8What purpose does paragraph 8 serve in the text?A.It explains additional factors identified by the simulation. B.It outlines how the simulation models the problem. C.It illustrates the results predicted by the simulation. D.It describes the variables used to create the simulation. 6789HuntingCullingNumber of BisonBisonDistributionWeather600015000400030002000Fire1000The model simulates the populations of the two main bison breeding herds in Yellowstone National Park as well as nine plant groups. Eight simulations spanning a period of 50 yearswere completed using the model to determine whether Yellowstone bison had exceeded their food-limited carrying capacity inside the park. The simulations did not allow Yellowstone bisonto expand their range beyond the park boundaries. The simulations predicted the sizes of the two main herds by estimating the mean size of each herd, the median size of each herd, andthe possible range in the size of each herd. These data were then compared to actual 2005 population data for Yellowstone bison. The results of the simulations and the 2005 bisonpopulation numbers are shown in figure 3.Range1820-3530MedianMeant [26702417PredationBisonPopulationPlantPopulationSoilsMean3776Range2430-5630PlantConsumptionMedian4030WaterBudget1484Figure 2 - Selected essential components of theSAVANNA ecosystem model. Modified from Whiteet al. (2011)3531SimulationSimulationResults2005Population2005PopulationResults(Northern Herd) (Central Herd) (Northern Herd) (Central Herd)Figure 3 - Simulation results and 2005 bisonpopulation data. Data from White et al. (2011)As shown, the simulated bison population was larger than the actual population in 2005. The actual population of the northern herd in 2005 was significantly smaller than the smallestpopulation predicted using the model, as well as smaller than the median and mean predictions. The smallest population size for the central herd predicted using the model was lower thanthe actual size of the central herd in 2005. However, the mean, median, and maximum predicted size of the central herd population were all significantly greater than the actual size of thecentral herd in 2005. These results suggest that actual bison numbers could have increased by approximately 200 to 2000 before the herd would have been in danger of exhausting its foodsupply. Food availability was the limiting factor in the SAVANNA model, so if actual bison numbers had been higher than those predicted by the model, it would suggest that Yellowstonebison had exceeded their food-limited carrying capacity inside the park. However, this was not the case. This led the researchers to conclude that the food-limited carrying capacity for theYellowstone bison had not been reached.However, the model also suggested that carrying capacity could vary from year to year due to other factors aside from food availability, including weather and competition for resources.Additionally, winter weather conditions resulting in deep snowpacks could limit the ability of Yellowstone bison to access food. Figure 2 shows that the model allows for the fact that weathercan affect plant consumption. If snow is extremely deep, bison may have trouble accessing the plants they need to survive. If they cannot obtain adequate nutrition during part of the year,the bison population may decrease due to this temporary food shortage. Therefore, bison deaths due to starvation could occur even when bison numbers are well below the food-limitedcarrying capacity.Scientists have suggested several possible explanations for the movement of Yellowstone bison outside of the park even though they have not exceeded their food-limited carryingcapacity. Variations in the local climate are one possible factor. Areas outside of the park where snow melts sooner because the elevation is lower would provide better foragingopportunities. The bison may also simply be expanding their range to reduce population density (the number of individuals in a specific area) and therefore lessen the competition for anarea's resources. This reduced competition and greater resource availability could have a positive effect on the Yellowstone bison's nutrition, reproduction, and survival.References:Coughenour, M. B. 2005. Spatial-dynamic modeling of bison carrying capacity in the Greater Yellowstone ecosystem: A synthesis of bison movements, population dynamics, andinteractions with vegetation. Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, Colorado.White, P., Plumb, G., Coughenour, M, and Wallen, R. "Carrying Capacity and Movements of Yellowstone Bison." Yellowstone Science 19.1 (2011). Web. 5. May. 2014 [Available from:http://www.nps.gov/yell/planyourvisit/upload/YS_19_1_sm.pdf] Carrying Capacity and the Bison of Yellowstone National ParkThe following text is adapted from an article in Yellowstone Science, a journal published by the National Park Service.12345An important part of the Yellowstone National Park ecosystem, bison are the largest land mammals in North America. Yellowstone bison historically occupied approximately 7,720 squaremiles (20,000 km²) in the headwaters of the Yellowstone and Madison rivers. Today, this range is restricted to primarily Yellowstone National Park and some adjacent areas of Montana. Thebison population is subdivided into the central and northern breeding herds.One of the key issues related to the Yellowstone bison population is how it should be managed. From the beginning of the twentieth century through 1966, bison numbers were kept incheck through regular culling. This culling was stopped in 1969. Officials decided to allow bison numbers to fluctuate according to such factors as weather, the availability of resources, andpredators. The result was a dramatic increase in the numbers of Yellowstone bison. Figure 1 shows population numbers for the central and northern herds for 1970-2010.Number of Bison400035003000250020001500100050001970* Central HerdNorthern Herd19801990Year20002010Figure 1 - Data for bison observed duringaerial surveys conducted between July 1970and August 2010. Source: NPSAs the number of Yellowstone bison increased, more bison began migrating to areas outside of the Yellowstone Park boundaries during the winter months. In the 1940s, Yellowstonebison were concentrated in two main areas comprising a relatively small portion of the park. By 2007, the range of Yellowstone bison was greatly expanded. Bison were found throughoutYellowstone Park and even beyond its boundaries.Bison are migratory. They move to lower elevation ranges during the winter months in response to snow accumulation and snowpack development. They also change their diets slightlyduring the winter, preferring to feed in lowland meadows where the growth of sedges and grasses is concentrated. The movement of the bison beyond park boundaries, however, raisedquestions about whether their numbers were too high and if the forage inside the park was inadequate to support the bison population.In 2011, Dr. P. J. White and others published a review paper addressing the question of whether Yellowstone bison were moving outside of the park because they had exceeded theircarrying capacity (White et al., 2011). As a population increases in size, the finite amount of water, food, and shelter in an area must sustain and support a larger number of individuals.Eventually, numbers may increase to the point where this is no longer possible. At this point, the carrying capacity has been exceeded. One study the researchers referenced was an earlierstudy by one of the study's coauthors (Coughenour, 2005). This study used an ecosystem model to evaluate whether bison had exceeded their carrying capacity inside Yellowstone NationalPark. The study focused on food availability as the limiting factor. The model developed was named the SAVANNA model. The model integrates data from several ecosystem-relatedvariables, including predator populations, the production of plant biomass, physical land features, and water availability. Figure 2 shows a simplified version of the model and some of theinterrelated variables used in the model. For example, hunting and culling as well as predation can reduce the size of the bison population. The SAVANNA model also uses weather datafrom various sites within the park to simulate winter snow accumulation as well as snow melt.

Question

8What purpose does paragraph 8 serve in the text?A.It explains additional factors identified by the simulation. B.It outlines how the simulation models the problem. C.It illustrates the results predicted by the simulation. D.It describes the variables used to create the simulation. 6789HuntingCullingNumber of BisonBisonDistributionWeather600015000400030002000Fire1000The model simulates the populations of the two main bison breeding herds in Yellowstone National Park as well as nine plant groups. Eight simulations spanning a period of 50 yearswere completed using the model to determine whether Yellowstone bison had exceeded their food-limited carrying capacity inside the park. The simulations did not allow Yellowstone bisonto expand their range beyond the park boundaries. The simulations predicted the sizes of the two main herds by estimating the mean size of each herd, the median size of each herd, andthe possible range in the size of each herd. These data were then compared to actual 2005 population data for Yellowstone bison. The results of the simulations and the 2005 bisonpopulation numbers are shown in figure 3.Range1820-3530MedianMeant [26702417PredationBisonPopulationPlantPopulationSoilsMean3776Range2430-5630PlantConsumptionMedian4030WaterBudget1484Figure 2 - Selected essential components of theSAVANNA ecosystem model. Modified from Whiteet al. (2011)3531SimulationSimulationResults2005Population2005PopulationResults(Northern Herd) (Central Herd) (Northern Herd) (Central Herd)Figure 3 - Simulation results and 2005 bisonpopulation data. Data from White et al. (2011)As shown, the simulated bison population was larger than the actual population in 2005. The actual population of the northern herd in 2005 was significantly smaller than the smallestpopulation predicted using the model, as well as smaller than the median and mean predictions. The smallest population size for the central herd predicted using the model was lower thanthe actual size of the central herd in 2005. However, the mean, median, and maximum predicted size of the central herd population were all significantly greater than the actual size of thecentral herd in 2005. These results suggest that actual bison numbers could have increased by approximately 200 to 2000 before the herd would have been in danger of exhausting its foodsupply. Food availability was the limiting factor in the SAVANNA model, so if actual bison numbers had been higher than those predicted by the model, it would suggest that Yellowstonebison had exceeded their food-limited carrying capacity inside the park. However, this was not the case. This led the researchers to conclude that the food-limited carrying capacity for theYellowstone bison had not been reached.However, the model also suggested that carrying capacity could vary from year to year due to other factors aside from food availability, including weather and competition for resources.Additionally, winter weather conditions resulting in deep snowpacks could limit the ability of Yellowstone bison to access food. Figure 2 shows that the model allows for the fact that weathercan affect plant consumption. If snow is extremely deep, bison may have trouble accessing the plants they need to survive. If they cannot obtain adequate nutrition during part of the year,the bison population may decrease due to this temporary food shortage. Therefore, bison deaths due to starvation could occur even when bison numbers are well below the food-limitedcarrying capacity.Scientists have suggested several possible explanations for the movement of Yellowstone bison outside of the park even though they have not exceeded their food-limited carryingcapacity. Variations in the local climate are one possible factor. Areas outside of the park where snow melts sooner because the elevation is lower would provide better foragingopportunities. The bison may also simply be expanding their range to reduce population density (the number of individuals in a specific area) and therefore lessen the competition for anarea's resources. This reduced competition and greater resource availability could have a positive effect on the Yellowstone bison's nutrition, reproduction, and survival.References:Coughenour, M. B. 2005. Spatial-dynamic modeling of bison carrying capacity in the Greater Yellowstone ecosystem: A synthesis of bison movements, population dynamics, andinteractions with vegetation. Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, Colorado.White, P., Plumb, G., Coughenour, M, and Wallen, R. &#34;Carrying Capacity and Movements of Yellowstone Bison.&#34; Yellowstone Science 19.1 (2011). Web. 5. May. 2014 [Available from:http://www.nps.gov/yell/planyourvisit/upload/YS_19_1_sm.pdf] Carrying Capacity and the Bison of Yellowstone National ParkThe following text is adapted from an article in Yellowstone Science, a journal published by the National Park Service.12345An important part of the Yellowstone National Park ecosystem, bison are the largest land mammals in North America. Yellowstone bison historically occupied approximately 7,720 squaremiles (20,000 km²) in the headwaters of the Yellowstone and Madison rivers. Today, this range is restricted to primarily Yellowstone National Park and some adjacent areas of Montana. Thebison population is subdivided into the central and northern breeding herds.One of the key issues related to the Yellowstone bison population is how it should be managed. From the beginning of the twentieth century through 1966, bison numbers were kept incheck through regular culling. This culling was stopped in 1969. Officials decided to allow bison numbers to fluctuate according to such factors as weather, the availability of resources, andpredators. The result was a dramatic increase in the numbers of Yellowstone bison. Figure 1 shows population numbers for the central and northern herds for 1970-2010.Number of Bison400035003000250020001500100050001970* Central HerdNorthern Herd19801990Year20002010Figure 1 - Data for bison observed duringaerial surveys conducted between July 1970and August 2010. Source: NPSAs the number of Yellowstone bison increased, more bison began migrating to areas outside of the Yellowstone Park boundaries during the winter months. In the 1940s, Yellowstonebison were concentrated in two main areas comprising a relatively small portion of the park. By 2007, the range of Yellowstone bison was greatly expanded. Bison were found throughoutYellowstone Park and even beyond its boundaries.Bison are migratory. They move to lower elevation ranges during the winter months in response to snow accumulation and snowpack development. They also change their diets slightlyduring the winter, preferring to feed in lowland meadows where the growth of sedges and grasses is concentrated. The movement of the bison beyond park boundaries, however, raisedquestions about whether their numbers were too high and if the forage inside the park was inadequate to support the bison population.In 2011, Dr. P. J. White and others published a review paper addressing the question of whether Yellowstone bison were moving outside of the park because they had exceeded theircarrying capacity (White et al., 2011). As a population increases in size, the finite amount of water, food, and shelter in an area must sustain and support a larger number of individuals.Eventually, numbers may increase to the point where this is no longer possible. At this point, the carrying capacity has been exceeded. One study the researchers referenced was an earlierstudy by one of the study's coauthors (Coughenour, 2005). This study used an ecosystem model to evaluate whether bison had exceeded their carrying capacity inside Yellowstone NationalPark. The study focused on food availability as the limiting factor. The model developed was named the SAVANNA model. The model integrates data from several ecosystem-relatedvariables, including predator populations, the production of plant biomass, physical land features, and water availability. Figure 2 shows a simplified version of the model and some of theinterrelated variables used in the model. For example, hunting and culling as well as predation can reduce the size of the bison population. The SAVANNA model also uses weather datafrom various sites within the park to simulate winter snow accumulation as well as snow melt.

Accepted Answer

simulation models is used to represent or create a process that help to solve real world problem…

What purpose does paragraph 8 serve in the text? A. It explains additional factors identified by the simulation. B. It outlines how the simulation models the problem.