scholarly journals Comparative demography of two common scleractinian corals:Orbicella annularisandPorites astreoides

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3906 ◽  
Author(s):  
Francisco J. Soto-Santiago ◽  
Alex Mercado-Molina ◽  
Koralis Reyes-Maldonado ◽  
Yaileen Vélez ◽  
Claudia P. Ruiz-Díaz ◽  
...  
Keyword(s):  
Survival Rates ◽  
First Year ◽  
Vital Rates ◽  
Porites Astreoides ◽  
Population Growth Rates ◽  
Comparative Demography ◽  
Population Matrix Model ◽  
Similar Survival ◽  
Demographic Patterns ◽  
Management And Conservation

BackgroundStudies directed at understanding the demography and population dynamics of corals are relatively scarce. This limits our understanding of both the dynamics of coral populations and our capacity to develop management and conservation initiatives directed at conserving such ecosystems.MethodsFrom 2012 to 2014, we collected data on the growth, survival, and recruitment rates of two common Caribbean coral species, the stress-tolerantOrbicella annularisand the weedyPorites astreoides. A set of size-based population matrix model was developed for two localities in Northeastern Puerto Rico and used to estimate population growth rates (λ) and determine the life cycle transition(s) that contribute the most to spatiotemporal differences in λs. The model was parameterized by following the fate of 100 colonies of each species at the two sites for two years.ResultsOur data indicate that spatial variability in vital rates of both species was higher than temporal variability. During the first year, populations ofO. annularisexhibited λs below equilibrium at Carlos Rosario (0.817) and Palomino (0.694), followed by a considerable decline at both sites during the second year (0.700 and 0.667). Populations ofP. astreoidesshowed higher λs thanO. annularisduring the first census period at Carlos Rosario (0.898) and Palomino (0.894) with a decline at one of the sites (0.681 and 0.893) during the second census period. Colony fate in both species exhibited a significant interaction with respect to location but not to time (G2 = 20.96;df= 3 forO. annularisandG2 = 9.55;df= 3 forP. astreoides).DiscussionThe similar variability of λs as well as the similar survival rates for both species during the two-year census period (2012–2014) show similar variability on demographic patterns in space and time. Our results suggest that location rather than time is important for the resiliency in coral colonies. Also,P. astreoideswill show higher resistance to disturbance in the future thanO. annularis.

scholarly journals Demographic cost and mechanisms of adaptation to environmental stress in resurrected Daphnia

2016 ◽  
Vol 75 (s2) ◽  
Author(s):  
Stefan Sommer ◽  
Roberta Piscia ◽  
Marina M. Manca ◽  
Diego Fontaneto ◽  
Arpat Ozgul
Keyword(s):  
Population Growth ◽  
Life Table ◽  
Survival Rates ◽  
Copper Tolerance ◽  
Lower Probability ◽  
Vital Rates ◽  
Population Growth Rates ◽  
Life Table Response Experiments ◽  
Reproductive Rates ◽  
Table Data

A characteristic feature of the <em>Daphnia</em> (Crustacea: Cladocera) life cycle are the so-called ephippia, which are fertilised eggs that need to undergo diapause. When they are shed by the female, they sink to the lake bottom, where they may become embedded in the sediment and may remain viable for decades. Extracting and hatching ephippia in the laboratory and subjecting resurrected lineages to conditions representative of historic lake environments allows retrospective investigation of life-history responses to environmental change. Here we reanalyse data from such a resurrection experiment (Piscia <em>et al.</em>, 2015: Bull. Environ. Contam. Toxicol. 94:46–51). Contemporary and past lineages of <em>Daphnia galeata</em> Sars 1863 were obtained from Lake Orta (Italy), a deep, subalpine lake with a well-documented history of industrial copper pollution. Experimental <em>Daphnia</em> were subjected to three copper treatments representative of two levels of historic as well as to current (i.e., unpolluted) lake conditions, and life-table data were collected. With these data at hand, we first estimated vital rates (survival, maturation, and reproduction) and used these rates to project the asymptotic population growth rates (<em>λ</em>) for each population-by-treatment combination. Next, we performed life-table response experiments (LTRE) to estimate the contributions of the vital rates to observed differences in <em>λ</em>. Finally, we used elasticity analysis to explore the functional relationship between <em>λ</em> and each of the vital rates. We found that survival rates were only compromised at elevated copper levels. Moreover, past, resurrected <em>Daphnia</em> had a higher <em>λ</em> at low copper concentrations compared to unpolluted conditions, but a lower <em>λ</em> when exposed to high copper levels. Contemporary <em>Daphnia</em>, on the other hand, only reproduced successfully in unpolluted water. Under these conditions, however, they had a higher population growth rate than the past <em>Daphnia</em>, suggesting a cost of copper tolerance in the latter. This cost was mainly due to a lower probability of reproduction and reduced fecundity, whereas survival remained largely unaffected. Finally, we found higher elasticity values of <em>λ</em> to survival than to reproductive rates. This suggests that any change in the environment that will affect survival rather than reproductive parameters will have a much larger impact on Lake Orta’s current <em>Daphnia</em> population.<em></em>

Demography and life history of two rattan species, Eremospatha macrocarpa and Laccosperma secundiflorum, in Côte d'Ivoire

2008 ◽  
Vol 24 (05) ◽  
pp. 493-503 ◽  
Author(s):  
Kouadio I. Kouassi ◽  
Sébastien Barot ◽  
Jacques Gignoux ◽  
Irié A. Zoro Bi
Keyword(s):  
Cote D'ivoire ◽  
Life Histories ◽  
Côte D’Ivoire ◽  
Survival Rates ◽  
Juvenile Stage ◽  
Vital Rates ◽  
Cote D’Ivoire ◽  
Population Growth Rates ◽  
Côte D'ivoire ◽  
Trade Offs

Abstract:Two rattans species were studied in Côte d'Ivoire using a stage-classified matrix model to compare their demography and life histories. Respectively 854 and 1009 genets ofEremospatha macrocarpa(pleonanthic) andLaccosperma secundiflorum(hapaxanthic) were censused every 6 mo over 18 mo. The population growth rates ofE. macrocarpa(λ = 0.979) andL. secundiflorum(λ = 0.959) were not significantly different from 1. This indicates that the populations were close to equilibrium. However, the difference between the stable stage distributions and the observed distributions indicated temporal variation in vital rates. Elasticity analysis showed that growth and fecundity had lower contributions to λ than the survival rates for the two species. A Life Table Response Experiment revealed that the survival of the first juvenile stage (all stems &lt; 6 m in length), fecundity, growth of the second juvenile stage (at least one stem &gt; 6 m in length) and adult (reproductive) survival highly contribute to the differences between the demography of the two species. Reproduction is postponed longer forL. secundiflorumthan forE. macrocarpaand the mean remaining life span for adult genets is shorter forL. secundiflorumthan forE. macrocarpa. Finally, our results suggest the existence of two trade-offs within reproduction which suggest that, although the two species have different demographic features, the λ of their populations are not significantly different from 1.

Inbreeding depression and floral type fitness differences in Viola canadensis (Violaceae), a species with chasmogamous and cleistogamous flowers

2000 ◽  
Vol 78 (11) ◽  
pp. 1420-1429 ◽  
Author(s):  
Theresa M Culley
Keyword(s):  
Inbreeding Depression ◽  
Survival Rates ◽  
Early Life History ◽  
Flower Number ◽  
Life History Stages ◽  
The North ◽  
History Of ◽  
Vegetative Biomass ◽  
Similar Survival ◽  
Cross Type

Few studies of inbreeding depression have focused on species producing both showy, chasmogamous (CH) flowers and self-pollinated, cleistogamous (CL) flowers. The goals of this investigation were to measure the level of inbreeding depression in the North American violet, Viola canadensis L., and to determine if any fitness differences were linked to floral type (CH versus CL) rather than to cross type (self versus outcross). Hand pollinations were carried out to produce self- and outcross-pollinated CH progeny, and CL seeds were also collected. In a greenhouse, selfed and outcrossed CH flowers produced similar numbers of seeds, and both types of progeny had similar survival rates and comparable numbers of CH flowers, although outcrossed CH progeny had 14% greater vegetative biomass than selfed CH progeny. The level of inbreeding depression in V. canadensis was low, indicating that there may be few drawbacks to selfing in this species. A comparison of CL and self-pollinated CH progeny showed that, although there were differences in CH flower number, overall fitness differences were minimal. The similar performance of selfed (CL and CH) and outcrossed progeny in early life-history stages of V. canadensis suggests a history of inbreeding in the population.Key words: cleistogamy, inbreeding depression, outcrossing, selfing, Viola canadensis.

Irish Demography in a Comparative Context: European Transition Theory vs. A Post-Colonial Understanding

1999 ◽  
Vol 9 (1) ◽  
pp. 60-76 ◽  
Author(s):  
Timothy J. White
Keyword(s):  
Demographic Change ◽  
Demographic Transition ◽  
Social Life ◽  
Demographic History ◽  
Transition Theory ◽  
Vital Rates ◽  
Irish Society ◽  
Death Rates ◽  
Post Colonial ◽  
Demographic Patterns

While studies of Irish society have concentrated on the effects of colonialism on late industrialisation and Irish social life, less work has been done on the uniqueness of Irish demographic change and its connection to the country's colonial past. The present article argues that Ireland demographic history has more in common with post-colonial societies than with European states that went through the so-called demographic transition. Irish demographic patterns differ even from peripheral societies of Europe, primarily because its historic pattern of emigration allowed for a stable population despite relatively high birth rates and rapidly declining death rates. Ireland's recent economic success, however, has dramatically altered this historic pattern and its vital rates now correspond more closely to the pattern of European countries that experienced an early demographic transition.

Management inferences from a demographic analysis of sea lamprey (Petromyzon marinus) in the Laurentian Great Lakes

2008 ◽  
Vol 65 (2) ◽  
pp. 227-244 ◽  
Author(s):  
Luis Antonio Vélez-Espino ◽  
Robert L McLaughlin ◽  
Thomas C Pratt
Keyword(s):  
Great Lakes ◽  
Life Stage ◽  
Petromyzon Marinus ◽  
Management Strategies ◽  
Sea Lamprey ◽  
Management Plan ◽  
Laurentian Great Lakes ◽  
Alternative Methods ◽  
Vital Rates ◽  
Population Growth Rates

We use matrix models incorporating uncertainty in values of life history traits and density-dependent survival to assess pest management strategies implemented by the Great Lakes Fishery Commission to control nonnative sea lamprey (Petromyzon marinus) in the Laurentian Great Lakes. The primary method of sea lamprey control has been treatment of rearing tributaries with chemical lampricides, but release of sterilized males and deployment of migratory barriers and traps are important components of the management plan. Uncertainties in the effectiveness of alternative control remain, however. Our models demonstrated that the management target of reducing lampricide use by 20% while maintaining current levels of control could be achieved if alternative methods are used to suppress current lake-wide fecundity rates by 49%–65%, assuming equal lampricide efficiency on larvae and metamorphosing individuals, or by 42%–55% when lampricide mortality on larvae is assumed to be half of that on metamorphosing individuals. At current levels of lampricide use, reduction to 72%–88% of current fecundity rates is recommended to ensure long-term control of sea lamprey populations in the face of uncertainty in current estimates of population growth rates. New control options targeting additional vital rates, such as survival of the parasitic life stage, could further reduce reliance on lampricides while maintaining effective sea lamprey control.

Similar Survival Rates for Rheumatoid and Non-rheumatoid Cancer Patients

1986 ◽  
Vol 15 (3) ◽  
pp. 285-289 ◽  
Author(s):  
T. Hakulinen ◽  
P. Knekt ◽  
O. Uotila ◽  
H. Isomäki
Keyword(s):  
Cancer Patients ◽  
Survival Rates ◽  
Similar Survival

Do short implants have similar survival rates compared to standard implants in posterior single crown?: A systematic review and meta-analysis

2018 ◽  
Vol 20 (5) ◽  
pp. 890-901 ◽  
Author(s):  
Patricia Tolentino da Rosa de Souza ◽  
Milena Binhame Albini Martini ◽  
Luciana Reis Azevedo-Alanis
Keyword(s):  
Systematic Review ◽  
Meta Analysis ◽  
Survival Rates ◽  
Short Implants ◽  
Single Crown ◽  
Similar Survival

scholarly journals Perturbation Analysis of Population Growth Rates in Taiwan

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Shun-Chieh Hsieh
Keyword(s):  
Perturbation Analysis ◽  
Census Data ◽  
Population Management ◽  
Management Policy ◽  
Demographic Parameters ◽  
Relative Importance ◽  
Vital Rates ◽  
Management Effectiveness ◽  
Substantial Impact ◽  
Population Growth Rates

The total fertility rate in Taiwan has fallen below 1.3 since 2003. The objective of the study is to use perturbation analysis with census data from 1992 to 2017 to identify which demographic parameters are most important to target for population management. The research shows that the fertility of older ages plays an important role for declining population in Taiwan. From a practical viewpoint, population management policy having a substantial impact on the survival of prereproductive females and the fertility of order females is likely to produce the most dramatic change in population trends. Therefore, the perturbation analysis is useful in understanding the relative importance of vital rates to increase management effectiveness.

Age, growth and the potential for growth overfishing of spot (Leiostomus xanthurus) from the Chesapeake Bay, eastern USA

2004 ◽  
Vol 55 (6) ◽  
pp. 553 ◽  
Author(s):  
Kevin R. Piner ◽  
Cynthia M. Jones
Keyword(s):  
Mortality Rate ◽  
Chesapeake Bay ◽  
Total Mortality ◽  
First Year ◽  
Leiostomus Xanthurus ◽  
Vital Rates ◽  
Population Parameters ◽  
Lack Of Information ◽  
Eastern Usa ◽  
Management Advice

Spot (Leiostomus xanthurus) are a popular commercial and sport fish in the Chesapeake Bay region (USA), but have not been managed with age-based models because of a lack of information on vital rates. This study determined that transversely sectioned otoliths were the most appropriate structure to age spot, and subsequently used those ages to estimate biological parameters and evaluate the potential for growth overfishing. Because spot are short-lived, this study explored estimating population parameters using both whole annulus counts and fractional ages. Although fractional ages may be more realistic, parameters estimated using fractions of a year should be interpreted with caution. Growth of spot was rapid (84% of length attained in the first year), the natural mortality rate was high (59% year−1), and the total mortality rate (natural + fishing) was very high (80–94% year−1). Spot maximised cohort biomass early in life (≈1 year) and were relatively impervious to growth overfishing. This study illustrates the difficulty in providing management advice for species that maximise cohort biomass about the same time as their first potential spawning event. This study also documents that high exploitation rates and size selective fishing gear probably affect estimates of population parameters.

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