Environmental Studies Assignment.pdf

Environmental Studies Assignment ON BIODIVERSITY

Name: Dhiraj Rana Roll No. 2017UIT2538 Semester: 4

What is biodiversity? o

Biodiversity is the variability among living organisms from all sources, including terrestrial, marine, and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species, and of ecosystems.

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Biodiversity forms the foundation of the vast array of ecosystem services that critically contribute to human wellbeing.

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Biodiversity is important in human-managed as well as natural ecosystems. o Decisions humans make that influence biodiversity affect the well-being of themselves and others

Defining Biodiversity Biodiversity is defined as “the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems.” The United Nations designated 2011–2020 as the United Nations Decade on Biodiversity. In biodiversity, each species, no matter how big or small has an important role to play in ecosystem. Various plant and animal species depend on each other for what each offers and these diverse species ensures natural sustainability for all life forms.

Biodiversity has three essential elements:   

Genetic diversity, Eco system diversity and Species diversity

Genetic diversity is the total number of genetic characteristics in the genetic makeup of a species. It is distinguished from genetic variability, which describes the tendency of genetic characteristics to vary. Genetic diversity serves as a way for populations to adapt to changing environments. With more variation, it is more likely that some individuals in a population will possess variations of alleles that are suited for the environment. Those individuals are more likely to survive to produce offspring bearing that allele. The population will continue for more generations because of the success of these individuals.

Species diversity: This refers to the variety of species within a particular region. The number of species in a region is a measure for such diversity. The richness of species in a given region provides a yard stick for species diversity. Species diversity depends as much on the genetic diversity as on the environmental condition. Colder regions support less than the warmer regions for species diversity. The good climate with good physical geography supports a better species diversity. Species richness is a term which is used to measure the biodiversity of a given site.

In addition to species richness, species endemism is a term used to measure biodiversity by way of assessing the magnitude of differences between species. In the taxonomic system similar species are grouped together in general, similar genera in families, families in orders and so on till in the level of kingdom. This process is a genuine attempt to find relationships between organisms. The higher taxa have thousands of species. Species that are very different from one another contributes more to overall biodiversity.

Ecological diversity: This is the number of species in a community of organisms. Maintaining both types of diversity is fundamental to the functioning of ecosystems and hence to human welfare. India is one of the 12 centres of diversity and origin of several cultivated plants in the world. It is estimated that 15,000 species of plants occur in India. The flowering plants comprise 15,000 species of which several hundred (5000-7500) species are endemic to India. The region is also rich in fauna, containing about 65,000 species of animals. Among these, more than 50,000 species of insects, 4,000 of molluscs. 6,500 of other invertebrates, 2,000 offish, 140 of amphibians, 420 of reptiles, 1,200 of birds and 340 of mammals are recorded from India. This richness in biological diversity is due to immense variety of climatic and altitudinal conditions coupled with varied ecological habitats.

These vary from the humid tropical Western Ghats to the hot desert of Rajasthan, from the cold desert of Ladakh and the icy mountains of Himalayas to the warm coasts of peninsular India including coastal region of Orissa. Gandhamardan Hills of Sambalpur is rich in biodiversity. The Indian tradition teaches us that all forms of life, human, animal and plants are so closely linked that disturbance in one gives rise to imbalance in the other. Our old scriptures tell lot about these things.

Bio-geographical Classification of India: Biogeography or biological geography is related to ecology and ecosystem of a region. Its studies include variation of flora and fauna over the earth surface. It also encompasses study of biosphere and its interaction with human population. Biogeography studies consider phytogeography (forest), zoogeography (animals, insects), pedology (soil) hydrology (water), oceanography (ocean).

The following is the Bio geographic zones of India and the types of vegetation found:

Many of the endangered and endemic species need human intervention for survival. Indian Government through various projects is trying to check this process of endangering of species.

Why is Biodiversity Important? Biodiversity has a number of functions on the Earth. These are as follows: 

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Maintaining balance of the ecosystem: Recycling and storage of nutrients, combating pollution, and stabilizing climate, protecting water resources, forming and protecting soil and maintaining ecobalance. Provision of biological resources: Provision of medicines and pharmaceuticals, food for the human population and animals, ornamental plants, wood products, breeding stock and diversity of species, ecosystems and genes. Social benefits: Recreation and tourism, cultural value and education and research.

The role of biodiversity in the following areas will help make clear the importance of biodiversity in human life: 

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Biodiversity and food: 80% of human food supply comes from 20 kinds of plants. But humans use 40,000 species for food, clothing and shelter. Biodiversity provides for variety of foods for the planet. Biodiversity and human health: The shortage of drinking water is expected to create a major global crisis. Biodiversity also plays an important role in drug discovery and medicinal resources. Medicines from nature account for usage by 80% of the world’s population.

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Biodiversity and industry: Biological sources provide many industrial materials. These include fiber, oil, dyes, rubber, water, timber, paper and food. Biodiversity and culture: Biodiversity enhances recreational activities like bird watching, fishing, trekking etc. It inspires musicians and artists.

Reason for Loss of Biodiversity The earth’s biodiversity is in grave danger. In the present era, human beings are the most dangerous cause of destruction of the earth’s biodiversity. In 2006, the terms threatened, endangered or rare were used to describe the status of many species. The “evil quartet” identified by Jared Diamond is overkill, habitat destruction, secondary extinctions and introduced species. Factors identified by Edward Wilson are described by the acronym- HIPPO standing for habitat destruction, climate change, invasive species, pollution, human overpopulation and over-harvesting. Habitat destruction is a major cause for biodiversity loss. Habitat loss is caused by deforestation, overpopulation, pollution and global warming. Species which are physically large and those living in forests or oceans are more affected by habitat reduction. Some expert’s estimate that around 30% of all species on earth will be extinct by 2050. According to the International Union for Conservation of Nature (IUCN), globally about one third of all known species are threatened with extinction. Even it is estimated that 25% of all mammals will be extinct within 20 years. Even if a small element of an ecosystem breaks down, the whole system’s balance is threatened. Fresh water ecosystems are nowadays the most threatened ecosystems. Invasive species refer to those that

would normally remain constrained from an ecosystem because of the presence of natural barriers. Since these barriers are no longer existing, invasive species invade the ecosystem, destroying native species. Human activities have been the major cause for encouraging invasive species. Species can also be threatened by genetic pollution- uncontrolled hybridization and gene swamping. For instance, abundant species can interbreed with rare species thus causing swamping of the gene pool. Over exploitation is caused by activities such as over fishing, over hunting, excessive logging and illegal trade of wildlife. Over 25% of global fisheries are being overfished at unsustainable levels. Global warming is also becoming a major cause for loss of biodiversity. For example if the present rate of global warming continues, coral reefs which are biodiversity hotspots will disappear in 20-40 years. 10% of all species might become extinct by 2015, if global warming continues. Thus we can see that biodiversity which is crucial for the well being of life on earth, is coming under the threat of many factors related to human activities. There is an urgent need to take action to protect the magnificent biodiversity of our planet. We must create economic policies in order to maintain the Earth’s biodiversity and take appropriate measures to protect habitats and species.

Distribution Biodiversity is not evenly distributed, rather it varies greatly across the globe as well as within regions. Among other factors, the diversity of all living things (biota) depends on temperature, precipitation, altitude, soils, geography and the presence of other species. The study of the spatial distribution of organisms, species and ecosystems, is the science of biogeography.

Diversity consistently measures higher in the tropics and in other localized regions such as the Cape Floristic Region and lower in polar regions generally. Rain forests that have had wet climates for a long time, such as Yasuní National Park in Ecuador, have particularly high biodiversity. Terrestrial biodiversity is thought to be up to 25 times greater than ocean biodiversity. A new method used in 2011, put the total number of species on Earth at 8.7 million, of which 2.1 million were estimated to live in the ocean. However, this estimate seems to under-represent the diversity of microorganisms.

Hotspots A biodiversity hotspot is a region with a high level of endemic species that have experienced great habitat loss. The term hotspot was introduced in 1988 by Norman Myers. While hotspots are spread all over the world, the majority are forest areas and most are located in the tropics. Brazil's Atlantic Forest is considered one such hotspot, containing roughly 20,000 plant species, 1,350 vertebrates and millions of insects, about half of which occur nowhere else. The island of Madagascar and India are also particularly notable. Colombia is characterized by high biodiversity, with the highest rate of species by area unit worldwide and it has the largest number of endemics (species that are not found naturally anywhere else) of any country. About 10% of the species of the Earth can be found in Colombia, including over 1,900 species of bird, more than in Europe and North America combined, Colombia has 10% of the world's mammals species, 14% of the amphibian species and 18% of the bird species of the world. Madagascar dry deciduous forests and lowland rainforests possess a high ratio of endemism. Since the island separated from mainland Africa 66 million years ago, many species and ecosystems have evolved

independently. Indonesia's 17,000 islands cover 735,355 square miles (1,904,560 km2) and contain 10% of the world's flowering plants, 12% of mammals and 17% of reptiles, amphibians and birds—along with nearly 240 million people.[73] Many regions of high biodiversity and/or endemism arise from specialized habitats which require unusual adaptations, for example, alpine environments in high mountains, or Northern European peat bogs. Accurately measuring differences in biodiversity can be difficult. Selection bias amongst researchers may contribute to biased empirical research for modern estimates of biodiversity. In 1768, Rev. Gilbert White succinctly observed of his Selborne, Hampshire "all nature is so full, that that district produces the most variety which is the most examined."

Threats In 2006, many species were formally classified as rare or endangered or threatened; moreover, scientists have estimated that millions more species are at risk which have not been formally recognized. About 40 percent of the 40,177 species assessed using the IUCN Red List criteria are now listed as threatened with extinction—a total of 16,119. Jared Diamond describes an "Evil Quartet" of habitat destruction, overkill, introduced species and secondary extinctions.[162] Edward O. Wilson prefers the acronym HIPPO, standing for Habitat destruction, Invasive species, Pollution, human over-Population and Over-harvesting. The most authoritative classification in use today is IUCN's Classification of Direct Threats (version 2.0 released in 2016) which has been adopted by major international conservation organizations such as the US Nature Conservancy, the World Wildlife Fund, Conservation International and BirdLife International. The 11 main direct threats to conservation are:

1. residential & commercial development

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housing & urban areas (urban areas, suburbs, villages, vacation homes, shopping areas, offices, schools, hospitals) commercial & industrial areas (manufacturing plants, shopping centers, office parks, military bases, power plants, train & ship yards, airports) tourism & recreational areas (skiing, golf courses, sports fields, parks, campgrounds)

2. farming activities 

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agriculture (crop farms, orchards, vineyards, plantations, ranches) aquaculture (shrimp or fin fish aquaculture, fish ponds on farms, hatchery salmon, seeded shellfish beds, artificial algal beds)

3. energy production & mining 

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renewable energy production (geothermal, solar, wind, & tidal farms) non-renewable energy production (oil and gas drilling) mining (fuel and minerals)

4. transportation & service corridors 

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service corridors (electrical & phone wires, aqueducts, oil & gas pipelines) transport corridors (roads, railroads, shipping lanes, and flight paths) collisions with the vehicles using the corridors associated accidents and catastrophes (oil spills, electrocution, fire)

5. biological resource usages  

hunting (bushmeat, trophy, fur) persecution (predator control and pest control, superstitions)

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plant destruction or removal (human consumption, free range livestock foraging, battling timber disease, orchid collection) logging or wood harvesting (selective or clear cutting, firewood collection, charcoal production) fishing (trawling, whaling, live coral or seaweed or egg collection)

6. human intrusions & activities that alter, destroy, simply disturb habitats and species from exhibiting natural behaviors 

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recreational activities (off-road vehicles, motorboats, jet-skis, snowmobiles, ultralight planes, dive boats, whale watching, mountain bikes, hikers, birdwatchers, skiers, pets in recreational areas, temporary campsites, caving, rock-climbing) war, civil unrest, & military exercises (armed conflict, mine fields, tanks & other military vehicles, training exercises & ranges, defoliation, munitions testing) illegal activities (smuggling, immigration, vandalism)

7. natural system modifications 

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fire suppression or creation (controlled burns, inappropriate fire management, escaped agricultural and campfires, arson) water management (dam construction & operation, wetland filling, surface water diversion, groundwater pumping) other modifications (reclamation projects, shoreline riprap, lawn cultivation, beach construction and maintenance, tree-thinning in parks) removing/reducing human maintenance (mowing meadows, reduction in controlled burns, lack of indigenous management of key ecosystems, ceasing supplimental feeding of condors)

8. invasive & problematic species, pathogens & genes 

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invasive species (feral horses & household pets, zebra mussels, Miconia tree, kudzu, introduction for biocontrol) problematic native species (overabundant native deer or kangaroo, overabundant algae due to loss of native grazing fish, locust-type plagues) introduced genetic material (pesticide-resistant crops, genetically modified insects for biocontrol, genetically modified trees or salmon, escaped hatchery salmon, restoration projects using non-local seed stock) pathogens & microbes (plague affecting rodents or rabbits, Dutch elm disease or chestnut blight, Chytrid fungus affecting amphibians outside of Africa)

9. pollution 

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household sewage & urban waste water (discharge from municipal waste treatment plants, leaking septic systems, untreated sewage, outhouses, oil or sediment from roads, fertilizers and pesticides from lawns and golf-courses, road salt) industrial & military effluents (toxic chemicals from factories, illegal dumping of chemicals, mine tailings, arsenic from gold mining, leakage from fuel tanks, PCBs in river sediments) agricultural & forestry effluents (nutrient loading from fertilizer run-off, herbicide run-off, manure from feedlots, nutrients from aquaculture, soil erosion) garbage & solid waste (municipal waste, litter & dumped possessions, flotsam & jetsam from recreational boats, waste that entangles wildlife, construction debris) air-borne pollutants (acid rain, smog from vehicle emissions, excess nitrogen deposition, radioactive

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fallout, wind dispersion of pollutants or sediments from farm fields, smoke from forest fires or wood stoves) excess energy (noise from highways or airplanes, sonar from submarines that disturbs whales, heated water from power plants, lamps attracting insects, beach lights disorienting turtles, atmospheric radiation from ozone holes)

10. catastrophic geological events 

earthquakes, tsunamis, avalanches, landslides, & volcanic eruptions and gas emissions

11. climate changes 

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ecosystem encroachment (inundation of shoreline ecosystems & drowning of coral reefs from sea level rise, sand dune encroachment from desertification) changes in geochemical regimes (ocean acidification, changes in atmospheric CO2 affecting plant growth, loss of sediment leading to broad-scale subsidence) changes in temperature regimes (heat waves, cold spells, oceanic temperature changes, melting of glaciers/sea ice) changes in precipitation & hydrological regimes (droughts, rain timing, loss of snowcover, increased severity of floods) severe weather events (thunderstorms, tropical storms, hurricanes, cyclones, tornadoes, hailstorms, ice storms or blizzards, dust storms, erosion of beaches during storms)

References https://en.wikipedia.org/wiki/Biodiversity#Number_of_species https://www.greenfacts.org/en/biodiversity/l-3/1-define-biodiversity.htm https://en.wikipedia.org/wiki/Biodiversity https://www.conserve-energy-future.com/what-is-biodiversity.php http://www.yourarticlelibrary.com/biodiversity/biodiversity-types-genetic-species-and-ecologicaldiversity/44744 https://bio.libretexts.org/Bookshelves/Ecology/Book%3A_Biodiversity_(Bynum)/11%3A_Ecosystem_ Diversity http://www.biodiversitya-z.org/content/biodiversity