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Ecosystems, Forests, and Livelihoods - Agricultural Practices and Shifting Cultivation

Grade 5CBSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

An ecosystem is a community of living organisms (biotic) interacting with their non-living (abiotic) environment like soil, water, and air.

Forests act as the 'Lungs of the Earth' by maintaining the balance of gases. Through photosynthesis, plants absorb CO2CO_2 and release O2O_2.

Shifting Cultivation (also known as Jhum cultivation) is a traditional agricultural practice where a patch of forest land is cleared by cutting and burning trees. The ash produced is rich in potash, which increases soil fertility.

Tribal communities or Adivasis depend heavily on forests for their livelihood, collecting 'Minor Forest Produce' such as honey, lac, herbs, and bamboo.

Deforestation leads to several environmental issues, including the loss of biodiversity and increased levels of CO2CO_2 in the atmosphere, contributing to global warming.

Sustainable agricultural practices include crop rotation and the use of organic manure to maintain soil health without chemical fertilizers.

📐Formulae

6CO2+6H2O+Light EnergyC6H12O6+6O26CO_2 + 6H_2O + \text{Light Energy} \rightarrow C_6H_{12}O_6 + 6O_2

Photosynthesis: Carbon Dioxide+WaterSunlightGlucose+Oxygen\text{Photosynthesis: Carbon Dioxide} + \text{Water} \xrightarrow{\text{Sunlight}} \text{Glucose} + \text{Oxygen}

C6H12O6+6O26CO2+6H2O+Energy (ATP)C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy (ATP)}

💡Examples

Problem 1:

Why is the ash from burnt trees important in Shifting Cultivation (Jhum)?

Solution:

The ash contains minerals like potassium which act as a natural fertilizer.

Explanation:

In shifting cultivation, trees are slashed and burnt. The resulting ash provides essential nutrients to the soil, allowing crops to grow without the need for synthetic chemical fertilizers.

Problem 2:

Explain the role of forests in the Water Cycle using scientific notation.

Solution:

Trees release water vapor (H2OH_2O) into the atmosphere through a process called transpiration.

Explanation:

The moisture released by forest canopies contributes to cloud formation and rainfall, ensuring that the local ecosystem remains hydrated and temperatures stay regulated.

Problem 3:

What happens to the level of CO2CO_2 in an ecosystem if a large area of forest is cleared?

Solution:

The level of CO2CO_2 increases significantly.

Explanation:

Since there are fewer trees to perform photosynthesis and absorb CO2CO_2, the gas accumulates in the atmosphere. Furthermore, burning the wood during clearing releases stored carbon back into the air as CO2CO_2.