Unit 1 Environment - Introduction PDF

Unit 1- Environment and People Introduction – The relationship between man and the environment was established in the early periods. Human beings live in the kingdom of nature and interact with it constantly. The influence of nature is in the form of the air he breathes...

Unit 1- Environment and People Introduction – The relationship between man and the environment was established in the early periods. Human beings live in the kingdom of nature and interact with it constantly. The influence of nature is in the form of the air he breathes, the water he drinks, the food he eats, and the flow of energy and information. Any change in the environment can not only result in devastating effects but can also pose a threat to the human race. 5th June of every year is observed as World Environment Day to emphasize the importance of a green environment in our lives and promote worldwide awareness of the environment. The concept of Climate Change and Environmental Management has greater scope and importance towards the People, Planet, and Profit Sustainability. This Course Sensitizes the urgent call for action by raising responsible behavior in managing Natural resources for the future of mankind. Hence the matter was discussed at the Stockholm Conference of the United Nations Educational, scientific, and Cultural Organizations (UNESCO) and several other multinational agencies. It was unanimously agreed that necessary steps be taken to establish an environmental education, which is interdisciplinary in approach. The meaning of environment may be better understood from the Oxford dictionary which states: the surroundings or conditions in which a person, animal, or plant lives. Meaning The term environment has been derived from the French word “Environia” which means to surround. It refers to both Abiotic (physical or non-living) and Biotic (living) environments. The word environment means surroundings, in which organisms live. Environment and organisms are two organized and complex components of nature. Environment controls the life of the organisms including human beings. Human beings interact with the environment more vigorously than other living beings. Ordinarily, environment refers to the materials and forces that surround the living organism. The environment can be defined as the surroundings or conditions in which a person, animal, or plant lives or operates. The term “environment” refers to all elements of the physical and biological world, as well as the interactions between them. Environment plays a pre-eminent role in the life cycle of human beings as human life is highly dependent on the environment. Define Environment Environmental Protection Act (1986) defined “Environment as the total of water, air, and land, their interrelationship among themselves and with the human beings, other living beings, and property.” 1  Environment can be defined as a total of all the living and non-living elements and their effects that influence human life. While all living or biotic elements are animals, plants, forests, fisheries, and birds, non-living or abiotic elements include water, land, sunlight, rocks, and air. Definition: Environment means surroundings and everything that affects an organism during its lifetime is collectively known as its environment. In other words, “Environment is total of water, air and land interrelationships among themselves and also with the human being, other living organisms and property”. It includes all the physical and biological surroundings and their interactions. Environmental studies provide an approach to understanding the environment of our planet and the impact of human life on the environment. Thus the environment is global in nature, it is a multidisciplinary subject including physics, geology, geography, history, economics, physiology, biotechnology, remote sensing, geophysics, soil science hydrology, etc. Human and Environment While there are many reasons for escalating nature’s bounty, there are also reasons for expressing worry regarding ecological problems. Environmental problems arise both due to natural processes and human actions. Human beings form an integral part of the environment and have the greatest environmental footmark either positively or negatively. Human overpopulation has been disturbing the environment by restructuring and managing various ecosystems for hundreds of years. Modifying the environment to fit the requirements of society leads to the extermination and reduction of many species that change the ecosystem structure and function. This chapter emphasizes the expanding boundaries of Human and Environment interactions and their possible solutions. What is the role of the environment to humans? All living beings including man and the environment are affecting each other in several ways and there is a dynamic equilibrium existing between them that passes with changing generations. Human development and activity have modified and altered the natural environment for centuries. From agriculture to industrialization, deforestation, global warming, pollution, overfishing, devastating animal habitats, and killing organisms, humans always produced environmental problems for generations. The primary effects include decreased water quality, increased pollution, greenhouse gas emissions, and depletion of natural resources all because of a series of actions taken by humans. Human settlements in geologically sensitive locations like mountains, flood plains, or coastal areas are the reasons for natural disasters which eventually increase the number of deaths. Also, there is a loss of important medicinal plants due to human activities, and afterward, humans have to rely upon Synthetic medicines. 2 How do humans affect the Environment? The following human activities are responsible for the degradation of the environment: Overpopulation: The world population has become an epidemic due to decreased death rates, the introduction of approaches of industrial farming, increased birth rate and decreased infant mortality rate, and better medical facilities that keep humans alive for much longer and increase the entire population. It would not be wrong to say that we reach the maximum carrying capacity that our earth can sustain. The most severe effect of overpopulation is the degradation of the environment. Humans are cutting down the forests for their accommodations, agricultural land, or industries which eventually results in the damage of ecosystems as there is not enough to filter the air which leads to an increase in CO2 levels which carries the potential to harm every single organism on Earth. Industrialization: The Industrial Revolution fulfilled the elementary needs of the world and is vital for the financial growth and development of society, at the same time released a lot of pollutants to the environment which caused health hazards, damaged crops, climate change, and made the environment incompetent for living organisms. Industries require a lot of fossil fuels which ultimately diminishes our natural resources. Genetic Modification: Genetically modified organisms (GMOs) give an advantage to the crop, but it causes the soil to dry faster and kill off good bacteria, making it non-fertile. To replenish the depleted soil, fertilizer is used, which is then causes a lot of environmental problems. Deforestation: The forests are cleared to provide timber and agricultural land to the increased population. An estimated 18 million acres of trees are clear-cut every year for making wood products and for new development and about 1.5 million hectares of forest cover vanishes every year in India alone. The process of deforestation results in decreasing rainfall, loss of topsoil, increasing greenhouse gases and global temperature, and Page | 3modification of climatic conditions. The trees are the prime producers of oxygen, so clearly deforestation is not a good thing for humans and specifically for the animals and the millions of species that live in forests. Deforestation is a chief threat to their existence. Pollution: Human activities increase fossil fuel combustion from motor vehicles, industrial factories, and power plants, releasing CO, ozone, and NOx into the atmosphere that causes the greenhouse effect, ozone layer depletion, acid rain, and smog formation which leads to serious health effects The disposal of sewage, agricultural and industrial wastes pollute water bodies and soil that spreads so many diseases. The noise due to industries, trains, airplanes, social functions, etc. causes noise pollution which affects both biotic and abiotic sections of the environment. The radiations generated by radioactive substances used in nuclear reactors and nuclear weapons impact the genetic materials of the body (DMA, RHA, etc.)Impact on Climate and Atmosphere Impact on Soil and Vegetation Human activities are accountable for the physical changes in the soil. Uncontrolled and heavy grazing, fire, or cutting for the clearance of forests for 3 domestic purposes and timber caused the disappearance of vegetation cover, soil erosion, and desertification. Air pollutants, Photochemical smog, and industrial fumes are toxic to plants, diminish the fertility of the soil enhance salinity, and kill vegetation. The chemical fertilizers also altered the chemistry of the soil. The food we are eating is contaminated which affects human health and hence 90% of the human population is suffering from various diseases. Humans have influenced both the quantity and quality of water. The construction of dams required deforestation and promoted earthquake activating, the build-up of soil salinity, changes in groundwater levels, and waterlogging. Humans get water supplies by pumping groundwater that reduces the groundwater and coastal areas’ freshwater is substituted by saltwater. Oceans are getting acidified which minimizes the production of necessary nutrients, lessens the pH levels in the water, and reduces the calcium concentrations, which is harmful to aquatic flora and fauna. The rivers are getting murky by pollutants. The rate of waterborne diseases is increasing day by day due to human activities. The objectives of environmental awareness should be Improving the quality of the environment. Creating an awareness among people on environmental problems and conservation. Creating such an atmosphere as people find themselves fit enough to participate in the decision-making process of environmental development programs. According to UNESCO (1971), the objectives of environmental studies are: ❖ Creating awareness about environmental problems among people. ❖ Imparting basic knowledge about the environment and its allied problems. ❖ Developing an attitude of concern for the environment. ❖ Motivating the public to participate in environmental protection and environmental improvement. ❖ Acquiring skills to help the concerned individuals in identifying and solving environmental problems. ❖ Striving to attain harmony with Nature. 4 ❖ According to UNESCO, the guiding principles of environmental education should be as follows: ❖ Environmental education should be compulsory, right from the primary up to the postgraduate stage. ❖ Environmental education should have an interdisciplinary approach by including physical, chemical, biological as well as socio-cultural aspects of the environment. It should build a bridge between biology and technology. ❖ Environmental education should take into account the historical perspective, the current, and the potential historical issues. ❖ Environmental education should emphasize the importance of sustainable development i.e., economic development without degrading the environment. ❖ Environmental education should emphasize the necessity of seeking international cooperation in environmental planning. ❖ Environmental education should lay more stress on practical activities and first- hand experiences. ❖ Importance of Environmental Science The Environment belongs to all living beings and thus is important for all. The environmental study deals with the analysis of the processes in water, air, land, soil, and organisms that lead to pollute or degrade the environment. It helps us establish standards for safe, clean, and healthy natural ecosystems. It also deals with important issues like safe and clean drinking water, hygienic living conditions and clean and fresh air, fertility of land, healthy food, and development. Sustainable environmental law, business administration, environmental protection, management, and environmental engineering are emerging as new career opportunities for environment protection and management. ❖ Need for Public Awareness With the ever-increasing development of modern man, large-scale degradation of natural resources has occurred, the public has to be 5  educated about the fact that if we are degrading our environment we are harming ourselves. To encourage meaningful public participation and the environment, it is necessary to create awareness about environmental pollution and related adverse effects. ❖ The United Nations Conference on Environment and Development held in Rio- de-Janeiro, followed by the Earth Summit on Sustainable Development has highlighted the key issues of global environmental concern and has attracted the general public towards the deteriorating environment. Any Government at its level can’t achieve the goal of environment conservation until the public has a participatory role in it. ❖ A public participatory role is possible only when the public is aware of the ecological and environmental issues. In short, if we want to manage on planet earth, we would have to make the entire population, environmentally educated. Some other important points 1. Clarification of modern environmental concepts like how to conserve biodiversity. 2. Helping people know the more sustainable way of living. 3. Making the masses understand how to use natural resources more efficiently. 4. Developing awareness about the behavior of organisms under natural conditions. 5. Creating knowledge about the inter-relationship between organisms in populations and communities. 6. Creating awareness and educating people regarding environmental issues and problems at local, national, and international levels. Environmental Study: Scope Scope of environmental studies The Environmental studies discipline has multiple and multilevel scopes. This study is important and necessary not only for children but also for everyone. The scopes are summarized as follows: The study creates awareness among the people to know about various renewable and nonrenewable resources in the region. The endowment or potential, patterns of utilization and the balance of various resources available for future use in the state of a country are analyzed in the study. It provides knowledge about ecological systems and cause-and-effect relationships. 6  It provides necessary information about biodiversity richness and the potential dangers to the species of plants, animals, and microorganisms in the environment. The study enables one to understand the causes and consequences of natural and main-induced disasters (flood, earthquake, landslide, cyclones etc.,) and pollution and measures to minimize the effects. It enables one to evaluate alternative responses to environmental issues before deciding an alternative course of action. The study enables environmentally literate citizens (by knowing the environmental acts, rights, rules, legislations, etc.) to make appropriate judgments and decisions for the protection and improvement of the earth. The study exposes the problems of overpopulation, health, hygiene, etc., and the role of arts, science, and technology in eliminating/ minimizing the evils from society. The study tries to identify and develop appropriate and indigenous eco- friendly skills and technologies for various environmental issues. It teaches the citizens the need for sustainable utilization of resources as these resources are inherited from our ancestors to the younger generation without deteriorating their quality. The study enables theoretical knowledge into practice and the multiple uses of the environment. What Should Policymakers Do? The policy implications of demographic influences on the environment are complicated and can sometimes be controversial. While some view large, rapidly growing populations in developing regions as the primary culprit in environmental decline, others focus on the costly environmental effects of overconsumption among the slowly increasing populations of developed nations. These differing emphases naturally point to radically different solutions: slow population increase in less-developed nations or change in destructive consumption and production patterns in more-developed nations. This debate, however, presumes a one-step solution to the complex problems created by population pressures on the environment. Both population size and consumption influence environmental change and are among the many factors that need to be incorporated into realistic policy debates and prescriptions. Examples of policies that could address the environmental implications of demographic factors include policies to promote effective family planning, more effective rural development to slow migration to crowded urban centers, and incentives to encourage sustainable levels of consumption and the use of efficient, cleaner technologies. 7 References 1. https://sudarshan800.files.wordpress.com/2016/03/our-environment.pdf 2. https://www.rand.org/pubs/research_briefs/RB5045.html Unit – 2 Resources and Environment A resource is a physical material that humans need and value such as land, air, and water. Resources are characterized as renewable nonrenewable; a renewable resource can replenish itself at the rate it is used, while a nonrenewable resource has a limited supply. Natural resources can be defined as the resources that exist (on the planet) independent of human actions. These are the resources that are found in the environment and are developed without the intervention of humans. Common examples of natural resources include air, sunlight, water, soil, stone, plants, animals, and fossil fuels. Natural resources are naturally occurring materials that are useful to man or could be useful under conceivable technological, economic, or social circumstances or supplies drawn from the earth, supplies such as food, building and clothing materials, fertilizers, metals, water, and geothermal power. For a long time, natural resources were the domain of the natural sciences. Types of Resources Based on the availability are two types of natural resources: 1. Renewable: resources that are available in infinite quantity and can be used repeatedly are called renewable resources. Example: Forest, wind, water, etc. 2. Non-Renewable: resources that are limited in abundance due to their non- renewable nature and whose availability may run out in the future are called non- renewable resources. Examples include fossil fuels, minerals, etc. 8 Difference between Renewable and Non-Renewable Resources Renewable resource Non-renewable resource It can be renewed as it is available in Once completely consumed, it cannot be renewed infinite quantity due to limited stock Sustainable in nature Exhaustible in nature Low-cost and environment-friendly High cost and less environment-friendly Replenish quickly Replenish slowly or do not replenish naturally at all The 5 Most Important Natural Resources are: 1. Air: Clean air is important for all the plants, animals, and humans to survive on this planet. So, it is necessary to take measures to reduce air pollution. 2. Water: 70% of the Earth is covered in water and only 2 % of that is freshwater. Initiative to educate and regulate the use of water should be taken. 3. Soil: Soil is composed of various particles and nutrients. It helps plants grow. 4. Iron: It is found as mineral silica and is used to build strong weapons, transportation, and buildings 5. Forests: Forests provide clean air and preserve the ecology of the world. Trees are being cut for housing and construction projects. Role of Individual in the conservation of Natural resources: Conservation of energy: Switch off light, fan, and other appliances when not in use. Use solar heater for cooking. Dry the cloth in the sunlight instead of driers. Use always pressure cookers Grow trees near the house to get a cool breeze instead of using AC and a cooler. Ride a bicycle or just walk instead of using the scooter for a short distance. Conservation of water: 9  ❖ Use minimum water for all domestic purposes. ❖ check the water leaks in pipes and repair them properly. ❖ Reuse the soapy water, after washing clothes for washing the courtyard, carpets etc. ❖ Use drip irrigation. ❖ A rainwater harvesting system should be installed in all the houses. ❖ Sewage treatment plants may be installed in all industries and institutions. ❖ Continuous running of water taps should be avoided. ❖ Watering of plants should be done in the evening. Conservation of soil: Grow different types of plants i.e. trees, herbs, and shrubs. In the irrigation process, using strong flow of water should be avoided. Soil erosion can be prevented by sprinkling irrigation. Conservation of food resources: Cook the required amount of food. Don’t waste the food, give it to someone before spoiling. Don’t store large amounts of food grains and protect them from damaging insects. Conservation of forest: Use non-timber products. Plant more trees. Grassing must be controlled Minimise the use of paper and fuel. Avoid the construction of dams, and roads in the forest areas. Development of a healthy environment without damaging natural resources. Unsustainable development; Degradation of the environment due to over-utilization of natural resources. Lifestyle in more developed countries: 22% of the world's population, 88% of its natural resources, and 85% of total global income. Consumption is more and pollution is more. Lifestyle in less developed countries: 78% of world population, 12% of its natural resources, and 15% of total global income. 10 CONSERVATION AND EQUITABLE USE OF NATURAL RESOURCES Role of an Individual Natural resources like forests, water, soil, food, minerals, and energy resources play an important role in the economy and development of a nation. Humans can play an important role in the conservation of natural resources. A little effort by individuals can help to conserve these resources which are a gift of nature to mankind. A brief description of the role of individuals in conserving different types of natural resources is given below: Roles to conserve water To minimise the evaporation losses irrigate the crops, the plants, and the lawns in the evening because water application during that time will lead to more loss of water due to a higher rate of evapotranspiration. Improve water efficiency by using the optimum amount of water in washing machines, dishwashers, and other domestic appliances, etc. Check for water leaks in pipes and toilets and repair them promptly. Don’t keep water taps running while they are not in use. Recycle water for washing of clothes for gardening. Installing rainwater harvesting structures to conserve water for future use. Energy conservation for future use Turn off all electric appliances such as lights, fans, televisions, computers, etc when not in use. Clean all the lighting sources regularly because dust on lighting sources decreases lighting levels up to 20-30% Try to harvest energy from natural resources to obtain heat for example drying the clothes in the sun and avoiding drying in the washing machine. Save liquid petroleum gas (LPG) by using solar cookers for cooking. Design the house with provision for sunspace to keep the house warm and to provide more light. Avoid misuse of vehicles for transportation and if possible share car journeys to minimise use of petrol/diesel. For small distances walk down or just use bicycles. Minimise the use of air conditioners to save energy Protect soil health Use organic manure/compost to maintain soil fertility To avoid soil erosion do not irrigate the plants by using the fast flow of water. Use sprinkler irrigation to conserve the soil. Design landscape of lawns in large areas which will help to bind soil to avoid erosion. 11  Provide vegetation cover by growing ornamental plants, herbs, and trees in your garden. Use vegetable waste to prepare compost to use in kitchen gardening. Promote sustainable agriculture Diversify the existing cropping pattern for the sustainability of agriculture Cultivate need-based crop Maintain soil fertility Make optimum use of fertilizers, pesticides, and other chemicals for the production and processing of agricultural products. Save grains in storage to minimize the losses. Improve indigenous breeds of milch animals for sustainable dairy production systems. Adopt post-harvest technologies for value addition. Equitable Use of Resources for Sustainable LifeStyle In the last 50 years, the consumption of resources in society has increased manyfold. There is a big gap in the consumer's lifestyle between developed and developing countries. Urbanisation has changed the lifestyle of the middle-class population in developing countries creating more stress on the use of natural resources. It has been estimated that More Developed Countries (MDC) of the world constitute only 22% of the world’s population but they use 88% of natural resources. These countries use 73% of energy resources and command 85% of income and in turn, they contribute a very big proportion of pollution. On the other hand, less developed countries (LDCs) have moderate industrial growth constitute 78% of the world’s population, and use only 12% of natural resources, 27% of energy, and only 15% of global income. There is a huge gap between rich and poor. In this age of development, the rich have gotten richer and the poor are becoming more poorer.. This has led to unsustainable growth. There is an increasing global concern about the management of natural resources. The solution to this problem is to have a more equitable distribution of resources and income. Two major causes of unsustainability are overpopulation in poor countries and overconsumption of resources by rich countries. A global consensus has to be reached for a balanced distribution of natural resources. For equitable use of natural resources, more developed countries/rich people have to 12 lower their level of consumption to a bare minimum so that these resources can be shared by poor people to satisfy their needs. Time has come to think that it is the need of the hour that rich and poor should make equitable use of resources for the sustainable development of mankind. Unit – 3 Ecosystem Concept of an Ecosystem What is an Ecosystem? An ecosystem is a structural and functional unit of ecology where living organisms interact with each other and the surrounding environment. In other words, an ecosystem is a chain of interactions between organisms and their environment. The term “Ecosystem” was first coined by A.G. Tansley, an English botanist, in 1935. Read on to explore the structure, components, types, and functions of the ecosystem in the notes provided below. Structure of the Ecosystem The structure of an ecosystem is characterized by the organization of both biotic and abiotic components. This includes the distribution of energy in our environment. It also includes the climatic conditions prevailing in that particular environment. The structure of an ecosystem can be split into two main components, namely: Biotic Components Abiotic Components The biotic and abiotic components are interrelated in an ecosystem. It is an open system where the energy and components can flow throughout the boundaries. Biotic Components Biotic components refer to all living components in an ecosystem. Based on nutrition, biotic components can be categorised into autotrophs, heterotrophs and saprotrophs (or decomposers). Producers include all autotrophs such as plants. They are called autotrophs as they can produce food through the process of photosynthesis. Consequently, all other organisms higher up on the food chain rely on producers for food. 13  Consumers or heterotrophs are organisms that depend on other organisms for food. Consumers are further classified into primary consumers, secondary consumers and tertiary consumers. Primary consumers are always herbivores as they rely on producers for food. Secondary consumers depend on primary consumers for energy. They can either be carnivores or omnivores. Tertiary consumers are organisms that depend on secondary consumers for food. Tertiary consumers can also be carnivores or omnivores. Quaternary consumers are present in some food chains. These organisms prey on tertiary consumers for energy. Furthermore, they are usually at the top of a food chain as they have no natural predators. Decomposers include saprophytes such as fungi and bacteria. They directly thrive on the dead and decaying organic matter. Decomposers are essential for the ecosystem as they help in recycling nutrients to be reused by plants. Abiotic Components Abiotic components are the non-living components of an ecosystem. It includes air, water, soil, minerals, sunlight, temperature, nutrients, wind, altitude, turbidity, etc. Functions of Ecosystem The functions of the ecosystem are as follows: 1. It regulates the essential ecological processes, supports life systems and renders stability. 2. It is also responsible for the cycling of nutrients between biotic and abiotic components. 3. It maintains a balance among the various trophic levels in the ecosystem. 4. It cycles the minerals through the biosphere. 5. The abiotic components help in the synthesis of organic components that involve the exchange of energy. So the functional units of an ecosystem or functional components that work together in an ecosystem are: Productivity – It refers to the rate of biomass production. Energy flow – It is the sequential process through which energy flows from one trophic level to another. The energy captured from the sun flows from producers to consumers and then to decomposers and finally back to the environment. 14  Decomposition – It is the process of breakdown of dead organic material. The top-soil is the major site for decomposition. Nutrient cycling – In an ecosystem nutrients are consumed and recycled back in various forms for the utilisation by various organisms. Types of Ecosystem An ecosystem can be as small as an oasis in a desert, or as big as an ocean, spanning thousands of miles. There are two types of ecosystems: Terrestrial Ecosystem Aquatic Ecosystem Terrestrial Ecosystem Terrestrial ecosystems are exclusively land-based ecosystems. There are different types of terrestrial ecosystems distributed around various geological zones. They are as follows: 1. Forest Ecosystem 2. Grassland Ecosystem 3. Tundra Ecosystem 4. Desert Ecosystem Forest Ecosystem A forest ecosystem consists of several plants, particularly trees, animals and microorganisms that live in coordination with the abiotic factors of the environment. Forests help in maintaining the temperature of the earth and are the major carbon sink. Grassland Ecosystem In a grassland ecosystem, the vegetation is dominated by grasses and herbs. Temperate grasslands and tropical or savanna grasslands are examples of grassland ecosystems. Tundra Ecosystem Tundra ecosystems are devoid of trees and are found in cold climates or where rainfall is scarce. These are covered with snow for most of the year. Tundra type of ecosystem is found in the Arctic or mountain tops. Desert Ecosystem 15 Deserts are found throughout the world. These are regions with little rainfall and scarce vegetation. The days are hot, and the nights are cold. Aquatic Ecosystem Aquatic ecosystems are ecosystems present in a body of water. These can be further divided into two types, namely: 1. Freshwater Ecosystem 2. Marine Ecosystem Freshwater Ecosystem The freshwater ecosystem is an aquatic ecosystem that includes lakes, ponds, rivers, streams and wetlands. These have no salt content in contrast with the marine ecosystem. Marine Ecosystem The marine ecosystem includes seas and oceans. These have a more substantial salt content and greater biodiversity in comparison to the freshwater ecosystem. Important Ecological Concepts 1. Food Chain The sun is the ultimate source of energy on Earth. It provides the energy required for all plant life. The plants utilize this energy for the process of photosynthesis, which is used to synthesize their food. During this biological process, light energy is converted into chemical energy and is passed on through successive trophic levels. The flow of energy from a producer, to a consumer and eventually, to an apex predator or a detritivore is called the food chain. Dead and decaying matter, along with organic debris, is broken down into its constituents by scavengers. The reducers then absorb these constituents. After gaining the energy, the reducers liberate molecules to the environment, which can be utilised again by the producers. 2. Ecological Pyramids 16 An ecological pyramid is the graphical representation of the number, energy, and biomass of the successive trophic levels of an ecosystem. Charles Elton was the first ecologist to describe the ecological pyramid and its principals in 1927. The biomass, number, and energy of organisms ranging from the producer level to the consumer level are represented in the form of a pyramid; hence, it is known as the ecological pyramid. The base of the ecological pyramid comprises the producers, followed by primary and secondary consumers. The tertiary consumers hold the apex. In some food chains, the quaternary consumers are at the very apex of the food chain. The producers generally outnumber the primary consumers and similarly, the primary consumers outnumber the secondary consumers. And lastly, apex predators also follow the same trend as the other consumers; wherein, their numbers are considerably lower than the secondary consumers. For example, Grasshoppers feed on crops such as cotton and wheat, which are plentiful. These grasshoppers are then preyed upon by common mouse, which are comparatively less in number. The mice are preyed upon by snakes such as cobras. Snakes are ultimately preyed on by apex predators such as the brown snake eagle. In essence: Grasshopper →Mouse→ Cobra → Brown Snake Eagle 3. Food Web A food web is a network of interconnected food chains. It comprises all the food chains within a single ecosystem. It helps in understanding that plants lay the foundation of all the food chains. In a marine environment, phytoplankton forms the primary producer. 17 Characteristics and functions of the following ecosystems What Is a Forest Ecosystem? it is an ecosystem of forests and resources. Forests are renewable natural resources. Forests are formed by a group of plants that are structurally defined by their trees, shrubs, herbs, climbers, and ground cover. Soil, animals, insects, microorganisms, and birds are the most important interacting units of a forest ecosystem. In India, the forests occupy about 18 - 20% of the total land area. 1. Abiotic Components of the forest include inorganic and organic components present in the soil along with temperature, rainfall, light, etc. 2. Biotic Components are represented by producers, and consumers, and decompose. Types of Forest Ecosystems There are a few types of forest ecosystems listed below: 1. Tropical Evergreen Rainforest: Only a small percentage of tropical forests are rainforests where average rainfall is 80-400 inches in a year. This forest is characterized by deep and dense vegetation consisting of tall trees reaching different levels. 2. Tropical Deciduous Rainforest: The main characteristics of tropical deciduous rainforest are broad-leaved trees along with dense bushes, shrubs, etc. Two main seasons – summer and winter – are distinctly visible there. This type of forest is found in many parts of the world. A large variety of flora and fauna are found here. 3. Temperate Evergreen Forest: Temperate evergreen forest is a type of forest that is characterized by a smaller number of trees but an adequate number of ferns and mosses. 4. Temperate Deciduous Forest: Temperate deciduous forest evolves in the moist temperate region with sufficient rainfall. Here also, winter and summer are well defined, and trees shed their leaves during winter. Dominant trees are maple, oak, peach, etc. 18  5. Taiga/Boreal: Situated just south of the Tundra, Taiga is characterized by evergreen conifers. The average temperature is below the freezing point for almost half of the year. Components of Forest Ecosystem 1. Producers: Producers can synthesize their own food by the photosynthesis process. All green plants are considered producers of the ecosystem as they convert sunlight into the chemical energy of food. 2. Primary Consumers: Since the consumers can not prepare their food, they depend on producers. Herbivorous animals get their food by eating the producers (plants) directly. Examples of primary consumers are grasshoppers, deer, etc. 3. Secondary Consumers: Secondary consumers draw their food from primary consumers. 4. Decomposers: The decomposers of the forest ecosystem break down dead plants and animals, returning the nutrients to the soil so that they can be used by the producers. Apart from bacteria, ants and termites are important decomposers in the Amazon rainforest. Millipedes and earthworms also help to break down dead matter. 5. Nutrient Cycle: The nutrient cycle is cyclic. For the proper functioning of ecosystems, nutrients are required. Carbon, hydrogen, oxygen, and `nitrogen constitute about 95% of the mass of living organisms. About 15 to 20 other elements are also needed in relatively small amounts. These are recycled repeatedly between the living and non - living components of the ecosystem. 6. Energy Flow: In a forest ecosystem, the grass, which draws its nutrition from sun, soil, and water, is eaten by the grasshopper, which in turn is eaten by frogs, snakes, and vultures in succession (different trophic levels). In this process of eating and being eaten, nutrients are passed from one step to the next in a food chain. (PPT) The flow of energy that occurs along a food chain is called energy flow. The pyramid of energy represents the total quantity of energy at each trophic level of a food chain. The flow of energy is always unidirectional. Characteristics of Forest Ecosystem 19  1. Warm temperatures and sufficient rainfall are characteristics of forests, resulting in the formation of numerous ponds, lakes, etc. 2. The forest maintains climate and rainfall. 3. The forest supports many wild animals and protects biodiversity. 4. The soil is rich in organic matter and nutrients, which support the growth of trees. Functions of Forest Ecosystem 1. Goods Obtained from Forests: There are various types of food products such as honey, wild meat, fruits, mushrooms, palm oil and wine, and medicinal plants obtained from forests. Other than edible parts, we can obtain timber, wood biomass, cork, etc. from forests. The fuel can be extracted from old trees that are buried under the soil. 2. Ecological Functions: Forests play an important role in maintaining ecological factors such as climate, carbon storage, nutrient cycling, and rainfall. 3. Culture and Social Benefits: The tribal people who live in the forests treat forests as nature goddesses. The traditional beliefs and spirituality save wild animals from hunting and cutting down of trees by urban people. A few modern people visit forests for recreation. What is a Grassland Ecosystem? Grassland Ecosystem is an area where the vegetation is dominated by grasses and other herbaceous (non-woody) plants. It is also called transitional landscape because grassland ecosystems are dominated by grass with few or no trees in the area where there is not enough for a forest and too much of a forest. (transitional landscapes are spaces/interfaces between city and countryside commonly experienced on the move) Grassland Ecosystem: Grasslands are the areas that are dominated by a nearly continuous cover of grasses. It is one of the most widespread of all major vegetation in the world. They occupy about 20% of the land on the surface of the earth. Grasslands are found in both tropical and temperate regions where rainfall is not enough to support the growth of trees. 20  They are also found in areas consisting of well-defined hot, dry, warm, and rainy seasons. These are known by different names in different regions of the world like steppes in Europe and Asia, pampas in South America, Veldt in South Africa, and Downs in Australia. Grassland is found where rainfall is about 15-75 cm per year not enough to support a forest, but more than that of a true desert. Typical grasslands are vegetation formations that are generally found in temperate climates. In India, they are found mainly high Himalayas. The rest of India’s grasslands are mainly composed of the Steppes and Savana. Steppe formations occupy large areas of sandy and saline soils. The components of the Grassland Ecosystem are discussed below: 1. Abiotic Components: These are non-living thing components consisting of carbon, hydrogen, sulfur, nitrogen phosphorous etc. 2. Biotic Components: These are living components and their sub-components are discussed below- (I) Producers: The primary producers of food are grasses such as Aristida, Cynodon, Digitaria, Desmodium, Setaria, etc. If herbs and shrubs are present, they also contribute to the primary production of food. (II) Consumers: The consumers in a grassland ecosystem are of three levels. (a) Primary consumers: These feed directly from the grasses (grazing) and include herbivores such as Cows, Buffaloes, Goats, Rabbits, mice, etc., and also insects, termites, centipedes, millipedes, etc. (b) Secondary consumers: These consumers are the carnivorous animals such as snakes, lizards, foxes, frogs, etc. which feed on the primary consumers. (c) Tertiary consumers: Hawk, Eagles, and vultures constitute the tertiary consumers in the grassland ecosystem which preys upon the secondary and primary consumers. (III) Decomposers: The organic matter of the grassland is decomposed by microbes like fungi, aerobic and anaerobic soil bacteria, etc. They release the minerals back into the soil thus making the soil fertile. Functions of the Grassland Ecosystem 21 The primary function of an ecosystem is productivity. The producers fix the solar energy and produce the complex organic matter with the help of minerals. It provides forage for livestock, protection and conservation of soil and water resources, furnishes habitat for wildlife, both flora and fauna, and (contribution to the attractiveness of the landscape. The functional aspects of the Grassland can be studied by two means: 1. Food Chain in an ecosystem: There is an important feature of the ecosystem that one level of an organism serves as food for another level of the organism. A series is formed which is known as the Food Chain. In an ecosystem, the food chain does not follow a linear pattern, but an organism may feed upon more than one organism in the same food chain or upon organisms of different food chains. Thus interconnected food chain system is formed known as a food web. 2. Nutrient cycle in an ecosystem: For any ecosystem to be successful, the constituent materials must move cyclically. The producers (green plants) take up the mineral elements from the soil and air, convert them into an organic form, and after passing through the different trophic levels, are again returned to the soil and air. Economic Importance of Grassland Ecosystem Grasslands biomes are important to maintain the crop of many domesticated and wild herbivores such as horses, cows, pigs, sheep, goats, buffalo, camel, deer, zebra, etc. which provides food, milk, wool, and transportation to man. Hence, we can say that the Grassland Ecosystem is a mixture of grass, clover, and other leguminous species, dicotyledonous, herbs, and shrubs which contribute to a high degree of preservation. Desert Ecosystem Despite several pieces of research about life on other planets, it has concluded that Earth is the only planet where living organisms are found. Survival requires specific forms of atmospheres, land formations, and ecosystems that only Earth comprises. Each continent on this planet includes a desert and comprises its ecology. The word desert is a largely barren, dry, and abandoned land without flora or fauna in the sand. It might be cold and hot. 22 The Desert is the most dried area on the planet that gets negligible precipitation on an annual basis. It receives less rainfall throughout the year. So, the desert ecosystem is the planet’s driest ecosystem, and thus, it has less diversity of life and little vegetation. Being a part of the terrestrial ecosystem, it houses animals and plants that can live in harsh weather conditions. The desert ecosystem is devoid of any precipitation and rainfall. So, the desert ecosystem is a community of non-living and living organisms living and interacting with each other in an abandoned environment. It’s the interaction between Abiotic and Biotic Components of this environment. Characteristics of Desert Ecosystem Less Rainfall or Precipitationless - precipitation is a significant desert feature and the reason behind its dryness. Deserts receive seasonal rainfall that occurs for a small duration (just around 25 to 30 centimeters). Aridity-Aridity implies a deficiency of dry moisture. As it experiences less rainfall, it results in aridity. Wind Velocity - Wind velocity is high in this ecosystem. That’s why deserts experience dust storms or sandstorms of higher intensity, forming sand dunes. Extreme temperature o This type of ecosystem experiences extreme hot or cold temperatures during night and day! The days happen to be hot, while nights are extremely cold. o Humidity - Its humidity level is low in the daytime, while it turns out to be high during the night. o Population Density - Population density happens to be low in the deserts. And there’s a dearth of food and water, plus the climatic conditions are harsh which is certainly not preferable for living. (Population density is a measurement of population per unit land area) o Scarcity of water- As it receives negligible rainfall, water is scarce. This shortage of water makes deserts experience drought for more than six months! o Biodiversity- Surviving in a desert ecosystem is challenging. But in spite of this fact, deserts house different animals and plants. o They have adapted the survival skills to live in such extreme and harsh conditions of a desert. o Soil Quality-Deserts are rocky, dry, sandy, and thin. Thus, it experiences low growth in vegetation. 23  o The soil is grey in color and does not have any organic contents such as phosphorus and nitrogen. Outlining the Desert Ecosystem Types Besides dry and hot areas, desert ecosystems also exist in arid, tropical, and extremely cold areas. Here are the types: 1. Hot & Dry: This ecosystem comprises dry and hot climatic conditions and receives low rainfall annually. Extreme variations in the temperature are there where the soil is harsh and rough. The best dry & hot desert ecosystem examples are South Asia, Central America, Africa, Australia, North America, etc. 2. Semi-Arid - It’s similar to the prior one. This ecosystem has stable ground, hard rocks, and lesser dunes. The temperature isn’t extreme. The best example of this kind of desert ecosystem is the Great Basin, which gets a good amount of rainfall. 2. Coastal - It’s found in the large water bodies’ coastal lines such as seas and oceans and is affected by ocean currents. Besides receiving winter fog, the climate is hospitable. Namib in Africa and the Atacama Desert in Chile have a coastal desert ecosystem. 4. Cold desert ecosystem comprises abundant rainfall during winters and less during summers. It has chilling winters and snowfall, shorter summers, and a moderately moist & hot climate. The ecosystem is covered with snow dunes. The best cold desert ecosystem examples are Antarctica and Greenland. Functions of Desert Ecosystem The Desert ecosystem happens to be a significant part of our planet. And regardless of how dry or harsh this ecosystem is, it has a function to play. Each function of the desert ecosystem in the bullet point has a significant part to contribute to the planet. It serves as a habitat to multiple species of animals and plants and, these animals and plants have adapted, and they survive in extreme environments. It acts as the carbon sink. That means the bacteria in sands help in storing CO2 or carbon dioxide to prevent it from getting into the atmosphere. The ecosystem is a huge source of natural gas, oil, and minerals. The Desert ecosystem contributes to the production of salt. It’s a perfect ecosystem for preserving the historical belongings of Mother Nature. So, deserts have huge significance in archaeological discoveries. They have unusual landscapes & oases. 24 People get attracted to its scenic beauty due to its natural formation. Thus, deserts have become a tourist’s favorite location. Desert sands act as the carbon sink. Scientists found that bacteria that are living in Africa’s Kalahari Desert helps store the carbon dioxide and CO2 from the air. Tundra Ecosystem What is the Tundra Ecosystem? The ecosystem, which is devoid of trees and covered with snow for most of the year is called the tundra ecosystem. These types of ecosystems are mainly found in cold climates and in those regions with limited or scarce rainfall. Polar regions are some examples of the tundra ecosystem. Arctic and Alpines are two types of tundra ecosystems. Compared to the alpine tundra, the arctic tundra is colder. (PPT) This type of ecosystem is found at lower altitudes and is characterized by severe cold environmental conditions, which are similar to deserts. In these regions, the soil is frozen throughout the year and during the summer season, the snow-covered land melts and produces shallow ponds. Small plants with flowers and different types of lichens can be rarely found, as these regions are habitually treeless and always covered by snow. Features of Tundra Ecosystems 1. This ecosystem usually has a long cold winter and a very short hot summer. 2. The tundra ecosystem is extremely windy with high humidity and less rainfall. 3. The temperature in these regions goes below freezing point at night times. During the daytime, the temperature still permits the growth of plants. 4. The major nutrients found in these regions are phosphorus and nitrogen. The phosphorus is generally produced by precipitation, whereas from the biochemical process, these regions produce nitrogen. 25 Animals Of Tundra Ecosystems Tundra is the coldest region of all the biomes and the animals of these regions include herbivores, carnivores and omnivores. Wolf, foxes, hare, collembolas, muskox, reindeer, marmots, mountain goats, sheep, elk and other different types of worms, flies, butterflies, and wild insects are examples of notable animals in the tundra ecosystem. Plants Of Tundra Ecosystems A few types of sparse vegetation found in these regions are herbs, mosses and lichens. Other plants include: Sedge Rushes Birches Crustose Cotton grass Dwarf heath Heath shrubs Dwarf willows Dryland sedges Sphagnum moss Aquatic Ecosystem What is the Aquatic Ecosystem? The aquatic ecosystem definition states it is a water-based environment, wherein, living organisms interact with both physical and chemical features of the environment. These living creatures whose food, shelter, reproduction, and other essential activities depend on a water-based environment are known as aquatic organisms. Water plays a significant role in the management of world-scale ecosystem processes in aquatic systems, connecting the atmosphere, lithosphere, and biosphere by transferring material between them and allowing chemical reactions to occur. Water has unique physicochemical features that reflect the water body's quality. The physicochemical characteristics of an aquatic ecosystem determine how well it functions and how long it can support life forms. 26 In the same way as sediments in terrestrial ecosystems provide substrate, nutrients, and a home for live aquatic resources, sediments in aquatic ecosystems are equivalent to the soil in terrestrial ecosystems. Sediments are significant catalysts in environmental food cycles and the two water quality dynamics. *** Substrate: the surface or material or from which organism lives. The quality of sediment has a direct or indirect impact on the functioning of an aquatic ecosystem. The many physicochemical properties of sediment determine its quality. Similarly, the biotic mix of an aquatic environment determines how well it functions. In the aquatic environment, they serve as a trophic level and a source of energy. Fish have a significant ecological role in the whole food web at the trophic level. Some of the most common aquatic organisms are – nekton, plankton, and benthos. Additionally, lakes, oceans, ponds, rivers, swamps, coral reefs, wetlands, etc. are a few popular aquatic ecosystem examples. Features of Aquatic Ecosystem Salient features of the aquatic ecosystem are highlighted in this figure below – Freshwater or saltwater can be used to make them. They serve as a home for a variety of aquatic animals. The majority of the vegetation is made up of algae and corals. They have a lot of biological diversity, which makes them the most productive and wealthiest ecosystems on the planet. They help regulate the hydrological cycle and act as a pollution filter, among other things. Types of Aquatic Ecosystems In general, there are two types of aquatic ecosystems, namely marine ecosystems and freshwater ecosystems. Both marine and freshwater ecosystems are further divided under different aquatic ecosystems. The Aquatic Ecosystem and its Types Below. A. Marine Water Ecosystem 27  This particular ecosystem is the largest aquatic ecosystem and covers over 70% of the earth’s total surface. This ecosystem is relatively more concentrated in terms of salinity. Nonetheless, the body of aquatic organisms is well-adjusted to saline water, and they may find it challenging to survive in freshwater. The following categories comprise the marine ecosystem. Ocean Ecosystem Pacific Ocean Atlantic Ocean Indian Ocean Arctic Ocean Southern Ocean- are the five major oceans on earth. Notably, the Pacific Ocean is the largest and deepest of these five, while the Atlantic is the second largest in terms of size. Also, the Southern Ocean harbors the largest population of Krill among them. Other than that, the oceans serve as home to aquatic organisms like – turtles, crustaceans, plankton, corals, shellfish, blue whale, sharks, tube worms, reptiles, etc. Estuaries Typically, it is the meeting point of a sea and rivers, which makes the water slightly more saline when compared to freshwater and more diluted when compared to the marine ecosystem. Biologically, estuaries are considered to be productive as they stimulate primary production and trap plant nutrients. Some examples of estuaries include – tidal marshes, river mouth, and coastal bays. Coral Reefs These are fondly referred to as the Rain Forest of Oceans as they harbor a wide diversity of aquatic flora and fauna. (Flora and fauna refer to the collection of all plants and animals living in a particular region or environmental situation. The collection of flora (plants) and fauna (animals) of an area usually interact in various degrees to form an ecosystem.) A coral reef is an aquatic ecosystem made up of corals that form reefs. Coral polyps are held together by calcium carbonate in the formation of reefs. Stony corals, whose polyps cluster in groups, make up the majority of coral reefs. The animal phylum Cnidaria includes sea anemones and jellyfish, and coral is part of the class Anthozoa.(Anthozoa is a class of marine invertebrates that include sea anemones, stony coral, and soft corals. It is attached to the seabed) Corals secrete hard carbonate exoskeletons that support and protect them, unlike sea anemones. 28  Warm, shallow, clear, sunny, agitated water is ideal for most reefs. At the beginning of the Early Ordovician, 485 million years ago, coral reefs displaced the Cambrian's microbial and sponge reefs. Coastal Ecosystem o Coastal ecosystems are formed when land and water meet. o The structure, variety, and energy flow of these ecosystems are all unique. The bottom of the coastal environment is dominated by plants and algae. Insects, snails, fish, crabs, shrimp, lobsters, and other animals make up the fauna. It is one of the major aquatic ecosystems and is quite distinct in terms of structure and diversity. The coastal ecosystem is formed in the union of land and water. Coastal ecosystems harbor a variety of plants and algae and serve as a home to snails, shrimps, crabs, lobsters, and fish. B. Freshwater Ecosystem This aquatic ecosystem covers less than 1% of the earth’s surface and is broadly divided into – wetlands, lentic and lotic ecosystems. Swamps and Wetlands These are marshy areas that are often covered in water and harbor a variety of flora and fauna. Wetlands are known to be a home of water lilies, marshes, swamps, Northern Pikes, dragonflies, Green Heron, etc. Lentic Ecosystems It includes standing water bodies like ponds and lakes and is home to both floating and rooted plants, algae, and invertebrates. All standing water habitats, such as lakes and ponds, are included in lentic ecosystems. Algae, rooted and floating-leaved plants, and crustaceans like crabs and shrimp live in these habitats. Frogs and salamanders, as well as reptiles like alligators and water snakes, can be found here. Salamanders, frogs, water snakes, and alligators are commonly found in lentic ecosystems. Lotic Ecosystems These aquatic ecosystems are characterized by rapid flowing water moving in one direction. They are a hub of a wide variety of insects like beetles, mayflies, and stoneflies, among others. Also, it harbors species like river dolphins, beavers, otters, eel, minnow, and trout. Functions of Aquatic Ecosystem These pointers highlight the importance of aquatic ecosystem - Facilitates recycling of nutrients Helps to purify water Recharges groundwater 29  Is a habitat for aquatic flora and flora Mitigates flood (The term lentic (from the Latin lentus, meaning slow or motionless), refers to standing waters such as lakes and ponds (lacustrine), or swamps and marshes (paludal), while lotic (from the Latin lotus, meaning washing), refers to running water (fluvial or fluviatile) habitats such as rivers and streams. 30