Interacting Effects of Density‐dependent and Density‐independent Factors on Growth Rates in Southwestern Cutthroat Trout Populations

2021 ◽  
Author(s):  
Brock M. Huntsman ◽  
Abigail J. Lynch ◽  
Colleen A. Caldwell
Keyword(s):  
Growth Rates ◽  
Cutthroat Trout ◽  
Density Dependent ◽  
Effects Of Density

scholarly journals EFFECTS OF DENSITY-DEPENDENT AND STOCHASTIC PROCESSES ON THE REGULATION OF COD POPULATIONS

Ecology ◽  
2001 ◽  
Vol 82 (2) ◽  
pp. 567-579 ◽  
Author(s):  
Jean-Marc Fromentin ◽  
Ransom A. Myers ◽  
Ottar N. Bjørnstad ◽  
Nils Chr. Stenseth ◽  
Jakob Gjøsæter ◽  
...  
Keyword(s):  
Stochastic Processes ◽  
Density Dependent ◽  
Effects Of Density

Effects of density on growth rates of four benthic diatoms and variations in biochemical composition associated with growth phase

2012 ◽  
Vol 24 (6) ◽  
pp. 1427-1437 ◽  
Author(s):  
G. Courtois de Viçose ◽  
A. Porta ◽  
M. P. Viera ◽  
H. Fernández-Palacios ◽  
M. S. Izquierdo
Keyword(s):  
Growth Phase ◽  
Growth Rates ◽  
Biochemical Composition ◽  
Benthic Diatoms ◽  
Effects Of Density

Do abiotic mechanisms determine interannual variability in length-at-age of juvenile Arcto-Norwegian cod?

2002 ◽  
Vol 59 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Geir Ottersen ◽  
Kristin Helle ◽  
Bjarte Bogstad
Keyword(s):  
Growth Rates ◽  
Gadus Morhua ◽  
Barents Sea ◽  
Water Masses ◽  
Inverse Relation ◽  
Lower Growth ◽  
Density Dependent ◽  
The Barents Sea ◽  
The Mean ◽  
Dependent Growth

For the large Arcto-Norwegian stock of cod (Gadus morhua L.) in the Barents Sea, year-to-year variability in growth is well documented. Here three hypotheses for the observed inverse relation between abundance and the mean length-at-age of juveniles (ages 1–4) are suggested and evaluated. Based on comprehensive data, we conclude that year-to-year differences in length-at-age are mainly determined by density-independent mechanisms during the pelagic first half year of the fishes' life. Enhanced inflow from the southwest leads to an abundant cohort at the 0-group stage being distributed farther east into colder water masses, causing lower postsettlement growth rates. We can not reject density-dependent growth effects related to variability in food rations, but our data do not suggest this to be the main mechanism. Another hypothesis suggests that lower growth rates during periods of high abundance are a result of density-dependent mechanisms causing the geographic range of juveniles to extend eastwards into colder water masses. This is rejected mainly because year-to-year differences in mean length are established by age 2, which is too early for movements over large distances.

scholarly journals Effects of density-dependent scenarios of in-medium nucleon-nucleon interactions in heavy-ion collisions

2020 ◽  
Vol 102 (2) ◽  
Author(s):  
Gao-Feng Wei ◽  
Chang Xu ◽  
Wei Xie ◽  
Qi-Jun Zhi ◽  
Shi-Guo Chen ◽  
...  
Keyword(s):  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Nucleon Nucleon ◽  
Density Dependent ◽  
Ion Collisions ◽  
Nucleon Interactions ◽  
Effects Of Density

Production and Population Dynamics of the Crayfish Orconectes virilis in Three Michigan Lakes

1977 ◽  
Vol 34 (11) ◽  
pp. 2030-2040 ◽  
Author(s):  
Walter T. Momot ◽  
Howard Gowing
Keyword(s):  
Population Dynamics ◽  
Growth Rates ◽  
Age Groups ◽  
Mortality Rates ◽  
Reproductive Age ◽  
Annual Production ◽  
Effective Density ◽  
Orconectes Virilis ◽  
Brood Stock ◽  
Density Dependent

Fluctuations in mortality rather than in growth rates produced most of the year-to-year differences in biomass accumulation of three different populations of the crayfish Orconectes virilis. Yearly biomass changes resulted from density-dependent control of mortality and fecundity during certain portions of the life cycle. Density-dependent changes in mortality rates controlled population size for adults in all lakes and for young-of-the-year in two of the three study lakes. Growth rates were much less responsive to fluctuating densities. Disparity between the number of ovarian and attached eggs increased as density of age I+ crayfish increased. This provided a strong density regulator on fecundity. Differences occurred in the number of recruits produced by a brood stock that survive to the end of the first growing season in the various lakes. Yet the number of females surviving to reproductive age 2 yr later was strongly regulated. Strong population regulation produced two female recruits of breeding age for every two–six parental breeding females. The high biomass and production levels of crayfish discovered in West Lost Lake in 1962–63 also occurred in the other area lakes. Higher but variable levels of recruitment resulted in larger standing crops and production in West Lost lake. This resulted from less effective density controls on the mortality rates of younger age-groups in that lake. Despite great variation in biomass of from 46 to 213 kg/ha and annual production from 60 to 142 kg/ha, the annual turnover ratio of the biomass was found to vary only between 0.94 and 1.53. Key words: crayfish, Orconectes virilis, population dynamics, annual production, Michigan lakes

Positive solutions of certain elliptic systems with density-dependent diffusions

1995 ◽  
Vol 125 (5) ◽  
pp. 1031-1050 ◽  
Author(s):  
Inkyung Ahn ◽  
Lige Li
Keyword(s):  
Positive Solutions ◽  
Growth Rates ◽  
Smooth Boundary ◽  
Elliptic Systems ◽  
Biological Interactions ◽  
Bounded Region ◽  
Density Dependent ◽  
Existence Of Positive Solutions ◽  
Image Position ◽  
Increasing Functions

Results are obtained on the existence of positive solutions to the following elliptic system:in a bounded region Ω in Rn with a smooth boundary, where the diffusion terms φ ψ are non-negative functions and the system could be degenerate, β γ are strictly increasing functions, k,σ ≧ 0 are constants. We assume also that the growth rates f, g satisfy certain monotonicities. Applications to biological interactions with density-dependent diffusions are given.

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