MEGA Elementary Education Multi-Content Practice Test

What is the primary environmental issue leading to a reduction in Earth's biodiversity in recent decades?

1. global warming

2. tropical deforestation

3. desertification

4. soil salinization

The correct answer is: tropical deforestation

The primary environmental issue leading to a reduction in Earth's biodiversity in recent decades is tropical deforestation. This phenomenon significantly affects biodiversity because tropical forests are among the most biologically rich ecosystems on the planet, housing an immense variety of species. Deforestation involves the clearing of large areas of forest for agricultural, urban, or industrial use, which destroys the habitats that countless species rely upon for survival. As forests are cut down or degraded, many species face extinction due to loss of habitat, decreased genetic diversity, and increased competition for resources. This not only disrupts local ecosystems but can also have far-reaching effects on global biodiversity and ecosystem services, including carbon storage and climate regulation. The impact of deforestation is particularly pronounced in tropical regions, where the rich diversity of flora and fauna is being rapidly diminished, leading to an alarming decline in the number of species. While global warming, desertification, and soil salinization also contribute to environmental challenges, they do not specifically target the same immediate and direct loss of habitat as tropical deforestation does, making the latter the most critical issue for biodiversity loss in recent decades.