The Living World: Biodiversity
Liam Thomas
11 min read
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Study Guide Overview
This study guide covers biodiversity (species, genetic), including species richness and species evenness, and its ecological relevance. It also explores ecosystem services (provisioning, regulating, cultural, supporting) and their importance. Additionally, it examines ecological tolerance, resistance, resilience, natural disruptions, and ecological succession (primary, secondary) with a focus on pioneer species. Key terms like Shannon's Index are also included.
#AP Environmental Science: Unit 2 - Ecosystems and Biodiversity
Hey there! Let's dive into Unit 2, where we'll explore how organisms interact with their environment. This unit is all about connections and how everything is linked. Get ready to see the bigger picture! 🌍
#Biodiversity: The Variety of Life
Biodiversity is all about how much variety there is in a specific place. It's not just about counting species; it's about understanding how diverse and healthy an ecosystem is. This is a really important concept, so let's break it down:
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Biodiversity: The variety of life in a particular habitat or ecosystem. It's like the spice rack of nature – the more variety, the richer the flavor! 🌶️
- Ecological Relevance: This is how we measure the importance of an area based on its biodiversity. It helps us decide where to build, conserve, etc.
#Species Diversity
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Species Diversity: The total number of different species in an ecosystem. A high number of species usually means a healthier ecosystem. Think of it like a diverse team – each member brings unique skills! 🤝
- Species Richness: Just the number of different species present. If you have 10 species, the richness is 10. * Species Evenness: How evenly distributed the species are. If you have 100 animals, and 90 are squirrels, evenness is low. If you have 33 squirrels, 33 rabbits, and 34 birds, evenness is high.
#Genetic Diversity
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Genetic Diversity: The variety of genes within a species. More genetic diversity means a population is more resilient to changes. It's like having a backup plan for everything! 🧬
- Alleles: Different versions of a gene (like different eye colors). More alleles mean more genetic diversity.
- Phenotypes: The physical traits that result from genes (like blue eyes or brown hair).
Key Point: High biodiversity (both species and genetic) makes ecosystems more stable and able to bounce back from disasters. Think of it as a diverse investment portfolio – it's more likely to weather a storm!
Memory Aid: Richness is just a count, evenness is about balance. Think of a rich person (richness) and how evenly they distribute their wealth (evenness).
#Shannon's Index
- Shannon's Index: A mathematical way to measure species diversity using both species richness and evenness. It helps ecologists get a more accurate picture of ecosystem health.
Practice Question
Practice Question:
Multiple Choice:
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Which of the following best describes species evenness? (a) The total number of different species in an ecosystem. (b) The variety of genes within a species. (c) The relative abundance of each species in an ecosystem. (d) The ability of an ecosystem to withstand a disturbance.
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A forest has a high number of different tree species, but one species makes up 80% of the population. Which statement is true? (a) The forest has high species richness and high species evenness. (b) The forest has high species richness and low species evenness. (c) The forest has low species richness and high species evenness. (d) The forest has low species richness and low species evenness.
Free Response Question:
An ecologist is studying two different ecosystems: a grassland and a forest....
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