1. Population ecology is the study of populations in relation to their environment, including factors influencing population density, distribution, age structure, and size variations.
2. A population is defined as a group of the same species living in the same area. Population density and dispersion patterns are influenced by environmental and social factors.
3. Population growth and size are determined by the balance between birth and death rates. Populations typically follow a logistic growth model where growth slows as carrying capacity is approached.
Exponential growth: Resource (food and space) availability is
obviously essential for the unimpeded growth of a population.
Ideally, when resources in the habitat are unlimited, each species
has the ability to realise fully its innate potential to grow in number,
as Darwin observed while developing his theory of natural
selection.
Exponential growth: Resource (food and space) availability is
obviously essential for the unimpeded growth of a population.
Ideally, when resources in the habitat are unlimited, each species
has the ability to realise fully its innate potential to grow in number,
as Darwin observed while developing his theory of natural
selection.
sustainable development & the water, energy food security nexus is discussed. The content throws light on sustainable development : Effects on the livelihood of common man.
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.
This is the 7th lesson of the course - Foundation of Environmental Management taught at the Faculty of Social Sciences and Humanities, Rajarata University of Sri Lanka
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.
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.
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
sustainable development & the water, energy food security nexus is discussed. The content throws light on sustainable development : Effects on the livelihood of common man.
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.
This is the 7th lesson of the course - Foundation of Environmental Management taught at the Faculty of Social Sciences and Humanities, Rajarata University of Sri Lanka
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.
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.
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
Effect of development on environment and population ecologyMegha Majoe
Brief idea on the Impact of ongoing human development on our environment and Describing and understanding population ecology - Patterns of dispersion, Survivorship curve, Population growth, Exponential growth, ecological footprint etc
Natural farming @ Dr. Siddhartha S. Jena.pptxsidjena70
A brief about organic farming/ Natural farming/ Zero budget natural farming/ Subash Palekar Natural farming which keeps us and environment safe and healthy. Next gen Agricultural practices of chemical free farming.
WRI’s brand new “Food Service Playbook for Promoting Sustainable Food Choices” gives food service operators the very latest strategies for creating dining environments that empower consumers to choose sustainable, plant-rich dishes. This research builds off our first guide for food service, now with industry experience and insights from nearly 350 academic trials.
"Understanding the Carbon Cycle: Processes, Human Impacts, and Strategies for...MMariSelvam4
The carbon cycle is a critical component of Earth's environmental system, governing the movement and transformation of carbon through various reservoirs, including the atmosphere, oceans, soil, and living organisms. This complex cycle involves several key processes such as photosynthesis, respiration, decomposition, and carbon sequestration, each contributing to the regulation of carbon levels on the planet.
Human activities, particularly fossil fuel combustion and deforestation, have significantly altered the natural carbon cycle, leading to increased atmospheric carbon dioxide concentrations and driving climate change. Understanding the intricacies of the carbon cycle is essential for assessing the impacts of these changes and developing effective mitigation strategies.
By studying the carbon cycle, scientists can identify carbon sources and sinks, measure carbon fluxes, and predict future trends. This knowledge is crucial for crafting policies aimed at reducing carbon emissions, enhancing carbon storage, and promoting sustainable practices. The carbon cycle's interplay with climate systems, ecosystems, and human activities underscores its importance in maintaining a stable and healthy planet.
In-depth exploration of the carbon cycle reveals the delicate balance required to sustain life and the urgent need to address anthropogenic influences. Through research, education, and policy, we can work towards restoring equilibrium in the carbon cycle and ensuring a sustainable future for generations to come.
UNDERSTANDING WHAT GREEN WASHING IS!.pdfJulietMogola
Many companies today use green washing to lure the public into thinking they are conserving the environment but in real sense they are doing more harm. There have been such several cases from very big companies here in Kenya and also globally. This ranges from various sectors from manufacturing and goes to consumer products. Educating people on greenwashing will enable people to make better choices based on their analysis and not on what they see on marketing sites.
Micro RNA genes and their likely influence in rice (Oryza sativa L.) dynamic ...Open Access Research Paper
Micro RNAs (miRNAs) are small non-coding RNAs molecules having approximately 18-25 nucleotides, they are present in both plants and animals genomes. MiRNAs have diverse spatial expression patterns and regulate various developmental metabolisms, stress responses and other physiological processes. The dynamic gene expression playing major roles in phenotypic differences in organisms are believed to be controlled by miRNAs. Mutations in regions of regulatory factors, such as miRNA genes or transcription factors (TF) necessitated by dynamic environmental factors or pathogen infections, have tremendous effects on structure and expression of genes. The resultant novel gene products presents potential explanations for constant evolving desirable traits that have long been bred using conventional means, biotechnology or genetic engineering. Rice grain quality, yield, disease tolerance, climate-resilience and palatability properties are not exceptional to miRN Asmutations effects. There are new insights courtesy of high-throughput sequencing and improved proteomic techniques that organisms’ complexity and adaptations are highly contributed by miRNAs containing regulatory networks. This article aims to expound on how rice miRNAs could be driving evolution of traits and highlight the latest miRNA research progress. Moreover, the review accentuates miRNAs grey areas to be addressed and gives recommendations for further studies.
Diabetes is a rapidly and serious health problem in Pakistan. This chronic condition is associated with serious long-term complications, including higher risk of heart disease and stroke. Aggressive treatment of hypertension and hyperlipideamia can result in a substantial reduction in cardiovascular events in patients with diabetes 1. Consequently pharmacist-led diabetes cardiovascular risk (DCVR) clinics have been established in both primary and secondary care sites in NHS Lothian during the past five years. An audit of the pharmaceutical care delivery at the clinics was conducted in order to evaluate practice and to standardize the pharmacists’ documentation of outcomes. Pharmaceutical care issues (PCI) and patient details were collected both prospectively and retrospectively from three DCVR clinics. The PCI`s were categorized according to a triangularised system consisting of multiple categories. These were ‘checks’, ‘changes’ (‘change in drug therapy process’ and ‘change in drug therapy’), ‘drug therapy problems’ and ‘quality assurance descriptors’ (‘timer perspective’ and ‘degree of change’). A verified medication assessment tool (MAT) for patients with chronic cardiovascular disease was applied to the patients from one of the clinics. The tool was used to quantify PCI`s and pharmacist actions that were centered on implementing or enforcing clinical guideline standards. A database was developed to be used as an assessment tool and to standardize the documentation of achievement of outcomes. Feedback on the audit of the pharmaceutical care delivery and the database was received from the DCVR clinic pharmacist at a focus group meeting.
Characterization and the Kinetics of drying at the drying oven and with micro...Open Access Research Paper
The objective of this work is to contribute to valorization de Nephelium lappaceum by the characterization of kinetics of drying of seeds of Nephelium lappaceum. The seeds were dehydrated until a constant mass respectively in a drying oven and a microwawe oven. The temperatures and the powers of drying are respectively: 50, 60 and 70°C and 140, 280 and 420 W. The results show that the curves of drying of seeds of Nephelium lappaceum do not present a phase of constant kinetics. The coefficients of diffusion vary between 2.09.10-8 to 2.98. 10-8m-2/s in the interval of 50°C at 70°C and between 4.83×10-07 at 9.04×10-07 m-8/s for the powers going of 140 W with 420 W the relation between Arrhenius and a value of energy of activation of 16.49 kJ. mol-1 expressed the effect of the temperature on effective diffusivity.
Artificial Reefs by Kuddle Life Foundation - May 2024punit537210
Situated in Pondicherry, India, Kuddle Life Foundation is a charitable, non-profit and non-governmental organization (NGO) dedicated to improving the living standards of coastal communities and simultaneously placing a strong emphasis on the protection of marine ecosystems.
One of the key areas we work in is Artificial Reefs. This presentation captures our journey so far and our learnings. We hope you get as excited about marine conservation and artificial reefs as we are.
Please visit our website: https://kuddlelife.org
Our Instagram channel:
@kuddlelifefoundation
Our Linkedin Page:
https://www.linkedin.com/company/kuddlelifefoundation/
and write to us if you have any questions:
info@kuddlelife.org
2. Population ecology is the study of
populations in relation to the environment
Includes environmental influences on
population density and distribution, age
structure, and variations in population size
3. Definition of a Population
A population is a group of individuals of the
same species living in the same general area
4. Density and Dispersion
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
5. Population density results from interplay of
processes that add individuals and those that
remove them from the population.
Immigration and birth add individuals
whereas death and emigration remove
individuals.
7. Patterns of dispersion: clumped
Clumped dispersion
Individuals aggregate in patches
Grouping may be result of the fact that multiple
individuals can cooperate effectively (e.g. wolf
pack to attack prey or antelope to avoid
predators) or because of resource dispersion
(e.g. mushrooms clumped on a rotting log)
9. Pattern of dispersion: uniform
Uniform dispersion
Individuals are evenly distributed
Usually influenced by social interactions such as
territoriality
11. Pattern of dispersion: random
Random dispersion: position of each individual is
independent of other individuals (e.g. plants
established by windblown seeds).
Uncommon pattern.
13. Demography
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
14. Life Tables
Life table is an age-specific summary of the
survival pattern of a population (first
developed by the insurance industry)
Constructed by following the fate of a
cohort (age-class of organisms) from birth
to death.
15. Life table
Life table built by determining number of
individuals that die in each age group and
calculating the proportion of the cohort
surviving from one age to the next.
Data for life tables hard to collect for wild
populations.
16.
17. Life table for ground squirrels shows death
rate for males is higher than that for
females.
Also, notice that mortality rate is quite
consistent from one year to the next.
18. Survivorship Curves
Data in a life table can be represented
graphically by a survival curve.
Curve usually based on a standardized
population of 1000 individuals and the X-
axis scale is logarithmic.
19.
20. Survivorship curves can be classified into three
general types
Type I, Type II, and Type III
Figure 52.5
I
II
III
50 100
0
1
10
100
1,000
Percentage of maximum life span
Number
of
survivors
(log
scale)
21. Type I curve
Type I curve typical of animals that produce
few young but care for them well (e.g.
humans, elephants). Death rate low until
late in life where rate increases sharply as a
result of old age (wear and tear,
accumulation of cellular damage, cancer).
22. Type II curve
Type II curve has fairly steady death rate
throughout life (e.g. rodents).
Death is usually a result of chance processes
over which the organism has little control
(e.g. predation)
23. Type III curve
Type III curve typical of species that produce
large numbers of young which receive little or no
care (e.g. Oyster).
Survival of young is dependent on luck. Larvae
released into sea have only a small chance of
settling on a suitable substrate. Once settled
however, prospects of survival are much better
and a long life is possible.
24. Reproductive Rates
A reproductive table, or fertility
schedule is an age-specific
summary of the reproductive rates
in a population.
Measured over life span of a
cohort. The fertility schedule
ignores males.
25. Reproductive Table
The table tallies the number of females
produced by each age group.
Product of proportion of females of a given
age that are breeding and the number of
female offspring of those breeding females.
27. Life History
Study of life histories focuses on
explaining why organisms differ in their
reproductive patterns.
28. Life History Traits
Life history traits are products of natural selection.
Life history traits are evolutionary outcomes reflected
in the development, physiology, and behavior of an
organism.
The current life history reflects the fact that organisms
in the past that adopted this strategy left behind on
average more surviving offspring than individuals who
adopted other strategies.
29. Life history diversity
Some species exhibit semelparity, or “big-
bang” reproduction. These species reproduce
once and die (bamboo, salmon, century plant).
Century Plant
30. Semelparous reproduction
Semelparous reproduction often an
adaptation to erratic climatic conditions.
Suitable breeding conditions occur rarely
and organisms devote all their resources to
reproduction when conditions are good (e.g.
century plant).
31. Iteroparous reproduction
Some species exhibit iteroparity, or repeated
reproduction and produce offspring repeatedly
over time.
E.g. humans, cats, birds.
32. Iteroparous reproduction
Iteroparous reproduction occurs when
organisms have good prospects of
reproducing in the future (i.e., they are
long-lived).
Characteristic of larger organisms and those
that experience more stable environmental
conditions.
33. “Trade-offs” and Life Histories
Organisms have finite resources, which lead to trade-
offs between survival and reproduction
For example kestrels whose broods were artificially
enlarged had reduced overwinter survivorship.
Conversely, birds whose broods were reduced had
higher overwinter survivorship.
34. Quantity vs. Quality of offspring
Organisms face tradeoffs between the number
and quality of young they can produce because
they have only a limited quantity of resources to
invest.
The choice is basically between a few large or
many small offspring.
35.
36. Population growth
Occurs when birth rate exceeds death rate
(duh!)
Organisms have enormous potential to
increase their populations if not constrained
by mortality.
Any organism could swamp the planet in a
short time if it reproduced without restraint.
37. Per Capita Rate of Increase
If immigration and emigration are ignored,
a population’s growth rate (per capita
increase) equals the per capita birth rate
minus the per capita death rate
38. Equation for population growth is
ΔN/Δt = bN-dN
Where N = population size, b is per capita
birth rate and d is per capita death rate.
ΔN/Δt is change in population N over a
small time period t.
39. The per capita rate of population increase is
symbolized by r.
r = b-d.
r indicates whether a population is growing
(r >0) or declining (r<0).
40. Ecologists express instantaneous population
growth using calculus.
Zero population growth occurs when the
birth rate equals the death rate r = 0.
The population growth equation can be
expressed as dN
dt
rN
43. The J-shaped curve of exponential growth
Is characteristic of some populations that are
rebounding
Figure 52.10
1900 1920 1940 1960 1980
Year
0
2,000
4,000
6,000
8,000
Elephant
population
44. Logistic Population Growth
Exponential growth cannot be sustained for
long in any population.
A more realistic population model limits
growth by incorporating carrying capacity.
Carrying capacity (K) is the maximum
population size the environment can support
45. The Logistic Growth Model
In the logistic population growth model the
per capita rate of increase declines as
carrying capacity is approached.
We construct the logistic model by starting
with the exponential model and adding an
expression that reduces the per capita rate of
increase as N increases
46. The logistic growth equation includes K, the
carrying capacity (number of organisms
environment can support)
dN
dt
(K N)
K
rmaxN
As population size (N) increases, the equation ((K-N)/K)
becomes smaller which slows the population’s growth
rate.
49. Logistic model predicts different per capita growth
rates for populations at low and high density. At
low density population growth rate driven
primarily by r the rate at which offspring can be
produced. At low density population grows
rapidly.
At high population density population growth is
much slower as density effects exert their effect.
50. Figure 52.13a
800
600
400
200
0
Time (days)
0 5 10 15
(a) A Paramecium population in the lab.
The growth of Paramecium aurelia in
small cultures (black dots) closely
approximates logistic growth (red curve)
if the experimenter maintains a constant
environment.
1,000
Number
of
Paramecium/ml
The Logistic Model and Real
Populations
The growth of laboratory populations of
paramecia fits an S-shaped curve
51. Some populations overshoot K before settling down
to a relatively stable density
Figure 52.13b
180
150
0
120
90
60
30
Time (days)
0 160
140
120
80 100
60
40
20
Number
of
Daphnia/50
ml
(b) A Daphnia population in the lab. The growth of a population of Daphnia in a
small laboratory culture (black dots) does not correspond well to the logistic
model (red curve). This population overshoots the carrying capacity of its artificial
environment and then settles down to an approximately stable population size.
52. Some populations fluctuate greatly around K.
Figure 52.13c
0
80
60
40
20
1975 1980 1985 1990 1995 2000
Time (years)
Number
of
females
(c) A song sparrow population in its natural habitat. The population of
female song sparrows nesting on Mandarte Island, British Columbia, is
periodically reduced by severe winter weather, and population growth is
not well described by the logistic model.
53. The Logistic Model and Life
Histories
Life history traits favored by natural selection may
vary with population density and environmental
conditions.
At low density, per capita food supply is relatively
high. Selection for reproducing quickly (e.g by
producing many small young) should be favored.
At high density selection will favor adaptations
that allow organisms to survive and reproduce
with few resources. Expect lower birth rates.
54. K-selection, or density-dependent selection
Selects for life history traits that are sensitive to
population density
r-selection, or density-independent selection
Selects for life history traits that maximize
reproduction
55. The concepts of K-selection and r-selection have
been criticized by ecologists as
oversimplifications.
Most organisms exhibit intermediate traits or can
adjust their behavior to different conditions.
57. Population Change and
Population Density
In density-independent populations birth rate and
death rate do not change with population
density.
For example, in dune fescue grass environmental
conditions kill a similar proportion of
individuals regardless of density.
58. In contrast in density-dependent populations
birth rates fall and death rates rise with
population density.
Density-dependent population regulation
much more common than density-
independent