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Limpopo/August 2024

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Question 3

Read the passage below, then answer the questions that follow.

A woodland area near Tsethana village located at Makhado, Limpopo, at the base of Soutpansberg mountain was studied. The village has a human population that is increasing each year. The area is dominated by Sclerocarya birrea, commonly known as Marula tree, where birds build their nests. Domestic animals enjoy shade from this tree and Sclerocarya birrea fruit. The population of Sclerocarya birrea in this area was studied and counted at the end of each year over a period of five years. The results were recorded in the table below.

Sclerocarya birrea serves as medicine while its fruits are used to make traditional drinks. The study indicates that one Sclerocarya birrea tree can absorb 22 kilograms of carbon dioxide per year.

The results of the study were recorded below.

\begin{tabular}{|l|l|l|}
\hline Year & \begin{tabular}{l} Number of Households \end{tabular} & \begin{tabular}{l} Sclerocarya birrea Population \end{tabular} \\
\hline 2019 & 1000 & 221 \\
\hline 2020 & 1200 & 210 \\
\hline 2021 & 2100 & 100 \\
\hline 2022 & 2200 & 80 \\
\hline 2023 & 2250 & 20 \\
\hline
\end{tabular}

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3.1.1 What is the relationship between the number of households and Sclerocarya birrea population? (1)

3.1.2 During which year did the number of Sclerocarya birrea decrease the most? (1)

3.1.3 Calculate the percentage decrease in the number of Sclerocarya birrea during the period of study. (2)

3.1.4 Calculate the total amount of carbon dioxide absorbed by Sclerocarya birrea trees in the year 2019. (2)

3.1.5 Calculate the total estimated amount of carbon dioxide that will accumulate in the atmosphere in the year 2020 because of the decrease in the number of trees between 2019 and 2020. (2)

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TOTAL: 40



Answer :

GinnyAnswer
### Detailed Solutions

3.1.1 What is the relationship between number of households and Sclerocarya birrea population?
There is an inverse relationship between the number of households and the population of Sclerocarya birrea. As the number of households increases, the population of Sclerocarya birrea decreases.

3.1.2 During which year did the number of Sclerocarya birrea decrease the most?
The most significant decrease in the population of Sclerocarya birrea occurred in the year 2021.

3.1.3 Calculate the percentage decrease in the number of Sclerocarya birrea during the period of study.
To find the percentage decrease:
1. Note the initial population in 2019: 221
2. Note the final population in 2023: 20
3. Calculate the decrease in population: 221 - 20 = 201
4. Calculate the percentage decrease:
[tex]\[ \text{Percentage Decrease} = \left(\frac{\text{Decrease}}{\text{Initial Population}}\right) \times 100 = \left(\frac{201}{221}\right) \times 100 \approx 90.95\% \][/tex]

3.1.4 Calculate the total amount of carbon dioxide absorbed by Sclerocarya birrea trees in the year 2019.
1. Each Sclerocarya birrea tree absorbs 22 kg of CO2 per year.
2. The number of trees in 2019 is 221.
3. Total amount of CO2 absorbed in 2019:
[tex]\[ 221 \times 22 = 4862 \text{ kg} \][/tex]

3.1.5 Calculate the total estimated amount of carbon dioxide that will accumulate in the atmosphere in the year 2020 because of the decrease in the number of trees between 2019 and 2020.
1. Number of trees decreased from 221 in 2019 to 210 in 2020 (decrease of 11 trees).
2. Each tree absorbs 22 kg of CO2 per year.
3. Total CO2 that will accumulate due to this decrease:
[tex]\[ 11 \times 22 = 242 \text{ kg} \][/tex]

These calculations provide insight into the environmental impact of the decreasing Sclerocarya birrea population and highlight the importance of preserving this species for its ecological benefits.

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