Term
Oecology
Part 1: Foundation Papers, defining ecology as a science |
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Definition
| Coined by Ernst Haeckel, refers to the study of the multifaceted struggle for existence |
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Thomas Robert Malthus
Part 1: Foundation Papers, defining ecology as a science |
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Definition
| Wrote Essay on Population, which states that a utopian society could never be obtained because population would grow and surpass food supply. Darwin read this paper which caused him to realize competition could come from within the species. |
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Herbert Spencer
Part 1: Foundation Papers, defining ecology as a science |
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Definition
| Worked with Darwin and coined survival of the fittest. he believed in a theory that adaptive, heredity change in direct response to the environment, known as "neo-Lamarckian" Spencer wrote about this which popularized the theory, and many believe that lamarks theory and darwins went hand in hand |
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Stephen Forbes
Part 1: Foundation Papers, defining ecology as a science |
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Definition
| 1870's, studied food webs to give agriculture a scientific basis, wrote " the lake as a microcosm" to analyze how harmony in nature is obtained through complex competition and predatory relations in a community |
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Henry Chandler Cowles
Part 1: Foundation Papers, defining ecology as a science |
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Definition
| studied sand dunes and developed the idea of "physiographic ecology". His study of Indiana sand dunes was the first workout of a complete succession series. He stated communities are always changing, and believed that all organisms in a community were connected in a symbiotic relationship. |
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Ecological Succession
Part 1: Foundation Papers, defining ecology as a science |
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Definition
| process of change in a species structure of an ecological community over time |
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Frederic Clements
Part 1: Foundation Papers, defining ecology as a science |
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Definition
| wrote the first ecological textbook "Research methods of Ecology". his theory rested on the ideas of ecological succession of plant formation and that the plant community was a complex organism undergoing a life cycle similar to the individual. Plants and their habitat acted upon each other in a reciprocal way until a stable state "climax" was reached. He thought communities were structured by plant formations, instead of animals. He thought competition was one of the most important things guiding succession. He later conceded that animals do affect their communities as well. |
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Henry Allen Gleason
Part 1: Foundation Papers, defining ecology as a science |
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Definition
| critic of Clements and developed the "individualist" concept of ecology. His main argument was that every plant association was a unique product of a fluctuating environment at a certain time and place, and that you could not compare a community to an organism. Plant associations existed separately from the community as a whole, and did not influence each other. |
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Charles Elton
Part 1: Foundation Papers, defining ecology as a science |
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Definition
| wrote "Animal Ecology" in 1927. This text defined the concept of niche in the context of the food chain. He used the term niche to describe an animals place on the food chain, and believed ecologists needed to pay closer attention to what the animal was actually doing in the community |
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Joseph Grinnell
Part 1: Foundation Papers, defining ecology as a science |
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Definition
| studied birds and connected the idea of competitive exclusion (two different species cannot occupy the same niche) to the term niche. In his usage, niche is roughly the same concept as habitat |
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Raymond Pearl
Part 1: Foundation Papers, defining ecology as a science |
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Definition
| statistician who studied human population change after WWI and discovered that human population growth seemed to follow an S shaped curve which he called a logistic curve. said to be the start of mathematical ecology |
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Vito Volterra and Alfred Lotka
Part 1: Foundation Papers, defining ecology as a science |
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Definition
| physicist who developed model for competition and a model of predation in a two-species system. Model is called the Lotka-Volterra equations.Also models predator-prey interactions mathematically. |
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Alexander Nicholson and Victor Bailey
Part 1: Foundation Papers, defining ecology as a science |
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Definition
| tried to improve the Lotka-Volterra model by taking into account the effects of competition from members of the same species, as well as delays caused by age distribution of a population. Nicholson considered competition the chief mechanism of population regulation. |
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Raymond Lindeman
Part 1: Foundation Papers, defining ecology as a science |
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Definition
| combined physiological and community ecology which he called the "trophic-dynamic aspect" of ecology. This attempted to show how the day to day processes of a lake affected the long term changes of ecological succession. Lindeman focused on the trophic or nutritional relationships within the lake and grouped inhabitants according to their position on the food chain. It became clear that biotic and abiotic factors are entangled. He concluded that the lake was an integrated system of both biotic and abiotic and coined the term ecosystem. |
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Term
The number of Species in a community
Part 2: Theoretical Advances, The role of theory in the Rise of Modern Ecology |
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Definition
| Frank Preston (1948) wrote a paper to try and mathematically estimate number of species in a community. Prior to this it had been relative (2x greater). Preston used octaves where species were grouped based on log to base 2. Species abundance is log normally distributed. Robert MacArthur developed the broken stick model (s amount of species, break the stick in s-1 places, calculate the fragments for species abundance) Preston showed this model wasn't correct because it did not generate a log-normal distribution. Robert May argued that relative abundances are likely governed by interaction of multiple independent factors. May stated that the canonical distribution is merely a mathematical property of all log-normal distributions for large numbers of species S. |
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Term
Niche Theory
Part 2: Theoretical Advances, The role of theory in the Rise of Modern Ecology |
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Definition
| First use of niche was in Grinnell's paper "The niche-relationships of the California Thrasher" In this paper, niche referred to the species place and location in an environment, emphasizing adaptation to the physical structure of the habitat. Elton redefined niche as its functional role in the community, its "status". Gause adapted the eltonian concept and expanded it to include competitive interactions among different species. Gause formed the exclusion principle "2 species cannot occupy the same niche" Hutchinson wrote a paper that defined the niche concept, defined niche as a set, and that the algebra of sets could be used to describe species interaction, specifically competition. He also coined realized niche, the part of fundamental niche that an organism occupies as a result of limiting factors present in the habitat. |
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Term
Demography and Single-species population growth
Part 2: Theoretical Advances, The role of theory in the Rise of Modern Ecology
Cole |
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Definition
| Lack was an ornithologist who studied clutch size in birds and noted that when an egg is taken, a new one comes up. He said that a species reduces fecundity to maximize number of young who live to reproduce. Cole took these theories and studied the link between life history phenomena and population growth. He compared species that reproduced once and died, vs those that had multiple seasons. He penned the paradox that states that that it would be easier to add one young per litter and die than to have the evolutionary adaptations needed for a long life. However, Murdoch suggested that there are trade-offs between fecundity and survivor ship, and these trade-offs, plus the uncertainty of juvenile survivor ship promote long life. |
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Term
Demography and Single-species population growth
Part 2: Theoretical Advances, The role of theory in the Rise of Modern Ecology
May |
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Definition
| wrote a paper which explores the complex, dynamic behavior implicit in some simple forms of population growth models. Before may, many thought pop. growth was simple in pattern: pops would grow until the upper limit was reached, and then would stay there. However, populations rarely follow such a simple pattern. May pointed out that in many cases, population growth is discrete with non-overlapping generations and (more importantly) he wanted to demonstrate the full implications of such simple, nonlinear discrete time models. The discrete time equation generates a wide variety of dynamic behaviors depending on parameter values. |
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Individual Behavior
Part 2: Theoretical Advances, The role of theory in the Rise of Modern Ecology |
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Definition
| MacArthur and Pianka were the first to model the strategies by which organisms exploit resources most efficiently. They focused on two major problems faced by foragers: number of different food types to include in a diet and types of patches to include in a foraging excursion. Charnov suggested an alternative formula to the patch choice problem with the marginal value theorem which states that if it is on average better for the organism to move than stay, it moves. Schoener expanded on the ideas of MacArthur and Pianka and stated that optimization criterion can be different for different organisms. He stated that an organism might employ two strategies: minimize the time spent acquiring a given amount of energy or maximize total energy acquisition per unit time. |
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Multi-species Interactions
Part 2: Theoretical Advances, The role of theory in the Rise of Modern Ecology |
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Definition
| Ross and Thompson used math models to explain host-parasite interactions in the 1920s. Lotka and Volterra used sets of coupled differential equations to describe species interactions. L develop early version of the general systems theory: community can be put into components and the change in one is some function of the rest. V used physical analogies, in the mass acquisition model, two species interaction is determined by the likelihood of the encounter, which is proportional to their densities. Nicholson and Bailey introduced an alternative difference equation to modeling host-parasite interactions. Margalef said that if there are many species in a system, a disturbance would have little effect on the whole assemblage.. May (1975) wrote that when a number of interacting species increases, the requirements for stability are more restrictive. |
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Term
Movement and Scale
Part 2: Theoretical Advances, The role of theory in the Rise of Modern Ecology |
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Definition
| Skellam (1951) wrote a paper on the biology of dispersal. He provided a rigorous derivation and motivation for the diffusion model. This model captures many of the prominent features of population spread. He also encouraged further research into the asymptomatic speeds of propagation to the spread of an introduced species. He also developed the critical patch size. Diffusion lost through boundaries will be proportional to the length of the perimeter of the patch. If a favorable region for growth is small, losses exceed growth, and the species goes extinct. Beyond a certain threshold, a region of favorable conditions will be sufficient to support growth. In nature, one should not see patches smaller than the critical size. |
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Term
Tansley
Part 3: Theses, Antithesis and Syntheses, Conversational Biology and Ecological Debate |
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Definition
| 1935, wrote a paper which is a tribute to the power of words in scientific debate. Argued against Clement's ideas, stating that the ideas of community succession and progressive development do not hold for plants. Tansley coined the term "ecosystem" and stated that it includes both biotic and abiotic factors. Studied competition in plants in different soil types |
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Term
Hutchinson
Part 3: Theses, Antithesis and Syntheses, Conversational Biology and Ecological Debate |
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Definition
| 1959, wrote a paper which synthesized the ideas on niche (geometric hypervolume with both biotic and abiotic dimensions) The paper, Homage to Santa Rosalia, states that scientists need to develop a theory on why x number of species is there, instead of another number. He emphasizes niche diversification in gaining diversity. He states that there are so many species because a complex trophic organisation is more stable than a simple one |
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Term
Hairston, Smith, and Slobodkin
Part 3: Theses, Antithesis and Syntheses, Conversational Biology and Ecological Debate |
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Definition
| wrote a note that synthesized many of the ideas on populations. They stated that the principle factor limiting population growth depends on the trophic level in question. They stated that many of the disagreements about the importance of resource limitation and competition are due to comparing different trophic levels. The world is green observation suggested that the predation on herbivores allows plants to flourish. |
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Term
Harper
Part 3: Theses, Antithesis and Syntheses, Conversational Biology and Ecological Debate |
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Definition
| 1967, called for an approach to plant ecology that focused on the individual. Wanted to emphasize the properties of plants (plasticity and vegetative reproduction) that had hindered development of plant demography. He highlights the importance of self-thinning (more biomass taken up by fewer trees as the tree stands grow and they compete for limited resources) for both surviviorship curves and fitness. He stated that competition in plants and population dynamics can be analyzed quantitatively. |
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Ehrlich and Raven
Part 3: Theses, Antithesis and Syntheses, Conversational Biology and Ecological Debate |
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Definition
| 1964, studied butterflies and trophic level interactions. They define the process of coevolution: the plants evolve a chemical to keep predators away, the butterflies evolve a new way to bypass said chemicals. They stated that coevolution is the key to diversity in these butterflies. It also gave an alternative to HSS green world hypothesis: its not green because the insects aren't eating, but because the plants are inedible |
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Term
Schoener
Part 3: Theses, Antithesis and Syntheses, Conversational Biology and Ecological Debate |
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Definition
| 1971, synthesized two important trends: first was to develop more quantitative descriptions of the process of feeding and foraging and the other was the identification of ecological currencies (carbon, energy, etc). He provided framework for testing these models: choose a currency, choose the cost-benefit functions, and solve for the optimum. |
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Term
Von Post
Reconstructing Ecological History
Part 4: Methodological Advances, New Approaches and Methods in Ecology |
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Definition
| wrote a paper that recovered pollen grains from anaerobic sediments in peat bogs. This paper laid the foundation for paleoecology. His legacy is that it opened the door to studying pollen, plankton in sediments, and other artifacts to get a picture of life for the past 20,000 years |
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Patrick Leslie
Age and Stage structured Populations
Part 4: Methodological Advances, New Approaches and Methods in Ecology |
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Definition
| developed the mathematical treatment of life tables that is still used today.He used a simple matrix of diagonal elements of probabilities of surviving from x to x+1 and one row of elements containing the average number of offspring born to an individual of age x. This matrix, if survival probabilities and fecundity are constant, can calculate proportional changes in each age class, distribution, population increase, etc. This was important because it was easy to obtain for a field or lab biologist, and it showed a simple mathematical technique being used to make all the important demographic projections. |
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Term
Birch
Measuring Population Parameters
Part 4: Methodological Advances, New Approaches and Methods in Ecology |
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Definition
| studied rice weevils in laboratory conditions. It was the first paper that showed a population growing exponentially under controlled conditions. Birch calculated a life table of age-specific mortality and fecundity values and calculated net reproductive rate, average generation time, etc. This paper also measured temperature on increase, which showed that even with unlimited resources, environmental conditions can greatly influence a population's growth. He also showed the effects of variation of life history traits on population growth; he also stated that reducing immature stages could greatly increase the intrinsic rate of increase. |
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Term
Holling
The behavior and impact of predators
Part 4: Methodological Advances, New Approaches and Methods in Ecology |
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Definition
| studied the predation of the pine sawfly by small mammals. The paper's most important feature is the breakdown of predation into behavioral and population components. Holling described two levels of predation: the behavioral acts performed by an individual predator searching for and consuming prey and the population processes of mortality and fecundity influencing the growth of predator and prey populations |
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Term
Porter and Gates
A biophysical approach to Physiological Ecology
Part 4: Methodological Advances, New Approaches and Methods in Ecology |
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Definition
| 1969, made three contributions in one paper: the use of mathmatical models to identify the variables that affect energy exchange, the use of physical models to measure the interacting influences of key variables under lab and field conditions, and the development of the concept of climate space to characterize the range of physical conditions where an individual can survive and reproduce. |
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Term
Bray and Curtis
New Perspectives on Succession and Human Ecology
Part 4: Methodological Advances, New Approaches and Methods in Ecology |
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Definition
| Wrote a paper that developed and applied a new method to classify quantitatively plant assemblages on the basis of some measure of the abundance or importance of the component species. |
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Term
Eugene Odum
New Perspectives on Succession and Human Ecology
Part 4: Methodological Advances, New Approaches and Methods in Ecology |
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Definition
Wrote Fundamentals of Ecology in 1953. Wrote a paper trying to bridge the gap between ecosystem ecology (which he led) and evolutionary ecology (which macarthur led). He tried to develop relationships between the processes of energy flow and nutrient cycling (ecosystem) and the phenomena of population growth, community organization, and adaptation (evolution).
He applied his paper to human ecology as well, he pointed out that humans cannot exist apart from nature, and we affect the ecosystems as well. He warned about the dangers of managing ecosystems for stability, argued to reduce the use of chemical pesticides, and argued for land use zoning to limit the nature and distribution of human activities on the landscape.
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Term
Andrewartha
Case Studies of Specific system
Part 5: Case Studies in Natural Systems, lessons from nature |
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Definition
| Davidson set out to study thrip population and its relationship to weather. He took up Davidson's task, and discovered that thrip population was not controlled by density, but by climate. This caused him to reconsider the importance of competition in a population. |
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Term
Teal
Case Studies of Specific Systems
Part 5: Case studies in natural systems, lessons from nature |
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Definition
| Studied energy flow in marshes. The results were surprising (70% energy loss through respiration by Spartina) and his paper is considered classic because of the surprising results and the research these results inspired. |
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Term
Whittaker
Case Studies of Specific Systems
- Part 5: Case Studies in Natural Systems, Lessons from Nature |
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Definition
| studied plants in the smoky mountains. He sought to test whether Gleason or Clements had the correct idea of community ecology. (Individualism versus holism). He went into the study thinking that the truth was in the middle, but was surprised to discover that his data supported Gleason |
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Term
Davis
Case Studies of Specific Systems
- Part 5: Case Studies in Natural Systems, Lessons from Nature |
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Definition
studied pollen influx rates at Roger’s lake. The lasting contributions of her paper were using pollen influx data to study current species abundance. The paper also concluded that dominant species in the area did not arrive at the same time, and that their migration rates were strongly individualist, which support Gleason’s view of a community.
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Term
A.S. Watt
Process Studies
- Part 5: Case Studies in Natural Systems, Lessons from Nature
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Definition
studied processes of small-scale cyclic succession occurring within stable communities. Watt discussed that these patches were dynamic and varied in time and space and that these patches were in various stages of development, which was against the common thought that climax communities were stable and homogenous. (1947) He also said that death, and its replacement, was part of the internal dynamics of a community.
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Term
MacArthur
Process Studies
- Part 5: Case Studies in Natural Systems, Lessons from Nature |
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Definition
ntroduced to ecology the power of the hypothetical-deductive approach. His methodology was a combination of theory and hypothesis, which was extremely influential to the field. After his death, two camps developed in animal community ecology. One advocated of developing analysis of nature based on sight, and others called for a more rigorous null hypothesis and statistical tests.
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Term
Brooks and Dodson
Process Studies
- Part 5: Case Studies in Natural Systems, Lessons from Nature |
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Definition
studied lakes in connecticut with and without an introduced fish. They observed that lakes with the fish lacked larger species of zooplankton. The said that without the fish, the large zooplankton have a competitive advantage, and that the zooplankton are being specifically targeted by the introduced fish because the fish can see them. Without the fish, the biodiversity of zooplankton is greatly increased. This study furthered the discussion on trophic levels interacting. It also showed how a predator could control the trophic level on which it feeds.
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Term
Kettlewell
Selection in Natural Systems: Ecological Genetics
Part 6: Experimental Manipulations in Lab and Field Systems, manipulative experiments as tests of ecological theory |
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Definition
ecological genetics studies the forces determining patterns of genetic change across different geographic locations. Kettlewell (1955) studied genetic differences in moths and their fitness in different locations. In a polluted forest with dark trunks, the darker moths did better, in a non polluted forest, the lighter moths did better because they were harder to see. He focused on quantifying the selective mechanism.
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Term
Park
Community Structure and Species interactions
Part 6: Experimental Manipulations in Lab and Field Systems, manipulative experiments as tests of ecological theory |
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Definition
(1948) studied interspecific competition between two different species of grain beetles in a lab. He used single species treatments to establish which aspects of competition could be measured. His experiments showed, that under lab conditions, when two species were in competition, the demise of one of the species was inevitable, the winner was predictable but not absolute. One species out competed the other in hot-wet environment, and the other did better in cold and dry.
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Term
Connell
Community Structure and Species interactions
Part 6: Experimental Manipulations in Lab and Field Systems, manipulative experiments as tests of ecological theory |
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Definition
studied competition in barnacles. He observed that a species of barnacle had larvae at both high and low portions of the shore, but the larvae only survived higher up where another species of barnacle didn't live. He tested several theories, at it was discovered that the larvae could not compete with the other species. They could not survive in the middle zone because of competition, and in the lower zone because of predation. His work was important because it involved a gradient environment (intertidal zone) and showed how direct interference on the environment could be used in experiments to test competition. His paper was also the first to test competition and how it is affected by patterns of distribution.
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Term
Robert Paine
Community Structure and Species interactions
Part 6: Experimental Manipulations in Lab and Field Systems, manipulative experiments as tests of ecological theory
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Definition
studied biodiversity in tidepools. His experiments involved the removal of the ochre star from tide pools and observing the biodiversity. Without the ochre star, the california mussel takes over, driving down biodiversity. Paine coined the term keystone species to refer to organisms who greatly impact the biodiversity of an area (exert influence over other members of their communities out of proportion to their abundance).
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Term
Huffaker
Spatial Scale, its implications for predation, biogeography, and ecosystems
Part 6: Experimental Manipulations in Lab and Field Systems, manipulative experiments as tests of ecological theory
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Definition
| studied the predator prey system in mites. He manipulated the spatial environment in which the mites interacted. He discovered that increasing the patchiness enables the prey not to go extinct for longer, because they could colonize before the predator got them. This provided evidence that spatial heterogeneity and patchiness of an environment had direct effects on the predator-prey relationship. |
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Term
Simberloff and Wilson
Spatial Scale, its implications for predation, biogeography, and ecosystems
Part 6: Experimental Manipulations in Lab and Field Systems, manipulative experiments as tests of ecological theory
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Definition
The macArthur-Wilson equilibrium theory that describes island biogeography by predicting the number of species based off of immigration and extinction rates. S+W set to test this theory by setting up tents in the florida keys and killing all the species in the tents, and then recording recolonization. They discovered that the number of species there fit the equilibrium model. The recolonization curves reached equilibrium, and once that equilibrium was reached, there was rapid turnover in species composition.However, the equilibrium theory does have weak points:assumes species composition is stochastic and equivalent across all species.
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Term
Likens and Bormann
Spatial Scale, its implications for predation, biogeography, and ecosystems
Part 6: Experimental Manipulations in Lab and Field Systems, manipulative experiments as tests of ecological theory
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Definition
undertook the first planned manipulation of an ecosystem to study the importance of vegetation in regulation biogeochemical cycles. They studied the hubbard brook forest and inhibited the regrowth of vegetation for two years. They discovered that deforestation increased average stream water concentrate for all major ions, detritus and debris increased with deforestation, and annual runoff was well above the control over the three year period of deforestation. This showed that vegetation is extremely important in governing the retention of important nutrients in an ecosystem, and that the biotic community is more than a passive responder to the abiotic.
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