This document provides an overview of population ecology, including terminology, patterns of dispersion, population growth, survival patterns, factors influencing population growth, methods for determining population size, human population trends, and social organization. Some key points include:
- Population ecology is the study of populations in relation to their environment. A population is a group of the same species in the same area. Density, dispersion, demography, birth and death rates are important concepts.
- Population growth can follow exponential or logistic patterns. Carrying capacity is the maximum population an environment can sustain. Survival patterns include Type I, II, and III curves.
- Population growth is influenced by density-dependent factors like competition, disease, predation, and
Community ecology, study of the organization and functioning of communities, which are assemblages of interacting populations of the species living within a particular area or habitat.
This presentation is on carrying capacity of the ecosystem. Here in the presentation we explained about the ecosystem and it's example. It also explained about the the how population and growth pattern takes place in particular a ecosystem and it's effect on carrying capacity.This presentation is taken by Dr. Sachin mandavgane faculty of chemical engineering VNIT Nagpur as a part of our course in sustainable engineering.
Community ecology, study of the organization and functioning of communities, which are assemblages of interacting populations of the species living within a particular area or habitat.
This presentation is on carrying capacity of the ecosystem. Here in the presentation we explained about the ecosystem and it's example. It also explained about the the how population and growth pattern takes place in particular a ecosystem and it's effect on carrying capacity.This presentation is taken by Dr. Sachin mandavgane faculty of chemical engineering VNIT Nagpur as a part of our course in sustainable engineering.
It is as per the syllabus of M.Sc. NRM including detailed study of population ecology
It describes the meaning of population with respect to ecology and includes population attributes, dynamics, dispersal, Population growth models, survivorship curves and limitations.
It also entails factors that influence and regulate population growth on the basis of density.
presentation contain different type of interactions, competition-intra and inter-specific, mechanism of competition-Exploitation and Interference, Mathematical models of Competition i.e. Hutchinson Ratio, Exponential Growth, Logistic Model, Lotka-Volterra Competition Model, Tilman's Resource Model, Results of Competition i.e. Range restriction, Competitive Displacement, Competitive Exclusion , Competitive Displacement Hypothesis, Ecological Niche, Evolution of new species, Factors Affecting Competition, Case studies
Ppt is made vailable for public for scientifc use.
Population ecology concept and its characteristics explained by using practical examples in a simple language. data is significant for competitive examinations
Ecological Interactions - Mutualism, Commensalism & NeutralismRahul M. Prathap
Ecological interactions are the effects an organism have on another in an ecosystem. This slide describes Mutualism, Commensalism and Neutralism with examples.
Ecological Succession is the process of change in the species structure of an ecological community over a period of time.
But, over a long period of time, the climate conditions of an ecosystem is bound to change.
No ecosystem has existed or will remain unchanged over a Geological Time Scale.
South Africa is food secure at the national level, but household food insecurity is pervasive and rising concern. This presentation provides an overview of food security in South Africa vis-a-vis the rest of the world and supplies a summary of legislative and policy interventions underway to address hunger at the household level.
It is as per the syllabus of M.Sc. NRM including detailed study of population ecology
It describes the meaning of population with respect to ecology and includes population attributes, dynamics, dispersal, Population growth models, survivorship curves and limitations.
It also entails factors that influence and regulate population growth on the basis of density.
presentation contain different type of interactions, competition-intra and inter-specific, mechanism of competition-Exploitation and Interference, Mathematical models of Competition i.e. Hutchinson Ratio, Exponential Growth, Logistic Model, Lotka-Volterra Competition Model, Tilman's Resource Model, Results of Competition i.e. Range restriction, Competitive Displacement, Competitive Exclusion , Competitive Displacement Hypothesis, Ecological Niche, Evolution of new species, Factors Affecting Competition, Case studies
Ppt is made vailable for public for scientifc use.
Population ecology concept and its characteristics explained by using practical examples in a simple language. data is significant for competitive examinations
Ecological Interactions - Mutualism, Commensalism & NeutralismRahul M. Prathap
Ecological interactions are the effects an organism have on another in an ecosystem. This slide describes Mutualism, Commensalism and Neutralism with examples.
Ecological Succession is the process of change in the species structure of an ecological community over a period of time.
But, over a long period of time, the climate conditions of an ecosystem is bound to change.
No ecosystem has existed or will remain unchanged over a Geological Time Scale.
South Africa is food secure at the national level, but household food insecurity is pervasive and rising concern. This presentation provides an overview of food security in South Africa vis-a-vis the rest of the world and supplies a summary of legislative and policy interventions underway to address hunger at the household level.
This PowerPoint was one very small part of my Ecology Interactions Unit from the website http://sciencepowerpoint.com/index.html .This unit includes a 3 part 2000+ Slide PowerPoint loaded with activities, project ideas, critical class notes (red slides), review opportunities, challenge questions with answers, 3 PowerPoint review games (125 slides each) and much more. A bundled homework package and detailed unit notes chronologically follow the PowerPoint slideshow.
Areas of Focus within The Ecology Interactions Unit: Levels of Biological Organization (Ecology), Parts of the Biosphere, Habitat, Ecological Niche, Types of Competition, Competitive Exclusion Theory, Animal Interactions, Food Webs, Predator Prey Relationships, Camouflage, Population Sampling, Abundance, Relative Abundance, Diversity, Mimicry, Batesian Mimicry, Mullerian Mimicry, Symbiosis, Parasitism, Mutualism, Commensalism, Plant and Animal Interactions, Coevolution, Animal Strategies to Eat Plants, Plant Defense Mechanisms, Exotic Species, Impacts of Invasive Exotic Species.
If you have any questions please feel free to contact me. Thank you again and best wishes.
Sincerely,
Ryan Murphy M.Ed
www.sciencepowerpoint@gmail.com
This PowerPoint is one small part of the Astronomy Topics unit from www.sciencepowerpoint.com. This unit consists of a five part 3000+ slide PowerPoint roadmap, 12 page bundled homework package, modified homework, detailed answer keys, 8 pages of unit notes for students who may require assistance, follow along worksheets, and many review games. The homework and lesson notes chronologically follow the PowerPoint slideshow. The answer keys and unit notes are great for support professionals. The activities and discussion questions in the slideshow and meaningful. The PowerPoint includes built-in instructions, visuals, and follow up questions. Also included are critical class notes (color coded red), project ideas, video links, and review games. This unit also includes four PowerPoint review games (110+ slides each with Answers), 38+ video links, lab handouts, activity sheets, rubrics, materials list, templates, guides, and much more. Also included is a 190 slide first day of school PowerPoint presentation. Teaching Duration = 5+ weeks. Areas of Focus in the Astronomy Topics Unit: The Solar System and the Sun, Order of the Planets, Our Sun, Life Cycle of a Star, Size of Stars, Solar Eclipse, Lunar Eclipse, The Inner Planets, Mercury, Venus, Earth, Moon, Craters, Tides, Phases of the Moon, Mars and Moons, Rocketry, Asteroid Belt, NEOs, The Torino Scale, The Outer Planets and Gas Giants, Jupiter / Moons, Saturn / Moons, Uranus / Moons, Neptune / Moons, Pluto's Demotion, The Kuiper Belt, Oort Cloud, Comets / Other, Beyond the Solar System, Types of Galaxies, Blackholes, Extrasolar Planets, The Big Bang, Dark Matter, Dark Energy, The Special Theory of Relativity, Hubble Space Telescope, Constellations, Spacetime and much more. If you have any questions please feel free to contact me. Thanks again and best wishes. Sincerely, Ryan Murphy M.Ed www.sciencepowerpoint@gmail.com
It is as per the syllabus of M.Sc. NRM including detailed study of population ecology
It describes the meaning of population with respect to ecology and includes population attributes, dynamics, dispersal, Population growth models, survivorship curves and limitations.
It also entails factors that influence and regulate population growth on the basis of density.
A population is generally a group of particular species occupying a particular area at a specific time. Some of the ecologists however recognize two types of population;
Monospecific population- a population with individuals only one species
Mixed or Polyspecific population- a population of more than one species
However in Ecology, a polyspecific population is considered as a COMMUNITY, and the term POPULATION is used for a group of individuals of any kind of organism.
POPULATION ECOLOGY is the study of individuals of the same species where the processes are aggregation, interdependencies between individuals etc, and the various factors governing such processes are emphasized.
Introduction organisms and populations class 12
Ecology is the scientific study of the interactions among organisms and their environment, encompassing a diverse array of living and non-living components. In the context of Class 12 Biology, the study of ecology specifically delves into the intricate relationships between organisms and populations. This branch of biology seeks to unravel the dynamics of life at both individual and collective levels, exploring how organisms adapt to their surroundings and influence one another in the grand tapestry of ecosystems. By investigating topics such as population ecology, community dynamics, and the delicate balance of ecosystems, students gain insights into the mechanisms governing life on Earth. Understanding these ecological principles is fundamental not only to appreciating the complexities of the natural world but also to addressing contemporary challenges related to biodiversity conservation, environmental sustainability, and the impact of human activities on ecosystems. Through the lens of ecology, students in Class 12 embark on a journey to comprehend the interconnected web of life and the factors shaping the diversity, distribution, and interactions of organisms and populations in their ever-changing environments.
For more information, visit. www.vavaclasses.com
Population ecology is a field of scientific research that examines the dynamics of populations of living organisms within a given environment. It involves the study of various aspects of populations, including their growth, distribution, density, age structure, and the factors that affect these attributes. Key components of population ecology include:
Population Dynamics: Population ecologists study how the size of a population changes over time. This involves examining birth rates (natality), death rates (mortality), immigration, and emigration.
Population Distribution: Understanding how individuals in a population are spatially distributed is essential. Populations can be clumped, evenly dispersed, or randomly distributed in a habitat.
Population Density: This refers to the number of individuals of a species per unit area or volume of habitat. Population density can have significant ecological and environmental implications.
Age Structure: The age distribution within a population can provide insights into its growth potential and reproductive capacity. It can help in predicting future population trends.
Population Growth Models: Population ecologists use mathematical models to describe and predict population growth, such as exponential and logistic growth models.
Limiting Factors: Population growth is limited by various factors, including availability of resources, predation, competition, disease, and environmental conditions. Population ecologists study how these factors influence population dynamics.
Carrying Capacity: The carrying capacity of an environment is the maximum population size that can be sustained by available resources without causing environmental degradation or resource depletion.
Interactions: Populations do not exist in isolation. Interactions with other species, such as predation, competition, and mutualism, are essential considerations in population ecology.
Conservation and Management: Population ecology plays a critical role in the conservation and management of endangered species and ecosystems. It helps in making informed decisions to protect and sustainably manage populations.
Research Methods: Population ecologists employ various field and laboratory techniques, including population censuses, mark and recapture studies, and modeling, to gather data and understand population dynamics.
2. POPOULATION
ECOLOGY
Population ecology is the study of
populations in relation to environment,
including environmental influences on
density and distribution, age structure,
and population size.
3. 1. TERMINOLOGY
A population is a group of individuals
of the same species living in the same
area at the same time.
Density is the number of individuals
per unit area or volume.
Dispersion is the pattern of spacing
among individuals within the
boundaries of the population.
4. TERMINOLOGY
Density is the result of an interplay
between processes that add individuals
to a population and those that remove
individuals.
Immigration is the influx of new
individuals from other areas
Emigration is the movement of
individuals out of a population
6. TERMINOLOGY
Demography is the study of the vital
statistics of a population and how they
change over time. Death rates and
birth rates are of particular interest to
demographers.
7. 2. PATTERNS OF DISPERSION
Environmental and social factors influence spacing of
individuals in a population:
1. In a clumped dispersion, individuals
aggregate in patches. A clumped dispersion may
be influenced by resource availability and
behaviour.
2. A uniform dispersion is one in which
individuals are evenly distributed. It may be
influenced by social interactions such as
territoriality
3. In a random dispersion, the position of each
individual is independent of other individuals.
It occurs in the absence of strong attractions or
repulsions.
9. 3.Patterns of Population Growth
in an Ecosystem
• Many factors affect population growth, but
one factor is a species' intrinsic growth rate.
• The birth rate minus the death rate with no
environmental restrictions defines a species
intrinsic growth rate.
• Within an ecosystem, however, resource limits
and predation also effect population growth.
10. There are two main patterns of
population growth:
• Exponential growth/J-pattern: only
one reproductive chance is given to
members of the population during their
entire lifespan. Once mission accomplishes,
they die. Many insects and annual plants
reproduce in this manner.
• Logistic growth/S-pattern: members
experience many reproductive events
throughout their lifetime. Most vertebrates,
and trees have this pattern of reproduction.
11. • Exponential growth/J-pattern
Lag phase: Growth is slow because population base
is small.
Exponential growth phase: Growth is accelerating,
that is, the rate of growth itself grows.
14. • Logistic growth/S-pattern:
Lag phase: Growth is slow because the
population base is small, organisms adapt.
Exponential growth phase: Growth is
accelerating, that is, many offspring born at a
fast rate.
Deceleration phase: The rate of population
growth slows down – individuals start to die.
Stable equilibrium phase: Little growth
because births and deaths are about equal.
Area has reached its carrying capacity.
16. Carrying capacity:
Carrying capacity (K) is the maximum
population size the environment can support
In the logistic population growth model, the
rate of increase declines as carrying capacity
is reached.
17. 4. Survival patterns/curves
Survivorship curves can be classified into three
general types:
• Type I: low death rates during early and
middle life, then an increase among older
age groups
• Type II: the death rate is constant over the
organism’s life span
• Type III: high death rates for the young,
then a slower death rate for survivors.
19. 5. Factors that influence and
regulate population growth
There are two general questions about
regulation of population growth:
• What environmental factors stop a
population from growing indefinitely?
• Why do some populations show radical
fluctuations in size over time, while
others remain stable?
20. Factors that influence and regulate
population growth : density
• In density-independent populations,
birth rate and death rate do not change
with population density.
• In density-dependent populations,
birth rates fall and death rates rise with
population density.
21. Density-dependent populations
• The population growth in density-
dependent populations are affected by
many factors, such as :
competition for resources,
territoriality,
disease,
predation,
toxic wastes, and
intrinsic factors
22. INTRASPECIFIC COMPETITION FOR
RESOURCES
• In crowded populations, increasing
population density intensifies
competition for resources and results in
a lower birth rate.
• Resources like: water, shelter, food,
space, access to mates, ecological
niches.
23. TERRITORIALITY
• In many vertebrates and some invertebrates,
competition for territory may limit density
• Cheetahs are highly territorial, using
chemical communication to warn other
cheetahs of their boundaries.
24. DISEASES
• Population density can influence the health
and survival of organisms
• In dense populations, pathogens can spread
more rapidly.
25. PREDATION
• As a prey population builds up, predators
may feed preferentially on that species.
• This will decrease the prey population size –
and later decrease the predator population
size. – Predator-prey relationship (Graph)
26. TOXIC WASTE
• Accumulation of toxic wastes can contribute
to density-dependent regulation of
population size.
27. 6. How to determine the size of a
population
In most cases, it is impractical or impossible
to count all individuals in a population.
Sampling techniques can be used to
estimate densities and total population
sizes
Method to determine population size can be
estimated by:
Census taking – counting each individual
Mark-recapture method
Quadrant method (will be done as an
assignment)
28. MARK-RECAPTURE METHOD
(PETERSON METHOD)
One way to estimate the size of a population is
to capture and mark individuals from the
population, release them, and then resample to
see what fraction of individuals carry marks.
Useful when sampling closed populations --
choose populations that do not change in size
at all or very much during the study period
due to births, deaths, immigration, or
emigration.
29. MARK-RECAPTURE METHOD
(PETERSON METHOD)
N = estimated population size
M = the number of individuals marked in the
first sample
C = total number of individuals captured in 2nd
sample
R = number of individuals in 2nd sample that are
marked
N = CM
R
30. ASSUMPTIONS OF THE MARK-
RECAPTURE METHOD (PETERSON
METHOD)
The population is "closed", so N is constant.
All animals have the same chance of getting
caught in the first sample.
Marking individuals does not affect their
mobility and chance to be caught again.
Animals do not lose marks between the two
sampling periods.
All marks are reported on discovery in the
second sample.
31. 7. HUMAN POPULATION
The human population is no longer growing
exponentially but is still increasing rapidly.
No population can grow indefinitely, and
humans are no exception.
The human population increased relatively
slowly until about 1650 and then began to grow
exponentially.
32. HUMAN POPULATION
Though the global population is still growing, the
rate of growth began to slow during the 1960s
33. REGIONAL PATTERNS OF
POPULATION CHANGE
• To maintain population stability, a regional
human population can exist in one of two
configurations:
• Zero population growth =
High birth rate – High death rate
• Zero population growth =
Low birth rate – Low death rate
• The demographic transition is the move from
the first state toward the second state
34. REGIONAL PATTERNS OF
POPULATION CHANGE
• The demographic transition is associated with an
increase in the quality of health care and
improved access to education, especially for
women
• Most of the current global population growth is
concentrated in developing countries.
38. POPULATION GROWTH IN SOUTH
AFRICA
• The Population; total in South Africa was
last reported at 49991300 in 2010.
• The Population; total in South Africa was
49320150 in 2009.
• The Population; total in South Africa was
reported at 48793022 in 2008.
39. AGE AND GENDER STRUCTURES
• One important demographic factor in present
and future growth trends is a country’s age
and GENDER structure
• Age structure is the relative number of
individuals at each age.
• Age structure diagrams can predict a
population’s growth trends
• They can illuminate social conditions and help
us plan for the future.
43. How many humans can the
biosphere support?
What is the earth’s carrying
capacity?
Our carrying capacity could
potentially be limited by food,
space, non-renewable resources,
or build-up of wastes
44. 8. SOCIAL ORGANISATION
An organism that is highly interactive with other
members of its species is said to be a social
animal.
All mammals (and birds) are social to the extent
that mothers and offspring bond.
A few species, notably insects (ants, bees wasps
and termites) show an extreme form of sociality,
involving highly organized societies, with
individual organisms specialized for distinct roles.
This form of social behaviour is referred to as
eusociality.
45. Vertebrate societies may exhibit one
of more of these behaviours:
cooperative rearing of young by the group
overlapping generations living in a
permanent, as opposed to seasonal, group
cooperative foraging or hunting
cooperative defence from predators and
competitors
social learning (such as a young chimpanzee
learning by observation to use a twig to fish
for termites)
48. SOCIAL ORGANISATION
Many herbivores (e.g. zebra) are always in herds,
to outnumber the predators.
Wolves, hyena's and wild dogs – hunt in packs –
guarantee a kill.
Bee’s and ants divide their daily tasks to get
everything done.
50. 9. COMMUNITY STRUCTURES
A biological community is an
assemblage of populations of various
species living close enough for potential
interaction, in a specific area, at a
specific time.
Community includes the producers
(plants), consumers (herbivore,
carnivores, omnivores) and
decomposers.
51. COMMUNITY STRUCTURES
Ecologists call relationships between species
in a community interspecific interactions
Examples are competition, predation,
herbivory, and symbiosis (parasitism,
mutualism, and commensalism)
Interspecific interactions can affect the
survival and reproduction of each species,
and the effects can be summarized as
positive (+), negative (–), or no effect (0).
52. COMPETITION
Interspecific competition (–/– interaction)
occurs when different species compete for a
resource in short supply (e.g. water, food,
shelter, space, light)
Strong competition can lead to competitive
exclusion, local elimination of a competing
species.
The competitive exclusion principle states
that two species competing for the same
limiting resources cannot coexist in the same
place.
53. COMPETITION
The total of a species’ use of biotic and
abiotic resources is called the species’
ecological niche
An ecological niche can also be thought of as
an organism’s ecological role
Ecologically similar species can coexist in a
community if there are one or more
significant differences in their niches.
Resource partitioning is differentiation of
ecological niches, enabling similar species to
coexist in a community
54. Resource partitioning example:
Seven species of Anolis lizards live close to each
other, all feed on the same insects, but competition
for food is reduced because they prefer different
perches (niches)
55. PREDATION
Predation (+/– interaction) refers to interaction
where one species, the predator, kills and eats the
other, the prey
Some feeding adaptations of predators are claws,
teeth, fangs, stingers, and poison.
Prey display various defensive adaptations.
Behavioral defenses include hiding, fleeing,
forming herds or schools, self-defence, and alarm
calls.
Animals also have morphological and
physiological defence adaptations
Cryptic coloration, or camouflage, makes prey
difficult to spot
57. HERBIVORY
• Herbivory (+/– interaction) refers to an
interaction in which a herbivore eats parts of
a plant or alga.
• It has led to evolution of plant mechanical
and chemical defences and adaptations by
herbivores.
58. SYMBIOSIS
• Symbiosis is a relationship where two or
more species live in direct and intimate
contact with one another.
• 3 TYPES:
PARASITISM
MUTUALISM
COMMENSIALISM
59. PARASITISM
• In parasitism (+/– interaction), one
organism, the parasite, derives
nourishment (benefits), from another
organism, its host, which is harmed in
the process.
• Parasites that live within the body of
their host are called endoparasites;
parasites that live on the external
surface of a host are ectoparasites
61. MUTUALISM
• Mutualistic symbiosis, or mutualism
(+/+ interaction), is an interspecific
interaction that benefits both species.
• A mutualism can be:
Obligate, where one species
cannot survive without the other.
Facultative, where both species
can survive alone.
62. MUTUALISM
Anemones provide the
Clown Fish with
protection from predators
whilst Clown fish defend
the Anemones from
Butterfly fish who like to
eat Anemones.
The flower is pollinated
and the butterfly gets
nectar. – both benefit
63. COMMENSALISM
• In commensalism (+/0 interaction), one
species benefits and the other is
apparently unaffected
Cattle egrets/tick
birds benefits
(insects) and
water buffalo (not
affected)
64. 10. ECOLOGICAL SUCCESSION
• Ecological succession is the sequence of
community and ecosystem changes
after a disturbance.
• Primary succession occurs where no
soil exists when succession begins.
• Secondary succession begins in an area
where soil remains after a disturbance.
65. • Example of ecological succession of a
glacial retreat at Glacier Bay, Alaska.
66. ECOLOGICAL SUCCESSION
• The first inhabitants of a disturbed area are called
the pioneer community.
• As more organisms inhabit the area – it reaches a
climax community – no more new comers can be
accommodated.