Why are grasslands well-suited to natural fire regimes? why are grasslands nutrient-rich while rainsoforest...

Question

so nutrient-poor?

Answer 1

Grasslands tend to be rolling hills or flat-lands. The rainfall measurements tend to be moderate. The soil itself is the reservoir of the nutrients and contains a vast biomass of microorganisms and invertebrates. The rainfall is not sufficient to remove much of the soil nutrients.

High direct sunlight is conducive to annual plants which dry during one season, leaving the possibility of fire high. The fire rapidly returns Potassium and other minerals to the soil.

Rainforests, on the other hand, have very high rainfall rates and tend to lock the nutrients in the perennial plants rather than the soil. Nutrients, but especially minerals, which are not taken up by plants are very quickly leeched into the water system and removed.

By the way, flat-lands which have high relative rainfall rates tend to be swamps and different rules apply.