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Huffaker's Mite Experiment
In 1958, Carl B. Huffaker, an ecologist and agricultural entomologist at the University of California, Berkeley, did a series of experiments with predatory and herbivorous mite species to investigate predator–prey population dynamics. In these experiments, he created model universes with arrays of rubber balls and oranges (food for the herbivorous mites) on trays and then introduced the predator and prey mite species in various permutations. Specifically, Huffaker was seeking to understand how spatial heterogeneity and the varying dispersal ability of each species affected long-term population dynamics and survival. Contrary to previous experiments on this topic (especially those by Georgii Gause), he found that long-term coexistence was possible under select environmental conditions. He published his findings in the paper, "Experimental Studies on Predation: Dispersion Factors and Predator–Prey Oscillations". Experimental design The aim of Huffaker’s 1958 experiment was to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Barton Huffaker
Carl Barton Huffaker (September 30, 1914 in Monticello, Kentucky – October 10, 1995 in Lafayette, California) was an American biologist, ecologist and agricultural entomologist. Huffaker graduated from the University of Tennessee (1938 B.S., 1939 M.S.) then gaining a PhD from Ohio State University in 1942. Huffaker was one of the first entomologists to study the use of DDT to control mosquito populations. After working as a medical entomologist in Colombia, Haiti, and the Dominican Republic he was recruited by Harry Scott Smith in 1946 to work as an assistant entomologist for the Division of Biological Control of the University of California. Huffaker's first assignment was the control of Klamath weed, particularly the use of ''Chrysolina quadrigemina''. He remained at Berkeley until his retirement in 1984. He published more than 200 scientific papers and edited and contributed to books "citation classics" in population ecology, biological control, and integrated pest manageme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecological Experiments
Ecology () is the study of the relationships between living organisms, including humans, and their biophysical environment, physical environment. Ecology considers organisms at the individual, population, community (ecology), community, ecosystem, and biosphere level. Ecology overlaps with the closely related sciences of biogeography, evolutionary biology, genetics, ethology, and natural history. Ecology is a branch of biology, and it is not synonymous with environmentalism. Among other things, ecology is the study of: * The abundance (ecology), abundance, biomass (ecology), biomass, and distribution of organisms in the context of the environment * Life processes, antifragility, interactions, and adaptations * The movement of materials and energy through living communities * The ecological succession, successional development of ecosystems * Cooperation, competition, and predation within and between species * Patterns of biodiversity and its effect on ecosystem processes Ecol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overexploited
Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to replenish. The term applies to natural resources such as water aquifers, grazing pastures and forests, wild medicinal plants, fish stocks and other wildlife. In ecology, overexploitation describes one of the five main activities threatening global biodiversity. Ecologists use the term to describe populations that are harvested at an unsustainable rate, given their natural rates of mortality and capacities for reproduction. This can result in extinction at the population level and even extinction of whole species. In conservation biology, the term is usually used in the context of human economic activity that involves the taking of biological resources, or organisms, in larger numbers than their populations can withstand. The term is also used and defined so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ricker Model
The Ricker model, named after Bill Ricker, is a classic discrete population model which gives the expected number ''N'' ''t''+1 (or density) of individuals in generation ''t'' + 1 as a function of the number of individuals in the previous generation, : N_ = N_t e^.\, Here ''r'' is interpreted as an intrinsic growth rate and ''k'' as the carrying capacity of the environment. The Ricker model was introduced in 1954 by Ricker in the context of stock and recruitment in fisheries. The model can be used to predict the number of fish that will be present in a fishery. Subsequent work has derived the model under other assumptions such as scramble competition,Brännström and Sumpter(2005) within-year resource limited competition or even as the outcome of source-sink Malthusian patches linked by density-dependent dispersal.Bravo de la Parra et al (2013) The Ricker model is a limiting case of the Hassell modelGeritz and Kisdi (2004) which takes the form : N_ = k_1 \frac. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spatial Heterogeneity
Spatial heterogeneity is a property generally ascribed to a landscape or to a population. It refers to the uneven distribution of various concentrations of each species within an area. A landscape with spatial heterogeneity has a mix of concentrations of multiple species of plants or animals (biological), or of terrain formations (geological), or environmental characteristics (e.g. rainfall, temperature, wind) filling its area. A population showing spatial heterogeneity is one where various concentrations of individuals of this species are unevenly distributed across an area; nearly synonymous with "patchily distributed." Examples Environments with a wide variety of habitats such as different topographies, soil types, and climates are able to accommodate a greater amount of species. The leading scientific explanation for this is that when organisms can finely subdivide a landscape into unique suitable habitats, more species can coexist in a landscape without competition, a phenom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Predation
Predation is a biological interaction In ecology, a biological interaction is the effect that a pair of organisms living together in a community have on each other. They can be either of the same species (intraspecific interactions), or of different species ( interspecific interactio ... where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the host) and parasitoidism (which always does, eventually). It is distinct from scavenging on dead prey, though many predators also scavenge; it overlaps with herbivory, as seed predators and destructive frugivores are predators. Predators may actively search for or pursue prey or wait for it, often concealed. When prey is detected, the predator assesses whether to attack it. This may involve ambush predation, ambush or pursuit predation, sometimes after stalking the prey. If the attack ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Typhlodromus Occidentalis
''Typhlodromus'' is a genus of predatory mites belonging to the family Phytoseiidae. Members of this genus feed largely on other mites, such as red spider mites, and several species that are popular as biological control agents to control these pests. Species * '' Typhlodromus acacia'' Xin, Liang & Ke, 1980 * ''Typhlodromus acaciae'' Schultz, 1973 * '' Typhlodromus accessorius'' Kolodochka, 1993 * '' Typhlodromus adenensis'' Ueckermann, 1996 * '' Typhlodromus admirabilis'' (Wainstein, 1978) * ''Typhlodromus aenaulus'' Ueckermann, 1996 * ''Typhlodromus aestivalis'' Athias-Henriot, 1960 * ''Typhlodromus agilis'' (Chaudhri, 1975) * ''Typhlodromus ailanthi'' Wang & Xu, 1985 * ''Typhlodromus aktherecus'' (Kolodochka, 1979) * ''Typhlodromus algonquinensis'' Chant, Hansell & Yoshida-Shaul, 1974 * ''Typhlodromus americanus'' Chant & Yoshida-Shaul, 1989 * ''Typhlodromus andrei'' Karg, 1982 * ''Typhlodromus apoxys'' van der Merwe, 1968 * ''Typhlodromus applegum'' Schicha, 1983 * ''Typhlod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of California, Berkeley
The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant university and the founding campus of the University of California system. Its fourteen colleges and schools offer over 350 degree programs and enroll some 31,800 undergraduate and 13,200 graduate students. Berkeley ranks among the world's top universities. A founding member of the Association of American Universities, Berkeley hosts many leading research institutes dedicated to science, engineering, and mathematics. The university founded and maintains close relationships with three national laboratories at Berkeley, Livermore and Los Alamos, and has played a prominent role in many scientific advances, from the Manhattan Project and the discovery of 16 chemical elements to breakthroughs in computer science and genomics. Berkeley i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georgii Gause
Georgy Frantsevich Gause (russian: Гео́ргий Фра́нцевич Га́узе; December 27, 1910 – May 2, 1986), was a Soviet and Russian biologist and evolutionist, who proposed the competitive exclusion principle, fundamental to the science of ecology. Classic of ecology, he would devote most of his later life to the research of antibiotics. Early life Gause was born December 27, 1910, in Moscow, Russia to parents Frants Gustavovich Gause, a professor of architecture at Moscow State University, and Galina Gause, an industrial worker at an automotive steel plant. As a boy and into his teenage years, Gause and his extended family took summer vacations to the Caucasus Mountains in southern Russia for months at a time. Although his family was not wealthy, they were allowed these respites because his father, being a government architect, helped to build many structures at the university. It was during these trips to the Caucasus Mountains that Gause grew fond of nature, ofte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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