Forests are vital natural ecosystems that play a crucial role in supporting life and maintaining environmental balance. The chapter begins with a discussion about a proposal to clear a forest area for a factory, highlighting the differing perspectives on development versus environmental preservation. A scientist refers to forests as "green lungs" and "water purifying systems," emphasizing their importance.

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Visit To A Forest

To understand the significance of forests, children embark on a visit to a forest trail. Upon entering the forest, they are signalled to remain quiet, as noise can disturb the wildlife. From an elevated viewpoint, they observe that the forest land is completely covered by the canopies (treetops) of different trees, forming a continuous green cover, though not uniform. The atmosphere inside is peaceful and cool.

Sudden sounds of birds or movements in the upper branches are normal, sometimes caused by animals like monkeys. The children learn that other animals like boar, bison, jackals, porcupine, and elephants also inhabit deeper parts of the forest, reinforcing the idea that forests serve as a **habitat** (home) for a wide variety of plants and animals.

The forest floor is uneven and covered with numerous plants. Children identify various types of trees (sal, teak, neem, bamboo, etc.), and are told about the presence of shrubs, herbs, and grasses, along with creepers and climbers covering the vegetation and forest floor.

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Activity 17.1

Listing objects in our homes made from materials potentially obtained from forests (e.g., furniture, paper, plywood, matches, gum, oils, spices, medicines). This activity highlights the **diverse products and resources** that humans obtain from forests, demonstrating our reliance on them beyond ecological benefits.

Forest trees produce seeds that germinate on the forest floor, which provides favourable conditions for seedlings and saplings to grow into new trees, allowing the forest to regenerate naturally. The branchy part of a tree above the stem is called the **crown**.

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Activity 17.2

Visiting a forest or park and observing/identifying trees, noting their characteristics like height, leaf shape, crown shape, and presence of flowers/fruits. Drawing the crowns of different trees reveals their varied shapes and sizes, contributing to the layered structure of the forest vegetation.

Different tree crown shapes and sizes, along with shrubs and herbs, create distinct **horizontal layers** within the forest, known as **understoreys**. The tallest trees form the top layer (**canopy**), followed by layers of shrubs and tall grasses, with herbs forming the lowest layer. This layering provides different niches and shelter for various animals.

The types of plants and animals found vary from forest to forest depending on climatic conditions.

The forest floor is often dark due to the limited sunlight penetrating the canopy and is covered with a layer of dead and decaying organic matter (leaves, fruits, seeds, twigs) and small plants. This decaying layer is typically moist and warm.

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Activity 17.3

Digging a small pit, filling it with vegetable waste and leaves, covering it with soil, and adding water. Checking the pit after a few days reveals that the decaying matter inside feels **warm**. This indicates that the process of decomposition by micro-organisms generates heat.

The children notice numerous insects, spiders, and other small animals living on the bark of trees, plant leaves, and within the decaying layer on the forest floor.

Discussing the potential impact of cutting trees for a factory leads to an understanding of the interconnectedness of the forest ecosystem. Plants (autotrophs) are producers. Animals (herbivores and carnivores, heterotrophs) ultimately depend on plants for food. This forms **food chains** (e.g., Grass $\rightarrow$ insect $\rightarrow$ frog $\rightarrow$ snake $\rightarrow$ eagle). Many such food chains are linked in a forest, forming a complex **food web**. Disturbing one part, like removing trees (producers), affects the entire system, as all components are interdependent.

Tiny organisms and micro-organisms, including fungi and bacteria, live in the soil and on decaying matter. These are known as **decomposers** (saprotrophs). Decomposers feed on dead plant and animal tissues and convert them into a dark-coloured substance called **humus**. Humus is found in the topsoil (A-horizon) and is essential for soil fertility, providing nutrients to living plants. Decomposers play a vital role in nutrient cycling in the forest; they release nutrients from dead organisms back into the soil, where plant roots can absorb them, ensuring that **nothing goes to waste** in a forest.

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Forests are called "**green lungs**" because plants release oxygen through **photosynthesis** (Chapter 1), providing oxygen for animals to breathe. Plants also use carbon dioxide from the atmosphere for photosynthesis, helping maintain the balance of oxygen and carbon dioxide. (See diagram of $O_2$/$CO_2$ balance).

Forests significantly influence the **water cycle**. Trees absorb water through roots and release water vapour into the air through **transpiration**. This adds moisture to the atmosphere, contributing to rainfall. Also, the forest floor, covered with decaying matter, acts like a sponge, absorbing rainwater and allowing it to seep into the ground (infiltration) slowly. The canopy and understorey layers intercept raindrops, slowing their speed and preventing direct impact on the soil. Tree roots bind the soil, preventing soil erosion. By facilitating water seepage and preventing rapid runoff, forests help maintain the **water table** and ensure a steady supply of water in streams and nearby areas, thus helping in **flood control** and preventing **soil erosion**.

Animals play a role in forest growth and regeneration. Animals that eat fruits or seeds often **disperse seeds** to new locations through their droppings or by carrying them. Decaying animal droppings also provide nutrients for germinating seeds and seedlings. This helps the forest to grow and regenerate naturally.

The diverse variety of plants provides ample food and habitat for herbivores, which in turn support a variety of carnivores. The interplay between plants, animals, and decomposers keeps the forest healthy and vibrant. The forest is therefore described as a "**dynamic living entity**" that is full of life and continuously growing and regenerating.

Beyond ecological benefits, forests are lifelines for **forest-dwelling communities** who rely on them for food, shelter, water, and traditional medicines. They possess valuable knowledge about the forest's resources.

Villagers living near forests often benefit from increased rainfall, cooler air, and reduced noise pollution from nearby highways due to the forest's presence.

Despite their importance, forests face threats from **deforestation** (clearing forests), driven by increasing population, demand for housing, industry, roads, and wood. Overgrazing by animals can also hinder forest regeneration. Preserving forests requires wise management and balancing development needs with environmental conservation.

The disappearance of forests would have severe consequences:

• Increased levels of carbon dioxide in the atmosphere (as plants absorb $CO_2$), contributing to rising Earth temperature (global warming).
• Lack of food and shelter for animals, threatening their survival.
• Reduced water absorption by soil and increased runoff, leading to floods.
• Increased soil erosion.
• Disruption of the water cycle and oxygen balance.
• Loss of biodiversity and useful forest products.

Therefore, preserving forests is essential for the health of our planet and all life on it.

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