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Ecology Unit : PPT Notes Mr. DistasioName ____________________________________________ per ______
The BiosphereEcosystems and Communities
Populations
The Biosphere
The part of the Earth that supports life It includes the __________________,
__________________ and _____________________
What is Ecology?Definition: ___________________________________________
___________________________________________
___________________________________________
_________________________________________________________________________________
Levels of Organization
______________________: one living thing
______________________: a group of one species
______________________: different species
______________________: communities + environment
______________________: large grouped similar ecosystems
______________________: all the parts of earth that support life
__________________________________________________________________________________
Key Theme in Ecology Interconnectedness:
• No organism is isolated; all living things depend or rely on others (____________________)• Organisms also depend on the physical environment• Sometimes called “Web of Life”• ______________________: “The Father of Ecology”, stressed this interconnectedness
Environmental Factors____________________ Factors: Living components
____________________ Factors: Non-living components (physical environment)
Although they are nonliving, they influence and support the biotic parts of the ecosystem.
_______________________________________________________________________________
Ecological Methods
What methods are used in ecological studies?
Regardless of their tools, modern ecologists use three methods in their work:
________________________
________________________
________________________
_______________________________________________________________________________
Energy, Producers & ConsumersProducers
______________________ members of the ecosystems Include all ____________, certain protists (__________) and certain bacteria
(__________________ & ________________________)
Consumers
_____________________ members of an ecosystem Include animals, fungi, most protists, & most bacteria Receive energy by ______________ other organisms
_____________________________________________________________________________________
Types of Consumers
________________: eat only producers
________________: eat only other consumers. Meat-eaters
________________: eat both producers and consumers
________________: eat the “garbage” of the ecosystem (dead organisms, fallen leaves, etc..)
________________: cause decay by breaking down complex molecules in dead tissue into simpler molecules (bacteria & fungi)
_____________________________________________________________________________________
Energy Flow in Ecosystems
All organisms require energy to carry out life processes. In an ecosystem, energy is transferred from the ________to __________________ to _________________________
Trophic Levels
An organisms position in the _________consumer sequence of energy transfers _________consumer
A “______________ level” an organism occupies in a food chain. _________consumer
_________consumer
Energy Pyramid
Only _________ of the energy is available to the next organism
________ of the available energy in an organism is used in ________________, lost as __________, or simple not eaten or used by the consumer
The amount of ________________available also decreases as one progresses up the food chain. A BIOMASS ________________ is formed.
Food Chains & Food Webs______________: single direct line of feeding relationships
Why are typical Food Chains so short?
Most food chains have very few steps due to the loss of __________________ at each step.
Most food chains do not exceed 4 or 5 steps
______________: A more realistic view of the interconnectedness of an ecosystem
Cycles of Matter Unlike the one-way flow of________________,
matter is ________________ within and between ecosystems
The Earth is a ______________ system. Elements pass from one organism to another and among parts of the biosphere through closed loops called biogeochemical _____________.
Recycling in the Biosphere
Matter is recycled in a number of ways:
_________________ processesEx. Photosynthesis, Respiration, excretion, consumption
________________ ProcessesEx. Volcanic eruptions, weathering
__________________________________ ProcessesEx. Weather, water flow, lightening
____________________ ActivitiesEx. Mining, combustion of fossil fuels, deforestation, chemical manufacturing
Biogeochemical cycles
Water Cycle – moves water around the earth and through organisms Carbon Cycle - moves carbon around the earth and through organisms Nitrogen Cycle - moves nitrogen around the earth and through organisms
The Water Cycle Scientifically known as The Hydrologic Cycle
_______________________: __________________________________________ _______________________: __________________________________________ _______________________: __________________________________________ _______________________: __________________________________________ _______________________: __________________________________________ _______________________: __________________________________________
_____________________________________________________________________________________
The Carbon Cycle __________________and __________________________ form the basis of this Cycle
Photosynthesis : _________________ take carbon dioxide out of the air to make carbohydrates
Respiration : ______________________break down carbohydrates and release carbon dioxide back into the air
Human Impacts to the Carbon Cycle Over the last 150 years, the concentration of CO2 has increased nearly 30%
Causes: Burning of __________________(Coal, oil, gas)
P
D
CR
Rainforest Destruction: Lack of producers takes less CO2 out of the air, while
burning the forests puts up more CO2 into the air
_______________________________________________________________________________
The Nitrogen Cycle Nitrogen gas is readily abundant in the atmosphere (_____% of total gases) However, most organisms cannot use nitrogen in its natural form (N
2)
Most plants use nitrogen in the form of _________________(NO3
)
Nitrogen Fixation
Accomplished by: 1) nitrogen fixing ______________________in soils and on roots of certain plants (Legumes – clover, peanuts, soybean, beans )
2) ______________________________
3) ______________________________
Recycling Nitrogen Ammonification : decomposers break down dead organisms and their wastes (urine, dung)
A release of ammonia occurs as a result
Nitrification : bacteria take the ammonia and convert it to nitrites and nitrates
Plants can now absorb the nitrates from the soil to be used
Animals receive their nitrogen by _______________ plants and other organisms
Denitrification: anaerobic bacteria break down nitrates and release nitrogen back into the _____________________________
Ecosystems & CommunitiesNiches and Community Interactions
Succession
N2
NH3 NO2
NO3
Niches and Community InteractionsEcology: Levels of Organization
__________________: one living thing
__________________: a group of one species
__________________: different species – groups of populations
__________________: biotic communities + abiotic environment
__________________: large grouped similar ecosystems
__________________: all the parts of earth that support life (13 miles)
Some terms….. ___________________ : the living factors in an ecosystem
___________________ : the non-living factors in an ecosystem Eg. pH, temperature, sunlight, climate, etc.
___________________ : any necessity of life Eg. Water, nutrients, food, light etc…
___________________ : the place where an organism lives
___________________ : the ability to survive under a range of environmental circumstances
___________________ : the role an organism plays in its environment
The changing environment ….. Within any ecosystem, the abiotic factors change constantly !!!
E.g.________________________________: Changes monthly, weekly, daily, hourly Changes within a habitat (sun vs. shade)
The organisms exposed to these changing environmental conditions exhibit a _______________________________________ for each abiotic factor.
Response to a changing environment…
Range of Tolerance Curve:A graph depicting overall performance vs. environmental variables (usually bell shape)
A _______________ can be described as the range of physical & biological conditions in which a species lives and the way the species obtains what it needs to survive and reproduce.
The ____________________________states that no two species can occupy the same niche at the same time. If niches overlap, ___________________for the resource will occur.
Instead of direct competition between species whose niches overlap, species often resort to dividing resources … “______________________________”
Symbiosis Means “___________________________”
All organisms live with and depend on each other in order to survive
1. Predation Probably the most powerful symbiotic relationship affecting species
___________________ –, kills, and consumes another individual
___________________ – organisms that is killed
Predators, Prey, & Natural SelectionPredator Species: must be adapted to _________________ and _______ prey
Ex: Sharp senses, teeth structure, camouflage, quickness, etc…
Prey Species: Must be adapted to _____________ predationEx: Sharp senses, quickness, camouflage
Mimicry: One way in which some organisms prevent predation on themselves One organism _________________________ another organism that is typically
dangerous, poisonous, or distasteful.
Example 1: King Snake & Coral Snake The king snake mimics the poisonous coral snake
Example 2: Viceroy & Monarch Butterfly Distasteful Monarchs develop before the Viceroys.
2. Parasitism Resembles predation, however in many cases, the harmed individual is______________. __________________: Invades, and deprives another organism of a vital body resource
____________: Individual that is weakened by the parasite
Types of Parasites Ectoparasites: ____________________
(ticks, fleas, lice, leech, mosquitoes)
Endoparasites: ___________________ (bacteria, tapeworm, protists)
3. Mutualism A relationship in which ____________ species derive some _______________
Some even require one another to survive
Examples of Mutualism Ants & Acacia:
Ants nest inside the thorns of acacia shrub while receiving food. The ants protect the shrub from herbivore predation and also trim back
the vegetation allowing more sunlight Pollination
Insects (pollinators) & Flowers Insects receive food, Flowers accomplish sexual reproduction
Clownfish & Anemones Clownfish receive food by cleaning debris from the anemone and is
also protected from predators
Clownfish are immune to the stings of anemones
4. Commensalism Relationship in which one species ______________, while the other is
______________________
Examples of Commensalism Egrets and Buffalo
Egrets hitch a ride on the buffalo’s back. The egrets have an easy time finding food as the buffalo kicks up small food (insects)
Shark and remora
Ecological Succession
The gradual, sequential growth or re-growth of species (plants) in a particular area A ________________ and _________________ series of changes in which one type of
ecosystem is __________________ with another until a _____________ community is reached
Whenever a new habitat is created, or an existing habitat is damaged by_________________, the open site is available for invasion
Types of Succession There are two primary types of succession
_______________________
_______________________
Primary Succession:
The development of species in an area that ________________supported life previouslyExamples: bare rock, sand dune, island formed by volcano
A closer look at Primary Succession: Is extremely __________! May take thousands of years Most of these places lack the proper ____________ nutrients to grow plants However, over time, weather erodes rock, decomposition takes place, and soil is formed
Pioneer Species/Ecosystems Definition: hardy species, including ________________ and ______________________, that is one of the first to establish itself at the start of the process of succession
Tend to be _________ and consist of relatively _____ species. Tend to grow ________, reproduce _________, and spread quickly Tend to require few ______________
Eventually, pioneer species are out-competed and __________________ by communities that develop in the later stages of succession.
Secondary Succession:
The development of species in an area that has been greatly disrupted ____________________ is already present Examples: forest fire, hurricane, forest clear-cutting, agriculture
(Many times - human induced)
A closer look at Secondary Succession: Occurs quicker, due to a pre-existing nutrient rich __________ base. Takes about 100 years to re-establish the community Follows the same logical patterns of primary succession; only _______________.
At each step ….. changes in wildlife ___________ occur
.. _______________ changes occur beneath the canopy... plant & animal activities continue to add/change _________ nutrients.
End Point: Climax Community Throughout succession, each organism creates an environment that is more favorable for
the next organisms to invade In theory, a climax community occurs when no more major changes will occur. A climax community is a stable non-changing ecosystem In reality, ecosystems are constantly changing ! Ecosystems constantly “reset”
themselves
The type of climax vegetation that results is dependent upon ... ________________________
________________________
________________________
________________________
________________________
Effects of Human Activities on Succession _________________________ _________________________ _________________________ _________________________
Aquatic Succession Ponds and lakes gradually fill up with ____________from soil erosion
As this occurs, the water body gets ____________ & warmer
More plants are able to grow in the water (able to receive sunlight) Starts at the shoreline and gradually moves out to the deeper parts, until all is filled
in
Population EcologyPopulation Dynamics
_______________________: All the individuals of a species that live together in an area
_______________________:The statistical study of populations, allows predictions to be made about how a population will changePopulation
Group of organisms belonging to the ___________ _________________ and live in _________ _____________________ to one another at the _________ ____________.
Example: ___________________________________________________________________
Three Key Features of Populations1. ___________________________
2. ___________________________
3. ___________________________
1) Size: ____________________________________________________________
Difficult to measure Small, immobile populations are easy to determine, but large, widespread
populations are difficult – usually estimated
Growth Rate: ___________ Rate (natality) - ________________ Rate (mortality) How many individuals are born vs. how many die Birth rate (b) − death rate (d) = rate of natural increase (r)
2. Density: measurement of population per _________________________________
Pop. Density = # of individuals ÷ unit of space
Population Density Indicates the number of individuals per unit of area, or how “crowded” a population
is. Has greater impact than just plain population numbers.
Factors that affect the density of a population…
_____________________: movement of individuals into a population
_____________________: movement of individuals out of a population
_________________________ Biotic factors in the environment that have an increasing effect as population size increases
(disease, competition, parasites)
: Abiotic factors in the environment that affect populations regardless of their density (temperature, weather)
3. Dispersion: _____________________________________________________ __________________________ __________________________ __________________________
Clumped Dispersion: Individuals _________________ together Occurs when _______________________such as food/habitat are clumped (ant hill,
bee hive) Also, occurs with __________________ groups (herds, packs, flocks, schools)
Even(Uniform)Dispersion: Individuals are separated by a fairly ___________________distance
Occurs in those that stake out _______________ –or- places where resources
are limited (Desert cactus, nesting sites)
Random Dispersion: Organisms may be found with no ______________ between them
Occurs when seeds are dispersed by wind, water, animals, (dandelion)
How Are Populations Measured? Population density = _____________________of individuals in a given ________ or volume
Count all the individuals in a population Estimate by ___________________ Mark-Recapture Method
Sampling A small area is counted and then multiplied over the entire region. If 25 oak trees are found in a 5 acre plot, then one could estimate that 125 oak trees would be found in a 25 acre forest
How Do Populations Grow?Idealized models describe three kinds of population growth:
1. _________________ Growth
2. _________________ Growth
3. _________________ Growth
Population Growth Rates ______________________: study of population dynamics
______________________: The amount of a population’s size changes in a given time
Determined by 4 main factors: B ________________: increase
D ________________: decrease
I _________________: increase
E ________________: decrease
Exponential Growth Population grows at a________________ rate or percentage
The larger the population gets, the ___________ it grows. (it will double at a fixed rate)
Only under rare conditions, can most populations grow exponentially Can not grow indefinitely due to limited __________________
All populations are limited by their environment or by what we call _________________________________
Exponential Growth: J-Shaped Curve
In most cases, a population crash (high death rate) follows exponential growth
The Logistic Growth Model Population grows exponentially at first, then accounts for____________________, which causes it
to level off.
Birth rate = Death Rate once population stabilizes
Logistic Growth Curve = “___” shaped
Carrying Capacity
Carrying Capacity (k): __________________________________________________________________
__________________________________________________________________
There can only be as many organisms as the environmental _______________can support
Brings into account the carrying capacity (K) of the population
Carrying capacity (K) = _____________________________________________
Demographers assume K remains constant, but in reality is constantly changing.
Factors Limiting Growth Rate
Declining birth rate or increasing death rate are caused by several factors including: _________________________________________
_________________________________________
_________________________________________
_________________________________________
Population Regulation Two kinds of limiting factors:
1. Density _________________________Factors – no relationship to population sizeEx: Weather, floods, fire, earthquakes, pollution
1. Density _________________________ Factors – Directly related to population size Ex: Limited food, shelter, water (the higher the density, the less resources are available)
“Booms” and “Busts”
Comparing reproductive strategies ….
r-selective vs K-selective R Strategists
____________ life span
____________ body size
Reproduce _________________
Have _____________ young
_____________ parental care
Ex: cockroaches, weeds, bacteria
Pattern of Mortality Depicts the likelihood of survival/dying at different ages throughout the lifetime of an organism.
Type I: Chances of dying is small until later in life (humans, elephants, large mammals
Type II: Probability of dying does not change throughout the lifespan (Birds, squirrels, small reptiles)
Type III: Many organisms are likely to die while young. However, if they survive
K Strategists __________ life span
__________ body size
Reproduce _______________
Have ____________ young
Provides parental care
Ex: humans, elephants
this early period, then chances are good to survive until much older. (Insects, fish, sea turtles, trees )
Age Distribution Distribution of ______________ and _____________ in each age group of a population
Used to predict future population growth
Depicted in a graph called a _____________________
Age Structure/Histograms Depicts age structure & sexes of populations Helps with predicting growth
Large % of young: rapid growth (reproductive years) Large % of old: population decline (not reproducing)
Human Population Growth ___ curve growth
Grows at a rate of about 80 million yearly r =1.3%
Why doesn’t environmental resistance take effect?
Altering their ____________________________
______________________ advances The ________________ revolution The ________________ revolution The _____________________________ revolution
The Human Population
Doubled three times in the last three centuries
About 7 billion and may reach 9.3 billion by the year 2050
Improved health and technology have lowered death rates
History of the Human Population