Biology by Bradford
8.6.A, 8.6.BTwo communities
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8.6 Biodiversity: revision map
The subtopic in the middle and four tasks round it: label a diagram, complete a table and fill 9 gaps. Every box rests on a learning objective of the topic in the AP Biology course and exam description. Type into the blanks and check them, or print it on A4, Letter or A3 with an answer key.
Biodiversity
AP Biology · Unit 8 EcologyHover over a box to see it. Untick it to leave it off this sheet and its printout.
Name8.6.BWhy diversity matters
Biodiversity includes the genetic variation within species, the number of species and the range of ecosystems. A community with many species is usually more : if one species fails, others can do its job, so the community recovers more easily from drought, disease or a change in climate. High genetic diversity lets a species adapt to change, and diverse ecosystems provide services that people depend on, such as pollination and clean water.
Topic 8.6Biodiversity
8.6.ASimpson's diversity index
| Community | Counts of 3 species | D = 1 − Σ(n/N)² |
|---|---|---|
| A | 10, 10, 10 | 1 − (3 × 0.111) = |
| B | 28, 1, 1 | 1 − (0.871 + 0.001 + 0.001) = |
Both have the same number of species, so the same richness. D is higher in A because the individuals are shared out evenly among the species, so community A is more .
8.6.AMeasuring
Species richness is the number of different species in a community, and evenness is how equally the individuals are divided among them. A diversity index combines both. Ecologists estimate numbers by sampling, with quadrats for plants and slow animals, and mark-recapture for animals that move, where the population is the number marked times the number caught the second time, divided by the number of .
Word bank 0.130.67communitydiversedominant speciesevenly spread speciesrare speciesrecapturedresilient
Answer key
Every box on the sheet with its gaps filled in, as the subtopic reads in full.
LabelTwo communities
- evenly spread species
- dominant species
- rare species
- community
TableSimpson's diversity index
Community Counts of 3 species D = 1 − Σ(n/N)² A 10, 10, 10 1 − (3 × 0.111) = 0.67 B 28, 1, 1 1 − (0.871 + 0.001 + 0.001) = 0.13 Both have the same number of species, so the same richness. D is higher in A because the individuals are shared out evenly among the species, so community A is more diverse.
GapsWhy diversity matters
Biodiversity includes the genetic variation within species, the number of species and the range of ecosystems. A community with many species is usually more resilient: if one species fails, others can do its job, so the community recovers more easily from drought, disease or a change in climate. High genetic diversity lets a species adapt to change, and diverse ecosystems provide services that people depend on, such as pollination and clean water.
GapsMeasuring
Species richness is the number of different species in a community, and evenness is how equally the individuals are divided among them. A diversity index combines both. Ecologists estimate numbers by sampling, with quadrats for plants and slow animals, and mark-recapture for animals that move, where the population is the number marked times the number caught the second time, divided by the number of recaptured.