ESS - Topic 2.5 - Investigating ecosystems

The Lincoln index formula, used to estimate motile populations where

N1 is the initial number trapped and marked

N2 is the number recaptured the second time

Nm the number marked that were recaptured

is...?

• (N1 x N2) / Nm

• (Nm x N2) / N1

• (N1 x Nm) / N2

• N1 x N2

Species data was collected from 2 different sites.  
Site A: Species 1 (S1) = 3 organisms; S2 = 5; S3 = 4 
Site B: S1 = 8; S2 = 1; S3 = 2; S4 = 1; S5 = 1  
Choose the option with the highest SDI and Species Richness (SR)

• Higher SDI = Site B / Higher SR = Site A

• Higher SDI = Site A / Higher SR = Site A

• Higher SDI = Site A / Higher SR = Site B

• Higher SDI = Site B / Higher SR = Site B

The units of measurement for the Simpson's diversity index is ...?

• population per area

• number of organisms

• No units

• number of species

Estimate the population of rabbits on an island where 250 were trapped, marked and released. A week later, another 250 had been trapped of which 50 had marks on them.

• 12500

• 6250

• 62500

• 1250

The Simpson's Diversity Index (SDI) measures diversity by counting the

• total population of all species only

• number of species in an area

• population of the most dominant species in an area

• number of species and the population of each species in an area

Determining the number of species in an area is known as

• Species richness

• Biodiversity

• Biomass

• Total population

What kind of characteristics do dichotomous keys use to help us identify organisms?

• The organisms habitat

• What the organisms eats

• Response to climatic factors

• The organisms physical features

An advantage of direct measurements is....?

• allows us to identify unknown pollutants

• that the impacts of several pollutants can be analysed

• the pollutant can be quantified and clearly identified

• it tells us how the ecosystem will be affected

Typical values calculated by the Simpson's diversity index using quadrats range between

• 0 and 5

• 1 and 10

• -10 and 10

• 0 and 1

Below is raw data collected from 2 different sites. Which site will have the higher SDI? 
Site A: Species 1 (S1) = 3 organisms; S2 = 5; S3 = 4 
Site B: S1 = 8; S2 = 1; S3 = 2; S4 = 1; S5 = 1  
Choose the option with the correct explanation and higher SDI.

• Site B, because it has more species

• Site A, because it has fewer species

• Site B, because it has a larger total population

• Site A, because each species has similar sized populations