Read the following passage carefully and answer the given questions.

Productivity in the Ecosystem

The flow of energy through a terrestrial ecosystem starts with the harnessing of sunlight by autotrophs. The radiant energy is converted by photosynthesis to organic compounds is known as productivity. The productivity is expressed in units of energy per unit of area per unit time. The amount of organic matter present at any given time is biomass. The productivity of any ecosystem is affected by many parameters like weather conditions, nutrient availability etc. The productivity of any ecosystem does vary seasonally and yearly.

The amount of organic matter accumulated in an ecosystem at a given time is known as-

Standing crop

The correct answer is Option (2) → Standing crop

Each trophic level within an ecosystem has a specific amount of living material present at a given point in time, which is referred to as the "standing crop." This standing crop can be quantified by measuring either the biomass (mass of living organisms) or the population number of organisms within a defined unit area.

Biomass is typically expressed in terms of either fresh weight (total mass of living organisms as they are) or dry weight (mass of living organisms after removing water content through drying). These measures of standing crop help ecologists and scientists study the energy flow and dynamics within ecosystems and understand the distribution of living organisms across different trophic levels.