Answer:
available nutrients are stored in tropical forest vegetation, so when the ground cover and trees are removed, the nutrients are removed, too.
Step-by-step explanation:
Rainforests are biomes with the highest productivity and variety of species on the planet. They are also called tropical rainforest or rainforest because of the high rainfall in the regions where they are located. Despite supporting a huge variety of plants, tropical forest soils are poor. Its productivity is guaranteed by the high water availability and high temperature. Moreover, the nutrients needed are mostly in the biomass of the living trees themselves than in the soil, and for this reason rainforests are not suitable for intensive agriculture.
In other words, tropical forests are not suitable for intensive agriculture because available nutrients are stored in tropical forest vegetation; therefore, when soil cover and trees are removed, nutrients are also removed.