What term describes the production or assimilation of biomass by different components of an ecosystem?

Name: Kerala PSC Learning App
Availability: InStock

AProductivity

BEnergy Flow

CProduction

DSuccession

Answer:

Production in an ecological context refers to the rate at which biomass (organic matter) is generated or assimilated by different trophic levels within an ecosystem. It is a fundamental concept for understanding energy flow and nutrient cycling.
It is typically measured in terms of energy (e.g., kilocalories per square meter per year - kcal/m²/yr) or fresh/dry weight of organic matter (e.g., grams per square meter per year - g/m²/yr).

Primary Production: This is the synthesis of organic compounds from inorganic sources, primarily carbon dioxide, by autotrophs (producers).

This process is mainly carried out through photosynthesis (using sunlight) by plants, algae, and cyanobacteria.
A smaller but significant portion occurs through chemosynthesis by certain bacteria, often found in deep-sea hydrothermal vents.
Primary producers form the base of most food webs, converting solar or chemical energy into usable forms for other organisms.

Secondary Production: This refers to the assimilation of organic matter by heterotrophic organisms (consumers).

It involves the conversion of consumed organic matter into new biomass by herbivores, carnivores, and decomposers.
It is the rate at which consumers convert the chemical energy from their food into their own body tissues.

Gross Primary Production (GPP): This is the total amount of organic matter or energy produced by producers through photosynthesis or chemosynthesis during a given period. It represents the total energy captured.
Net Primary Production (NPP): This is the GPP minus the energy lost by producers during respiration (R). Essentially, NPP = GPP - R.

NPP represents the energy available to the next trophic level (herbivores) and is crucial for sustaining the entire ecosystem.
It is often considered the most important measure for comparing the productivity of different ecosystems.

Net Community Production (NCP): This is the GPP minus the total respiration of all organisms (producers, consumers, and decomposers) in the ecosystem. It indicates the overall rate of organic matter accumulation in the entire community.

Light Intensity: Crucial for photosynthetic organisms.
Temperature: Affects metabolic rates and enzyme activity.
Nutrient Availability: Especially nitrogen, phosphorus, and potassium, which are often limiting factors.
Water Availability: Essential for plant growth in terrestrial ecosystems.
CO₂ Concentration: A key raw material for photosynthesis.

The oceans, despite their vast size, have lower average NPP per unit area compared to terrestrial ecosystems due to nutrient limitation in vast open ocean areas. However, their sheer volume means they contribute significantly to global NPP.
Tropical rainforests and coral reefs are among the most productive ecosystems per unit area on Earth due to high light availability, warmth, and nutrient cycling.
Deserts and the open ocean generally have very low NPP per unit area.
The 10% Law of Energy Transfer (Lindeman's Law) states that on average, only about 10% of the energy from one trophic level is transferred to the next, with the remaining 90% lost primarily as heat during metabolic processes. This rapid decrease in energy limits the number of trophic levels in an ecosystem.
Understanding production is vital for studying ecological pyramids (pyramid of numbers, biomass, and energy). The pyramid of energy is always upright because energy flows unidirectionally and decreases at successive trophic levels.

Challenger App