“Biological Diversity” means the (a) variability among living organisms from all sources including, among others, terrestrial, sea and other fresh water ecosystems, and the ecological complexes of which they are part; it includes diversity within species between species, and of ecosystems. Literal meaning of biodiversity is the (b) diversity of all life forms on earth. This includes the various races and species of all micro-organisms, plants, and animals that live on earth, including their genetic differences.
Bangladesh is a (c ) transitional zone of flora and fauna, because of its geographical settings and climatic characteristics. There are many rivers and streams existing in the country covering a length of 22,155 km. In addition to the regular inland waters, seasonally a large part of the country remains (d) submerged for 3-4 months during monsoon.
This country is rich in fish and aquatic (e) resources, and other biodiversity. Bangladesh’s inland water bodies are known to be the (f) habitat of 266 species of indigenous fish, 13 exotic fish, 56 prawns, about 26 freshwater molluscs, and 150 birds. The marine water bodies (200 nautical miles along the seashore) are also (g) remarkable for being habitat of 442 species of fish. There are at least 36 species of marine shrimps. About 336 species of molluscs, covering 151 genera have been identified from the Bay of Bengal. In addition, several species of crabs, and 31 species of turtles and tortoises, of which 24 live in freshwater, are found in Bangladesh.
In Bangladesh only about 8-10 per cent of the land area is covered by tree. It supports approximately 5000 species of angiosperms, out of which about 300 species are being cultivated. The list of medicinal plants is currently being revised at the Bangladesh National Herbarium (BNH), and is expected to exceed 5000 species. There are 224 species of timber-yielding plants found in Bangladesh.
The IUCN Bangladesh Red Data Book (2000) has described 266 species of inland fishes, 442 marine fishes, 22 amphibians, 109 inland reptiles, 17 marine reptiles, 388 resident birds, 240 migratory birds, 110 inland mammals, as well as 3 species of marine mammals in Bangladesh. According to the Red List of IUCN, 54 species of inland fishes, 8 amphibians, 58 reptiles, 41 resident birds, and 40 mammals are (h) threatened throughout the country. Among the marine and migratory species of animals, 4 fishes, 5 reptiles, 6 birds, and 3 mammals are threatened. So far, the Red Data Book on plants, which is under preparation at BNH, lists 96 seed-bearing plant species that are threatened. The loss of biodiversity is the result of various kinds of human development (i) intervention and activities, especially in the areas of agriculture, forestry, fisheries, urbanization, industries, chemicals, minerals, transport, tourism, and energy.
Without changing the meaning, replace the underlined words with the words in the list below. One is done for you. There are more words than you require.
Both flora and fauna in Bangladesh are threatened by the loss of habitat resulting from increasing human populations, and unwise utilization of bio-resources. Increasing demand for timber and fuel-wood, encroachment for other purposes, and Jhum (shifting) cultivation in the hilly districts, might be the aggravating factors in the annual rate of deforestation and degradation. The unplanned rapid urbanization and industrialization are leading to waste and pollution problems that affect natural ecosystems. As the land and water-based ecosystems are environmentally compromised, the flora and fauna populations are being seriously affected.
The loss of biodiversity is mostly caused by destruction of habitat, overexploitation of flora and fauna, and illegal trades. Other factorsinclude such as water pollution, especially industrial pollution and oil spillage, and land degradation with agrochemicals, encroachment in the natural forest and changes of land use pattern. Several wildlife species have become extinct in Bangladesh, and many more are threatened. Most of the economically important local plants, medicinalplants, etc., are also under equally great pressure, and are likely to be lost due to habitat destruction, and unsustainable harvesting.
Biological diversity is crucial for the survival and progress of nature and humanity. According to UNESCO (1994), biological diversity provides resources for food, construction, and raw materials for industry. It provides the basis for improvement of the domesticated species; maintains functions of ecosystems, including evolutionary processes; stores and cycles nutrients essential for life; absorbs and breaks down pollutants, including organic waste, pesticides, and heavy metals; recharges ground water, protects catchment basins, and buffers extreme water conditions; and produces soil and protects it from excessive erosion.
Biological resources and biological diversity form the basis of both the ecology and economy of Bangladesh. The country's agriculture, fisheries, and livestock, along with a number of other sectors are heavily dependent, directly or indirectly, on biological resources.
There is a great potential in Bangladesh for biodiversity-based sustainable development. In spite of threatened wild fauna and flora, there are nearly 10,000 species of plants, animals, and microbial organisms - a good percentage of which are found still in abundance. All out efforts are needed to be taken, so that these biological resources are not over-exploited and sustainable management plans need to be formulated and implemented.
Source: BANGLADESH: STATE OF THE ENVIRONMENT 2001
Use verbs, nouns and transitions from the table to construct 5 sentences using the diagram. One is done for you.
Verbs | Nouns | Transitions | Cause | Cause | Because (of) | Lead to | Reason | As a result (of) | Result in | Effect | Due to | Affect | Result | Since | Create | Impact | Consequently |
1. Increasing human population results in waste and pollution problems. 2. 3. 4. 5. 6.
Text 3
Complete the sentences below using words taken from the reading passage. 5 1. Sixty four species of vertebrates have been identified as ___________________________________ by IUCN (2000). 2. Baghair is one of the ______________________ species of fishes in Bangladesh. 3. The greater part of river ____________________ controls expansion of river weeds. 4. According to complied Red List of ICUN (2000), ______________ species of resident birds are threatened in Bangladesh. 5. In Bangladesh about ten species of ______________________ have become extinct in Bangladesh.
