Environment and Ecology BHM 403 Techno India ENVIRONMENT AND ECOLOGY BHM 403 (2008 -2017) PREPARED BY ANIS CHATTOPADHYAY ASST. PROFESSOR TECHNO INDIA EM-4/1, SECTOR –V, SALT LAKE KOLKATA -700091 1 Environment and Ecology BHM 403 Techno India 2008 GROUP – A ( Multiple Choice Type Questions ) 1. Choose correct answer from the given alternatives in each of the following questions : 10x1 = 10 i) Environmental Studies involve studies of a) evolution of life b) all aspects of human environment c) nitrogen cycle d) oxygen cycle. b ii) "Itai itai' disease is caused by a) Zinc b) Cadmium c) Mercury d) Iron. b iii) El Nino starts from a) Mediterranean coast b) Chinese coast c) South American cost d) Indian cost. C iv) The Greenhouse effect is due to a) Carbon dioxide, water vapour, methane and chlorofluorocarbons b) Nitrogen oxide c) Sulphur oxide d) Carbon monoxide. A v) The Ganga pollution is due to dumping of a) domestic and industrial sewages b) waste from forest c) food waste d) hospital waste. A vi) Biotic factor of ecosystem is a) Solar energy b) Temperature c) Soil d) Plants and animals. D vii) Medha Patkar is involved in a) Chipko movement b) Silent Valley movement c) Narmada Bachao movement d) none of these. C viii) The "Kyoto Protocol" is related with a) air pollution b) noise pollution c) water pollution d) none of these. A ix) BOD stands as a) Biochemical Oxygen Demand b) Biological Oxygen Demand c) Biggest Oxygen Demand d) Blown Out Dose. B x) The protective shield for life on earth is a) Carbon dioxide b) Ozone c) Oxygen d) Hydrogen. B 2 Environment and Ecology BHM 403 Techno India GROUP – B ( Short Answer Type Questions ) Answer any three of the following. 3 5 = 15 2. State the main components of ecosystem. Ans: The world we live in is composed of many, many different ecosystems, all interacting and playing off one another. Each of these ecosystems has parts, or components, which also interact within the ecosystem to produce the effects we observe and draw conclusions from. Although the components of ecosystems vary greatly from one place to another, in general we can categorize them to help better understand how they interrelate and what commonalities exist from one ecosystem to another. A basic division that is made when considering the components of any ecosystem is between the living, or "biotic," parts and the non-living, or "abiotic". The amount of sunlight a particular area receives; the temperature and climate over an extended period of time; and the amount of rainfall received are all examples of abiotic components of an ecosystem. For ecosystems that exist in water, the type of water (freshwater or salt) and the strength of water current are ecosystem-specific components. The biotic components of ecosystems can be further broken down into subcategories based on the feeding characteristics of a given animal. The most basic level of biotic components are the primary producers, or "autotrophs," which produce their own food usually using the chemical process known as photosynthesis. In a land ecosystem, these organisms would be the green plants, trees, bushes and the like; in a sea ecosystem, the primary producers are phytoplankton. Above the level of autotrophs are the "heterotrophs," animals which feed on other animals in order to get their necessary nutrients. Within this category there can be countless divisions again, depending on which level in the food chain a particular animal preys upon for its food. However, there are four subcategories which must be present in any ecosystem, which are: º Herbivores, which feed only on plants º Carnivores, which feed only on other animals º Omnivores, which feed on plants and animals, and º Detritivores, which feed on dead things. Now we must look briefly at how the components of ecosystems interact with and affect one another. Take, for example, a pond. The sunlight shines down into the water, and if the pond is relatively stagnant and nutrient-rich, tiny green algae will utilize the abiotic components to manufacture their own food. At the edge of the pond, the same sunlight is taken in by other plants, such as reeds and marshland plant life, to produce their food. Inside the pond, microscopic animals feed on the algae. Insects, such as water beetles and their young, will in turn feed on the microscopic animals, and become food for larger animals such as fish and birds. At the top of the chain lie the animals that only eat other animals, such as herons, which feed only on fish. The final step in the chain occurs when the animal dies, and is fed on by bacteria as part of the decomposition process. 3 Environment and Ecology BHM 403 Techno India Or Components of an Ecosystem (Organisation or Structural aspect of an ecosystem) An ecosystem comprises of two basic components i) Abiotic components and ii) Biotic components The relationship between the biotic components and abiotic components of an ecosystem is called 'holocoenosis'. Abiotic Components These include the non-living, physico - chemical factors such as air, water, soil and the basic elements and compounds of the environment. Abiotic factors are broadly classified under three categories. Climatic factors which include the climatic regime and physical factors of the environment like light, humidity, atmospheric temperature, wind, etc. Edaphic factors which are related to the structure and composition of soil including its physical and chemical properties, like soil and its types, soil profile, minerals, organic matter, soil water, soil organisms. Inorganic substances like water, carbon, sulphur, nitrogen, phosphorus and so on. Organic substances like proteins, lipids, carbohydrates, humic substances etc. Biotic Components It comprises the living part of the environment, which includes the association of a number of interrelated populations belonging to different species in a common environment. The populations are that of animal community, plant community and microbial community. Biotic community is distinguished into autotrophs, heterotrophs and saprotrophs. 4 Environment and Ecology BHM 403 Techno India Autotrophs (Gr: auto - self, trophos - feeder) are also called producers, convertors or transducers. These are photosynthetic plants, generally chlorophyll bearing, which synthesize high-energy complex organic compounds (food) from inorganic raw materials with the help of sunlight, and the process is referred as photosynthesis. Autortophs form the basis of any biotic system. In terrestrial ecosystems, the autotrophs are mainly the rooted plants. In aquatic ecosystems, floating plants called phytoplankton and shallow water rooted plants called macrophytes are the dominant producers. Heterotrophs (Gr: heteros - other; trophs - feeder) are called consumers, which are generally animals feeding on other organisms. Consumer's also referred as phagotrophs (phago - to ingest or swallow) or macroconsumers are mainly herbivores and carnivores. Herbivores are referred as First order consumers or primary consumers, as they feed directly on plants. For e.g., Terrestrial ecosystem consumers like cattle, deer, rabbit, grass hopper, etc. Aquatic ecosystem consumers like protozoans, crustaceans, etc. Carnivores are animals, which feed or prey upon other animals. Primary carnivores or Second order consumers include the animals which feed on the herbivorous animals. 5 Environment and Ecology BHM 403 Techno India For e.g., fox, frog, predatory birds, smaller fishes, snakes, etc. Secondary carnivores or Third order consumers include the animals, which feed on the primary carnivores. For e.g., wolf, peacock, owl, etc. Secondary carnivores are preyed upon by some larger carnivores. Tertiary carnivores or Quaternary consumers include the animals, which feed on the secondary carnivores. For e.g., lion, tiger, etc. These are not eaten by any other animals. The larger carnivores, which cannot be preyed upon further are called top carnivores. Saprotrophs (Gr: sapros - rotten; trophos - feeder) are also called decomposers or reducers. They break down the complex organic compounds of dead matter (of plants and animals). Decomposers do not ingest their food. Instead they secrete digestive enzymes into the dead and decaying plant and animal remains to digest the organic material. Enzymes act upon the complex organic compounds of the dead matter. Decomposers absorb a part of the decomposition products for their own nourishment. The remaining substances are added as minerals to the substratum (mineralisation). Released minerals are reused (utilised) as nutrients by the plants (producers). 6 Environment and Ecology BHM 403 Techno India 3. How do you explain Environmental Impact Assessment ? An environmental impact assessment is an assessment of the possible positive or negative impact that a proposed project may have on the environment, together consisting of the environmental, social and economic aspects. The purpose of the assessment is to ensure that decision makers consider the ensuing environmental impacts when deciding whether to proceed with a project. The International Association for Impact Assessment (IAIA) defines an environmental impact assessment as "the process of identifying, predicting, evaluating and mitigating the biophysical, social, and other relevant effects of development proposals prior to major decisions being taken and commitments made."[1] EIAs are unique in that they do not require adherence to a predetermined environmental outcome, but rather they require decision makers to account for environmental values in their decisions and to justify those decisions in light of detailed environmental studies and public comments on the potential environmental impacts of the proposal.[ The eight guiding principles... There are eight guilding principles that govern the entire process of EIA and they are as follows: Participation: An appropriate and timely access to the process for all interested parties. Transparency: All assessment decisions and their basis should be open and accessible. Certainty: The process and timing of the assessment should be agreed in advanced and followed by all participants. Accountability: The decision-makers are responsible to all parties for their action and decisions under the assessment process.