20.2. Habitat destruction
A subsection of Biology, 0610, through 20. Human influences on ecosystems
Listing 10 of 65 questions
For Examiner's Use The table shows the area of tropical forests in some parts of the world and the rate of their destruction during the period 1990 – 2000. region of the world area of forest in 2000 / km2 area destroyed each year 1990 – 2000 / km2 annual percentage rate of destruction A 697 000 13 000 1.8 B 1 389 000 18 000 1.3 C 2 154 000 15 000 0.7 D 117 000 2 000 1.7 E 434 000 12 000 2.8 F 8 399 000 84 000 1.0 State which region had the greatest area of forest destroyed each year. State which region had the highest annual percentage rate of destruction. Use the data to suggest what the area of tropical forest in Region F will be in 2100. Predict which region will have the smallest area of forest in the year 2010. Tropical forests produce a large mass of dead vegetation each year which is decomposed. Name one type of microorganism that decomposes this dead plant matter. Name two substances that are released during decomposition that benefit the plants in the forest. For Examiner's Use Tropical forest is often cleared to provide ground for crop growth. However, after about three years, this land has to be abandoned and a new area is cleared. Suggest why a new area is needed after about three years of crop growing.
0610_s07_qp_2
THEORY
2007
Paper 2, Variant 0
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For Examiner's Use Tropical rainforest is one of the habitats with the greatest number of species on the Earth but it is being rapidly destroyed. Table 5.1 shows data from six countries that have large areas of tropical rainforest. Table 5.1 country area of rainforest in 1990 / thousand ha area of rainforest in 2005 / thousand ha Brazil 520 027 477 695 Ecuador 13 817 10 853 Indonesia 116 567 88 497 Madagascar 13 692 12 855 Philippines 10 561 7 181 Venezuela 52 026 47 713 Which country had the largest area of tropical rainforest in 2005? Calculate the total area of rainforest lost in the Philippines between 1990 and 2005. answer = thousand ha In the space below calculate the percentage of tropical rainforest lost in the Philippines between 1990 and 2005. Show your working. answer = % For Examiner's Use One method of deforestation is to remove the large trees for timber and then burn the rest of the vegetation. Explain why deforestation is considered harmful to the environment.
0610_s12_qp_22
THEORY
2012
Paper 2, Variant 2
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For Examiner's Use Tropical rainforest is one of the habitats with the greatest number of species on the Earth but it is being rapidly destroyed. Table 5.1 shows data from six countries that have large areas of tropical rainforest. Table 5.1 country area of rainforest in 1990 / thousand ha area of rainforest in 2005 / thousand ha Brazil 520 027 477 695 Ecuador 13 817 10 853 Indonesia 116 567 88 497 Madagascar 13 692 12 855 Philippines 10 561 7 181 Venezuela 52 026 47 713 Which country had the largest area of tropical rainforest in 2005? Calculate the total area of rainforest lost in the Philippines between 1990 and 2005. answer = thousand ha In the space below calculate the percentage of tropical rainforest lost in the Philippines between 1990 and 2005. Show your working. answer = % For Examiner's Use One method of deforestation is to remove the large trees for timber and then burn the rest of the vegetation. Explain why deforestation is considered harmful to the environment.
0610_s12_qp_23
THEORY
2012
Paper 2, Variant 3
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An investigation studied the effect of fertilisers on grass yield and species diversity in a grassland ecosystem. Some plots within the grassland were treated with fertilisers containing nitrogen, magnesium and phosphate. The control plots did not have any added fertiliser. The average yields were: • plots with fertiliser 1733 g m–2 year –1 • plots without fertiliser (control plots) 1009 g m–2 year –1 Calculate the difference between the average yields of the two plots within the field as a percentage of the average yield of the control plots. Show your working and give your answer to the nearest whole number. % Explain why the average yield increased as a result of adding the fertiliser. State the name of the process that occurs when fertiliser washes off land into rivers and causes an algal bloom. The researchers counted the number of different plant species in each of the plots in the grassland to determine species diversity. Counting started at the beginning of the growing season and was repeated every three weeks. The average number of plant species in each type of plot is shown in . time / weeks species diversity / average number of plant species m–2 plots without fertiliser (control plots) plots with fertiliser Describe the effect of fertiliser on the plant species diversity shown in . Suggest why some species of plants survive in grassland and others do not.
0610_s17_qp_43
THEORY
2017
Paper 4, Variant 3
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Questions Discovered
65