2.5 Investigating Ecosystems

Question 1

Lincoln Index

Answer 1

Statistical method used for estimating the population size of a species based on the capture/mark/recapture technique

Question 2

4 Steps for the Lincoln Index

Answer 2

Step 1: capture as any organisms as possible and denote the number of organisms n1
Step 2: mark them and let them back into wilderness
Step 3: capture as many organisms as possible in round 2 and denote the number of organisms in round 2 as n2 and the number of recaptured organisms nm
Step 4: using the Lincoln Index the population estimate can be calculated using the formula N= (n1xn2)/(nm)

Question 3

Quadrat sampling

Answer 3

It involves randomly placing square frames in a study area to quantify and analyse the distribution and abundance of organisms within the defined plots, providing a representative sample of the larger ecosystem

Question 4

Determinations possible with quadratic sampling

Answer 4

Abundance, distribution, diversity of species within a specific area, providing data for ecological studies and biodiversity assessments

Question 5

Population density

Answer 5

Number of species per unit area

Question 6

Percentage cover

Answer 6

Percentage of area within a Quadrat that is overhead by the species of interest

Question 7

Percentage frequency

Answer 7

Percentage of the total number of Quadrats sampled contain a particular species

Question 8

Estimation of biomass

Answer 8

Measuring dry weight of organic matter in a given sample, obtained through methods such as harvesting and drying plant material or using allometric equations based on size measurements for trees

Question 9

Measurement of energy content

Answer 9

Calorimetry

Question 10

Simpsons diversity index

Answer 10

Indicator used to quantify biodiversity;
formula D=(N(N-1))/sum (n(n-1)) D is biodiversity index, N is the total number of organisms in a habitat, n is the number of individuals of each species

Question 11

Simpson Index limitation

Answer 11

Only usable to compare habitats of similar size and types of organisms