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Water Ecology
Published in Frank R. Spellman, Handbook of Water and Wastewater Treatment Plant Operations, 2020
Webster’s Third New International Dictionary defines population as “the total number or amount of things especially within a given area; the organisms inhabiting a particular area or biotype; and a group of interbreeding biotypes that represents the level of organization at which speciation begins.” The concept of population is interpreted differently in various sciences. In human demography a population is a set of humans in a given area. In genetics a population is a group of interbreeding individuals of the same species, which is isolated from other groups. In population ecology a population is a group of individuals of the same species inhabiting the same area.
The agroecosystem concept
Published in Stephen R. Gliessman, V. Ernesto Méndez, Victor M. Izzo, Eric W. Engles, Andrew Gerlicz, Agroecology, 2023
Stephen R. Gliessman, V. Ernesto Méndez, Victor M. Izzo, Eric W. Engles, Andrew Gerlicz
At the next level of organization are groups of individuals of the same species. Such a group is known as a population. The key characteristics of populations are their size and the rate at which they grow. Population size and growth rate are determined by the interactions among the individuals that make up the population and their response to the environment. The study of populations is called population ecology. Agronomists have applied the principles of population ecology in the experimentation that has led to the highest-yielding density and arrangement of individuals in a field.
Water Ecology
Published in Frank R. Spellman, The Science of Water, 2020
The term population is interpreted differently in various sciences. For example, in human demography, a population is a set of humans in a given area. In genetics, a population is a group of interbreeding individuals of the same species, which is isolated from other groups. In population ecology, a population is an interbreeding group of organisms of the same species, inhabiting the same area at a particular time.
Colonial rodent control in Tanganyika and the application of ecological frameworks
Published in Annals of Science, 2023
This view also influenced the emergent field of disease ecology, in which microbiologists and pathologists begin to apply population ecology to understanding disease transmission. From the Central Asian plains to the Central Valley of California, ecologically-minded biologists began to pay attention to climatic oscillations that corresponded with population fluctuations of small mammals suspected to be reservoirs of plague and other infectious diseases. ‘The most important conclusion which can be drawn,’ Charles Elton wrote in a summary of data collected about the occurrence of plague in Central Asian marmots and other small mammals, ‘is that epidemics have a definite periodicity in many cases, i.e. instead of being irregular and unpredictable phenomena, they obey regular laws.’93 Elton argued that epidemics, which resulted in mass deaths of a population of animals, were the mechanism by which most rodents regulate their numbers. Given that both disease and rodent outbreaks are part of a natural cycle of population fluctuations, the transmission of zoonotic diseases among human populations becomes something to predict and anticipate, a view that further emphasizes human mastery over those very human-animal interactions that smuggle along the threat of disease.
Participatory modelling: precedents and prospects for civil engineering
Published in Civil Engineering and Environmental Systems, 2022
Bryann Avendano-Uribe, M. Milke, D. Castillo-Brieva
Environmental systems researchers learned this lesson when starting from ecological models and expanding to socio-ecological models (Schlüter, Müller, and Frank 2019). To understand social-ecological systems, ecologists use classifications for understanding and name multiple components of a system (Anderies, Janssen, and Ostrom 2004), and include stakeholders’ perspectives to complement adjustments of parameters and variables of the model (Voinov and Bousquet 2010). The model can take the form of mathematical equations commonly used in population ecology (Newman et al. 2014), systems ecology (Kingsland 1986). Those classifications allow researchers to draw interconnections using conceptual models and mathematical models. In participatory processes, the model allows analysis and simulation of hypothetical consequences for each parameter changed in the system.
Laboratory testing of an innovative tube fishway concept
Published in Journal of Ecohydraulics, 2020
John H. Harris, William L. Peirson, Brent Mefford, Richard T. Kingsford, Stefan Felder
Reversing the worldwide declines of freshwater fish while making sustainable use of water resources requires effective and economical fishways to restore fish migrations at barriers. Poor fishway performance and high costs are frustrating attempts at high-head (>5 m) dams and weirs to conserve fish species threatened by habitat fragmentation and obstructed migrations. High fishways, other than trap-and haul systems (USBR 2015; Harris et al. 2019), have seldom been shown to effectively pass multiple species with differing physiological characteristics, swimming ability, body size and behaviour. Most constrain the passage of fish communities and few have performed effectively when assessed against objective ecological standards (Bunt et al. 2012; Brown et al. 2013; Winemiller et al. 2016). Improved evidence is needed of high-head fishway designs’ effectiveness, limitations and alternatives (Silva et al. 2017). The failures of such fishways to meet conservation goals, and their impacts on population ecology, particularly for native, non-salmonid species, were reviewed by Wilkes et al. (2018). They have rarely transferred adequate proportions of fish populations and communities or re-established upstream populations (Peterken 2001; Oldani and Baigun 2002; Ferguson et al. 2011; DEEDI 2011; Brown et al. 2013; Walsh et al. 2014; Harris et al. 2016; Winemiller et al. 2016).