EVS pptxIndia has a number of programs and initiatives to address food security, including
- 1. ENVIRONMENTAL SCIENCE Population Ecology (UNIT-2) PRESENTING BY :Itishree Nath
- 2. CONTENT •Population Ecology •Characteristics •Individuals, Species, Community •Population •Control Methods of Population •Over population •Urbanization and its effects on Society •Communicable Diseases and its Transmission •Non-Communicable Diseases
- 3. Basic Concept • Population: All the individuals of a species that live together in an area. • Ecology: The branch of biology that deals with the relations of organisms to one another and to their physical surroundings. • Individual: An individual is any living thing or organism. • Species: A group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding. • Community: A group of people living in the same place or having a particular characteristic in common.
- 5. Population Ecology • Population ecology is the branch of ecology that studies the structure and dynamics of populations. • The definition of population ecology is the study of how various factors affect population growth, rates of survival and reproduction, and risk of extinction. • The term population refers to a group of members of a species living in the same area. • A population is the number of organisms of the same species that live in a particular geographic area at the same time, with the capability of interbreeding. • Ecologist recognize two types of population- – Monospecific Population- It is the population of individuals of only species. – Polyspecific Population- It is the population of individuals of more than one species.
- 6. Characteristics of population • Population Size & Density – Total size is generally expressed as the number of individuals in a population. Density is the number per unit area of environment. • Natality or Birth rate – The rate at which the new individuals are added to the population by reproduction. • Mortality or Death rate – The rate at which the individuals are lost by death. • Dispersal – The rate at which the individuals immigrate into the population and emigrate out of the population. • Age Distribution – The proportion of individuals of different ages in the group. • Population Growth Form – The net result of Natality, Mortality , Dispersal etc.
- 7. Community • Community is the group of organisms that live together and interact with each other within an environment or habitat. • There are two main types of community. – Major Community - A major community is the smallest ecological unit which is able to sustain itself and is self-regulating. These communities are usually relatively independent of other communities, for example a pond, a forest, a grassland or lake. – Minor Community - Minor communities, which make up major communities, are smaller ecological units that are not individually self-sustaining and rely on interactions with other communities. An example of a minor community is the collection of organisms, which lives within a piece of deadwood on the forest floor.
- 8. Population • The term population refers to a group of members of a species living in the same area. • A population is the number of organisms of the same species that live in a particular geographic area at the same time, with the capability of interbreeding.
- 9. Control Methods of Population Measure Of Population Control Social Measure Economic Measure Other
- 10. 1.Social Measure: • Minimum age of Marriage • Raising the Status of Women • Spread of Education • Adoption • Change in Social Outlook • Social Security
- 11. 2.Economic Measures • More employment opportunities • Development of Agriculture and Industry • Standard of Living • Urbanization
- 12. 3.Other Measures • Late Marriage • Self Control • Family Planning • Publicity • Incentives • Employment to Woman
- 14. Over population • Overpopulation refers to a population which exceeds its sustainable size within a particular environment or habitat. • Overpopulation is an undesirable condition where the number of existing human population exceeds the carrying capacity of Earth. • According to Wikipedia, “Overpopulation occurs when a species’ population exceeds the carrying capacity of its ecological niche. It can result from an increase in births (fertility rate), a decline in the mortality rate, an increase in immigration, or an unsustainable biome and depletion of resources.”
- 16. Causes of Overpopulation – Decline in the Death Rate – Better Medical Facilities – More Hands to Overcome Poverty – Technological Advancement in Fertility Treatment – Immigration. – Lack of Family Planning
- 17. Effects of Overpopulation – Depletion of Natural Resources – Degradation of Environment – Conflicts and Wars – Rise in Unemployment – High Cost of Living
- 20. Solutions to Overpopulation – Better Education – Making People Aware of Family Planning – Tax Benefits or Concessions
- 22. Urbanization • Urbanization is a process whereby populations move from rural to urban area, enabling cities and towns to grow. • Urbanization refers to the population shift from rural to urban areas, the decrease in the proportion of people living in rural areas, and the ways in which societies adapt to this change.
- 25. Causes of Urbanization – Industrialization – Commercialization – Social benefits and services – Employment opportunities – Modernization and changes in the mode of living – Rural urban transformation
- 27. Effects of Urbanization – Positive effects of urbanization – Housing problems – Overcrowding – Unemployment – Development of slums – Water and sanitation problems – Poor health and spread of diseases – Traffic congestion – Urban crime
- 33. Solutions of Urbanization –Building sustainable and environmentally friendly cities –Provision of essential services –Creation of more jobs –Population control
- 35. Diseases • A disease is any condition which results in the disorder of a structure or function in a living organism that is not due to any external injury. • A disorder of structure or function in a human, animal, or plant, especially one that produces specific symptoms or that affects a specific location and is not simply a direct result of physical injury. • A diseased organism commonly exhibits signs or symptoms indicative of its abnormal state.
- 37. Communicable Diseases • A communicable disease is one that is spread from one person to another through a variety of ways that include: contact with blood and bodily fluids; breathing in an airborne virus; or by being bitten by an insect. • People sometimes refer to communicable diseases as “infectious” or “transmissible” diseases. • There are many examples of communicable diseases. • Common Cold • Hepatitis • HIV/AIDS • Flu
- 39. How do these communicable diseases spread? • How these diseases spread depends on the specific disease or infectious agent. • Some ways in which communicable diseases spread are by: – physical contact with an infected person, such as through touch (staphylococcus), sexual intercourse (gonorrhea, HIV), fecal/oral transmission (hepatitis A), or droplets (influenza, TB) – contact with a contaminated surface or object (Norwalk virus), food (salmonella, E. coli), blood (HIV, hepatitis B), or water (cholera); – bites from insects or animals capable of transmitting the disease (mosquito: malaria and yellow fever; flea: plague); – travel through the air, such as tuberculosis or measles.
- 40. Transmission of communicable diseases • Infectious diseases are transmitted from person to person by direct or indirect contact. Certain types of viruses, bacteria, parasites, and fungi can all cause infectious disease. 1. Direct contact – Infectious diseases are often spread through direct contact. Types of direct contact include: • Person-to-person contact- Infectious diseases are commonly transmitted through direct person-to-person contact. Transmission occurs when an infected person touches or exchanges body fluids with someone else. • Droplet spread - The spray of droplets during coughing and sneezing can spread an infectious disease. You can even infect another person through droplets created when you speak. Since droplets fall to the ground within a few feet, this type of transmission requires close proximity.
- 41. Cont… 2. Indirect contact – Infectious diseases can also be spread indirectly through the air and other mechanisms. For example: • Airborne transmission - Some infectious agents can travel long distances and remain suspended in the air for an extended period of time. • Contaminated objects - Some organisms can live on objects for a short time. If you touch an object, such as a doorknob, soon after an infected person, you might be exposed to infection. Transmission occurs when you touch your mouth, nose, or eyes before thoroughly washing your hands. Germs can also be spread through contaminated blood products and medical supplies. • Food and drinking water - Infectious diseases can be transmitted via contaminated food and water. E. coli is often transmitted through improperly handled produce or undercooked meat. • Animal-to-person contact - Some infectious diseases can be transmitted from an animal to a person. This can happen when an infected animal bites or scratches you or when you handle animal waste.
- 42. Cont… • Insect bites (vector-borne disease) - Some zoonotic infectious agents are transmitted by insects, especially those that suck blood. These include mosquitos, fleas, and ticks. • Environmental reservoirs - Soil, water, and vegetation containing infectious organisms can also be transferred to people.
- 43. Non Communicable Diseases • A non-communicable disease (NCD) is a disease that is not transmissible directly from one person to another. • Non-Communicable Disease is a non-infectious disease or medical condition. • Stroke • Cancer • Asthma • Heart Disease • Diabetes • Chronic Kidney Disease • Chronic Lung Disease
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