Environmental Science Midterm PDF

GROUP 1 Abiotic Components MAJOR TYPE OF ECOSYSTEM Ecological relationships are ➤ The term ecosystem was coined in 1935 manifested in by the Oxford ecologist A.G. Tensely to...

GROUP 1 Abiotic Components MAJOR TYPE OF ECOSYSTEM Ecological relationships are ➤ The term ecosystem was coined in 1935 manifested in by the Oxford ecologist A.G. Tensely to physicochemical environment. encompass the interactions among biotic Abiotic component of and abiotic components of the ecosystem includes basic environment at a given site. inorganic elements and ➤Ecosystem was defined in its presently compounds, such as soil, accepted form by Eugene Odum, "an unit water, oxygen, calcium that includes all the organisms, i.e., the carbonates, phosphates and community in a given area interacting with a variety of organic the physical environment so that a flow of compounds. energy leads to clearly defined trophic It also includes such physical structure, biotic diversity and material factors and ingredients as cycles, i.e., exchange of materials moisture, wind currents and between living and non-living, within the solar radiation. system". Radiant energy of sun is the Characteristics of Ecosystem only significant energy source The ecosystem is a major for any ecosystem. structural and functional unit Biotic Components of ecology. The biotic components The structure of an ecosystem include all living organisms is related to its species diversity present in the environmental in the sense that complex system. ecosystem have high species The biotic components can diversity. be grouped into two basic The function of ecosystem is nutritive components: related to energy flow and (i) Autotrophic components material cycles within and (ii) Heterotrophic components outside the system. The autotrophic components Young ecosystems develop include all green plants which and change from less fix the radiant energy of sun complex to more complex and manufacture food from ecosystems, through the inorganic substances. process called succession. The heterotrophic Each ecosystem has its own components include non- energy budget, which cannot green plants and all animals be exceeded. which take food from Adaptation to local autotrophs. environmental conditions is Biotic components of an the important feature of the ecosystem can be described biotic components of an under the following three ecosystem, failing which they heads: might perish. Producers (Autotrophic Structure of Ecosystem components) All ecosystems consist of the following Consumers basic components: Decomposers or reducers and 1. Abiotic components transformers 2. Biotic components The amount of biomass at any 3. The structure of an ecosystem time in an ecosystem is known is basically a description of the as standing crop which is organisms and physical usually expressed as fresh features of environment. weight, dry weight or as free including the amount and energy in terms of distribution of nutrients in a calories/meter. particular habitat.  Tertiary consumers are the top carnivores like lion, tiger etc. Decomposer include microorganism like fungi, bacteria, and actinomycetes. Natural Ecosystem These ecosystems are capable of operating and maintaining themselves without any major interference by man A classification based on their habitat: Grassland Ecosystem Terrestrial ecosystem These occupy a Aquatic ecosystems comparatively fewer area, Terrestrial Ecosystem roughly 19 percent of the Terrestrial ecosystem, are earth’s surface. many because there are so The various components of many different sorts of places grassland ecosystem are: on Earth. ABIOTIC COMPONENTS: These Some of the most common include the nutrient present in terrestrial ecosystem that are soil and the aerial found are the folowing: environment. FOREST ECOSYSTEM Tertiary consumers are the top GRASSLAND ECOSYSTEM carnivores like lion, tiger etc. DESERT ECOSYSTEM C, H, O, N, P, S, are supplied by Carbon dioxide, water, Forest Ecosystem nitrates, phosphates, and Forest occupy roughly 40 sulphates. percent of the land. BIOTIC COMPONENTS: These In India these occupy roughly may be categorized as: one-tenth of the total land Producers: These are mainly area. grasses e.g. Cynodont species, The difference components of Dicanthium species etc. forest ecosystem include: Shrubs also be present ABIOTIC COMPONENTS: Consumers: There occur in the Include inorganic and organic following sequence: substances present in soil and Primary consumers are the atmosphere. Dead organic herbivores feeding on grasses debris is also present in forest. are mainly grazing animals as BIOTIC COMPONENTS: These cows, deer’s and rabbit etc. include producers like trees, Besides them there are insects, shrubs and ground vegetation. termites, and millipedes that Among the primary consumers feed on leaves. are the herbivores which Secondary consumers: include animal feeding on Carnivores feeding on tree leaves as ants, flies, herbivores e.g. Snakes, frogs, beetles, spiders etc. and larger Lizards etc. animals like elephants, deer Decomposer: Microbes etc. including fungi like Mucor, Secondary consumers are the Aspergillus, Rhizopus and some carnivores like snakes, birds, bacteria and actinomycetes and fox etc. Desert Ecosystem photosynthesis bacteria. Desert occupy about 17 Theses are following types: percent of land, occuring in Macrophytes are mainly regions with annual rainfall of rooted larger plants e.g. about 25 centimeters. Trapa, Typha, Nymphae etc. The species compositions of Some free floating forms like such an ecosystem is varied Azolla, Wolffia, Lemma etc. and typical due ti the also occur in pond. extremes of temperature and Phytoplanktons are minute ater factors floating or suspended lower The biotic components plants e.g. Zygnema, include: Spinogyra etc. Producers are shrubs Consumers are heterotrophs. especially bushes, some Most of the consumers are grasses and few trees. herbivorse few are insects and Consumers include animals large fishes are carnivorous like reptiles and insects which feeding on herbivorse. are able to live under xeric The herbivores are further conditions. In addition, there differentiated as Benthos and are some nocturnal rodents Zooplanktons. and birds. The camel feeds on Secondary consumers are tender shoot of the plants. carnivores which includes Decomposer are very few, as insects and fish. due to poor vegetations the Tertiary consumers are also amount of dead organic carnivores and includes some matter is correspondingly less. large fish feeding on smaller They are some fungi and ones. bacteria. Decomposers includes variety of microbes chiefly bacteria, Aquatic Ecosystem actinomycetes and fungi An aquatic ecosystem is an ecosystem that exists in water. Ocean Ecosystem Within an aquatic ecosystem, The oceans cover about 70 the environment is a watery percent of the earths surface. one. Each ocean represents a Aquatic ecosystem can be stable ecosystem. divided into freshwater The biotic components of an ecosystem (such as fresh rivers ecosystem are as follows: or freshwater lakes) and Producers are autotrophs marine ecosystem such as the which include the sea and rock pools. phytoplankton's such as diatoms and dinoflagellates. In Pond Ecosystem addition, brown and red Pond serves as an examples of algae also contribute. freshwater ecosystem. Consumers include herbivores It exhibits a self- sufficient and eg, crustaceans, molluses, self- regulating system. carnivores (Herring. shad) The components of the pond feeding on herbivores. ecosystem are as follows: Tertiary consumers include Abiotic components: The chief carnivorous fishes like Cods, substances are heat, light, pH Haddock etc. that feed on value of water and the basic secondary consumers. inorganic and organic Decomposers are the compounds. microbes that feed on dead Biotic components: This organic matter of producers include; and macroconsumers e.g. Producers are autotrophic, Bacteria and fungi. green plants and some  Group 2 ENVIRONMENTAL CRISIS What is Environmental Crisis? - Environmental crises refer to critical situations that arise due to the degradation of the natural environment, often resulting from human activities, such as pollution, deforestation, and climate change. These crises pose significant challenges to sustainability and human well-being, Man-made Ecosystem highlighting the urgent need for effective management and solutions. man-made ecosystem is created by The impact of these crises can lead to humans and includes environments like resource shortages, population farms, gardens, parks, and cities. These displacement, and increased competition ecosystems are designed to support for dwindling resources. certain plants and animals and often have controlled conditions, such as irrigation for FACTORS OF SOCIO-CULTRUAL crops or landscaping in parks. ENVIRONMENT Decomposer: Microbes including fungi like  In environmental science, the socio- Mucor, Aspergillus, Rhizopus and some cultural environment plays a crucial bacteria and actinomycetes role in shaping how communities Cropland Ecosystem interact with and manage natural In nature we find another kind resources. It encompasses the social of ecosystems, where man is and cultural dimensions that very much involved in their influence human behavior toward operation. the environment. These are called as cropland ecosystems, that are artificial 1. Cultural Beliefs and Values: or man engineered. Attitudes toward nature, religious views, In order to obtain more food, and traditional beliefs can shape how timber etc. Man becomes people treat the environment. Some responsible for the cultures prioritize sustainability, while others replacement of natural may focus more on consumption and ecosystems. exploitation. Thus, a Cropland ecosystem is 2. Social Norms and Practices an artificial ecosystem aimed Local customs and behaviors influence primarily to grow a single how communities use resources. For species of one's choice e.g. example, norms around water use, farming Wheat, maize, paddy etc. practices, or waste management can either promote environmental protection Aquarium Ecosystem or degradation. closed environment where 3. Education and Awareness: fish, plants, and other aquatic The level of environmental education in a organisms live together in society affects awareness of water. It includes both living environmental issues. Higher education (biotic) components, like fish, levels often correlate with more sustainable plants, and microorganisms, practices and environmental activism. and non-living (abiotic) 4. Economic and Social Structures components, such as water, Wealth distribution, poverty levels, and temperature, and lighting. social inequality can affect how resources are used. Poorer communities may rely more heavily on natural resources for survival, often leading to over-exploitation. 5. Population Dynamics: Population size, growth rates, and density directly influence the demand for resources. Rapid urbanization can lead to - The garbage problem underscores the pollution and resource depletion if not importance of recycling and recovering managed well. resources from waste. While recycling can 6. Political and Legal Frameworks: help reduce the strain on landfills and the Government policies, laws, and need for raw materials, it requires proper enforcement around environmental infrastructure, public education, and policy protection shape how societies manage support. their environment. Some socio-cultural 5. ENVIRONMENTAL AND HEALTH IMPACTS contexts have strong legal protections for - Poor waste management contributes to nature, while others might prioritize environmental pollution, including soil economic development over contamination, water pollution, and environmental concerns. greenhouse gas emissions. It also poses 7. Technology and Innovation: health risks to communities, particularly in The availability and adoption of developing countries, where waste is often technology can influence environmental burned or left to decompose openly. outcomes. For instance, access to cleaner 6. CIRCULAR ECONOMY APPROACH energy technology can reduce pollution, - The garbage problem teaches that we while reliance on outdated methods may need to transition from a linear economy harm the environment. (take, make, dispose) to a circular 8. Historical and Colonial Legacy: economy where products and materials The historical exploitation of natural are reused, recycled, and designed for resources, especially in post-colonial longer lifespans. This reduces waste and societies, has long-term socio-cultural maximizes resource efficiency. impacts on how these societies view 7. COMMUNITY AND GOVERNMENT environmental management today. RESPONSIBILITY - Solving the garbage problem requires Garbage Problems collaboration between governments, - The garbage problem is a significant industries, and communities. Governments environmental crisis that highlights issues in need to enforce waste regulations, waste management, pollution, and promote sustainable products, and support sustainability. waste reduction initiatives. Communities 1. OVERCONSUMPTION AND WASTE must adopt better habits, such as GENERATION reducing, reusing, and recycling. - Modern consumer lifestyles have led to 8. PUBLIC AWARENESS AND BEHAVIOR massive amounts of waste, much of it non- CHANGE biodegradable, such as plastic. The more - Raising public awareness about the people consume, the more waste they impact of waste and the importance of produce. Reducing overconsumption is responsible consumption is crucial. essential to minimizing waste generation. Behavioral change campaigns can help 2. INADEQUATE WASTE MANAGEMENT people make informed choices to reduce SYSTEMS waste, such as choosing eco-friendly - Many regions lack efficient waste products and practicing proper waste collection, recycling, and disposal systems. disposal. This leads to illegal dumping, overflowing 9. INNOVATION IN WASTE SOLUTIONS landfills, and pollution of land, air, and - Technological innovation, such as water bodies. Strengthening waste waste-to-energy plants, biodegradable management infrastructure is vital to materials, and advanced recycling mitigate the environmental impacts. technologies, provides new solutions to the 3. PLASTIC POLLUTION AND NON- garbage crisis. Encouraging innovation BIODEGRADABLE WASTE and investing in research can improve - Plastics, which are slow to degrade, have waste management systems. become a major environmental issue. They 10. Global and Local Action accumulate in oceans, rivers, and - The garbage crisis is a global issue that ecosystems, harming wildlife and entering requires coordinated international efforts, the food chain. This crisis has emphasized but it also has local implications. Each the need for biodegradable alternatives community must take responsibility for and reducing plastic use. managing its waste, while global 4. RECYCLING AND RESOURCE RECOVERY agreements are needed to address cross- border waste issues, such as ocean  Intensive farming and plastics. agrochemicals (like fertilisers and pesticides) POLLUTION  Oil Spills Pollution is the introduction of  Acid rain which is caused by air contaminants into the natural environment pollution that cause adverse change. Pollution can  Industrial accidents take the form of any substance (solid, 4. NOISE POLLUTION liquid, or gas) or energy (such as - Noise pollution refers to the excessive radioactivity, heat, sound, or light). amount of noise in the surrounding that disrupts Pollutants, the components of pollution, the natural balance. Usually, it is man-made, can be either foreign substances/energies though certain natural calamities like or naturally occurring contaminants. volcanoes can contribute to noise pollution. 1. AIR POLLUTION - refers to the release of harmful Noise pollution has several contributors, contaminants (chemicals, toxic gases, which include: particulates, biological molecules, etc.)  Industry-oriented noises such as into the earth’s atmosphere. These heavy machines, mills, factories, etc. contaminants are quite detrimental and in  Noise from social events some cases, pose serious health issues. (loudspeakers, firecrackers, etc.) Some causes that contribute to air  Transportation noises from vehicles, pollution are: aeroplanes, etc. Burning fossil fuels  Construction noises Mining operations  Household noises (such as mixers, Exhaust gases from industries TV, washing machines, etc.) and factories 2. WATER POLLUTION -is said to occur when toxic 5. LIGHT POLLUTION pollutants and particulate matter are - also referred to as photo pollution, is introduced into water bodies such as lakes, an excessive amount of light that creates a rivers and seas. These contaminants are glow in the night sky. Light pollution is another generally introduced by human activities type of pollution that people might not like improper sewage treatment and oil consider because it is less widely spoken about spills. However, even natural processes such as eutrophication can cause water pollution. Group 3 3. SOIL POLLUTION Climate Change and other Related -also called soil contamination, refers to Phenomena’s the degradation of land due to the presence (Biodiversity Loss, Greenhouse Effect, and of chemicals or other man-made substances in Ecosystem Degration) the soil. The xenobiotic substances alter the natural composition of soil and affect it GLOBAL WARMING negatively. - Global warming most commonly - These can drastically impact life refers to the rising temperatures brought on by directly or indirectly. For instance, any toxic human activities over the last 100 to 150 years. chemicals present in the soil will get absorbed This increase is caused by an excess of by the plants. Since plants are producers in an greenhouse gas emissions (carbon dioxide, environment, it gets passed up through the nitrous oxide, methane, ozone, and water food chain. Compared to the other types of vapor) in the Earth’s atmosphere - mainly due pollution, the effects of soil pollution are a little to the burning of fossil fuels. As the level of more obscured, but their implications are very emissions trapped in the Earth’s atmosphere noticeable. continues to rise, so to do global temperatures. SOME OF THE COMMON CAUSES OF SOIL CAUSES OF GLOBAL WARMING POLLUTION ARE: Deforestation  Improper industrial waste disposal Use of Vehicles  Mining activities Chlorofluorocarbo Agriculture  Overpopulation 1. How much of the gas exists in the EFFECTS OF GLOBAL WARMING atmosphere. Rise in Temperature 2. How long the gas remains in the Threats to the Ecosystem atmosphere, otherwise known as its Climate Change lifetime. High Mortality Rates 3. How effective the gas is at trapping Loss of Natural Habitat heat. This is referred to as its global warming potential (GWP) and is a measure of the total energy that a gas absorbs over BIODIVERSITY LOSS a given period of time (usually 100 years) WHAT IS BIODIVERSITY? relative to the emissions of 1 ton of carbon  Biodiversity refers to the variety of dioxide living species on Earth, including plants, animals, bacteria, and WHAT ARE GREENHOUSE GAS EMISSIONS? fungi  The release of greenhouse gases WHY IS BIODIVERSITY IMPORTANT? associated with human activities  Biodiversity provides us with clean and climate change is referred to as air, fresh water, good quality soil greenhouse gas emissions, or climate and crop pollination. It helps us pollution. fight climate change and adapt to it as well reduce the impact of 5 MAJOR GREENHOUSE GASES natural hazards. Carbon dioxide WHAT IS BIODIVERSITY LOSS? Accounting for almost 80 percent of  Biodiversity loss, also called loss of global human-caused emissions, carbon biodiversity, a decrease in dioxide sticks around for quite a while. biodiversity within a species, an Once it’s emitted into the atmosphere, 40 ecosystem, a given geographic percent still remains after 100 years, 20 area, or Earth as a whole percent after 1,000 years, and 10 percent as long as 10,000 years later. CAUSES OF BIODIVERSITY LOSS Methane  Climate Change Methane (CH4) persists in the  Pollution atmosphere for around 12 years, which is  Destruction of Habitats less time than carbon dioxide, but it is  Over exploitation of the natural much more potent in terms of the environment greenhouse effect. In fact, its global  Invasive alien species warming impact is almost 30 times greater EFFECTS OF BIODIVERSITY LOSS than that of carbon dioxide over a 100-  Extinction of species year period. Methane can come from  Threat to human beings natural sources like wetlands, more than  Proliferation of pests half of all global methane emissions come  Increase in CO2 emissions from human activities like natural gas SOLUTIONS TO BIODIVERSITY LOSS production and livestock-based Sustainable mobility agriculture. Sustainable food Nitrous oxide Reducing pollution Nitrous oxide (N2O) is a powerful Responsible consumption greenhouse gas: It has a GWP that is Recycling practice around 270 times that of carbon dioxide on a 100-year time scale, and it remains in the GREEN HOUSE EFFECT atmosphere, on average, a little more than WHAT ARE GREENHOUSE GASES? a century from sources like the fertilizers  Earth’s greenhouse gases trap heat used in agriculture. in the atmosphere and warm the Fluorinated gases planet. Emitted from a variety of manufacturing and industrial processes, HOW MUCH ONE GREENHOUSE GAS fluorinated gases are man-made. There INFLUENCES GLOBAL WARMING DEPENDS are four main categories: ON THREE KEY FACTORS: hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF6), and nitrogen trifluoride (NF3). land that is then converted to non-forest Although fluorinated gases are emitted in use. smaller quantities than other greenhouse Soil erosion gases, they trap substantially more heat. Water vapor Soil erosion is a gradual process that The most abundant greenhouse gas occurs when the impact of water or wind overall, water vapor differs from other detaches and removes soil particles, greenhouse gases in that changes in its causing the soil to deteriorate. human atmospheric concentrations are linked not activities are a major cause of soil erosion to human activities directly, but rather to in general. Construction of roads and the warming that results from the other buildings, logging, mining, and agricultural greenhouse gases we emit. Warmer air production have resulted in large amounts holds more water and since water vapor is of soil erosion. a greenhouse gas, more water absorbs more heat Water pollution WHERE DO GREENHOUSE GASES COME Water pollution is the contamination of FROM? water sources by substances that make ===According to the Intergovernmental the water unusable for drinking, cooking, Panel on Climate Change (IPCC), the cleaning, swimming, and other activities. burning of fossil fuels for electricity and transportation, as well as land use patterns Burning of fossil fuels, coal, and mineral and agriculture, and industrial processes oil drive nearly all human-caused, or Why burning fuels like oil and coal is bad anthropogenic, greenhouse gas emissions. for the ecosystem? Because it releases Most common sources of Greenhouse large amounts of greenhouse gases, Gases: particularly carbon dioxide (CO2), into the 1. Electricity and Heat production atmosphere, and this excess carbon 2. Agriculture and Land Use dioxide traps heat causing global 3. Industry temperature to rise 4. Transportation 5. Buildings WHAT CAN WE DO TO CONTROL THE CONSEQUENCES OF THE ECOSYSTEM DEGRADATION? GREENHOUSE EFFECT By planting more trees. Today, concentrations of human-caused Rainwater harvesting. greenhouse gases in the atmosphere are higher than ever and the planet is heating Reduce, Reuse, and Recycle. up. Between preindustrial times and now, Reduce fuel consumption the earth’s average temperature has increased almost 17 degrees Celsius. Treating the industrial effluents before dumping them in water bodies. *Driven by the burning of fossil fuels, global warming is altering the earth’s climate Reducing the use of fertilizers. systems in many ways Control population growth. ECOSYSTEM DEGRADATION GLOBAL CLIMATE CHANGE  The deterioration of the environment WHAT IS GLOBAL CLIMATE CHANGE? through depletion or pollution of Climate change refers to resources such as air, water, and soil significant, long-term changes that causes the destruction of in the global climate. ecosystems and the extinction of The global climate is the wildlife. connected system of sun, earth and oceans, wind, rain EXAMPLES OF ECOSYSTEM DEGRATION and snow, forests, deserts and Deforestation savannas, and everything people do, too. Deforestation or forest clearance is the Climate change refers to removal of a forest or stand of trees from long-term shifts in  temperatures and weather Using transportation/ Transportation patterns. Such shifts can be Most cars, trucks, ships, and planes run on natural, due to changes in the fossil fuels. That makes transportation a sun’s activity or large volcanic major contributor of greenhouse gases, eruptions. But since the 1800s, especially carbon-dioxide emissions. Road human activities have been vehicles account for the largest part, due the main driver of climate to the combustion of petroleum-based change, primarily due to the products, like gasoline, in internal burning of fossil fuels like coal, combustion engines. oil and gas. THE GLOBAL CLIMATE SYSTEM EFFECTS Hotter temperatures The global climate system arises from the As greenhouse gas concentrations rise, so interaction of 5 systems interacting does the global surface temperature. The together. To understand our climate and last decade, 2011-2020, is the warmest on how it is changing, we first need to record. Since the 1980s, each decade has understand these 5 systems: been warmer than the previous one. 1. Atmosphere (the thin layer of Nearly all land areas are seeing more hot gases surrounding the earth) days and heat waves. 2. Lithosphere (the land surfaces Loss of species such as soil and rocks, and Climate change poses risks to the survival human-made surfaces such as of species on land and in the ocean. These roads and buildings) risks increase as temperatures climb. 3. Hydrosphere (the Earth’s liquid Exacerbated by climate change, the water in oceans, rivers, lakes world is losing species at a rate 1,000 times and underground) greater than at any other time in recorded 4. Cryosphere (the frozen water human history. One million species are at in ice and snow) risk of becoming extinct within the next few 5. Biosphere (the living things decades. Forest fires, extreme weather, such as plants and animals and invasive pests and diseases are including humans). among many threats related to climate change. Some species will be able to CAUSES AND EFFECTS OF CLIMATE CHANGE relocate and survive, but others will not. More health risks The main greenhouse gases that are Climate change is the single biggest causing climate change include carbon health threat facing humanity. Climate dioxide and methane. impacts are already harming health, Fossil fuels such as: through air pollution, disease, extreme coal, oil and gas are by far the largest weather events, forced displacement, contributor to global climate change, pressures on mental health, and increased accounting for over 75 per cent of global hunger and poor nutrition in places where greenhouse gas emissions and nearly 90 people cannot grow or find sufficient food. per cent of all carbon dioxide emissions. Poverty and displacement Climate change increases the factors that CAUSES put and keep people in poverty. Floods Generating power may sweep away urban slums, destroying Generating electricity and heat by homes and livelihoods. Heat can make it burning fossil fuels causes a large chunk of difficult to work in outdoor jobs. global emissions. Most electricity is still generated by burning coal, oil, or gas, which produces carbon dioxide and nitrous oxide – powerful greenhouse gases that blanket the Earth and trap the sun’s heat. Manufacturing goods Manufacturing goods produce emissions, mostly from burning fossil fuels to produce energy for making things like cement, iron, steel, electronics, plastics, clothes, and other goods.