Ecosystems — BIOLOGY STD 12 Science — Question

1. Aquatic ecosystem

Explanation:

Productivity is the rate of accumulation of energy containing organic matter by an ecosystem per unit area per unit time.

It is of 2 types, primary productivity (productivity of autotrophs) and secondary productivity (productivity of consumers).

Maximum primary productivity occurs in coral reefs and estuaries, followed by sugarcane fields and tropical forests.

Moderate productivity occurs in agricultural crops and temperate forests.

Low productivity is found in grassland.

Very low productivity is present in deserts and arctic regions.

In oceans and other aquatic ecosystems, productivity is limited by light as it decreases with depth. But on a global basis, aquatic ecosystems occupy more space on earth than any other biome and have good productivity in surface layers, which are euphotic.