Academic literature on the topic 'Recruitment limitation'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Recruitment limitation.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Recruitment limitation"
1
CHESSON, PETER. "Recruitment limitation: A theoretical perspective." Austral Ecology 23, no. 3 (June 1998): 234–40. http://dx.doi.org/10.1111/j.1442-9993.1998.tb00725.x.
Full text
2
Clark, J. S., B. Beckage, P. Camill, B. Cleveland, J. HilleRisLambers, J. Lichter, J. McLachlan, J. Mohan, and P. Wyckoff. "Interpreting recruitment limitation in forests." American Journal of Botany 86, no. 1 (January 1999): 1–16. http://dx.doi.org/10.2307/2656950.
Full text
3
HAN, Da-Yong, Wei ZHANG, YILIYASI Nuermaimaiti, and Yun-Fei YANG. "Recruitment limitation of plant population regeneration." Chinese Journal of Plant Ecology 45, no. 1 (2021): 1–12. http://dx.doi.org/10.17521/cjpe.2020.0246.
Full text
4
Tilman, David. "COMMUNITY INVASIBILITY, RECRUITMENT LIMITATION, AND GRASSLAND BIODIVERSITY." Ecology 78, no. 1 (January 1997): 81–92. http://dx.doi.org/10.1890/0012-9658(1997)078[0081:cirlag]2.0.co;2.
Full text
5
Morgan, SG, JL Fisher, and AJ Mace. "Larval recruitment in a region of strong, persistent upwelling and recruitment limitation." Marine Ecology Progress Series 394 (November 18, 2009): 79–99. http://dx.doi.org/10.3354/meps08216.
Full text
6
van Eck, W. H. J. M., H. M. van de Steeg, C. W. P. M. Blom, and H. de Kroon. "Recruitment limitation along disturbance gradients in river floodplains." Journal of Vegetation Science 16, no. 1 (2005): 103. http://dx.doi.org/10.1658/1100-9233(2005)016[0103:rladgi]2.0.co;2.
Full text
7
Ellrich, Julius A., Ricardo A. Scrosati, Katharina Romoth, and Markus Molis. "Adult Prey Neutralizes Predator Nonconsumptive Limitation of Prey Recruitment." PLOS ONE 11, no. 4 (April 28, 2016): e0154572. http://dx.doi.org/10.1371/journal.pone.0154572.
Full text
8
Peng, Z., S. Zhou, and D. Y. Zhang. "Dispersal and recruitment limitation contribute differently to community assembly." Journal of Plant Ecology 5, no. 1 (January 12, 2012): 89–96. http://dx.doi.org/10.1093/jpe/rtr041.
Full text
9
Eck, W. H. J. M., H. M. Steeg, C. W. P. M. Blom, and H. Kroon. "Recruitment limitation along disturbance gradients in river flood plains." Journal of Vegetation Science 16, no. 1 (February 2005): 103–10. http://dx.doi.org/10.1111/j.1654-1103.2005.tb02343.x.
Full text
10
Barrett, Juliana Panos, and John A. Silander. "SEEDLING RECRUITMENT LIMITATION IN WHITE CLOVER (TRIFOLIUM REPENS; LEGUMINOSAE)." American Journal of Botany 79, no. 6 (June 1992): 643–49. http://dx.doi.org/10.1002/j.1537-2197.1992.tb14606.x.
Full textDissertations / Theses on the topic "Recruitment limitation"
1
Johansson, Veronika A. "Recruitment ecology and fungal interactions in mycoheterotrophic Ericaceae." Doctoral thesis, Stockholms universitet, Institutionen för ekologi, miljö och botanik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-109160.
Full textAbstract:
There are generally two contrasting alternatives to what limits recruitment in plants, namely the availability of seeds (seed limitation) or the quality or quantity of suitable sites (microsite limitation). Dust seeds, the smallest existing seeds, lack or have minimal nutrient reserves. During germination and initial development they consequently parasitize on mycorrhizal fungi. This is called mycoheterotrophy, and can vary in degree of fungal dependency in adult plants from full, partial or initial mycoheterotrophy. The aim of this thesis was to investigate the recruitment ecology of mycoheterotrophic Ericaceae (tribe Pyroleae) species with dust seeds, and to determine what limits their recruitment. The investigated species were: Chimaphila umbellata, Moneses uniflora, Orthilia secunda, Pyrola chlorantha, P. minor and P. rotundifolia. This aim was achieved by combining field experiments (seed sowing) with isotope analysis and fungal host pyrosequencing. Results provide evidence that the species in Pyroleae are heterogeneous, not only with regard to their degree of mycoheterotrophy, but also concerning germination and early seedling development. A combination of microsite and seed limitation is thus likely to be of importance for all studied species, but the relative importance of these limitations varies among species. Despite having adaptations for wind dispersal the majority of the seeds were deposited in close vicinity of the seed source. But with high seed production at least some seeds should be able to disperse long-distance. Seedlings of all studied species were found to associate with a wide range of ectomycorrhizal fungi, at least during their initial developmental stages. There seems to be a tendency for host narrowing in some Pyroleae species, but not as strict as the host specialization seen in fully mycoheterotrophic Monotropa hypopitys, supporting the hypothesis of geographical and developmental host shifts.At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: In press. Paper 4: Manuscript.
2
Samuels, Ivan. "Invasion of chinese tallow (Sapium sebiferum) a test of dispersal and recruitment limitation in multiple habitats /." [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0004706.
Full text
3
Ens, Emilie-Jane. "Indigenous plant recruitment limitation by bitou bush (Chrysanthemoides monilifera spp. rotundata) effect on life history stages and allelopathic mechanisms /." Access electronically, 2007. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20080910.142510/index.html.
Full text
4
Almoussawi, Ali. "Importance relative des processus de dispersion et de recrutement dans la dynamique d'assemblage des communautés végétales en paysage agricole." Thesis, Amiens, 2019. http://www.theses.fr/2019AMIE0043.
Full textAbstract:
L'absence d'une espèce dans une communauté locale alors qu'elle est présente dans d'autres communautés du même paysage peut être expliquée, soit par une limitation de la dispersion, soit par une limitation du recrutement. Le présent travail vise à évaluer la part respective de ces deux limitations dans l'assemblage de différents types de communauté. J'ai d'abord étudié la relation entre les diversités locale et proximale à différentes échelles et pour différents niveaux de fragmentation forestière dans une matrice de paysage agricole. Les résultats soulignent l'importance de l'identité des espèces lors de l'étude de l'effet de la fragmentation sur la structure de la communauté végétale. J'ai ensuite évalué le succès de la germination et la persistance d'espèces végétales à l'aide d'expériences semi-contrôlées. Dans la première expérience, j'ai étudié le succès de la germination et de la persistance d'espèces adventices des cultures semées, ainsi que leurs effets sur le rendement des cultures, sous des pratiques agricoles contrastées. Nous avons mis en évidence un effet de filtre des pratiques agricoles sur la composition locale en espèces. Dans la deuxième expérience, j'ai évalué le potentiel des haies pour servir d'habitat aux espèces herbacées forestières. J'ai semé et transplanté différentes espèces forestières dans des haies, avec et sans élimination de végétation résidente, afin d'évaluer plus avant le rôle de la compétition. Mes résultats préliminaires montrent que peu d'espèces germent et survivent dans les haies, ce qui suggère des limitations en matière de recrutement et de dispersion. Les résultats de ces travaux soulignent l'importance de la dispersion dans la colonisation de fragments surfaciques ; et du recrutement dans celle d'habitats linéaires. Les conséquences pour la conservation des écosystèmes et le maintien des services fournis sont discutéesThe absence of a species from a focal community may be due to either dispersal limitation or recruitment limitation. The present work aims to assess species behavior in different types of landscapes. I first investigated the relationship between alpha and gamma diversity at different scales and for different fragmentation levels in forest fragments embedded in an agricultural landscape matrix. Results highlight the importance of considering species identity when studying the effect of fragmentation on the plant community structure. I then assessed the germination success and persistence of vascular plant species (weeds and herbaceous plants), using semi-controlled experiments. In the first experiment, I studied the germination and persistence success of sown weed species, and their subsequent effect on crop yield, under contrasted agricultural practices. We evidenced a sorting effect of agricultural practices on local plant species composition. In the second experiment, I assessed the potential of hedgerows to serve as habitats for forest plant species. We sought seeds and transplanted seedlings in both hedgerows and forest to monitor germination and persistence, respectively, each time with and without resident vegetation removal to further assess the role of competition. Our preliminary results show that few species germinate and survive in hedgerows, suggesting that both dispersal and recruitment limitations are at play. Results from this work emphasize the importance of community assembly processes in ecosystem conservation and maintaining its delivered services
5
Berry, Christopher J. J. "Post-dispersal seed predation in a conifer-broadleaf forest remnant : the importance of exotic mammals." Lincoln University, 2006. http://hdl.handle.net/10182/666.
Full textAbstract:
Despite extensive international acceptance of the critical role of mammalian post-dispersal seed predation in many plant communities, in New Zealand we have limited knowledge of these predators’ influence on plant recruitment in our forests. The principle objective of my thesis was to determine the importance of exotic mammals as post-dispersal seed predators in a New Zealand conifer-broadleaf forest remnant. To address this goal, I used a series of field-based experiments where the actions of different post-dispersal seed predators were separated by wire-mesh exclosures. My study was conducted at Mount Peel Forest Park Scenic Reserve, South Canterbury, New Zealand. Being a human modified conifer forest currently dominated by broadleaf species, it is typical of forest remnants in New Zealand. This presented an opportunity to study a wide range of both potential post-dispersal seed predators and broadleaf tree species. My findings indicate that exotic mammals are not only post-dispersal seed predators at Peel Forest, but are responsible for the majority of post-dispersal predation events observed. Ship rats (Rattus rattus) were the dominant post-dispersal seed predators, while brushtail possums (Trichosurus vulpecula), house mice (Mus musculus) and native invertebrates were also important post-dispersal seed predators for several tree species. Through use of time-lapse video and cafeteria experiments I found that exotic mammalian seed predators, when compared to native invertebrate seed predators, preyed upon larger-seeded plant species and were responsible for considerable seed losses of several tree species. However, exotic mammalian seed predators do share several foraging characteristics with native invertebrate seed predators, as predators foraged in similar habitats and responded in a similar way to changes in seed density. In investigating if post-dispersal seed predation by mammals had a flow-on effect to plant recruitment, I observed natural seedling densities at Peel Forest were significantly higher in the absence of mammalian seed predators, but I found no evidence that the presence of mammals significantly altered the overall species richness. At the community level, I did not find an interaction between habitat and exotic mammals, however I present evidence that for individual plant species a significant mammal : habitat interaction occurred. Consequently, even though my cafeteria experiment implied there was no significant difference in the overall amount of seed preyed upon within different habitats, the less favourable microsite conditions for germination under an intact continuous canopy allows mammals to exacerbate habitat-related patterns of seed mortality and have a noticeable effect on seedling establishment. In an effort to validate the use of manipulative experiments to predict the long-term effect of post-dispersal seed predation on plant dynamics, I attempted to link results of my cafeteria experiment with observed seedling abundance at Peel Forest. Seven tree species were used in this comparison and a strong correlation was observed. This result shows that the level of post-dispersal seed predation determined in the cafeteria experiment provided a good predictor of the effect of mammalian post-dispersal seed predation on seedling establishment. To fully gauge the impact of mammalian post-dispersal seed predators on seedling establishment, the relationship between these seed predators and the type of recruitment limitation experienced by a plant species was also investigated. By using a combination of seed addition, plot manipulations and seed predator exclusion I was able to investigate this relationship. I found evidence that seed limitation at Peel Forest is positively correlated with seed size, and that while mammalian post-dispersal seed predators can further reduce plant recruitment of plant species experiencing seed limitation, the influence of mammals in determining plant recruitment was limited for plant species experiencing microsite limitation. My study has proven that exotic mammals are now the dominant post-dispersal seed predators at Peel Forest, the amount of seed preyed upon varies among plant species, and post-dispersal seed predation by mammalian species can lead to differences in seedling richness and abundance. I proved that the influence of exotic mammals on seedling establishment is also linked to habitat structure and recruitment limitations. When combined these observations suggest that exotic mammalian post-dispersal seed predators may play an important role in determining landscape abundance and distribution of plants at Peel Forest.
6
MacDougall, Andrew Stewart. "Joint effects of competition, recruitment limitation, and fire suppression in an invaded oak savanna ecosystem." Thesis, 2004. http://hdl.handle.net/2429/15990.
Full textAbstract:
Competition is often assumed to determine relative abundance in plant communities, especially in the absence of disturbance. At the community level, however, the relationship between competitive ability and abundance is rarely tested. Emerging evidence supports an alternative model where species abundance is determined as much or more by differences in dispersal ability. If true, this suggests that factors that restrict dispersal in contemporary landscapes, such as habitat fragmentation, may be more limiting for native species than competition by invasive flora. I tested the relative importance of competition and dispersal in an invaded and fire-suppressed oak savanna in southwestern British Columbia. Dominance by two exotic perennial grasses strongly suggests that competition is restricting the occurrence of native flora, many of which are presently rare. Extreme fragmentation of this savanna (habitat loss > 95%), however, suggests that dispersal may also limit their occurrence. I explored these alternatives using a combination of experimental (field and glasshouse) and biogeographical approaches. My results confirmed the importance of competition for structuring this plant community. Removal of the dominant grasses greatly increased the cover of previously subordinate native forbs. A pair-wise competition experiment revealed that the most abundant species, the invasive perennial grass Poa pratensis, dominates by limiting light availability and recruiting by tillering in the light-limited understory. Seed addition experiments, however, also confirmed the importance of recruitment limitation for native species. Despite low light, most native species established and survived in the grass sward. B y reducing the dominant grasses and eliminating the litter layer, experimental burning increased the survival of added species but was not a necessary pre-condition for recruitment. For community structure generally, burning transformed the savanna from a grass-dominated system to one dominated by native forbs. However, because forbs are substantially less productive than grasses, litter levels dropped so that fire could not occur continuously over time, which in turn favours recruitment by grasses. Based on these results, I surmise that this system formerly oscillated between domination by grasses and forbs with fire. Long-term fire suppression explains the domination by grasses in many remnant areas presently. In combination, my work revealed that competition and dispersal interact to structure this oak savanna. Disturbance, soil depth, and annual variations in climate also have an impact on the interaction of these two factors.Science, Faculty of
Botany, Department of
Graduate
7
Padgett, Trevor Clive, and Trevor Clive Padgett. "An Assessment of Recruitment Limitation of Ficus benjamina var. bracteata (Moraceae) in a Seasonal Karst Forest in Southern Taiwan." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/25341286483834584963.
Full textAbstract:
碩士國立東華大學
自然資源與環境學系
102
Tropical forests are the most diverse terrestrial ecosystems on Earth. Despite consistent effort and multiple hypotheses there remains no clear answer as to why they are so diverse or how they stay so diverse. Of the many hypotheses that aim to explain this excessively high diversity, recruitment limitation stands out as a highly important and influential process. This study assesses the mechanisms driving recruitment limitation in a population of Ficus. benjamina var. bracteata in a sub-tropical seasonal karst forest of Taiwan. To understand this process in this species of fig, five components of recruitment were studied: fecundity, seed viability, seed arrival, seed predation and microsite. During the study period between (February) 2012 to (March) 2013, the individuals present in the 10-ha forest plot produced approximately 1.26 crops per year, but with only 0.02% potential seed production during the entire study period. Seeds produced were of high quality, with an average 96% germination rate. Additionally, these seeds were found to germinate well on all substrates tested such as tree branches, coral rock and soil, when moisture was available. When moisture was limited germination potential decreased significantly. Further, based on seed trap arrival data, 43 out of 72 traps received no fig seeds or syconia over the entire 6-year period for which there is data, indicating strong limitation in seed distribution. It is concluded that fecundity, seed distribution, and microsite condition are the main bottlenecks contributing to the observed recruitment limitation in this population, it is further suggested that the water limiting features of a seasonal karst forest enhance these recruitment bottlenecks. Figs are exceptionally important to many forest ecosystems, especially seasonal forests where fruit production is lower than more aseasonal forests. While their recruitment limitation may not offer substantial impacts on forest ecology in the short term, the lack of recruitment is important as a long term consequence to population maintenance and resource availability. This raises interesting questions about fig longevity and the persistence potential of this notoriously recruitment limited genus.
8
Gabler, Christopher. "Restoration ecology of ecosystems invaded by Triadica sebifera (Chinese tallow tree): theory and practice." Thesis, 2012. http://hdl.handle.net/1911/71650.
Full textAbstract:
Invasive exotic species threaten biodiversity and ecosystem functions globally, creating need for and encumbering ecological restoration. When restoring exotic plant-dominated ecosystems, reinvasion pressure is the rate of new exotic recruitment following mature exotic removal. It can vary broadly among similarly invaded habitats and is crucial to restoration outcomes and costs, but is difficult to predict and poorly understood.
Initial results from the experimental restoration of a wetland dominated by Triadica sebifera led us to develop the ‘outgrow the stress’ hypothesis. It holds: (1) Variation in reinvasion pressure is driven by differences in propagule abundance and spatiotemporal availability of realized recruitment windows, which are defined by abiotic conditions and biotic interactions. (2) Differences in reinvasion pressure become masked by exotic dominance when increases in niche breadth during development enable exotic persistence across sites where recruitment windows range from frequent to episodic.
We validated this hypothesis. First, we used greenhouse and field experiments to quantify Triadica’s moisture niche early in development. By two months post-germination, seedling tolerances broadened to include conditions unsuitable for germination. This clearly demonstrated a rapid ontogenetic niche expansion, which could decouple mature Triadica density and average reinvasion pressure.
Second, we used a greenhouse mesocosm experiment to quantify how recruitment window duration, competition and fertility impacted population-level Triadica establishment in stressful environments. As ‘outgrow the stress’ predicts, longer windows increased Triadica success and multi-factor interactions were common, with competition and fertility effects varying among environmental contexts.
Third, we substantiated predictions of ‘outgrow the stress’ regarding propagule availability and soil moisture by manipulating these in a multi-site field experiment spanning eleven experimental restorations of Triadica-dominated habitats along a moisture gradient. Triadica reinvasion pressure varied broadly among sites but correlated with moisture and fertility. Propagule availability drove reinvasion in favorable environments, but availability of suitable conditions trumped propagules in extreme environments. Competition reduced Triadica performance and sometimes survival. Triadica prevalence reduced native plant prevalence. Six restorations require minimal Triadica management for success.
This work advances our understanding and enables better predictions of reinvasion pressure and invasions in general. Accurate predictions enhance restoration efficiency by informing site selection and optimal management strategies.
9
Kladivová, Anna. "Význam regenerace ze semen pro změny druhového složení v důsledku pastvy." Master's thesis, 2010. http://www.nusl.cz/ntk/nusl-295845.
Full textAbstract:
Despite its long tradition in our country, livestock grazing almost disappeared from Czech landscape. This form of land use has winded down in the middle of 20th century, when compulsory co-operative farming was introduced. Decrease of pasturage is especially visible on fragmented areas of steep slopes and in dry places. These areas are often highly valuable and protected for its nature richness. When a grazing management is introduced, its effects on plant species communities are not clear. Also the exact mechanisms of vegetation changes caused by grazing are often unknown. In 2005, administration of PLA Český kras reinstated grazing management as a mean of preservation of dry grassland ecosystems. As part of this project I studied, how generative regeneration contributes to vegetation changes. The aim of the present study is to ascertain: a) how is seedling recruitment and survival affected by grazing, b) what are limitations of generative reproduction, and c) what is the contribution of soil seed bank to vegetation changes. In 2005, monitoring of seedling recruitment and survival had started, repetitive sowing experiment was performed and species composition of persistent seed bank was analyzed. Grazing had a positive effect on seedling - both numbers of seedling and their species composition....
Book chapters on the topic "Recruitment limitation"
1
Josefson, Alf B. "Resource limitation in marine soft sediments — differential effects of food and space in the association between the brittle-star Amphiura filiformis and the bivalve Mysella bidentata?" In Recruitment, Colonization and Physical-Chemical Forcing in Marine Biological Systems, 297–305. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-017-2864-5_24.
Full text
2
Posthumus, Jan. "Conclusion, Limitations, and Recommendations." In Use of Market Data in the Recruitment of High Potentials, 149–58. Wiesbaden: Springer Fachmedien Wiesbaden, 2015. http://dx.doi.org/10.1007/978-3-658-10376-7_5.
Full text
3
Rosen, H., and S. Gordon. "The contribution and limitations of CR3-dependent recruitment of macrophages to inflammatory and lymphoid sites." In Mononuclear Phagocytes, 21–30. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-015-8070-0_3.
Full text
4
Mieriņa, Inta. "An Integrated Approach to Surveying Emigrants Worldwide." In IMISCOE Research Series, 13–33. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-12092-4_2.
Full textAbstract:
Abstract This chapter describes the research design applied in the research project The Emigrant Communities of Latvia: National Identity, Transnational Relations and Diaspora Politics, which forms the empirical core of this volume. It discusses this methodology in the context of other migration studies and major surveys on migration. Compared to previous studies The Emigrant Communities of Latvia is the most inclusive in terms of the target audience. All Latvians and Latvian nationals abroad were invited to participate in the survey, applying a broad and open definition of ‘Latvian diaspora’ based on personal identification with the Latvian nation and/or citizenship. Being Web-based, the survey did not impose any limitations as to geographic location, aiming at all countries in the world. Combining a wide range of respondent recruitment channels and techniques and supported by a media campaign, the survey reached 14,068 respondents in 118 countries. Innovative solutions were used to increase response rates and to decrease attrition. Several research topics in this study required separate qualitative research approaches. Thus, 159 partly-structured in-depth interviews were also conducted in countries where the Latvian diaspora is largest, as well as in-depth interviews with return migrants and diaspora policy experts. The new methodology has far-reaching potential to be applied to the study of other migrant groups in Europe and beyond. Importantly, The Emigrant Communities of Latvia project has tested and empirically proven the potential of Web surveys in collecting the opinions of large populations of migrants in many countries.
5
"Biology, Management, and Protection of North American Sturgeon." In Biology, Management, and Protection of North American Sturgeon, edited by Paul J. Anders, Diana L. Richards, and Madison S. Powell. American Fisheries Society, 2002. http://dx.doi.org/10.47886/9781888569360.ch6.
Full textAbstract:
<em>Abstract.</em>—The Kootenai River ecosystem in Idaho, Montana and British Columbia, Canada has been altered and degraded during the past 75 years. By the mid-1960s, phosphorus concentrations increased 15-fold, and nitrogen doubled from baseline conditions in the Kootenai River due to municipal and industrial development. Pollution abatement beginning in the late 1960s, and subsequent impoundment of the Kootenai River (Libby Dam 1972) reversed this culturally eutrophic condition. By the mid-1990s the Kootenai River was classified as ultraoligotrophic, as it remains today. Reverberating trophic responses to cultural denutrification were temporally correlated with the collapse of the functional Kootenai River ecosystem and its endemic white sturgeon <em>Acipenser transmontanus</em> population. Natural recruitment of white sturgeon in the Kootenai River has been virtually absent during the past 30 years, with several exceptions. In response to consistent natural recruitment failure, the Kootenai River white sturgeon population was listed as endangered on September 6, 1994, under the U.S. Endangered Species Act. Depressed biological productivity, alteration of spawning and rearing habitats, fish species abundance changes, altered predator–prey dynamics, and consistent white sturgeon recruitment failure constituted biological (ecological) responses to Kootenai River Basin development. We propose an integrated hypothesis to explain natural recruitment failure in the Kootenai River white sturgeon population. This hypothesis suggests that, during some years, natural recruitment failure may have been caused by female stock limitation. In other years (those lacking female stock-limitation), we propose that recruitment failure was due to one or more postspawning early life mortality factors.
6
"Biology, Management, and Protection of North American Sturgeon." In Biology, Management, and Protection of North American Sturgeon, edited by Henriette I. Jager, Webster Van Winkle, James A. Chandler, Ken B. Lepla, Phil Bates, and Timothy D. Counihan. American Fisheries Society, 2002. http://dx.doi.org/10.47886/9781888569360.ch11.
Full textAbstract:
<em>Abstract.</em>—Five of the nine populations of white sturgeon <em>Acipenser transmontanus</em>, located between dams on the Middle Snake River, have declined from historical levels and are now at risk of extinction. One step towards more effectively protecting and managing these nine populations is ranking factors that influence recruitment in each of these river segments. We developed a model to suggest which of seven mechanistic factors contribute most to lost recruitment in each river segment: (1) temperature-related mortality during incubation, (2) flow-related mortality during incubation, (3) downstream export of larvae, (4) limitation of juvenile and adult habitat, (5) mortality of all ages during summer episodes of poor water quality in reservoirs, (6) entrainment mortality of juveniles and adults, and (7) angling mortality. We simulated recruitment with, and without, each of the seven factors, over a typical series of hydrologic years. We found a hierarchical pattern of limitation. In the first tier, river segments with severe water quality problems grouped together. Poor water quality during summer had a strong negative effect on recruitment in the river segments between Swan Falls Dam and Hell’s Canyon Dam. In the second tier, river segments with better water quality divided into short river segments and longer river segments. Populations in short river segments were limited by larval export. Populations in longer river segments tended to be less strongly limited by any one factor. We also found that downstream effects could be important, suggesting that linked populations cannot be viewed in isolation. In two cases, the effects of a factor on an upstream population had a significant influence on its downstream neighbors.
7
Giménez, Luis. "Phenotypic Plasticity and Phenotypic Links in Larval Development." In Developmental Biology and Larval Ecology, 285–309. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780190648954.003.0010.
Full textAbstract:
Marine crustaceans show a suite of phenotypically plastic responses to the environment, with some restricted to the larval phase and others transcending life history boundaries, linking life phases or generations. Maternal effects include the effects of allocation of reserves into eggs as well as effects of the embryonic environment on tolerance to low salinity or larval body mass. Within the larval phase, there is a diversity of plastic responses involving changes in body size, growth, and developmental rate; they can occur within the molt cycle, involve several molting stages, or result in the development of alternative pathways characterized by the different larval stages. In feeding larvae, the effects of stressors on body mass may be attenuated by delayed development; however, in nonfeeding larvae (e.g., barnacle cyprids), delayed metamorphosis reduces juvenile body size and habitat selectivity. Also, larval food limitation and increased temperatures away from the optimum lead to reduced body mass during metamorphosis. Overall, many of these responses are adaptive and lead to the maintenance of basic functions at the expense of morphogenesis and growth. Some plastic responses that lead to changes in size during metamorphosis can also have consequences for juvenile size growth and survival. These “latent effects” appear to represent forms of developmental trade-offs and may have important ecological and evolutionary consequences. Larval plasticity, by generating phenotypic variation, may influence the capacity to compete, capture resources, tolerate stressors, and, ultimately, may affect recruitment dynamics. In addition, plastic responses linking life history stages also result in genetic links and hence drive the evolution of crustaceans with complex life cycles.
8
Chambers, Silvana, and Kim Nimon. "Conducting Survey Research Using MTurk." In Crowdsourcing, 410–39. IGI Global, 2019. http://dx.doi.org/10.4018/978-1-5225-8362-2.ch022.
Full textAbstract:
This chapter presents an introduction to crowdsourcing for survey participant recruitment. It also discusses best practices and ethical considerations for conducting survey research using Amazon Mechanical Turk (MTurk). Readers will learn the benefits, limitations, and trade-offs of using MTurk as compared to other recruitment services, including SurveyMonkey and Qualtrics. A synthesis of survey design guidelines along with a sample survey are presented to help researchers collect the best quality data. Techniques, including SPSS and R syntax, are provided that demonstrate how users can clean resulting data and identify valid responses for which workers could be paid. An overview and syntax for conducting longitudinal studies is provided as well.
9
Chambers, Silvana, and Kim Nimon. "Conducting Survey Research Using MTurk." In Social Entrepreneurship, 639–69. IGI Global, 2019. http://dx.doi.org/10.4018/978-1-5225-8182-6.ch033.
Full textAbstract:
This chapter presents an introduction to crowdsourcing for survey participant recruitment. It also discusses best practices and ethical considerations for conducting survey research using Amazon Mechanical Turk (MTurk). Readers will learn the benefits, limitations, and trade-offs of using MTurk as compared to other recruitment services, including SurveyMonkey and Qualtrics. A synthesis of survey design guidelines along with a sample survey are presented to help researchers collect the best quality data. Techniques, including SPSS and R syntax, are provided that demonstrate how users can clean resulting data and identify valid responses for which workers could be paid. An overview and syntax for conducting longitudinal studies is provided as well.
10
Chambers, Silvana, and Kim Nimon. "Conducting Survey Research Using MTurk." In Advances in Library and Information Science, 258–88. IGI Global, 2018. http://dx.doi.org/10.4018/978-1-5225-5164-5.ch016.
Full textAbstract:
This chapter presents an introduction to crowdsourcing for survey participant recruitment. It also discusses best practices and ethical considerations for conducting survey research using Amazon Mechanical Turk (MTurk). Readers will learn the benefits, limitations, and trade-offs of using MTurk as compared to other recruitment services, including SurveyMonkey and Qualtrics. A synthesis of survey design guidelines along with a sample survey are presented to help researchers collect the best quality data. Techniques, including SPSS and R syntax, are provided that demonstrate how users can clean resulting data and identify valid responses for which workers could be paid. An overview and syntax for conducting longitudinal studies is provided as well.
Conference papers on the topic "Recruitment limitation"
1
Līce, Anita, and Biruta Sloka. "Which skills, competencies and attitudes are employers looking for in recruitment process in Latvia?" In Contemporary Issues in Business, Management and Economics Engineering. Vilnius Gediminas Technical University, 2019. http://dx.doi.org/10.3846/cibmee.2019.058.
Full textAbstract:
Purpose – the purpose of the study is to evaluate the opinion of employers on the importance of employability competencies in recruitment in Latvia, considering increasingly global and changing labour market. Research methodology – total of 750 companies participated in this research. A list of 17 skills, competencies and attitudes, important for individual employability in changing labour markets, was rated using a four-point Likert scale. Findings – the research results show that employers value attitudes, emotional and self-management competencies the most when hiring potential employees, which are followed by social competencies. Although academic skills were assessed as the least important in the list of all competencies, the majority of employers consider academic skills important in the recruitment process. Research limitations – as this research is not sector-specific, it is limited only to those competencies that can be equally applicable to all occupations. Practical implications – research provides valuable, easily acquirable information for various stakeholders in the area of human resource planning and development, including educational institutions which aim to update programmes to facilitate graduate employability. Originality/Value – research offers three complex factors explaining the elements of individual employability, based on empirical analysis
Reports on the topic "Recruitment limitation"
1
McPhedran, R., K. Patel, B. Toombs, P. Menon, M. Patel, J. Disson, K. Porter, A. John, and A. Rayner. Food allergen communication in businesses feasibility trial. Food Standards Agency, March 2021. http://dx.doi.org/10.46756/sci.fsa.tpf160.
Full textAbstract:
Background: Clear allergen communication in food business operators (FBOs) has been shown to have a positive impact on customers’ perceptions of businesses (Barnett et al., 2013). However, the precise size and nature of this effect is not known: there is a paucity of quantitative evidence in this area, particularly in the form of randomised controlled trials (RCTs). The Food Standards Agency (FSA), in collaboration with Kantar’s Behavioural Practice, conducted a feasibility trial to investigate whether a randomised cluster trial – involving the proactive communication of allergen information at the point of sale in FBOs – is feasible in the United Kingdom (UK). Objectives: The trial sought to establish: ease of recruitments of businesses into trials; customer response rates for in-store outcome surveys; fidelity of intervention delivery by FBO staff; sensitivity of outcome survey measures to change; and appropriateness of the chosen analytical approach. Method: Following a recruitment phase – in which one of fourteen multinational FBOs was successfully recruited – the execution of the feasibility trial involved a quasi-randomised matched-pairs clustered experiment. Each of the FBO’s ten participating branches underwent pair-wise matching, with similarity of branches judged according to four criteria: Food Hygiene Rating Scheme (FHRS) score, average weekly footfall, number of staff and customer satisfaction rating. The allocation ratio for this trial was 1:1: one branch in each pair was assigned to the treatment group by a representative from the FBO, while the other continued to operate in accordance with their standard operating procedure. As a business-based feasibility trial, customers at participating branches throughout the fieldwork period were automatically enrolled in the trial. The trial was single-blind: customers at treatment branches were not aware that they were receiving an intervention. All customers who visited participating branches throughout the fieldwork period were asked to complete a short in-store survey on a tablet affixed in branches. This survey contained four outcome measures which operationalised customers’: perceptions of food safety in the FBO; trust in the FBO; self-reported confidence to ask for allergen information in future visits; and overall satisfaction with their visit. Results: Fieldwork was conducted from the 3 – 20 March 2020, with cessation occurring prematurely due to the closure of outlets following the proliferation of COVID-19. n=177 participants took part in the trial across the ten branches; however, response rates (which ranged between 0.1 - 0.8%) were likely also adversely affected by COVID-19. Intervention fidelity was an issue in this study: while compliance with delivery of the intervention was relatively high in treatment branches (78.9%), erroneous delivery in control branches was also common (46.2%). Survey data were analysed using random-intercept multilevel linear regression models (due to the nesting of customers within branches). Despite the trial’s modest sample size, there was some evidence to suggest that the intervention had a positive effect for those suffering from allergies/intolerances for the ‘trust’ (β = 1.288, p<0.01) and ‘satisfaction’ (β = 0.945, p<0.01) outcome variables. Due to singularity within the fitted linear models, hierarchical Bayes models were used to corroborate the size of these interactions. Conclusions: The results of this trial suggest that a fully powered clustered RCT would likely be feasible in the UK. In this case, the primary challenge in the execution of the trial was the recruitment of FBOs: despite high levels of initial interest from four chains, only one took part. However, it is likely that the proliferation of COVID-19 adversely impacted chain participation – two other FBOs withdrew during branch eligibility assessment and selection, citing COVID-19 as a barrier. COVID-19 also likely lowered the on-site survey response rate: a significant negative Pearson correlation was observed between daily survey completions and COVID-19 cases in the UK, highlighting a likely relationship between the two. Limitations: The trial was quasi-random: selection of branches, pair matching and allocation to treatment/control groups were not systematically conducted. These processes were undertaken by a representative from the FBO’s Safety and Quality Assurance team (with oversight from Kantar representatives on pair matching), as a result of the chain’s internal operational restrictions.