The nutrient cycle in the rainforest
The majority of nutrients in the tropical rainforest are stored in the biomass. The biomass is all the living things in an ecosystem, including plants and animals.
Nutrients are rapidly recycled in the tropical rainforest biome. The warm, moist climate provides ideal conditions for decomposers to break down organic material in the litter layer very quickly. The litter layer is all the dead organic material such as fallen leaves, dead wood or dead animals on the surface of the soil. Vegetation takes up nutrients which are dissolved in the soil.
The soil is formed by the mixing of dead organic material with weathered bedrock. Soils in the rainforest are mainly thin and poor. Nutrient levels in the soil are low due to the leaching (washing away of nutrients) by the heavy equatorial rain. This leaching means that the lower layers of the soils lack the nutrients and minerals needed by the lush vegetation. Also, rainforest vegetation rapidly absorbs nutrients from the soil. Soils are often red in colour as they are rich in iron.
The nutrient cycle in the rainforest is an excellent example of interdependence. the diagram above shows the links between different stores of nutrients in the rainforest. Decomposers rely on fallen leaves, branches and dead animals to thrive. In turn, nutrients from decomposed matter enter the soil providing nutrients to support the growth of vegetation that is consumed by primary consumers.
The nutrient cycle in the rainforest is very fragile. If a nutrient flow changes this can have a negative impact on the ecosystem. For example, when deforestation occurs the litter layer no longer receives organic matter and the soil quickly becomes infertile. Because there is no vegetation cover to protect the soil nutrients are rapidly leached by heavy equatorial rainfall.
Use the images below to explore related GeoTopics.
How has rainforest vegetation adapted to the climate?
Take a look at our new resources in the shop