Samacheer Class 8 Science - Conservation of Plants and Animals

Gir national park – Gujarat
Sundarabans National Park – West Bengal
Indira Gandhi National Park – Tamil Nadu
Corbett National Park – Uttarangal
Kanha National Park – Madhya Pradesh

A biosphere reserve is a protected area designated to conserve biodiversity while allowing sustainable human activities and economic development within its boundaries. The human population also forms an integral part of the biosphere reserve system. These reserves typically cover an area of around 5000 square kilometers or more and are designed to conserve the ecosystem, species, and genetic resources of a region. Biosphere reserves serve the dual purpose of protecting natural habitats and biodiversity while also promoting sustainable economic development and improving the quality of life of local communities. They function as living laboratories where conservation and development go hand in hand, demonstrating how humans can coexist with nature in a balanced and sustainable manner.

An endangered species is an animal or plant that is considered to be at high risk of extinction in the near future. It means that there are only a few individuals of that species remaining on Earth, and if conservation measures are not taken, they might become extinct completely. Endangered species face threats from habitat loss, poaching, pollution, and climate change. Examples of endangered animals in India include the Snow Leopard, which is threatened by habitat loss and poaching in the Himalayan regions, and the Bengal Tiger, which faces threats from habitat destruction and illegal hunting. Other endangered species include the Asiatic Lion, the Purple Frog, and the Indian Giant Squirrel, all of which require urgent conservation efforts to ensure their survival.

The Red Data Book is an important conservation tool that provides comprehensive information about endangered and threatened species. It helps to evaluate and monitor the population trends of particular species over time, providing data that can be used to assess the status of species at the global level. The risk of a species becoming globally extinct can be estimated with the help of the information and data provided in this book, allowing conservationists to prioritize their efforts. The Red Data Book provides guidelines and recommendations for implementing protective measures and conservation strategies for endangered species, helping governments and organizations develop effective conservation policies. It also serves as a reference document for scientists, researchers, and policymakers to make informed decisions about wildlife protection and management.

Conservation of forests is essential for several important reasons. First, forests are home to a vast majority of the world's biodiversity, including countless species of plants, animals, insects, and microorganisms. According to the World Wildlife Fund, there has been a significant decrease in the population of animals, birds, fish, reptiles, and amphibians over recent decades, making conservation critical to protect endangered species. Second, conservation of forests helps protect and maintain the natural resources and ecosystems that support all life on Earth, including water sources, soil quality, and air purification. Third, we have a responsibility to leave something valuable for future generations, and conserving forests now ensures that our children and grandchildren will have access to these natural resources and the benefits they provide. Fourth, conservation of biodiversity through forest protection helps us protect, maintain, and recover endangered animal and plant species from extinction, preserving the genetic diversity that is essential for the health of ecosystems and human survival.

Bio-magnification is the process by which the concentration of toxic or contaminated substances increases progressively at each successive level of the food chain. The contaminants involved are typically heavy metals such as mercury and arsenic, and pesticides such as polychlorinated biphenyls and DDT (Dichloro Diphenyl Trichloro ethane). These harmful substances are taken up by organisms through the food they consume. When organisms at higher trophic levels feed on organisms at lower trophic levels that contain these toxins, the toxins accumulate in the bodies of the higher organisms. Since the higher organisms consume many lower organisms over their lifetime, the concentration of these toxins becomes much greater in their bodies than in the organisms they feed upon. This means that top predators accumulate the highest concentrations of these toxic substances, even though the initial concentration in the environment may be very low. Bio-magnification is a serious environmental concern because it can cause severe health problems and even death in animals at the top of the food chain, including humans who consume contaminated organisms.

Destruction of forests in order to make the land available for different uses is known as deforestation.
Causes of Deforestation:
Fires and floods are the natural causes for deforestation.
Human activities are responsible for deforestation include agricultural expansion, cattle breeding, illegal logging, mining, oil extraction, dam construction and infrastructure development.
1. Agricultural Expansion:
With increasing population, there is an overgrowing demand for food production.
Hence, large amount of trees are chopped down for crops and for cattle grazing.
2. Urbanization:
Increase in population needs the expansion of cities.
More land is needed to establish housing and settlement.
Requirements like construction of roads, development of houses, mineral exploitation and expansion of industries also arise due to urbanisation.
Forests are destroyed to meet all these needs.
3. Mining:
Mining of coal, diamond and gold require a large amount of forest land.
Large number of trees are cut down to clear the forest area. The waste that comes out from mining pollutes the environment and affects the nearby plants.
4. Construction of dams:
To provide water supply to the increasing population, large size dams are constructed. Hence, a great extend of forest area is being cleared.
5. Timber Production:
Wood-based industries like paper, match-sticks, furniture need a substantial amount of wood supply.
Wood is the most commonly used fuel, thus, a large number of trees are being cut down for fuel supplies.
Illegal wood cutting is the main reason for the destruction of some valuable plants.
6. Forest fire:
Forest fire be caused by humans, accidents or natural factors.
Forest fires wipe out thousands of acres of forest land each year all over the world. This has tremendous effects on biodiversity and the economy as well.
7. Cyclones:
Cyclones destroy the trees on a massive scale.
Effects of Deforestation:
1. Extinction of species:
Deforestation has resulted in the loss of many wonderful species of plants and animals and many are on the verge of extinction.
2. Soil Erosion:
When the trees are cut down, soils are exposed to the Sun’s heat.
Extreme temperature of the summer dries up the moisture and makes the nutrients to evaporate, ft also affects the bacteria that helps in the breakdown of organic matter.
3. Water cycle:
When trees are cut down, the amount of water vapour released decreases for transpiration and hence there is a decrease in the rainfall. ‘
4. Floods:
When the trees are cut down, the flow of water is disrupted and it leads to flooding.

In-situ conservation refers to the protection and management of species within their natural habitats and ecosystems. The advantages of in-situ conservation include that species can remain adapted to their natural habitat and continue to evolve naturally. Species can interact with each other and maintain their ecological relationships and food chains. The natural habitat and biodiversity are preserved in their original form. This method is generally less expensive and easier to manage compared to other conservation approaches. Additionally, the interests and rights of indigenous people who depend on these forests and wildlife are protected. Ex-situ conservation, on the other hand, involves protecting species outside their natural habitats, such as in zoos, botanical gardens, and breeding centers. The advantages of ex-situ conservation include that it can prevent the decline and extinction of endangered species by providing a safe environment for their survival. Endangered animals can be bred in captivity under controlled conditions, which increases their population numbers. Threatened species can be bred in these facilities and then released back into their natural environment to restore wild populations. Ex-situ conservation is also useful for conducting scientific research and educational work about species biology, behavior, and genetics. Both approaches are important and complementary in overall wildlife conservation strategy.

Conservation is the protection, preservation, management of wildlife and natural resource such as forest and water.
Types:
In-situ conservation:
It is conservation of living resources within the natural ecosystem in which they occur.
1. National Parks:
It is an area which is strictly reserved for the betterment of the wildlife.
Here, activities like forestry, grazing or cultivation are not permitted.
Eg – Guindy National Park in Chennai district.
2. Wildlife sanctuaries:
A sanctuary is a protected area reserved for the conservation of animals only.
Human activities like harvesting of timber, collection of forest products and private ownership rights are allowed here.
Controlled interference like tourist activity is also allowed.
3. Biosphere reserves:
It is a protected area where human population also forms the part of the system.
The area of these places will be around 5000 square kilometers.
They conserve the eco system, species and genetic resources.
Eg – These areas are set up mainly for economic development.
Ex-situ Conservation:
It is the conservation of wildlife outside their habitat. Establishing zoos and botanical gardens, conservation of genes, seedling and tissue.
1. Botanical gardens:
It is a place where flowers, fruits and vegetables are grown.
These places provide a healthy and calm environment.
2. Zoological parks:
Zoological parks are the areas where wild animals are conserved.
In India there are about 800 zoological parks.
3. Tissue Culture:
It is a technique of growing plant cells, tissues, organs, seeds or other plant parts in a sterile environment on a nutrient medium.
4. Seed bank:
The seed bank preserves dried seeds by storing them in a very low temperature.
5. Cryo Bank:
It is a technique by which a seed or embryo is preserved at a very low temperature.

1. Blue Cross is a registered animal welfare charity in the United Kingdom, founded in 1897 as Our Dumb Friends League.
2. The vision of this charity is that every pet will enjoy a healthy life in a happy home.
3. The charity provides support for pet owners who cannot afford private veterinary treatment, helps to find homes for unwanted animals, and educates the public in the responsibilities of animal ownership.
4. Captain V. Sundaram founded the Blue Cross of India, the largest animal welfare organization of Asia in Chennai in the year 1959.
5. He was an Indian pilot and animal welfare activist. Now, Blue Cross of India the country’s largest animal welfare organizations and it runs several animal welfare events like pet adaptation and animal right awareness.
6. Blue Cross of India has received several international and national awards.
7. This organization is entirely looked after by volunteers.
8. The main office is located at Guindy, Chennai, with all amenities like hospitals, shelters, ambulance services and animal birth controls, etc.
9. Activities of the organization include, providing shelters, re-homing, adoption, animal birth control, maintaining hospitals and mobile dispensary and providing ambulance services.

Deforestation involves the destruction and removal of forests by human activities to make the land available for agriculture, urbanization, industrial development, and other uses. When forests are destroyed, the wild animals that live in these forests lose their natural habitats and are left homeless. These animals are forced to move out and search for shelter and suitable living conditions elsewhere. As animals migrate away from their original habitats, the food chains and food webs that existed in the forest ecosystem are disrupted and broken. Animals cannot find adequate food in their new surroundings because the plants and prey species they depend on are not available. Additionally, when animals are displaced from their natural habitats, they become isolated from their groups and families, which disrupts their social structures and breeding patterns. Displaced animals may be killed in accidents when they wander into human settlements or cross roads and highways. They may also be hunted by humans or killed by predators in unfamiliar territories. Furthermore, the loss of habitat reduces the overall population of these species, making them vulnerable to extinction. Deforestation thus has severe negative consequences for wildlife populations and biodiversity.

The numbers of tigers and black bucks have decreased significantly due to multiple interconnected factors. Excessive hunting by humans has been a major cause of their population decline, as these animals were hunted for their skin, meat, and other body parts. Deforestation has destroyed large areas of forest habitat where these animals lived, leaving them with reduced space for survival and movement. Habitat degradation, caused by human activities such as logging, agriculture, and urban expansion, has further reduced the quality of the remaining forests and grasslands. For tigers specifically, there is an additional critical problem of prey depletion. As forests disappear, the populations of herbivores such as deer, wild boar, and other prey animals that tigers depend on for food have also decreased dramatically. With fewer prey animals available, tigers cannot find sufficient food to survive and reproduce, leading to malnutrition and starvation. This creates a cascading effect where the loss of vegetation leads to loss of herbivores, which then leads to loss of carnivores like tigers. The combined effects of hunting, habitat loss, and food chain disruption have pushed both tigers and black bucks toward endangered status, making their conservation a critical priority.