotropics. Bronx, N.Y: New York Botanical Garden, 2009.

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J, Dennis Andrew, a cura di. Seed dispersal: Theory and its application in a changing world. Oxfordshire: CAB International, 2007.

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Boivin, Nicole, Michael Petraglia e Remy Crassard, a cura di. Human Dispersal and Species Movement. Cambridge: Cambridge University Press, 2017. http://dx.doi.org/10.1017/9781316686942.

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Capitoli di libri sul tema "Dispersal"

Cumming, Jeffrey M., Bradley J. Sinclair, Charles A. Triplehorn, Yousif Aldryhim, Eduardo Galante, Ma Angeles Marcos-Garcia, Malcolm Edmunds et al. "Dispersal". In Encyclopedia of Entomology, 1233. Dordrecht: Springer Netherlands, 2008. http://dx.doi.org/10.1007/978-1-4020-6359-6_947.

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Fenner, Michael. "Dispersal". In Seed Ecology, 38–56. Dordrecht: Springer Netherlands, 1985. http://dx.doi.org/10.1007/978-94-009-4844-0_3.

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Díaz Vélez, M. Celeste, Ana E. Ferreras e Valeria Paiaro. "Seed dispersal interactions promoting plant invasions." In Plant invasions: the role of biotic interactions, 90–104. Wallingford: CABI, 2020. http://dx.doi.org/10.1079/9781789242171.0090.

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Abstract Animal dispersers are essential for many non-native plants since they facilitate seed movement and might promote seed germination and seedling establishment, thereby increasing their chances of invasion. This chapter reviews the published literature on seed dispersal of non-native plant species by native and/or non-native animals. The following questions are addressed: (i) Are interactions between non-native plants and their animal dispersers evenly studied worldwide? (ii) Which are the distinctive traits (i.e. geographical origin, life form, dispersal strategy and propagule traits) of non-native plants that are dispersed by animals? (iii) Which are the most studied groups of dispersers of non-native plants around the world? (iv) Does the literature provide evidence for the Invasional Meltdown Hypothesis (non-native plant-non-native disperser facilitation)? (v) What is the role of animal dispersers at different stages of the non-native plant regeneration process? Our dataset of 204 articles indicates that geographical distribution of the studies was highly heterogeneous among continents, with the highest number coming from North America and the lowest from Asia and Central America. Most of the non-native plants involved in dispersal studies were woody species from Asia with fleshy fruits dispersed by endozoochory. More than the half of the animal dispersal agents noted were birds, followed by mammals, ants and reptiles. The dominance of bird-dispersal interactions over other animal groups was consistent across geographical regions. Although most of the studies involved only native dispersers, interactions among non-native species were detected, providing support for the existence of invasional meltdown processes. Of the total number of reviewed articles reporting seed removal, 74% evaluated seed dispersal, but only a few studies included seed germination (35.3%), seedling establishment (5.4%) or seed predation (23.5%). Finally, we discuss some research biases and directions for future studies in the area.

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Stenseth, N. C., e W. Z. Lidicker. "The study of dispersal: a conceptual guide". In Animal Dispersal, 5–20. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2338-9_1.

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Sinclair, A. R. E. "Do large mammals disperse like small mammals?" In Animal Dispersal, 229–42. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2338-9_10.

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Pusey, A. E. "The primate perspective on dispersal". In Animal Dispersal, 243–59. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2338-9_11.

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Watson, A. "A red grouse perspective on dispersal in small mammals". In Animal Dispersal, 260–73. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2338-9_12.

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Roderick, G. K., e R. L. Caldwell. "An entomological perspective on animal dispersal". In Animal Dispersal, 274–90. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2338-9_13.

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Lidicker, W. Z., e N. C. Stenseth. "To disperse or not to disperse: who does it and why?" In Animal Dispersal, 21–36. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2338-9_2.

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Barton, N. H. "The genetic consequences of dispersal". In Animal Dispersal, 37–59. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2338-9_3.

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Atti di convegni sul tema "Dispersal"

R Scott Greene, B Heath Ward e David L Lindbo. "Remote Wastewater Dispersal Fields". In Eleventh Individual and Small Community Sewage Systems Conference Proceedings, 20-24 October 2007, Warwick, Rhode Island. St. Joseph, MI: American Society of Agricultural and Biological Engineers, 2007. http://dx.doi.org/10.13031/2013.24011.

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Torres Garcia, Bryan. "Gopher Tortoise Seed Dispersal Monitoring". In MME Undergraduate Research Symposium. Florida International University, 2022. http://dx.doi.org/10.25148/mmeurs.010561.

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Gopher tortoises are native to Florida and vital to the ecosystem due to the underground boroughs they build, which provide shelter to other animals, and for their key role in seed dispersion. In order to improve our understanding of the role of gopher tortoises on biodiversity, we aim to investigate the digestive track of gopher tortoises. Data on seed dispersion distance and gut retention time are critical to effective and efficient endangered plant species conservation efforts. In a multidisciplinary project between Department of Earth and Environment, College and Engineering, and the Miami Zoo, we are fabricating an ingestible device to monitor and map the digestive tract of gopher tortoises. The device needs to be properly encapsulated to prevent any harm to the animal. Device encapsulation has been developed, but requires extensive validation before deployment. To mimic the passage of the device and the effect of the gut, device encapsulation is tested on small plastic beads. The integrity of the coating is analyzed by measuring the cross-section thickness. In addition, UV-Vis was used to quantify scratches in the coating. Enclosure for the external trackers were designed and 3D printed to hold in place an external device that serves as a logger and aids in data transmission, placed on the tortoise's shell.

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Yamada, Ryoto, Ryuta Kamiya, Keito Nagata, Lu Dewei, Takashi Inoue e Masahiro Hagino. "Relationship between Flow Field of Cutting Edge and Chip Dispersal during CFRP Drilling". In 2022 International Conference on Machining, Materials and Mechanical Technologies. Switzerland: Trans Tech Publications Ltd, 2024. http://dx.doi.org/10.4028/p-iz9azy.

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Recently, the use of carbon fiber-reinforced plastic (CFRP) has been picking up in aerospace and automotive industries. However, machining of CFRP produces fine cutting chips, which disperse in the machining environment and can be hazardous to workers and machine tools. Therefore, a cutting-chip disposal technology is required to address this problem. This study investigated the chip dispersal behavior during the drilling of CFRP to identify the factors that affect the dispersal of cutting chips. The focus of this study was the airflow field generated by drill rotation. Therefore, a simulation analysis for around the drill edge was used. The results of the drill edge simulation and chip discharge behavior during CFRP drilling were validated experimentally. The results suggested that the airflow field around the drill edge caused by drill rotation did not significantly affected chip dispersal.

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Hideg, Attila, Laszlo Blazovics e Bertalan Forstner. "Uniform dispersal of oblivious mobile robots". In 2016 7th IEEE International Conference on Cognitive Infocommunications (CogInfoCom). IEEE, 2016. http://dx.doi.org/10.1109/coginfocom.2016.7804569.

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Hideg, Attila, Laszlo Blazovics e Bertalan Forstner. "Uniform Dispersal of Cheap Flying Robots". In 2019 10th IEEE International Conference on Cognitive Infocommunications (CogInfoCom). IEEE, 2019. http://dx.doi.org/10.1109/coginfocom47531.2019.9089977.

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Krawczyk, Hugo. "Distributed fingerprints and secure information dispersal". In the twelfth annual ACM symposium. New York, New York, USA: ACM Press, 1993. http://dx.doi.org/10.1145/164051.164075.

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Mar, Kheng Kok, ZhengQing Hu, Chee Yong Law e Meifen Wang. "Securing cloud data using information dispersal". In 2016 14th Annual Conference on Privacy, Security and Trust (PST). IEEE, 2016. http://dx.doi.org/10.1109/pst.2016.7907014.

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Prandle, D. "Effluent Dispersal in European Coastal Waters". In 19th International Conference on Coastal Engineering. New York, NY: American Society of Civil Engineers, 1985. http://dx.doi.org/10.1061/9780872624382.207.

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Gouda, M. G., e E. Jung. "Certificate dispersal in ad-hoc networks". In 24th International Conference on Distributed Computing Systems, 2004. Proceedings. IEEE, 2004. http://dx.doi.org/10.1109/icdcs.2004.1281629.

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KELLER, V. "Status of warm fog dispersal research". In 23rd Aerospace Sciences Meeting. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1985. http://dx.doi.org/10.2514/6.1985-10.

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Rapporti di organizzazioni sul tema "Dispersal"

Parent, M. Polyphase glacial dynamics and clast dispersal patterns in glaciofluvial and glacial sediments in north-central Quebec, with application to diamond exploration. Natural Resources Canada/CMSS/Information Management, 2023. http://dx.doi.org/10.4095/331425.

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The regional dynamics of shifting ice-flow directions and ice-divide migrations were estab-lished in the Saindon-Cambrien corridor of north-central Quebec by two independent means: 1) the measurement of crosscutting striations; and 2) the glacial dispersal patterns of distinctive lithological markers from outliers of the Sakami Formation. Clasts from two outliers were successively dispersed to the north-northeast, northwest, and west-southwest. They form composite dispersal trains consisting of 200 km long ribbon-shaped trains toward the west-southwest and palimpsest trains caused by the westward re-entrainment of dispersal trains formed during earlier flow phases. Widespread evidence of basal sliding and abrasion recorded by striations associated with successive flow systems, together with the development of long dispersal trains, indicates that protracted warm-based conditions prevailed in north-central Quebec. This improved understanding of glacial dynamics and dispersal in the core region of the eastern Laurentide Ice Sheet helps us to interpret the distribution of legacy kimberlite indicator mineral data sets in eskers and to assess the diamond prospectivity of the Saindon-Cambrien corridor.

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Bosey, Lynita Jean. Radiological Dispersal Devices. Office of Scientific and Technical Information (OSTI), gennaio 2018. http://dx.doi.org/10.2172/1417127.

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Seamans, Thomas, e Allen Gosser. Bird dispersal techniques. U.S. Department of Agriculture, Animal and Plant Health Inspection Service, agosto 2016. http://dx.doi.org/10.32747/2016.7207730.ws.

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Conflicts between humans and birds likely have existed since agricultural practices began. Paintings from ancient Greek, Egyptian, and Roman civilizations depict birds attacking crops. In Great Britain, recording of efforts at reducing bird damage began in the 1400s, with books on bird control written in the 1600s. Even so, the problem persists. Avian damage to crops remains an issue today, but we also are concerned with damage to homes, businesses, and aircraft, and the possibility of disease transmission from birds to humans or livestock. Bird dispersal techniques are a vital part of safely and efficiently reducing bird conflicts with humans. The bird must perceive a technique as a threat if it is to be effective. No single technique can solve all bird conflicts, but an integrated use of multiple techniques, each enhancing the other, generally provides relief.

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Paulen, R. C., R. D. King, I. R. Smith e S. J. A. Day. Heavy mineral dispersal studies. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2017. http://dx.doi.org/10.4095/306093.

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Wohletz, K., T. Kunkle e W. Hawkins. KISMET tungsten dispersal experiment. Office of Scientific and Technical Information (OSTI), dicembre 1996. http://dx.doi.org/10.2172/432871.

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Harris, J. R., D. Viljoen, G. F. Bonham-Carter e N. Brown. Dispersal train identification algorithm (DTIA). Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2004. http://dx.doi.org/10.4095/215623.

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Shilts, W. Principles of Glacial Dispersal and Sedimentation. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 1991. http://dx.doi.org/10.4095/132390.

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Kineke, Gail C. Sediment Dispersal from the Apennine Rivers. Fort Belvoir, VA: Defense Technical Information Center, settembre 2002. http://dx.doi.org/10.21236/ada627772.

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Kineke, Gail C. Sediment Dispersal from the Apennine Rivers. Fort Belvoir, VA: Defense Technical Information Center, settembre 2003. http://dx.doi.org/10.21236/ada629753.

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Cummings, D. I., A. L. Bergen, M. D. Pyne e H. A. J. Russell. Glacial dispersal trains in Arctic Canada. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2018. http://dx.doi.org/10.4095/311186.

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