Streamflow and Population Change in the Lower Salt River Valley of Central Arizona, ca. A.D. 775 to 1450

2008 ◽  
Vol 73 (1) ◽  
pp. 136-165 ◽  
Author(s):  
Scott E. Ingram
Keyword(s):  
Population Growth ◽  
Growth Rates ◽  
Population Change ◽  
River Valley ◽  
Channel Changes ◽  
Population Growth Rates ◽  
Salt River ◽  
Floods And Droughts ◽  
Salt River Valley ◽  
Irrigation Agriculture

Floods and droughts and their effects on Hohokam canal systems and irrigation agriculture play a prominent role in many cultural-historical interpretations of the Hohokam trajectory in the lower Salt River valley (modern-day Phoenix, Arizona metropolitan area). Catastrophic floods and associated geomorphic stream channel changes may have contributed to settlement and population changes and the substantial depopulation of the lower Salt River valley ca. A.D. 1450 or later. In this study, archaeological data on Hohokam domestic architecture is used to infer changes in prehistoric population growth rates from ca. A.D. 775 through 1450 in the most thoroughly documented canal system in the Salt River valley. Changes in growth rates are compared to the retrodictions of annual streamflow discharge volumes derived from tree-ring records. Contrary to expectations, population growth rates increased as the frequency, magnitude, and duration of inferred flooding, drought, and variability increased. These results challenge existing assumptions regarding the relationship among floods and droughts, conditions for irrigation agriculture, and population change in the lower Salt River valley.

scholarly journals Population growth rates: issues and an application

2002 ◽  
Vol 357 (1425) ◽  
pp. 1307-1319 ◽  
Author(s):  
H. Charles J. Godfray ◽  
Mark Rees
Keyword(s):  
Growth Rate ◽  
Population Dynamics ◽  
Population Growth ◽  
Growth Rates ◽  
Population Growth Rate ◽  
Population Change ◽  
Evolutionarily Stable Strategy ◽  
Model Systems ◽  
Population Growth Rates

Current issues in population dynamics are discussed in the context of The Royal Society Discussion Meeting 'Population growth rate: determining factors and role in population regulation'. In particular, different views on the centrality of population growth rates to the study of population dynamics and the role of experiments and theory are explored. Major themes emerging include the role of modern statistical techniques in bringing together experimental and theoretical studies, the importance of long-term experimentation and the need for ecology to have model systems, and the value of population growth rate as a means of understanding and predicting population change. The last point is illustrated by the application of a recently introduced technique, integral projection modelling, to study the population growth rate of a monocarpic perennial plant, its elasticities to different life-history components and the evolution of an evolutionarily stable strategy size at flowering.

scholarly journals The impact of human activity on anthropogenic dust emission over global semi-arid regions

2016 ◽  
Author(s):  
X. Guan ◽  
J. Huang ◽  
Y. Zhang ◽  
Y. Xie ◽  
J. Liu
Keyword(s):  
Population Growth ◽  
Growth Rates ◽  
Human Activities ◽  
Arid Regions ◽  
Population Change ◽  
Dust Emission ◽  
Dust Production ◽  
Population Growth Rates ◽  
The Impact ◽  
Semi Arid

Abstract. Anthropogenic dust is acknowledged as a product of human activities on disturbed soil, and is generated mainly from sensitive and fragile regions including croplands, pastures, and urbanized regions. In this study, we analyzed the behaviour of anthropogenic dust in semi-arid region of globe, and its relationship to human activities. An obvious peak in the total anthropogenic dust column, much higher magnitude than those of wet regions, was observed in semi-arid regions with population growth rates of more than 11.46 %. Four typical semi-arid regions, East China, India, North America and North Africa were selected to explore the local difference in anthropogenic dust production. The population growth rates in these areas were approximately 6.16 %, 17.71 %, 11.21 %, and 29.26 %, and the anthropogenic dust levels were 0.17 g m−2, 0.38 g m−2, 0.10 g m−2 and 0.21 g m−2, which are higher than the natural dust column burden. The anthropogenic dust column burden is positively correlated with the population and population change, indicating a contribution from human activities to the anthropogenic dust production. Based on the fact that anthropogenic dust can act as warming aerosol, the radiative effect of anthropogenic dust in semi-arid regions can not be ignored and requires further investigation.

scholarly journals Life-history predicts global population responses to the weather in the terrestrial mammals

2021 ◽  
Author(s):  
John Jackson ◽  
Christie Le Coeur ◽  
Owen R Jones
Keyword(s):  
Life History ◽  
Population Growth ◽  
Growth Rates ◽  
Population Change ◽  
Absolute Magnitude ◽  
Effect Of Temperature ◽  
Population Growth Rates ◽  
Terrestrial Mammals ◽  
Climate Change Responses ◽  
Annual Population

AbstractWith the looming threat of abrupt ecological disruption due to a changing climate, predicting which species are most vulnerable to environmental change is critical. The life-history of a species is a promising candidate for explaining differences in climate-change responses, but we now need data linking population change, weather and life-history to explore these predictions. Here, we use long-term abundance records from 157 species of terrestrial mammals to investigate the link between weather and annual population growth rates. Overall, we found no consistent effect of temperature or precipitation anomalies on annual population growth rates, but there was variability in weather responses for populations within a species. Crucially, however, long-lived mammals with smaller litter sizes had responses with a reduced absolute magnitude compared to their shorter-living counterparts with larger litters. These results highlight the role of species-level life-history in driving responses to the environment.

scholarly journals Estimates of regional annual abundance and population growth rates of white sharks off central California

2021 ◽  
Vol 257 ◽  
pp. 109104
Author(s):  
Paul E. Kanive ◽  
Jay J. Rotella ◽  
Taylor K. Chapple ◽  
Scot D. Anderson ◽  
Timothy D. White ◽  
...  
Keyword(s):  
Population Growth ◽  
Growth Rates ◽  
Central California ◽  
Population Growth Rates

scholarly journals ATIVIDADE ACARICIDA DE ÓLEOS ESSENCIAIS SOBRE Tetranychus ludeni (Zacher) (Acari: Tetranychidae) EM DUAS CULTIVARES DE ALGODOEIRO

Nativa ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 469
Author(s):  
Yasmin Bruna de Siqueira Bezerra ◽  
José Vargas de Oliveira ◽  
Taciana Keila dos Anjos Ramalho ◽  
Douglas Rafael e Silva Barbosa ◽  
Carlos Romero Ferreira de Oliveira ◽  
...  
Keyword(s):  
Population Growth ◽  
Essential Oils ◽  
Growth Rates ◽  
Ocimum Basilicum ◽  
Alternative Control ◽  
Population Growth Rates ◽  
Colored Cotton ◽  
Potential Alternative ◽  
Tetranychus Ludeni ◽  
Corymbia Citriodora

O presente trabalho teve como objetivo avaliar os efeitos repelentes e as taxas de crescimento populacional de óleos essenciais de Corymbia citriodora, Ocimum basilicum e Myracroduon urundeuva sobre o ácaro vermelho Tetranychus ludeni (Zacher) em algodoeiro de fibra colorida. Para o teste de repelência, óleos de Corymbia citriodora, Ocimum basilicum e Myracroduon urundeuva foram testados em diferentes concentrações sobre fêmeas adultas de T. ludeni, assim como para o teste de crescimento populacional, onde as cultivares foram tratadas com óleos essenciais.  O efeito repelente foi verificado para todos os óleos testados nas duas cultivares de algodão colorida. As taxas instantâneas de crescimento populacional para T. ludeni nas cultivares de algodoeiro BRS Verde e BRS Rubi foram todas positivas (ri> 0), indicando que a população está em estado ascendente, no entanto, a população cresceu a uma taxa menor quando comparada ao controle. Os óleos essenciais de C. citriodora, O. basilicum e M. urundeuva apresentam efeito acaricida e potencial controle alternativo de T. ludeni em algodoeiro de fibras coloridas sem causar danos ao algodoeiro.Palavras-chave: ácaro vermelho; algodão colorido; controle alternativo; taxa instantânea de crescimento; repelência. ACARICIDAL ACTIVITY OF ESSENTIAL OILS ON RED MITETetranychus ludeni (Zacher) (Acari: Tetranychidae) IN TWO COTTON CULTIVARS ABSTRACT: The objective of this work was to evaluate the repellent and population growth rates of essential oils of Corymbia citriodora, Ocimum basilicum and Myracroduon urundeuva on the red mite Tetranychus ludeni (Zacher) in cotton fiber. For the repellency test, oils of Corymbia citriodora, Ocimum basilicum and Myracroduon urundeuva were tested in different concentrations on adult females of T. ludeni, as well as for the population growth test, where the cultivars were treated with essential oils. The repellent effect was verified for all tested oils the two cultivars of colored cotton. The instant population growth rates for T. ludeni in the cultivars BRS Verde and BRS Rubi were all positive (ri> 0), indicating that the population is in an upward, however, the population grew at a lower rate when compared to the control. The essential oils of C. citriodora, O. basilicum and M. urundeuva have an acaricidal effect and potential alternative control of T. ludeni in cotton from colored fibers without causing damage to the cotton.Keywords: Red mite; colored cotton; essential oils; instant growth rate; repellency.

An Evaluation of RNA–DNA Ratio as a Measure of Long-Term Growth in Fish Populations

1973 ◽  
Vol 30 (2) ◽  
pp. 195-199 ◽  
Author(s):  
Terry A. Haines
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Growth Rates ◽  
Population Growth Rate ◽  
Environmental Changes ◽  
Age Distribution ◽  
Smallmouth Bass ◽  
Fish Populations ◽  
Population Growth Rates

The value of RNA–DNA ratio as a measure of long-term growth of fish populations under semi-natural conditions and when subjected to environmental manipulations was determined. Populations of carp and smallmouth bass of known age distribution were established in artificial ponds maintained at two fertility levels. After 15 months, population growth rates (as percent increase in weight) and RNA–DNA ratios of muscle tissue from selected fish were measured. Each species exhibited a range of population growth rates. The relation between population growth rate and individual fish RNA–DNA ratio for each species was significant. When reproduction occurred, the relation was not significant unless young-of-the-year fish were excluded from population growth rate calculations. Age of fish was also found to have an important effect on RNA–DNA ratio, with the ratio being higher in younger fish.RNA–DNA ratio can be a reliable indicator of long-term population growth in fish when population age structure is known and recruitment is controlled. The method has potential for use in detecting response to environmental changes before growth rate changes become severe.

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.

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