Free Forest Ecology MCQs with Answers

• A. Oxygen and nitrogen
• B. Phosphorus and CO2
• C. Phosphorus and Sulphur
• D. Phosphorus and nitrogen

Explanation: Sedimentary cycles have their main reservoirs in rocks and sediments; phosphorus and sulphur are the standard examples.

• A. 25%
• B. 50%
• C. 10%
• D. 5%

Explanation: Only about 10% of the energy at one trophic level is typically transferred to the next, with the remainder lost mainly as heat and through…

• A. Place of occurrence
• B. Competitive ability
• C. Centre of origin
• D. Function at its place of occurrence

Explanation: A habitat describes where a species lives, whereas its niche describes how it lives, including its role and function in the ecosystem.

• A. All the above
• B. Electrification of nitrogen
• C. Industries
• D. Biological nitrogen fixation

Explanation: Nitrogen enters ecosystems through biological fixation, lightning, and industrial processes such as fertilizer production.

• A. Lime rocks contribute to CO2 of water
• B. 75% of total carbon lies in geological component
• C. CO2 is returned by combustion of fuel
• D. Atmospheric CO2 gets dissolved in water

Explanation: Limestone weathering can add carbon dioxide to water, dissolved CO2 remains part of the cycle, and combustion returns CO2 to the…

• A. FeS and Fe2S3
• B. Organic sulphates and -SH
• C. Soluble inorganic sulphates
• D. All of these

Explanation: Soluble inorganic sulphates are carried into the ocean through leaching and contribute to marine sulphate deposits.

• A. Grasslands
• B. Epiphytes
• C. Planktons
• D. Forests

Explanation: Forests regulate the hydrological cycle by intercepting rainfall, promoting infiltration, storing water and releasing it through…

• A. 8 x 10^12 kg
• B. 9 x 10^13 kg
• C. 9 x 10^11 kg
• D. 8 x 10^10 kg

Explanation: Global photosynthesis fixes roughly 9 × 10^13 kg of carbon dioxide annually, although the exact estimate varies with the method and period…

• A. 150
• B. 1,500
• C. 300
• D. 3,000

Explanation: Odum gives approximately 1,500 kcal/m²/day as the light energy absorbed by plant cover.

• A. Metabolism of producers
• B. Metabolism of consumers
• C. Both (a) & (b)
• D. Combustion of fuel

Explanation: Combustion of coal, petroleum and other sulphur-containing fuels oxidizes sulphur and releases sulphur dioxide into the atmosphere.

• A. Atmospheric CO2
• B. CO2 of carbonic rocks
• C. Fossil fuel
• D. All of the above

Explanation: Plants obtain their carbon mainly by taking atmospheric CO₂ into leaves during photosynthesis and converting it into organic compounds.

• A. Nitrogen
• B. Phosphorus
• C. Hydrologic
• D. Sulphur

Explanation: The hydrologic cycle is directly powered by solar energy, which evaporates water and drives atmospheric circulation and precipitation.

• A. Producers only
• B. Producers and consumers
• C. All of these
• D. Consumers and decomposers

Explanation: Consumers return sulphur through wastes and remains, while decomposers mineralize organic sulphur into inorganic forms in the soil.

• A. 75
• B. 65
• C. 85
• D. 95

Explanation: About 95% of Earth’s water is commonly represented in this classification as being bound in the lithosphere and sedimentary rocks, leaving…

• A. Tertiary productivity
• B. Secondary productivity
• C. Both (a) & (b)
• D. Net productivity

Explanation: Storage or production at a consumer trophic level is called secondary productivity, because consumers derive their biomass from consumed…

• A. 28.6
• B. 26.8
• C. 22.6
• D. 22.8

Explanation: Lindemann’s trophic-transfer calculations give about 28.6% of net production as being passed on to carnivores in the stated relationship.

• A. 0.2-0.4
• B. 2?4
• C. 4?6
• D. 0.6-0.8

Explanation: Sugarcane is a highly productive crop, with net productivity commonly placed around 2–4 kg/m²/year.

• A. Producers less than herbivores
• B. Producers equal to herbivores
• C. Producers more than herbivores
• D. Variable

Explanation: In forests, a relatively small number of large producer trees can support numerous herbivores such as insects, so producers may be fewer…

• A. Herbivore and detrivore
• B. Carnivore and detrivore
• C. Herbivore and carnivore
• D. All of these

Explanation: An omnivore consumes both plant material and animal matter, so it combines herbivore and carnivore feeding habits.

• A. Rhomboidal
• B. Inverted
• C. Linear
• D. Upright

Explanation: A biomass pyramid in a parasitic food chain is generally upright because the host organisms contain more total biomass than their…