scholarly journals Physical and biological factors contributing to changes in the relative importance of recruitment to population dynamics in open populations

2010 ◽  
Vol 412 ◽  
pp. 151-162 ◽  
Author(s):  
DM Munroe ◽  
T Noda
Keyword(s):  
Population Dynamics ◽  
Relative Importance ◽  
Biological Factors ◽  
Open Populations

Life history and environmental influences on population dynamics in sockeye salmon

2014 ◽  
Vol 71 (8) ◽  
pp. 1198-1208 ◽  
Author(s):  
Douglas C. Braun ◽  
John D. Reynolds
Keyword(s):  
Population Dynamics ◽  
Life History ◽  
Population Growth ◽  
Growth Rates ◽  
Environmental Conditions ◽  
Sockeye Salmon ◽  
Life History Traits ◽  
Relative Importance ◽  
Population Growth Rates ◽  
Habitat Variables

Understanding linkages among life history traits, the environment, and population dynamics is a central goal in ecology. We compared 15 populations of sockeye salmon (Oncorhynchus nerka) to test general hypotheses for the relative importance of life history traits and environmental conditions in explaining variation in population dynamics. We used life history traits and habitat variables as covariates in mixed-effect Ricker models to evaluate the support for correlates of maximum population growth rates, density dependence, and variability in dynamics among populations. We found dramatic differences in the dynamics of populations that spawn in a small geographical area. These differences among populations were related to variation in habitats but not life history traits. Populations that spawned in deep water had higher and less variable population growth rates, and populations inhabiting streams with larger gravels experienced stronger negative density dependence. These results demonstrate, in these populations, the relative importance of environmental conditions and life histories in explaining population dynamics, which is rarely possible for multiple populations of the same species. Furthermore, they suggest that local habitat variables are important for the assessment of population status, especially when multiple populations with different dynamics are managed as aggregates.

scholarly journals The relative importance of direct and indirect effects of hunting mortality on the population dynamics of brown bears

2015 ◽  
Vol 282 (1798) ◽  
pp. 20141840 ◽  
Author(s):  
Jacinthe Gosselin ◽  
Andreas Zedrosser ◽  
Jon E. Swenson ◽  
Fanie Pelletier
Keyword(s):  
Population Dynamics ◽  
Population Growth ◽  
Indirect Effects ◽  
Ursus Arctos ◽  
Brown Bear ◽  
Relative Importance ◽  
Direct And Indirect Effects ◽  
Negative Effects ◽  
Hunting Pressure ◽  
Demographic Rates

There is increasing evidence of indirect effects of hunting on populations. In species with sexually selected infanticide (SSI), hunting may decrease juvenile survival by increasing male turnover. We aimed to evaluate the relative importance of direct and indirect effects of hunting via SSI on the population dynamics of the Scandinavian brown bear ( Ursus arctos ). We performed prospective and retrospective demographic perturbation analyses for periods with low and high hunting pressures. All demographic rates, except yearling survival, were lower under high hunting pressure, which led to a decline in population growth under high hunting pressure ( λ = 0.975; 95% CI = 0.914–1.011). Hunting had negative indirect effects on the population through an increase in SSI, which lowered cub survival and possibly also fecundity rates. Our study suggests that SSI could explain 13.6% of the variation in population growth. Hunting also affected the relative importance of survival and fecundity of adult females for population growth, with fecundity being more important under low hunting pressure and survival more important under high hunting pressure. Our study sheds light on the importance of direct and indirect effects of hunting on population dynamics, and supports the contention that hunting can have indirect negative effects on populations through SSI.

scholarly journals Multimodel inference to quantify the relative importance of abiotic factors in the population dynamics of marine zooplankton

2018 ◽  
Vol 181 ◽  
pp. 91-98 ◽  
Author(s):  
Gert Everaert ◽  
Yana Deschutter ◽  
Marleen De Troch ◽  
Colin R. Janssen ◽  
Karel De Schamphelaere
Keyword(s):  
Population Dynamics ◽  
Abiotic Factors ◽  
Relative Importance ◽  
Multimodel Inference ◽  
Marine Zooplankton

scholarly journals Decomposing variation in population growth into contributions from environment and phenotypes in an age-structured population

2011 ◽  
Vol 279 (1727) ◽  
pp. 394-401 ◽  
Author(s):  
Fanie Pelletier ◽  
Kelly Moyes ◽  
Tim H. Clutton-Brock ◽  
Tim Coulson
Keyword(s):  
Population Dynamics ◽  
Population Growth ◽  
Age Structure ◽  
Life History Traits ◽  
Population Fluctuations ◽  
Relative Importance ◽  
Ecological Interactions ◽  
Structured Population ◽  
Individual Covariates ◽  
Age Structured

Evaluating the relative importance of ecological drivers responsible for natural population fluctuations in size is challenging. Longitudinal studies where most individuals are monitored from birth to death and where environmental conditions are known provide a valuable resource to characterize complex ecological interactions. We used a recently developed approach to decompose the observed fluctuation in population growth of the red deer population on the Isle of Rum into contributions from climate, density and their interaction and to quantify their relative importance. We also quantified the contribution of individual covariates, including phenotypic and life-history traits, to population growth. Fluctuations in composition in age and sex classes ((st)age structure) of the population contributed substantially to the population dynamics. Density, climate, birth weight and reproductive status contributed less and approximately equally to the population growth. Our results support the contention that fluctuations in the population's (st)age structure have important consequences for population dynamics and underline the importance of including information on population composition to understand the effect of human-driven changes on population performance of long-lived species.

scholarly journals Chaetognath assemblages along the Pacific Coast and adjacent inland waters of the Philippines: relative importance of oceanographic and biological factors

2012 ◽  
Vol 69 (3) ◽  
pp. 410-420 ◽  
Author(s):  
Mary Mar P. Noblezada ◽  
Wilfredo L. Campos
Keyword(s):  
Community Structure ◽  
Pacific Coast ◽  
Mass Movement ◽  
The Philippines ◽  
Inland Waters ◽  
Relative Importance ◽  
Biological Factors ◽  
Comprehensive Information ◽  
The Pacific ◽  
Plankton Distribution

Abstract Noblezada, M. M. P., and Campos, W. L. 2012. Chaetognath assemblages along the Pacific Coast and adjacent inland waters of the Philippines: relative importance of oceanographic and biological factors. – ICES Journal of Marine Science, 69: 410–420. When studying plankton distribution, it is necessary to investigate the biology of the target organisms and the surrounding physical environment. Station and species groupings are only useful if they provide insight into the environmental associations of the species in the group. The study covers two geographic regions: the Pacific Coast (Bicol Shelf) and inland waters (San Bernardino Strait, Ticao Pass, Sibuyan, and Visayan Seas) of the Philippines. Comprehensive information is provided on chaetognath assemblages and distribution within the regions. The findings are integrated with oceanographic conditions and phenomena that define the characteristics of the subareas and consideration given to how these conditions affect chaetognath ecology. A comparison is also provided of the community structure of the two regions, and the possible use of chaetognaths as indicator species of water mass movement and oceanographic phenomena explored. In all, 28 284 specimens were examined, and 33 species from 17 genera were identified. Chaetognath distributions, abundance, and community structure were analysed using dissimilarity indices and multiple regression. The results show that the distribution of chaetognaths agrees well with the movement of oceanic water from the Pacific into the central part of the archipelago.

scholarly journals Die Treiber der räumlichen Emergenz und Konzentration der Photovoltaik- Industrie in Deutschland

2015 ◽  
Vol 59 (3) ◽  
Author(s):  
Moritz Breul ◽  
Tom Broekel ◽  
Matthias Brachert
Keyword(s):  
Population Dynamics ◽  
Life Cycle ◽  
Relative Importance ◽  
Beneficial Effects ◽  
Industry Life Cycle ◽  
Regional Concentration ◽  
Early Phases ◽  
Shed Light ◽  
Unique Dataset

The drivers of the spatial emergence and clustering of the photovoltaic industry in Germany. Following the relatedness literature, we explore to what extent related industries influenced the regional emergence of the photovoltaic (PV) industry. In addition, we shed light on factors explaining selective processes of clustering. We particularly argue that generic resources and resources of related activities have been crucial for the regional concentration in early phases of the industry life cycle. With increasing maturity, industry-specific resources became more important. Based on a unique dataset containing population dynamics of the German PV industry, the hypotheses are tested empirically. Our results partially confirm the assumed beneficial effects of related industries for the emergence of the PV industry. Moreover, we observe changes in the relative importance of factors supporting regional concentration, with industry-specific resources becoming dominant as the industry matures.

Sign in / Sign up

Export Citation Format

Share Document