CBSE Notes Class 8 Science Chapter 5 - Conservation of Plants and Animals

Conservation of plants and animals is a critical endeavor aimed at protecting the rich biodiversity that sustains life on Earth. As human activities continue to impact natural ecosystems through deforestation, pollution, and climate change, the need for effective conservation strategies has never been more urgent. Healthy ecosystems provide essential services, such as clean air and water, climate regulation, and the preservation of soil fertility, all of which are vital for human survival.

1.0Deforestation and Its Causes

• A significant threat to the rich variety of life on Earth is deforestation, which refers to the clearing of forests for alternative uses. 
• This can happen for various reasons, such as creating agricultural land, constructing homes and factories, or harvesting wood for furniture and fuel. Natural events like forest fires and droughts also contribute to deforestation. 
• As a result, the intricate web of life that relies on these ecosystems faces alarming threats.

Consequences of Deforestation

• Deforestation leads to increased temperatures and pollution, primarily due to the rising levels of carbon dioxide in the atmosphere. 
• This disruption contributes to a decline in groundwater levels, affecting not only local flora and fauna but also the broader climate.
• Deforestation alters rainfall patterns and reduces soil fertility, leading to severe natural disasters like floods and droughts. 
• The students understood that trees play a crucial role in photosynthesis by consuming carbon dioxide. Fewer trees mean more carbon dioxide, exacerbating global warming by trapping heat rays in the atmosphere. 
• Additionally, soil erosion becomes more pronounced as fewer trees lead to the loss of topsoil, making once-fertile land susceptible to desertification. 
• This process reduces the land’s capacity to retain water, ultimately resulting in floods.

2.0Biosphere Reserve

• A biosphere reserve is a designated area aimed at promoting the conservation of biodiversity while allowing for sustainable development. 
• These reserves are recognized for their unique ecosystems, which often encompass a variety of habitats, including forests, wetlands, and grasslands. 
• The primary goal of a biosphere reserve is to balance ecological preservation with the needs of local communities.
• Core Areas: These are strictly protected regions where no human activity is allowed, safeguarding critical habitats and species.
• Buffer Zones: Surrounding the core areas, these zones allow for limited human activity that is compatible with conservation, such as research and education.
• Transition Areas: These are regions where sustainable development practices are encouraged, allowing communities to engage in agriculture, tourism, and other activities that support both their livelihoods and conservation goals.

Examples of Biosphere Reserves

1. Pachmarhi Biosphere Reserve (India)
2. Sundarbans Biosphere Reserve (India)

Endemic Species

• Endemic species are plants or animals that are found exclusively in a specific geographical area and are not naturally occurring anywhere else. 
• This unique characteristic makes them crucial for biodiversity and ecosystem health, as they often play specialized roles within their habitats. 
• Examples like the giant squirrel and local flora, such as sal and wild mango, highlight the biodiversity unique to Pachmarhi.

3.0Wildlife Sanctuary 

• A wildlife sanctuary is a protected area designated for the conservation of wildlife and their habitats. 
• These sanctuaries aim to provide a safe haven for various species, particularly those that are endangered or threatened, while promoting biodiversity and ecosystem health.

Examples - Bharatpur Bird Sanctuary (Keoladeo National Park), India

National park

• A national park is a protected area designated by a national government to conserve the natural environment and biodiversity while allowing for public enjoyment and education. 
• National parks are critical for preserving ecosystems, protecting wildlife, and promoting sustainable tourism.

The Red Data Book 

• This is a comprehensive record that documents the conservation status of various species of plants and animals. 
• It serves as a vital tool for assessing the health of global biodiversity and informing conservation efforts. 
• Compiled by organizations like the International Union for Conservation of Nature (IUCN), the Red Data Book categorizes species based on their risk of extinction.
• Endangered species are populations of plants and animals that are at risk of extinction due to low numbers or habitat destruction. Examples include tigers, blue whales, and Asiatic lions.

• Extinct species are those that have completely disappeared from the Earth. This can be caused by natural factors or human activities like habitat destruction and hunting. Examples include the passenger pigeon, dodo, and wooly mammoth.

• Vulnerable species are at risk of becoming endangered unless their circumstances improve. They are categorized by the International Union for Conservation of Nature (IUCN). Examples include African elephants, Nilgiri langurs, and giant pandas.

• Rare species are uncommon, scarce, or infrequently encountered. Examples include Himalayan brown bears, fennec foxes, and hornbills.

4.0Migration

• It is the regular and systematic movement of a group of organisms in search of suitable temporary shelter until they find a better place to live. 
• It's often described as the periodic movement of large populations of animals away from their native homes to other locations and then back again. 
• Examples include hummingbirds, tuna, and African elephants.
• The Siberian Crane, for instance, is native to Siberia. To escape the harsh winter conditions there, they travel long distances to India in groups. This migration allows them to find more favorable conditions for survival.

Recycling 

• Recycling involves the process of converting waste materials into new products to prevent resource depletion, reduce waste, and minimize environmental impact. Commonly recycled materials include: Plastics , Paper , Glass and Metals.

Reforestation

• It is the process of planting trees to replace those lost due to deforestation. 
• It's crucial to ensure that the replanted forests are diverse, with a variety of tree species and other vegetation, rather than monocultures like agricultural crops. 
• We should strive to plant at least as many trees as we cut down.
• India has implemented several laws to protect and conserve its forests. 
• The Forest (Conservation) Act of 1980 and the Wildlife (Protection) Act of 1972 (amended in 1991) are key examples. 
• These laws have led to the creation of protected areas like national parks and wildlife sanctuaries.