Biodiversity (OCR A-Level Biology A): Flashcards
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Practise the cards
10 cards from this deck
Species richness
Species richness
Total number of different species in an area
Species evenness
Species evenness
Relative abundance of different species in an area
Species frequency formula
Species frequency formula
(quadrats with species / total quadrats) × 100%
Species density formula
Species density formula
Total organisms / total area sampled
When to use percentage cover
When to use percentage cover
For abundant species where counting individuals is impossible
Purpose of random sampling
Purpose of random sampling
Prevents bias in data collection
Lincoln index formula
Lincoln index formula
(S₁ × S₂) / number marked in S₂
Simpson's index (D) formula
Simpson's index (D) formula
D = 1 - Σ(n/N)²
Simpson's index: D near 1 means
Simpson's index: D near 1 means
High diversity (many species with similar abundances)
ACFOR scale meaning
ACFOR scale meaning
Abundant, Common, Frequent, Occasional, Rare