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Apparent competition with an invasive plant hastens the extinction of
Apparent competition with an invasive plant hastens the extinction of

... assumption for two reasons. First, the natural densities of these endangered plant populations are low, and therefore population density likely does not currently limit individual vital rates (e.g., germination) or population growth. Second, in cases where populations are projected to grow, eventual ...
Paper-3.1-Landings-Obligation-Vision-6
Paper-3.1-Landings-Obligation-Vision-6

... a CFP transformed by the discard ban and other 2013 reforms. The landings obligation will be applied to the demersal fisheries in the North Sea in January 2016 for some species. Discard Plans will need to be developed and proposed by the NSRAC to cooperating member states well before that target dat ...
The niche construction paradigm in ecological time
The niche construction paradigm in ecological time

... the intersection of the two functions becomes an unstable point. Thus, any combination of N and E will result in either the extinction of the population or a continuously increasing population and niche. The latter is obviously impossible in the real world, so some constraining force must be involve ...
Lizard population dynamics in a controlled landscape of Florida Scrub
Lizard population dynamics in a controlled landscape of Florida Scrub

... populations can be documented with microsatellite DNA. The procedure for obtaining microsatellite DNA markers for genetic studies in small populations requires (1) extraction of DNA, (2) heating DNA to cause the double helix of DNA to separate into two strands, then (3) a primer molecule (an oligonu ...
Reprint
Reprint

... model [39], the generalized Ricker model [40], and the Hassell model [41]). In each model, the reproduction ratio f(Nt) = Nt+1/Nt depends on the population size (i.e. the population density) N, on the intrinsic growth rate r, on the carrying capacity K, and on a parameter b that controls the shape o ...
Recent advances in ecological stoichiometry: insights for population
Recent advances in ecological stoichiometry: insights for population

... in elemental composition) at these interfaces can constrain processes across many levels of ecological organization: individual growth (Elser et al. 1996, Stelzer and Lamberti 2002); population growth (Urabe and Sterner 1996), community dynamics such as trophic transfer and species coexistence (Urab ...
Recent advances in ecological stoichiometry: insights for population
Recent advances in ecological stoichiometry: insights for population

... in elemental composition) at these interfaces can constrain processes across many levels of ecological organization: individual growth (Elser et al. 1996, Stelzer and Lamberti 2002); population growth (Urabe and Sterner 1996), community dynamics such as trophic transfer and species coexistence (Urab ...
Chapter 18: Interactions of Living Things
Chapter 18: Interactions of Living Things

... temperature also affect the environment. The availability of sunlight is a major factor in determining where green plants and other photosynthetic organisms live, as shown in Figure 3. By the process of photosynthesis, energy from the Sun is changed into chemical energy that is used for life process ...
Environmental Science Final Exam Review Sheet
Environmental Science Final Exam Review Sheet

... Define environmental resistance. Define biomagnification. Describe the three survivorship curves and provide an example of an organism that exhibits each. List 3 types of plants that have a symbiotic relationship with nitrogen fixing bacteria. What is the world’s population? What is the leading caus ...
carrying capacity: a critique of the concept al~ its usefulness
carrying capacity: a critique of the concept al~ its usefulness

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... Poulin et al., 2010). Determining whether silvicultural techniques such as selection harvesting are contributing to avian population declines is important, because much of the hardwood forest in eastern North America, which represents valuable habitat for many songbird species, is currently subject ...
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... were observed in the region before deep snow had accumulated. At present I am analyzing scats left by foxes and pellets left by owls, to estimate how many lemmings these predators could have killed. Predation by weasels appears to have been minor: we saw few weasels until well into the summer of 199 ...
Apparent competition with an invasive plant hastens the extinction of
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... assumption for two reasons. First, the natural densities of these endangered plant populations are low, and therefore population density likely does not currently limit individual vital rates (e.g., germination) or population growth. Second, in cases where populations are projected to grow, eventual ...
grade 12 life sciences learner notes
grade 12 life sciences learner notes

...  Seeds are stored in cool, dry and sterile conditions and kept at –10 to –20 ºC, which may cause damage to the DNA in some plant species.  Seeds of most species remain viable for more than 100 years in these conditions.  Seed banks can be used to store seeds when the crop yield is high, like mone ...
AP Biology A: Ch 1, 52, 53 Test
AP Biology A: Ch 1, 52, 53 Test

... D) Carrying capacity cannot be found in the figure because species under densitydependent control never reach carrying capacity. 33) As N approaches K for a certain population, A) which of the following is predicted by the logistic equation? A) The growth rate will not change. B) The growth rate wil ...
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... ecosystems can compensate to a degree if disrupted, but that too much disruption throws the ecosystem out of balance, causing a cascade effect. This can occur due to the loss of one species, or the reduction of several species. Fisheries have been found to have a major impact on many ecosystems, alt ...
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... Cushman & Whitman (1989) found a positive density-dependence. Environmental conditions can also influence the balance – at low predator densities less protection is needed by the herbivores (Del-Claro & Oliveira 2000) – or even reverse the outcome of the association: the higher the quality of the hos ...
You share your habitat with wolves and they are your predator. 5
You share your habitat with wolves and they are your predator. 5

... time period. Which of the following is a likely alternate explanation for the change in the goatfish population? a. goatfish prey increased in the area b. aquatic plants in the area decreased c. the temperature of the area increased d. goatfish parasites decreased in the area 5. Squirrels eat acorns ...
Ungulates in western coniferous forests: habitat relationships
Ungulates in western coniferous forests: habitat relationships

... prevent their use of areas (Loveless 1967). During the heaviest snow accumulations in the Bridger Mountains, Montana, mule deer were restricted to only 20% to 50% of their winter range (Mackie et al. 1982). Forested habitats, therefore, may provide refugia for ungulates during periods of heavy snowf ...
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UNIT 2 - Hartismere

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BIOL4 - The Student Room
BIOL4 - The Student Room

... group has two alleles. The allele for Rhesus positive, R, is dominant to that for Rhesus negative, r. The diagram shows the inheritance of the Rhesus blood group in one ...
A-level Biology Question Paper Unit 04
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... group has two alleles. The allele for Rhesus positive, R, is dominant to that for Rhesus negative, r. The diagram shows the inheritance of the Rhesus blood group in one ...
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Slide 1

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Rare migration vs. Regular Migration
Rare migration vs. Regular Migration

... allele frequencies of populations that that are large vs. very small? A. Large populations will have a greater range in frequency; smaller populations will have a low range of variation in frequency B. Large populations will have a low range of variation in frequency; smaller populations will have a ...
Q. 1. Give two examples to biomes. Ans. (1) Desert (2) Rain forest Q
Q. 1. Give two examples to biomes. Ans. (1) Desert (2) Rain forest Q

... Ans. The major biomes are formed due to annual variation in the precipitation in a region. Q. 3. How are varieties of habitats formed in a biome? Ans. The variations at regional and local levels within a biome leads to the formation of habitats. Q. 4. How does the temperature affect the organisms? A ...
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Maximum sustainable yield

In population ecology and economics, maximum sustainable yield or MSY is theoretically, the largest yield (or catch) that can be taken from a species' stock over an indefinite period. Fundamental to the notion of sustainable harvest, the concept of MSY aims to maintain the population size at the point of maximum growth rate by harvesting the individuals that would normally be added to the population, allowing the population to continue to be productive indefinitely. Under the assumption of logistic growth, resource limitation does not constrain individuals’ reproductive rates when populations are small, but because there are few individuals, the overall yield is small. At intermediate population densities, also represented by half the carrying capacity, individuals are able to breed to their maximum rate. At this point, called the maximum sustainable yield, there is a surplus of individuals that can be harvested because growth of the population is at its maximum point due to the large number of reproducing individuals. Above this point, density dependent factors increasingly limit breeding until the population reaches carrying capacity. At this point, there are no surplus individuals to be harvested and yield drops to zero. The maximum sustainable yield is usually higher than the optimum sustainable yield and maximum economic yield.MSY is extensively used for fisheries management. Unlike the logistic (Schaefer) model, MSY has been refined in most modern fisheries models and occurs at around 30% of the unexploited population size. This fraction differs among populations depending on the life history of the species and the age-specific selectivity of the fishing method.However, the approach has been widely criticized as ignoring several key factors involved in fisheries management and has led to the devastating collapse of many fisheries. As a simple calculation, it ignores the size and age of the animal being taken, its reproductive status, and it focuses solely on the species in question, ignoring the damage to the ecosystem caused by the designated level of exploitation and the issue of bycatch. Among conservation biologists it is widely regarded as dangerous and misused.
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