Assertion (A): Unlike temperate forests, the tropical rain forests, if cleared, can yield productive farm-land that can support intensive agriculture for several years even without chemical fertilizers. Reason (R): The primary productivity of the tropical rain forest is very high when compared to that of the temperature forests.

1. This is an Assertion-Reason question comparing tropical rain forests and temperate forests in the context of agriculture. 2. Assertion (A): Unlike temperate forests, the tropical rain forests, if cleared, can yield productive farm-land that can support intensive agriculture for several years even without chemical fertilizers. This is false. Tropical rain forest soils (latosols) are generally nutrient-poor. The ecosystem's nutrients are locked up in the biomass itself. Once cleared, the thin topsoil is quickly depleted by farming and eroded by heavy rainfall, making it unsuitable for sustained intensive agriculture without significant inputs. Temperate forest soils are often more fertile. 3. Reason (R): The primary productivity of the tropical rain forest is very high when compared to that of the temperature forests. This is true. Due to high temperatures, abundant rainfall, and year-round growing seasons, tropical rain forests have extremely high rates of net primary productivity (NPP) – the rate at which biomass is produced. 4. Since Assertion (A) is false and Reason (R) is true, the correct option is (D).