Answer
When parts of the Amazonian forest are clear-cut:
a. “Nutrient export is likely to decline” is false.
b. “Atmospheric CO2 is likely to decline” is false.
c. “Soil moisture is likely to decline” is true.
d. “Species diversity is likely to decline” is true.
Work Step by Step
a. Amazonian forests are a rich source of nutrients due to the high rate of decomposition. In case a part of the forests is cut down, the soil will be exposed to erosion. As a result, the nutrient export will increase from the soil.
b. Amazonian forests are one of the biggest sinks for carbon on terrestrial land. These forests occupy a small area of the Earth but have the highest productivity rate. In case a portion of the forests is cut down, a huge part of the trapped carbon would be released from the plants and the soil. Thus, atmospheric carbon will increase.
c. The Amazonian forests lie over the equator where the intensity of the sunlight is highest. The forests store an enormous amount of moisture in the plants as well as in the soil. Therefore, removing a part of the forests will expose the soil to the solar radiations and evaporate the moisture. As a result, the soil moisture will decrease.
d. The Amazonian forests harbor a huge number and variety of animal and plant species. The highly fertile forests are a rich source of food and nutrients for the species. Thus, the species diversity will decline as a result of habitat destruction if a part of the forests is cut down.
