HSBTE, DMLT: Unit-I. IInd-Semester. Introduction: Basics of ecology, ecosystem,- concepts and sustainable development, sources, advantages, disadvantages of renewable and non-renewable energy. Rainwater harvesting, Deforestation- its effect and control measures

Unit-IUnit-I

BASICS OF ECOLOGY

Ecology is also known as bionomics. It includes the relationship between living organisms and the environment. Ecology is a multidisciplinary branch that includes physical science, biological science, and social science.

Definition: Ecology is the study of

• · Interrelationship among living organisms and

• · Interactions between living organisms and their environment.

Importance of ecology:

The study of ecology helps

• 1. To maintain a balance between

  • o Comforts in human life and natural environment,

  • o Comfort in human life and biotic communities,

  • o Comfort in human life and use of natural resources

  • o Comfort in human life and conservation of natural resources,

  • o Comfort in human life and local, regional, and global environmental problems.

• 2. To understand agriculture, forest, and aquatic life,

• 3. To solve the following problems

  • o Deforestation

  • o Land degradation,

  • o Water, air, and soil pollution

  • o Flood situation

  • o Resources conservation,

  • o Population explosion,

  • o Plant and animal species extinction,

  • o Energy supply demand

  • o Productivity.

Branches of ecology:

There are three branches of ecology. These are

• 1. Species ecology (Autecology): The study of the inter-relationship between the development of species and their environment is called species ecology.

• 2. Population ecology: The study of the inter-relationship between the development of a population and its environment is called population ecology.

• 3. Autecology: It includes species ecology and population ecology. The study of the inter-relationship between the development of population/species and their environment is called population ecology.

• 4. Synecology: The study of the interrelationship between communities’ development and their environment is called synecology. It also includes the composition and organization of communities. It also includes community ecology and ecosystem ecology.

ECOSYSTEM CONCEPTS:

It consists of biological communities and their environments. It explains the interaction between biological communities and the environment with the exchange of materials and energy. Forests are examples of natural ecosystems. Flower pots, aquariums, etc are artificial ecosystems. The geographic area that provides suitable conditions for life is called a biotope.

Ecosystem structures: The ecosystem consists of two components biotic system and abiotic system.

• 1. Biotic components: All living components of an ecosystem are biotic components of the ecosystem. Depending upon nutritional requirements, biotic components are divided into three groups. These are autotrophs, heterotrophs, and saprotrophs.

  • a. Autotrophs: Living organisms that can produce their food are called autotrophs. Example: plants. Autotrophs are considered as producers.

  • b. Heterotrophs: Living organisms that depend upon another organism for food are called heterotrophs. Heterotrophs are considered as consumers. Depending upon their food consumption pattern, heterotrophs are further divided into the following four categories.

    • i. Primary heterotrophs (Primary consumers): They depend upon plants for food. They are also called herbivores.

    • ii. Secondary heterotrophs (Secondary consumers): They depend upon primary heterotrophs for food. They are either carnivorous or omnivorous.

    • iii. Tertiary heterotrophs (Tertiary consumers): They depend upon secondary heterotrophs for food. They are also either carnivorous or omnivorous.

    • iv. Quaternary heterotrophs(Quaternary consumers): They depend upon tertiary heterotrophs for food. They are present inside food.

  • c. Saprotrophs: They depend upon dead organisms or decaying organic matter for food. Examples are bacteria and fungi. They are also considered as decomposers. Fig.

• 2. Abiotic components: All non-living components of an ecosystem are called abiotic components. Examples are air, water, soil, sunlight, nutrients, minerals, etc.

Functions of the ecosystem:

The ecosystem performs the following functions:

• 1. Regulation of ecological processes that support the life system and maintain stability in the life system.

• 2. Cycling of nutrients between biotic and abiotic components.

• 3. Cycling of minerals

• 4. Synthesis of organic components to generate energy.

Types of ecosystem:

The ecosystem is divided into two types

• 1. Terrestrial ecosystem: A land-based ecosystem is called a terrestrial ecosystem. There are four types of terrestrial ecosystems:

  • a. Forest ecosystem: It consists of plants, trees, animals, and microorganisms.

  • b. Grassland ecosystem: It consists of grasses and herbs.

  • c. Tundra ecosystem: It consists of landscapes without trees and little rainfall.

  • d. Desert ecosystem: It consists of a landscape with little vegetation and little rainfall.

• 2. Aquatic ecosystem: The ecosystem inside a water body is called an aquatic ecosystem. There are two types of aquatic ecosystems.

  • a. Freshwater ecosystem: A water body with little salt or no salt is called a freshwater ecosystem. Examples are rivers, ponds, lakes, etc.

  • b. Marine ecosystem: A water body with heavy salts is called a marine ecosystem. Examples are sea and ocean.

Ecological concepts:

1. Food chain: Plants utilize sun energy for the synthesis of food. Plants convert light energy to chemical energy. Plants also utilize organic matter produced by decomposers to generate chemical energy. Thus plants are considered as producers or autotrophs. Part of the energy captured by the plant is used as food for herbivores. Herbivorous generate energy from this food. Part of this energy is consumed by the carnivores. “Flow of chemical energy from producers to consumers (Heterotrophs) is called a food chain.” Chemical energy travels from solar to plant to herbivorous to carnivorous. Only 10% of energy transfer occurs from one to another in the food chain

.eg. Producer (1000K cal) to Herbivorous (100K cal) to Carnivorous (10 K cal).

1. pyramids:

The graphical arrangement of biomass, numbers, and energy of living organisms from producers to consumers is called an ecological pyramid.

Producers are the base of the ecological pyramid. Quaternary consumers are the apex of ecological pyramids. Ecosystems are arranged in the following order in the ecological pyramid. Producers followed by primary consumers followed by secondary consumers followed by tertiary consumers followed by quaternary consumers.

eg. Crop is food for grasshopper, the grasshopper is food for the mouse. The mouse is food for a snake, snake is food for an eagle.

Their numbers decrease from base to apex inside ecological pyramids.

2. Food web: A Network of interconnected food chains is called the food web. It involves the transportation of chemical energy from producers (Autotrophs) to consumers (Heterotrophs).

ECOSYSTEM SUSTAINABLE DEVELOPMENT:

Development that meets the needs of the present generation without compromising the ability of future generations to meet their own needs.

There should be a balance between economic sustainability, social sustainability, and environmental sustainability to achieve ecosystem-sustainable development.

• 1. Economic sustainability: Utilization of resources efficiently and responsibly.

• 2. Social sustainability: The ability of society to achieve good social well-being.

RENEWABLE AND NON RENEWABLE ENERGY

Renewable energy

It is exhaustible energy that can be replenished naturally. can sustain over a long period. They are an important source of energy because they can last forever if they are used within their renewability.

Sources: Renewable energy sources are natural and replenishable. They are continuously renewed by nature. Examples are

• 1. Solar energy: Solar energy comes from the sun and can be converted into electric energy by using solar panels.

• 2. Wind energy: They come from wind that can be converted into electric energy by using wind turbines.

• 3. Hydroelectric power: They come from water movement that can be used to generate electric energy by using a water turbine.

• 4. Geothermal energy: They come from the earth's heat that can be used to heat and cool buildings or generate electricity.

• 5. Tidal energy: They come from tides that can be used to generate electricity by using underwater turbine

• 6. Ocean thermal energy: They come from the temperature difference between warm surface water and cold deep water. They can be used to generate electricity.

7. Biomass energy: They come from organic matter such as plants and wastes. They can be used to generate heat and electricity

Advantages:

1. · Sustainability: Sources of renewable energy are natural and replenishable. They can provide energy forever if used within their renewability.

2. · Clean energy: They generate very little or no greenhouse gases. Thus they reduce the carbon footprint and produce very little air pollution.

3. · Cost effective: Initial cost to install them is high but it has very low operation cost or maintenance cost.

4. · Job creation: The generation of energy by using renewable sources is growing rapidly. Thus it is creating several jobs to manufacture, install, maintain and operate.

5. · Energy security: It reduces dependence on nonrenewable sources for energy. This helps to increase energy security and low disruption in energy supply.

6. · Diversification: It reduces the over-dependence on nonrenewable sources of energy.

Disadvantages:

1. · Time limitation: They are not available all the time. For example, sunshine is available only in the daytime. Wind can generate energy if there is sufficient wind. etc.

2. · High initial cost: The cost of installation is very high.

3. · Land use: It requires a large land area to install it,

4. · Wildlife impact: If not well planned it affects wildlife. eg. Wind turbine has an impact on the fish population. Energy storage: It can’t be stored. Electricity storage techniques like batteries are very expensive.

Non-renewable energy:

Non-renewable energy refers to energy sources that cannot be easily renewed within a short period. These sources are finite and run out if consumed at a rapid rate. The main types of non-renewable energy sources include:

• 1. Fossil fuels: This category includes coal, oil (petroleum), and natural gas. These fuels are formed from the remains of ancient plants and animals that have been subjected to heat and pressure over millions of years. Fossil fuels are currently the primary sources of energy for electricity generation, transportation, and heating in many parts of the world.

• 2. Nuclear Energy: Nuclear power is generated through the process of nuclear fission. The nucleus of an atom is split into smaller parts to release a significant amount of energy. Uranium and plutonium are the primary fuel sources for nuclear power plants. The availability of uranium and plutonium is limited. it is effectively non-renewable in the long term.

Non-renewable energy sources have been the backbone of global energy production for many years. This is mainly due to their high energy density and low cost of extraction and processing. The following are drawbacks of the renewable energy use.

• 1. Environmental Impact: The extraction, processing, and combustion of non-renewable energy sources cause environmental pollution and habitat destruction. Fossil fuels release greenhouse gases such as carbon dioxide (CO2) when burned. This contributes to climate change and air pollution.

• 2. Resources Depletion: Non-renewable energy sources are finite. It means they will be exhausted if consumed at a high rate. As reserves are exhausted, their extraction becomes more difficult and costly. This leads to higher energy prices and geopolitical conflicts over remaining resources.

• 3. Health Concern: The combustion of fossil fuels releases various pollutants such as particulate matter, sulfur dioxide, nitrogen oxides, and volatile organic compounds. These have harmful effects on human health. This leads to respiratory problems, cardiovascular diseases, and other health issues.

Renewable energy sources such as solar, wind, hydroelectric, and geothermal power, etc offer cleaner and more sustainable alternatives to non-renewable energy.

RAINWATER HARVESTING

It is the process to collect and store rain waterfalls on the rooftop and land surface. The collected rainwater is used for various purposes such as irrigation, domestic use, and industrial use. Rainwater can be harvested in the following manners:

• 1. Rooftop harvesting: Rainwater that falls on the rooftop of the building is collected in the water storage tank.

• 2. Surface run-off harvesting: Rainwater that falls on the land surface is stored in a pond or water storage tank by using water channels.

• 3. Infiltration pits: Rainwater is collected in small pits or allowed to sip into the soil to recharge groundwater.

• 4. Percolation tank: Rainwater is collected into a large tank. It is allowed to sip into the ground to recharge groundwater.

Advantages:

• 1. Conserve water: It conserves water by reducing the demand for traditional water sources, such as groundwater, rivers, lakes, etc.

• 2. Reduce runoff: It reduces surface runoff and erosion by blocking rainwater before it flows off the land surface.

• 3. Improve water quality: It generates clean water that is suitable for domestic and industrial use.

• 4. Reduce flood: It helps to reduce floods by blocking and stirring excess rainwater.

DEFORESTATION

The purposeful removal of trees from forests by humans for human activities is called deforestation. It is a serious threat to the environment and natural habitats.

Reasons for deforestation:

In rare conditions, deforestation occurs due to natural calamities, such as volcanoes, floods, hurricanes, parasites, etc. There are several reasons for deforestation. These are:

• 1. Human activities: In most cases, deforestation is due to human activities such as agriculture, mining, urban expansion as housing, factories, railway tracks, road

• 2. forest burning), demand for wood for furniture, paper, fuel, house construction, etc.

• 3. Forest fires

• 4. Weather: Strong storms and heavy snowing destroy trees heavily in the forest.

• 5. Pests: Several insects inside the forest destroy trees.

• 6. Overgrazing: Some animals destroy leaves present on lower branches of trees, damaging the trunk and roots of trees.

Effects of deforestation:

Large-scale deforestation affects adversely the ecosystem.

• 1. Effects on Environment: Deforestation affects the water cycle, soil erosion, and carbon dioxide levels in the atmosphere.

• a. Water cycle: Tree roots penetrate soil and form macropores. These macropores hold water and increase the water-holding capacity of the soil. Thus deforestation causes a decline in groundwater levels and develops desert land.

• b. Their roots absorb water from the soil and release it in the air. This maintains humidity in the air. Thus deforestation develops dryness in the air and makes the climate warmer.

• c. 30% of freshwater supply is from forest areas. Thus deforestation causes a shortage of fresh water and develops draught-like conditions.

• 2. Effects on soil erosion: Trees' roots bind the soil. Trees leaves and other parts of soil also protect soil. Thus deforestation causes soil erosion and landslides. Flood-like situation exaggerates the soil erosion problem.

• 3. Effects on biodiversity: Forests support wide varieties of wildlife. That is essential for the environment ecosystem. Several species have been are at extinct due to deforestation. This will have a very bad effect on the food web.

• 4. Effects on human health: Deforestation increases normal temperature, disturbs rainfall patterns, raises pollution levels, decreases oxygen levels in air, etc. These all are not favorable conditions for human life. Soil erosion causes water stagnation. That will be a breeding ground for mosquitoes and insects.

• 5. Effects on the economy: Over-cutting of wood and timber will hurt the economy in the long term. It will be mainly due to a decrease in forest area. An increase in floods due to deforestation also affects the economy.

• Deforestation: Control measures:

• 1. Legal protection: Deforestation can be controlled by implementing government laws, rules & regulations

• 2. Sustainable forest management: It ensures to utilization of trees without impacting the needs of future generations.

• 3. Reforestation: Encouragement of plantations to restore trees and the ecosystem

• 4. Alternative livelihood: Provide alternate means of livelihood to the local community who depend upon forests.

• 5. Consumer awareness: Educate consumers to buy products that do not promote deforestation

Dr. Pramila Singh