Statement I: Productivity, decomposition, energy flow, and nutrient cycling are the four important components of an ecosystem.

Statement II: Primary productivity is the rate of capture of solar energy or biomass production of the producers.

Both statement I and II are correct .

The correct answer is Option (3) -Both statement I and II are correct.

Statement I: The statement is accurate. Productivity, decomposition, energy flow, and nutrient cycling are indeed four crucial components of an ecosystem.

1. Productivity: Productivity refers to the rate at which energy or biomass is produced in an ecosystem. It can be classified into primary productivity and secondary productivity.
2. Decomposition: Decomposition is the process by which organic matter, such as dead plants and animals, is broken down by decomposers (bacteria, fungi, etc.) into simpler inorganic substances. This process releases nutrients back into the ecosystem, allowing them to be recycled and reused by other organisms.
3. Energy Flow: Energy flow refers to the transfer of energy from one organism to another within an ecosystem. It follows the trophic levels, starting with the producers (plants) and moving through the various levels of consumers (herbivores, carnivores, etc.). Energy flows in a unidirectional manner, with energy being transferred from lower trophic levels to higher trophic levels, and eventually being lost as heat.
4. Nutrient Cycling: Nutrient cycling involves the cycling and recycling of essential nutrients within an ecosystem. Nutrients such as carbon, nitrogen, phosphorus, and others are taken up by organisms, used in their growth and metabolism, and then returned to the environment through processes like decomposition and excretion. These nutrients are then available for uptake by other organisms, completing the nutrient cycle.

Statement II: The statement is correct. Primary productivity specifically refers to the rate at which autotrophic organisms (producers) capture solar energy or produce biomass through photosynthesis or chemosynthesis. It is a measure of the energy or biomass production by plants and other primary producers in an ecosystem. Primary productivity is a crucial aspect of an ecosystem as it forms the foundation of energy flow and supports the trophic structure of the ecosystem.