Population Viability Analysis Reading Answers: IELTS Reading Practice Test

Population Viability Analysis Reading Passage

Part A

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To make political decisions about the size and kind of forest in a region, it is essential to comprehend the implications of those decisions. Population viability analysis (PVA) is a tool for estimating the effect of forests on the ecosystem. It is a tool that predicts the possibility of extinction of a species in a certain area over a period of time. It has been used successfully in the United States to provide input on resource exploitation decisions and to help wildlife managers. There is now a huge possibility for using population viability to aid wildlife management in Australia’s forests.

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A species vanishes when the last person dies. This observation is a helpful starting point for any talk of destruction, as it highlights the part of luck and chance in the process of destruction. To make a prediction about destruction, we need to comprehend the methods that contribute to it, and these are the four wide types discussed below.

Part B

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Early attempts to assume population viability were based on population uncertainty. Whether a person will survive from one year to the next is frequently a prospect. Some couples can produce multiple pups in the same year, while others will not produce anything in the same year. Small populations will fluctuate greatly due to the inconsistency of birth and death, and these likely fluctuations will, on average, cause species extinction even as the population size increases. Considering only this uncertainty of reproductive ability, extinction is not possible if the number of people in a population is over 50 and the population is expanding.

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A small amount of breeding cannot be avoided by small populations. This is especially true if you have a very small number of genders. For illustration, if there are only 20 persons in a race and only one man, then all future persons in that species must be descended from that one man. For most animal species, such individuals are probably not able to survive and reproduce. Increases the chance of breeding extinction.

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Variation in a species is the raw material from which natural choice operates. Without genetic variation, a species does not have the ability to grow and adapt to changes in its environment or to new predators and new illnesses. Loss of genetic variation associated with population decline may contribute to the possibility of extinction.

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A recent study shows that other aspects need to be considered. Australia's environment is highly volatile from year to year. These changes add another degree of uncertainty to the survival of many organisms. Disasters such as fire, flood, drought, or epidemics can reduce the population to a small part of their average level. When these two additional uncertainties are paid for, the population needed to sustain a few hundred years can increase by thousands.

Part C

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Apart from these processes, we need to keep in mind the population distribution. A species that happens in five isolated areas does not have the possibility of extinction of a race of 100 persons in the same place with 20 persons each.

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Where trees are cut down, forest-dwelling creatures are forced to flee. Ground-dwelling plants can return within a decade. Nevertheless, arboreal marsupials (i.e., tree-dwelling animals) have not been able to regain pre-recorded density for more than a century. As more forests are destroyed, the number of animals will further decrease. Regardless of the theory or model we prefer, reducing the size of the population reduces the genetic variation of the population and raises the probability of extinction due to any or all of the methods listed above. So, it is a scientific truth that expanding the loaded area in any region will boost the chances of extinction of forest-dependent animals.

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