NEET Medical AIIMS PG
Notes Review in Biodiversity and Conservation
The variability of life on Earth is called Biodiversity. It refers to the variations of living organisms at species and genetic levels. Biodiversity takes into account all the living organisms present on Earth. Healthy and good biodiversity indicate a healthy and good ecosystem
Biodiversity and Conservation - CBSE Notes for Class 12 Biology
Biodiversity:
1. Biodiversity can be defined as the emergence of a variety of genes, genetic ponds, animal species, habitats and ecosystems in a given region.
(i) The term diversity was coined by the social scientist, Edward Wilson to describe the combined diversity at all levels of biological organization.
(ii) There are more than 20,000 species of ants, 3,00,000 species of beetles, 28,000 species of fish, and nearly 20,000 species of orchids.
(iii) Biodiversity can be divided into the following three categories:
(a) Genetic variation is genetic variation.
• It enables people to adapt to their own environment.
• India has more than 50,000 varieties of rice and 1,000 varieties of mangoes.
For example, genetic variation in the medicinal plant Rauwolfia vomitoria that grows in different parts of the Himalayas may depend on the intensity and filtering of the active chemicals (reserpine) produced by this plant.
(b) Biodiversity diversity at the level of species. For example, the Western Ghats have a wider range of aquatic and aquatic species than the Eastern Ghats.
(c) Biodiversity diversity. For example, India with its own deserts, rain forests, mangroves, coral reefs, swamps, estuaries and mountainous terrain is rich in natural diversity.
2. Biodiversity means that all living things on earth exist.
(i) According to the IUCN (2004) the total number of plant and animal species is slightly more than 1.5 million.
(ii) For most tax groups, biodiversity is far more complete than in the tropics.
(iii) Robert May's conservative and scientifically sound estimate puts the world's biodiversity at about seven million.
(iv) More than 70% of all species recorded by animals, while plants make up more than 22% of the total.
(v) Among animals, insects are many species of tax-rich species, making up about 70% of the total. That is, of the ten animals, seven are insects on earth.
3. Biodiversity in India
(i) Although India owns only 2.4% of the world's land area, its share of international diversity is 8.1%. This makes India one of the 12 different countries in the world.
(ii) About 45,000 species of plants and animals are twice as many as recorded from India.
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(iii) According to May international statistics, only 22% of the species have been recorded to date. If this standard is applied to a variety of Indian species, there may be more than 1,00,000 plant species and more than 3,00,000 species of animals to be identified and described.
4. Biodiversity patterns show that biodiversity is not the same worldwide as it is affected by:
(i) Latitudinal gradients show a decrease in biodiversity as we move from the equator to the poles.
(a) Tropical areas (range 23.5 ° N to 23.5 ° S) have more diversity than cooler or cooler areas.
(b) For example, Colombia near the equator has around 1,400 bird species, New York at 41 ° N has 105 species and greenland 71 ° N has only 56 species.
(c) Studies show that tropical areas are more diverse.
For example,
• India, with its tropical land area, has over 1,200 species of birds.
• The tropical rain forest of the equator has ten times as many species of arterial plants as the equatorial forest in the temperate region such as the midwest of the USA.
• The tropical Amazon rain forest of South America has the largest biodiversity in the world. It contains 40,000 plant species, 3,000 fish, 1,300 birds, 427 mammals, 427 amphibians, 378 reptiles and more than 1,25,000 invertebrates.
• Scientists estimate that in these rain forests, at least two million species of insects are waiting to be discovered and named.
(d) Causes of Great Tropical Diversity
• Clarification is usually a work of time. Low-lying regions have suffered from frequent snow attacks in the past, but the tropics remain relatively undisturbed, which is why they have evolved into a wide variety of species.
• Tropical areas, in contrast to tropical climates do not have a specific season, they are always comparable and predictable. Such permanent environments improve niche technology and lead to greater diversity of genres.
• More solar energy is available in the tropics, which contributes to higher productivity, which in turn can contribute indirectly to greater diversity.
(ii) Spatial and Geographical Relationships
(a) Alexander Von Humboldt, a German biologist and geologist noted that in the region, the number of species is increasing with a growing area of testing, but only to the limit.
(b) In fact, the relationship between the richness of species and the location of the various species of taxa (such as angiosperm, birds, bats, and freshwater fish) is a rectangular hyperbola.
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(c) According to the logarithmic scale, the relationship is a straight line as given in the following calculation
log S = log C + Z log A where, S = Species richness, A = Location
C = Y-kick, Z = Line slope (reverse coefficient)
(d) The value of Z lies in the range of 0.1-0.2 regardless of the taxonomic group or region.
(e) If we analyze the geographical relationship between the largest areas such as all continents, the slope of the line will be the strongest, i.e. the Z values in the range of 0.6-1.2. For example, with birds of prey and mammals in tropical forests of different continents, the slope is found to be 1.15.
5. The Importance of Biodiversity in the Ecosystem
(i) According to biologists, biodiversity societies tend to be more stable than those with less biodiversity.
(ii) The qualities of a stable society are
(a) He must not shoot
CONCLUISION:
(1) The diversity of micro-organisms, algae, fungi, plants and animals that occur on land may be in the terrestrial or aquatic and in the natural environment that forms part of them.
(2) Variations from macromolecules to biomes.
(3) The diversity of life on earth exists at three levels of organization:
(i) Genetic diversity
(ii) Variety of species
(4) Genetic diversity
(i) It is related to genetic diversity within the species.
(ii) Variations can be by a variety of genes (alleles), in all genes or in chromosomal structures.
(ii) Increases genetic diversity among animal products, more nutrition than natural spread.
(iii) Genetically predisposed people are more prone to disease.
(5) Variety of species
(i) is related to different types of region.
(ii) Biodiversity refers to the number of species in each area.
(iii) Species Evenness refers to the estimated quantity of each type represented in the area.
Biodiversity in India
(1) Of the twelve natural regions, India is one.
(2) India has 10 biogeographical regions, 89 national parks, 500 wildlife sanctuaries, 14 wildlife sanctuaries, six western hemisphere and 35 world heritage sites.
(3) There are about 45,000 species of plants and about 90,000-1,00,000 species of animals.
Biodiversity Patterns
(1) Biodiversity varies by varying in length or height.
(2) Minimum poles and adjacent dimensions or equator. Similarly, as a person descends from the upper to the lower extremities, biodiversity increases.
Biodiversity loss:
(1) It is caused by three factors - Population, Urban Migration and Industry.
(2) Human colonization of the tropical Pacific Islands has resulted in the extinction of more than 2000 species of native birds.
(3) Loss of biodiversity loss in the region results in:
(i) decreased crop production.
(ii) low resistance to environmental disturbances such as drought.
(iii) increased diversity in environmental processes such as crop production, water use, pests and diseases etc.
Biodiversity Conservation
In situ maintenance
(1) The best way to keep wildlife and plants in their natural habitat. This approach includes the conservation and protection of the entire ecosystem and its diversity through a network of protected areas.
(2) Common natural habitats (protected areas) set aside for the conservation of wildlife and plants include:
(i) National Parks
(ii) Wildlife habitats
(iii) Ecosystems
(iv) Several wetlands, mangroves and coral reefs.
(v) sacred streams and lakes.
(3) A biodiversity hotspot is those regions of specified biodiversity declared as a result of direct or indirect interference with human activities.
(4) There are 25 tropical regions of the earth, including two from India.
Ex
(1) Threatened animals and plants are removed from their natural habitat and placed in a special place where they can be protected and given special attention.
(2) Ex situ savings include the following:
(i) Sacred plants and home gardens
(iii) Vegetable gardens, Arborata, Zoological gardens, Aquaria.
Biodiversity Agreement:
(1) The "World Summit" held in Rio de Jeneiro in 1992 called on all nations to take appropriate measures for biodiversity conservation and the sustainable use of its benefits.
(2) The second international conference on sustainable development held in 2002 in Johannesburg, South Africa, 190 countries pledged their commitment to achieving by 2010 a significant reduction in the current rate of biodiversity loss at the global, regional and local levels.
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