General Ecology (1st ppt) Flashcards
Investigates the interactions among
organisms and between organisms and their environment.
Ecology
SEVEN PRINCIPLES OF ECOLOGY
- Nature knows best.
- All forms of life are equally important.
- Everything is connected to everything else.
- Everything changes.
- Everything must go somewhere.
- Ours is a finite Earth.
- Nature is beautiful and we are stewards of God’s creation.
“the comprehensive science of the relationship of the organism to the environment”
Ernst Haeckel 1866
Okologie comes from:
oikos - house
logia - study of
is the region around a
star where conditions allow life-bearing planets to exist.
Ecosphere
“scientific natural history”
Charles Elton 1927
“the study concerned with the distribution of
organisms”
Andrewarta, H.G. & Birch 1954
“the study of the structure & function of nature”
Eugene P. Odum 1963
“The scientific study of the interactions that determine the distribution and abundance of organisms”
Charles J. Krebs 1972
“an ecosystem is a sum total of living organisms, the environment and the process of interaction between the various components of the ecosystem.”
S. Mathavan
“The scientific study of the processes influencing the distribution and abundance of organisms, the interaction among organisms, and the interaction between organisms and flux of energy and matter.”
CARY INSTITUTE OF ECOSYSTEM STUDIES
“study of organisms and the
environment: the study of relationships between living organisms and their interactions with the natural or developed environment.”
ENCARTA 2009
defined as the number of entities and processes in the system under study.
complexity
DISCIPLINES OF ECOLOGY (8)
Zoology
Botany
Evolution
Genetics
Meteorology
Sociology
Geology
Microbiology
COMPONENTS OF ECOSYSTEM (5)
Issues (Depletion of fish fauna due to pollution)
Species (Channa sps, Angulla sps, riparian flora)
Activities (Dumping Industrial effluents, fishing, irrigation)
Habitat (Pools, Runs, Riffles, Cascades, Riparian zone, dams)
People (Fishermen, industies)
___ level studies focus on individuals.
Organism
___ level studies examine groups of conspecific
organisms living in a particular area.
Population
Includes all of the conditions
that affects survival and reproduction.
Environment
Factors in the environment (2)
Abiotic (nonliving)
Biotic (living)
___ level studies investigate interactions
between the populations of various species in an area.
Community
___ level studies examine how a community
interacts with the physical environment.
Ecosystem
Hierarchy of Ecology (4)
Organism Level
Population Level
Community Level
Ecosystem Level
Environmental factors that are directly utilized by an
animal are ___
Resources
Example of nonexpendable resource
Space
Example of expendable resource
Food
The space where an animal lives.
Habitat
The unique
multidimensional
relationship of a
species with its
environment is its
___.
Niche
___ can withstand a variety of environmental
conditions.
___ can only tolerate a narrow range.
Generalists
Specialists
___ describes the total
potential role that an organism could fill under ideal circumstances.
___ describes the actual role an organism fills.
Fundamental Niche
Realized Niche
___ is the study of populations in
relation to environment, including environmental
influences on population density and distribution, age
structure, and variations in population size.
Population ecology
Is a reproductively interactive group of
individuals of a single species.
Population
Caused when individuals migrate between populations.
Metapopulation
Perks of individuals migrating between populations (2)
Adds gene flow
Prevents speciation
Is an age-specific summary of the survival
pattern of a population.
Life table
A group of
individuals of the same age
cohort
Is a graphic way of
representing the
data in a life table
Survivorship Curve
Survivorship curve types (3)
Type I – high survival
early in life indicates
PARENTAL CARE OF FEWER OFFSPRING.
- Type II – CONSTANT DEATH RATE over life
span - Type III – drops sharply
at start indicating HIGH DEATH RATE FOR YOUNG;
lots of young, no care.
Populations that
contain multiple
cohorts exhibit ___.
Age structure
What indicates a growing population in the case of age structures?
More individuals in the younger cohorts.
Species that exhibit ___, or “___” reproduction reproduce a singletime and die.
semelparity
“big-bang”
Examples of organisms that exhibit semelparity.
Salmon
Agave
Species that exhibit ___, or repeated reproduction, produce offspring repeatedly over time
iteroparity
If immigration and emigration are ignored, a
population’s growth rate equals ___
birth rate - death
rate.
___ occurs when the birth rate
equals the death rate
Zero population growth
population growth equation
dN/dt = rN
Is population increase
under idealized conditions.
* Unlimited resources.
Exponential population growth
Under exponential population growth conditions, the rate of reproduction is at its maximum, called the ___.
intrinsic rate of increase (rmax).
exponential population growth equation
dN/dt = rmaxN
Exponential
population growth
results in a ___
curve.
It is characteristic of some
populations that are rebounding
J-shaped
In reality, there are one or more ___ that prevent exponential growth.
limiting resources
Is the maximum population size
the environment can support.
A more realistic population model limits growth by
incorporating it.
Carrying capacity (K)
In the___, the per capita rate of increase declines as carrying capacity is reached
logistic growth model
Logistic Growth Model Equation
dN/dt = rmaxN*(K-N)/K
The logistic
model of
population
growth
produces an ___.
The growth of
laboratory
populations of
Paramecia fits this curve.
S-shaped curve.
___, or density-dependent selection, selects for
life history traits that are sensitive to population density.
- Few, but larger offspring, parental care.
K-selection
___, or density-independent selection, selects for
life history traits that maximize reproduction.
* Many small offspring, no parental care.
r-selection
Extrinsic Limits to Growth
Abiotic limiting factors such as a storm or a fire are ___
density-independent
their effect does not change with population density.
Extrinsic Limits to Growth
* Biotic factors such as competition or predation or parasitism act in a ___ way
density-dependent
the effect does change with population density.
___ examines the interactions among the various populations in a community.
Community ecology
___ or ___ or association of populations of two or more different species occupying the same
geographical area and in a particular time.
Community, Bioeconosis assemblage
Interactions which are beneficial for one, negative for the other. (3)
Predation,
Parasitism,
Herbivory
Interaction which is beneficial for one, neutral for the other
Commensalism
Interaction which is beneficial for both
Mutualism
Is a symbiosis wherein an organism benefits from the association but generally harms its host
Parasitism
Is a type of interaction that has a
negative effect on both.
Community structure is often shaped by this.
Competition
___ occurs when only one of the
competitors incurs a cost.
Amensalism
___ occurs when two or more species share a limiting resource.
Competition
The interaction between two species in an ecosystem can often be
influenced by a third species.
Interspecific
Competition between the same species
Intraspecific
The principle of ___ suggests that organisms with exactly the same niche can’t co-occur.
competitive exclusion
___ occurs when the
species partition
the resource, using
different parts of it.
Appears as
differences in
morphology.
Character
displacement
Species that
exploit a resource
in a similar way
form a ___.
guild
These cycles are
influenced by
complex
interactions
between biotic
and abiotic
factors.
Many populations undergo regular cycles of this type.
boom-and-bust
Refers to an interaction where one species, the predator, kills and eats the other, the prey.
Predation
Feeding adaptations of predators (5)
Claws
Teeth
Fangs
Stingers
Poison
___ or camouflage, makes prey difficult to spot
Cryptic coloration
___ warns predators to stay away from prey.
Aposematic coloration
Types of coloration (2)
Cryptic
Aposematic
Types of mimicry (2)
Batesian
Müllerian
___ a palatable or harmless species mimics an unpalatable or harmful model.
Batesian mimicry
___, two or more unpalatable species resemble each other.
Müllerian mimicry
They exert strong control on a community by their
ecological roles, or niches.
Not necessarily abundant in their community.
Keystone species
Field studies of ___ exhibit their role as a keystone species in intertidal
communities.
sea stars
Observation of ___ populations and
their predation shows the effect
they have on ocean communities.
sea otter
Consists of all the organisms living in a
community as well as all the abiotic factors with which
they interact.
Ecosystem
Small ecosystem
Microcosm
Two processes an ecosystem’s dynamics are involved with:
Energy flow and Chemical cycling
*energy flows through ecosystems, while matter cycles within them
Primary Producers
Primary Consumers
Secondary Consumers
Autotrophs
Herbivores
Carnivores
____ in an ecosystem is the amount of
light energy converted to chemical energy by autotrophs during a given time period.
Primary production
Types of consumers (3)
Herbivores
Carnivores
Decomposers
____ mainly
bacteria and fungi, recycle essential chemical elements by decomposing organic material and returning elements to inorganic reservoirs.
Detritivores
Energy flows through an ecosystem
entering as ___ and existing as ___.
Light
Heat
Total primary production in an ecosystem is known as
that ecosystem’s ____
gross primary production (GPP)
is equal to GPP(Gross Primary Production) minus the
energy used by the primary producers for respiration.
*only available to consumers
Net primary production (NPP)
____ of an ecosystem is the
amount of chemical energy in consumers’ food that is converted to their own new biomass during a given
period of time.
secondary production
____ is the percentage of production transferred from one trophic level to the next.
* Usually ranges from 5% to 20%.
Trophic efficiency
This loss of energy with each transfer in a food chain can be represented by a
___.
pyramid of net production
represents the number of individual organisms in each trophic level.
pyramid of numbers
Most ___ show a sharp
decrease at successively higher trophic
levels.
* Occasionally inverted
biomass pyramids
highest amount of biomass in aquatic ecosystems
Plankton
(zooplankton and bottom fauna more biomass than phytoplankton however.)
Nutrient circuits that cycle matter through an ecosystem involve both biotic and abiotic components and are often called ___.
Biogeochemical cycles.
One of the reasons such toxins are so harmful, is that they become ____ in successive trophic levels of a food web.
more concentrated
In ___,toxins concentrate at ____ trophic levels because at these levels biomass tends to be lower.
biological magnification
higher
Levels of Biodiversity (3)
Genetic Diversity
Species Diversity
Ecosystem Diversity
comprises:
* The genetic variation within a
population.
* The genetic variation
between populations.
Genetic Diversity
Is the variety
of species in an ecosystem or
throughout the biosphere
of diff species
Species diversity
Identifies the variety of ecosystems in
the biosphere.
Ecosystem diversity
___ endangered species is one that is in danger of becoming extinct throughout its range.
endangered species
are those that are considered likely
to become endangered in the foreseeable future
Threatened species
IUCN Red List
EX EW CR EN VU NT LC
EX Extinct
EW Extinct in the Wild
CR CRitically endangered (<250)
EN ENdangered (<2,500)
VU VUlnerable (<10,000)
NT Near Threatened
LC Least Concern
____ encompass all the processes through which natural ecosystems and the species they contain help sustain human life on Earth.
Ecosystem services
Ecosystem services (4)
Purification of air and water.
Detoxification and decomposition of wastes.
Cycling of nutrients.
Moderation of weather extremes.
*and many others.
Four Major threats to Biodiversity
Habitat destruction
Introduced species
Overexploitation
Disruption of “interaction networks”
___ increases local extinction and speciation.
Habitat fragmentation
Five mass extinctions
Cretaceous
Triassic
Permian
Devonian
Ordovician
“It is not the strongest of the species that survives; nor the most intelligent that survives. It is the one that is more adaptable to change.”
Charles Darwin
