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Succession occurs in natural ecosystems - AQA - A-Level Biology - Question 1 - 2019 - Paper 2
Question 1
Succession occurs in natural ecosystems. Describe and explain how succession occurs. Figure 1 shows percentages of energy transferred from sunlight to a zebra in a ... show full transcript
Worked Solution & Example Answer:Succession occurs in natural ecosystems - AQA - A-Level Biology - Question 1 - 2019 - Paper 2
Step 1
Describe how succession occurs.
Answer
Succession in natural ecosystems generally begins with the process of colonization by pioneer species. These species are typically hardy organisms that can thrive in inhospitable environments, laying the groundwork for subsequent species to inhabit the area.
As pioneer species colonize the area, they change the environment, making it more habitable for other organisms. Over time, these changes can include alterations to the soil composition, water retention, and overall habitat conditions. This gradual process leads to increased biodiversity as more species establish themselves in the area, ultimately resulting in a more stable ecosystem.
Step 2
Explain the role of pioneer species in succession.
Answer
Pioneer species play a crucial role in succession as they initiate the ecological changes needed for later species to thrive. By altering the environment, such as improving soil quality or increasing organic matter, they create a more suitable habitat for new species to invade. As the environment becomes less hostile, more complex plants and animals can move in, leading to greater diversity and the eventual establishment of a climax community.