Question

Phosphorus usually becomes a limiting factor at certain times of the year in which ecosystem?
A. Aquatic ecosystem
B. Grassland ecosystem
C. Forest ecosystem
D. All of the above

Answer 1

Hint: An ecosystem is an area where plants, animals, microorganisms and other environmental factors are in continuous contact with each other. This contact may involve chemical or physical interactions. Both biotic and abiotic factors contribute to this interaction. Together all these factors constitute an ecosystem.

Complete step by step solution:
Ecosystem is a well coordinated system that is considered to be the basic unit of ecology. It is of several types but the major types are aquatic and terrestrial types of ecosystem.

In aquatic ecosystems, plants, animals, phytoplanktons etc inhabit the water bodies. Phosphorus inhibits proper growth of freshwater plants in aquatic ecosystems irrespective of amounts of nitrogen present in the water bodies.

Phosphorus is naturally present in low quantities in aquatic bodies as it is used up by both soil and organic matter. The remaining free phosphorus present is consumed by algae and large water bodies. This generally leads to algal blooms.

Algal blooms result in lowering oxygen concentrations in water bodies and that ceases the growth of plants.

Hence, phosphorus is a limiting factor in the aquatic ecosystem.

Phosphorus is an important nutrient in aquatic ecosystems but variation in its concentration can cause several alterations in the water bodies making it a limiting factor.

Note:
Excess man supplied phosphates through sewage, detergents or surface water run off result in algal blooms on the surface of water bodies. Algal blooms cause depletion of oxygen in the water bodies as they block the passage of sunlight to the phytoplanktons present in the water.