Human Impact on Ecosystems

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(This is a rather informal paper for a Biology class, it is by no means an accurate representation of my writing skills. I am only submitting it to have access to this site) Human Impact on Ecosystems There are 2 main models of population growth: exponential and logistic. The exponential model of population growth presents a constant per capita growth rate with no upper limit of individuals. Exponential growth will, theoretically, never reach its greatest growth rate because each new generation will have a greater number than the one before. The logistic growth curve represents a per capita growth rate that slows as the population reaches the maximum number of individuals that an environment can support. Logistic growth has its greatest growth rate at one half of carrying capacity. The carrying capacity of Earth is speculated to be 10-15 billion people. Human population growth is currently exponential; with 77 million people new individuals added each year. These increasing rates are due to modern medicine, but vary by country. It has been speculated that in 2050 the Earth will have 9 billion people. However, no population guesses are completely accurate. They merely go by the average offspring. The predicted trends could vary greatly from the predicted number. Deforestation is a major impact that humans have on the environment. Deforestation occurs for many reasons including urbanization and the need for land and wood/paper products. Deforestation damages the quality of the land and causes top soil to dry out. This leads to less fertile land. Also, the decrease in trees leads to greater greenhouse gas production because the trees no longer get rid of carbon dioxide. Deforestation rates have slowed but will never stop. Invasive species are another impact of humans on the environment. White nose fungus is an invasive species that is harming brown bats. This

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