Disturbance and Succession Q1: What type of survivorship curve do oysters have? Type 3 Q2: What two factors contribute to a decrease in population size? Mortality and Emigration Q3: What causes population size to level off at a carrying capacity? Factors such as insufficient space, food supply, or sunlight Q4: Which growth model takes carrying capacity into consideration? exponential / logistic / per capita The Logistic model incorporates a carrying capacity Q5: What is ecological succession? The process by which the structure of a biological community evolves over time. Includes primary and secondary succession. Q6: Distinguish between primary succession and secondary succession: Primary succession occurs in areas with virtually no soil, where soil is incapable of sustaining life as a result of such factors as volcanic eruptions, newly formed sand dunes or rocks from a glacier. Secondary succession happens in places where there was already life, such as a place where there was a forest fire. Q7: What are the first two types of multicellular organisms to colonize in primary succession? Lichens and Mosses Q8: Which species typically colonize next? Grasses and shrubs Q9: What two natural processes can result in virtually lifeless areas with no soil? Volcanoes and Glaciers Q10: What advantage do Dryas and alder have in colonizing the land exposed by the retreating glacier in Alaska? They are nitrogen fixing colonizers