Download ECOLOGY The study of our ecosystems

ECOLOGY
The Study of Our Ecosystems
**Last Unit of Biology**
ECOSYSTEMS
Ecosystems are important units of the natural world.
Humans are part of ecosystems and depend on them for
food and many products. Without healthy ecosystems,
humans would be in trouble!
Important Terms to Know:
• Ecology : the study of the interactions between
organisms and their environment (biotic and abiotic).
• Biotic: Living
Biotic Factors: living, once living, and waste of an
organism
• Abiotic: Nonliving
Abiotic Factors: oxygen, water, rocks, sand, sunlight,
temperature, climate
Important Terms to Know:
• Habitat : a place where organisms live
• Niche: the “role” of an organism in its environment, It
includes the place where the organism lives as well as all
the interactions it has with its biotic and abiotic
environment.
Seal Habitat
Important Terms to Know:
• Species: a group of similar organisms that can reproduce
and give rise to fertile offspring.
• Population : a group of organisms of the same species
that live together in the same area. Since they are members of
the same species, they interbreed
• Community : a group of various species (populations)
that live in the same area and interact with each other
• Ecosystem : all organisms that live in a particular place
together with the biotic and abiotic environment. (A community
of organisms and their abiotic environment)
Bee Population
Community
In this ecosystem, what
are the abiotic factors
and the biotic factors?
Biotic
•fish
• turtle
• bacteria
• plants
•dragonfly
• waste
material
Abiotic
•water
• sunlight
• rocks
• soil
•Oxygen
•Carbon
dioxide
Ecosystem
BIODIVERSITY:
• Variety of organisms in a
given area
 Physical factors affect
biodiversity
o Extreme temperatures
decrease biodiversity
o Limited water and food
decrease biodiversity
 High biodiversity = more able to resist damage
 Low biodiversity = unhealthy
ecosystem
Stop and Jot!
Draw a population of rabbits in their appropriate ecosystem.
SUCCESSION:
When we observe an ecosystem, it may look like an
unchanging feature of the landscape, however all
ecosystems change. As the ecosystem changes, the
types of species it supports also change. The
replacement of one kind of community by another at a
single place over a period of time is called succession
Forest
Lake
CHARACTERISTICS OF
SUCCESSION:
 Stages of succession are described by a dominant plant
and animal species
 Each stage of the succession Influences the environment
which leads to the next “stage”
Pioneer species -first species to colonize a new habitat

 Climax community -“final” stage of the succession
Examples of Succession-Change in an
Ecosystem: Volcanoes/Fires


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Volcanoes/fires devastate land – leave it changed
New organisms appear
First organisms to appear – pioneer species
Small , fast growing plants
Other plants replace pioneer species: grasses, shrubs,
trees
 Eventually forest – Equilibrium after Succession
Succession
Examples of Succession: Bare Rock
 Lichens and mosses -break down the rock to begin to
produce soil
 Pioneer grasses and ferns build up the soil
 Herbaceous plants
 Shrubs & bushes
 Trees
Examples of Succession:
Pond & Sand Dune
Sand Dune
Pond
Examples of Succession:
Abandoned Farm
Abandoned Farm
• First Year-annual weeds
• Second year-ragweed/golden
rod
• Third year-grasses
• Fourth year-pine trees
• Fifth year-oak trees
Examples of Succession: Pine Barrens
Fire
Fire (recall Pine Barrens Fire-1995)
Area was restored by 2007
Stop and Jot!
Draw succession in environment after a forest fire.
Major Biological Communities
As you drive along the United States, you will notice a
change in the plants and animals based on climate
• Climate – average weather condition in an area over a
long period of time
• Biome – large region characterized by a specific kind of
climate and certain kinds of plant and
animal communities
•Biomes – determined by temperature and precipitation
Organisms can only live within a certain temperature range
Major Biological Communities
Two types of biomes: terrestrial and aquatic
Terrestrial
Biomes
Aquatic
Biomes
Terrestrial Biomes
 Grouped by latitude into tropical , temperate and
high-altitude
Tropical Biomes-warm temperatures
 Located near equator – low latitudes, warm, receive
different amount of rain
 Tropical rain forests – large amounts of rain, warm all
year, greatest biodiversity
 Savannas – tropical grasslands, long dry season, short
wet season: zebras, giraffes, lions, elephants
 Tropical deserts – very little rain, less water, fewer
plants, less animals
Rain Forestabundant rain fall
Savanna-short
wet season
Desert-little
rain fall
Temperate Biomes-moderate temperatures
 Mid-latitude between 30-60 degrees, wide range of
temperature
 Temperate grasslands – moderate precipitation, cooler
temperatures than savannas: bison
 Temperate forests – mild climate, plenty of rain,
deciduous and evergreen trees: deer, bears, raccoons
 Temperate deserts – little precipitation, wide range of
temperatures: coyote, armadillo
Forest-plenty of
rain
Grasslands-moderate
precipitation
Desert-little
precipitation
High Latitude Biomes-cold
temperatures
 Cold temperatures
 60 degrees and higher in latitude
 Taiga – coniferous forests, cold, wet climate – winters
long, most precipitation falls in summer: moose, wolves,
bears
 Tundra – very little rain, short plants, water frozen most
of year: foxes, lemmings, owls, caribous
Taiga-wet climate
Tundra-permafrost
Aquatic BIOMES
• Largest biome 70% of earth is covered by water.
It is also the most stable biome because water
temperature does not change easily
 Organized into freshwater ecosystems, wetlands
estuaries and marine ecosystems
,
Aquatic Biomes-
Freshwater, Wetlands
 Freshwater– lakes, ponds, rivers
Freshwater

Wetlands – provide a link between the land and fully
aquatic habitats
Wetland
Aquatic Biomes-
Estuary and Marine
 Estuary – freshwater from a river mixes with salt
water from an ocean
Example: Peconic Bay
Estuary
• Marine
– salty waters of the oceans
Marine
Stop and Jot!
1. How do you figure out which biome you are in?
2. Choose 1 biome and draw it.
ENEGY FLOW IN ECOSYSTEMS
• Everything that organisms do requires energy . Every
species must somehow get food for energy. When an
organism dies, it is eaten by scavengers and decomposed
by bacteria. At each step of this process, energy flows
through the ecosystem.
TROPHIC LEVELS
 Each step in energy transfer through an ecosystem
– trophic level
TROPHIC LEVELS
 Primary source of energy - sun
 Producers-(Plants) turn energy from the sun into energy
they use
 Consumers - organisms eating other organisms
o Herbivore -animals that feed on plants and plant
materials
o Carnivore -animals that feed on other animals
 Predators- kill and consume prey (tigers)
 Scavengers -feed on dead animals they
find(buzzards)
o Omnivore -animals that feed on both plants and
animals (humans)
 Decomposers (saprophytes) - break down remains of
organisms ( bacteria, fungus)
TROPHIC LEVELS
Fourth Trophic LevelTertiary consumer-carnivore
Third Trophic LevelSecondary consumer-carnivore
Second Trophic LevelPrimary Consumer (Herbivore)
First Trophic Level-Producer
Food Chains
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Energy flow from one trophic levelto the next
First trophic level - producers
Second trophic level - herbivores - eat producers
Third trophic level - consumers - eat herbivores
Carnivore - meat eating animal
Omnivore - meat and vegetative eating animal
Food Webs
Energy never flows in a simple chain
Most organisms eat more than one type of food.
Complicated, interconnected group of food chains
LOSS OF ENERGY
• Energy stored in producers
and consumers when eaten
is lost as heat into the
environment
• Not recycled
• The Ten Percent Rule –
only about 10% of energy
from producers are stored
when eaten
Energy Pyramid
 Shows the loss of energy at
each trophic level
 Producers at the base of the
pyramid
– contains MOST energy
 Big predators at the top of the
pyramid
– contains LEAST energy
Biomass Pyramid
• Also considered BIOMASS PYRAMID
Stop and Jot!
Draw a food web.
Draw the energy pyramid which goes along with your food web.
CYCLING OF MATTER
Water, carbon, oxygen, nitrogen, and phosphorus are five
of the most important substances for life. An ecosystem
must be able to cycle these kinds of matter in order to
support life.
Each cycle involves a
reserve of the
nutrient, a
mechanisms for it to
be obtained by
plants and animals,
and a way to return
the nutrient to the
reserve.
Water Cycle
 Moves water between the atmosphere, land and oceans
• Water vapor condenses , falls to earth's surface –
precipitation
Some water percolates into soil - ground water
Runs across surface into rivers, lakes, oceans
Heated by sun - evaporates into atmosphere
Evaporation by plants - transpiration
Carbon and Oxygen Cycle
• Cycles tied closely together
 Carbon cycle - moves carbon
from nonliving environment
into living things and back
 Animals and plants cycle
both carbon and oxygen
throughout environment
Plants use CO2 during
photosynthesis - builds
organic molecules
Carbon and Oxygen Cycle-continued
O2 is released from
photosynthesis - animals use
this to break down organic
molecules ( respiration ) to
release energy and CO2 used by plants
Carbon released into
atmosphere as CO by 2
combustion burning of
substances ie: trees, fossil fuels
(oil/coal)
Nitrogen Cycle
• Need nitrogen to make proteins
 Nitrogen circulates among air,
soil, water and organisms
 78% air is nitrogen - can not
be used as a gas, must be
changed to a different form
 Bacteria in soil and roots
break down gaseous nitrogen
into a usable form –
Nitrogen Fixation
 Plants absorb fixed nitrogen
 Animals eat plants which
contain nitrogen
Phosphorus Cycle
phosphate to make DNA
• Movement of phosphorus in
different chemical forms from
surroundings to organisms
and back to surroundings
• Found in soil , rock dissolves in water to form
phosphate
• Roots of plants
phosphate absorb
• Organisms eat plants, reuse phosphate
• When organisms die, phosphate returned to soil
• Need
POPULATIONS
In the 1850’s about 2 dozen rabbits from
Europe were introduced into Australia. The
rabbits had plenty to eat, no competition and
no predators. By 1950, there were 600
million rabbits! They ate so much vegetation
that the numbers of native plants and animals
declined and crops were damaged.
What is a Population?
Do you remember the definition? Write it down again
A group of organisms of the same species that live
together in one place at one time and interbreed
• Populations may be small or large
• As organisms are born, others die therefore the
size may stay relatively constant
• If a population grows too fast, environmental
problems may occur
Population Growth
 Scientists use population models to show growth in
real populations
 Growth, shrinkage depends on births, deaths,
immigration and emigration
 Immigration– movement of individuals into population
 Emigration – movement of individuals out of
population
 A plot of population growth against time on a graph
creates a population growth curve
 Growth curves can be Exponential growth or logistic
growth
Exponential Growth
• More births than deaths
• Numbers increase by a certain factor in each successive time
period
• J shaped curve
• Small population size – slow growth
• Large population size – very fast growth
Logistic Growth

Population growth limited by food, predators, disease
 Only a certain number of organisms can be supported by
ecosystem
 Carrying capacity – largest population that environment
can support at any given time (due to resources available)
Carrying Capacity
Logistic Growth-continued
 Logistic growth – population growth starts with a
minimum number of organisms and reaches a maximum
depending on carrying capacity of habitat
 S shaped curve
Carrying Capacity
FACTORS AFFECTING
POPULATION SIZE
• Abiotic– weather, climate, technology
• Biotic – food, predators, humans
Human Population
 World population > 7 billion
 Better sanitation, hygiene, disease control,
agricultural and science technology
 Throughout history – population >10 million
 2000 years ago – 300 million
 During industrial revolution – population began to
grow exponentially
 Estimated 9 billion
by 2050
INTERACTIONS IN
COMMUNITIES
Interactions in communities can take many forms.
Predators and prey are locked in a struggle for
survival. Competition for food, parasites and
hosts try to get ahead of one another. Some
organisms depend on one another for survival.
Co-evolution -when two species are so closely
dependent upon each other that they need to
evolve together
PREDATOR-PREY
INTERACTIONS (+,-)
 Predation – one organism kills another for food
 Predator-prey relationships develop adaptations
in response to one another (Co-evolution)
Parasitism(+,-)
 Parasite – organism that feeds and lives on its Host
 Host almost always larger than parasite
 Parasite-host relationships develop adaptations in
response to one another (Co-evolution)
ie: tapeworms live in digestive system
Herbivory(+,-)
 Animals eat plants
 Plants try to defend themselves by thorns, spines,
chemicals/poisons
Other Interactions

Symbiosis – relationship which 2 species live in close
association with each other
 Mutualism and commensalism
Mutualism (+,+)
 Relationship where both species
benefit
 The organisms develop
adaptations in response to one
another (Co-evolution)
 Ie: Shrimp and fish on coral reefs
clean the bodies of large fish and
turtles
Commensalism (+,0)
• Relationship where 1 species benefit , the other is
neither harmed nor helped
• Ie: Remora and shark
Stop and Jot!
Draw and describe an interaction between two organisms.
SHAPING COMMUNITIES
No organism can live everywhere.
Each organism has its own set of
conditions where it can live and
where it does best. Some plants can
survive in deserts and not in places
with a lot of water. Other plants will
out compete the desert plants and
they will die.
Carving a Niche
• Recall the difference between a habitat and a niche:
Habitat
Place where
an organisms
lives
Niche
Role of an organism in
its environment, where
it lives, what it eats,
how it influences its
environment
Niche
 Niche – unique position occupied by a species, both in
terms of its physical use of its habitat and its function
in an ecological community
 Includes the role an organism plays in the community
 Ie: beavers cutting down trees with their sharp teeth to
build a dam
Competition For Resources
 Species occupying the same niche will compete
for food, shelter and resources
 One species will dominate over another species
 The species which loses either dies out, or migrates
 Some species -divide resources no competition ie:
warbler birds feeding on the same insects in different
portions of the same tree
Different Warbler Birds
occupying different
parts of the same tree,
therefore different
niche!
Competition For Resources continued
 Predation – reduces effects of competition
 More – biodiversitymore resiliency if catastrophe strikes
 All species of an ecosystem may depend on one species
– keystone species
Example: Sea Otter in North
Pacific
Number of sea otters
decreased
Sea otters feed on sea
urchins
As sea otter number ↓, sea
urchin numbers ↑.
Sea urchins feed on kelp. ↑
in sea urchins destroyed
THE ENVIRONMENT
We depend on the environment
for food, water, air, shelter, fuel,
and many other resources.
Human actions can affect the
quality and availability of these
resources. The study of the
impact of humans on the
environment is called
environmental science.
HUMANS AND THE
ENVIRONMENT
• 7 billion people, population to exceed 10 billion before it
stabilizes
• Humans live in almost every kind of ecosystemon Earth
• As population increases, impact on environment
increases
• As population increases, impact on environment
increases
AIR POLLUTION
 Caused by natural processes - volcanoes
 Caused by burning of fossil fuels release CO2, SO2
(sulfur dioxide) and NO2, NO3 (nitrogen oxides) into air
 Causes respiratory problems; results in;
acid rain damages the ozone layer; affects
temperature global
Acid Rain

Acid rain – precipitation
has a high concentration
of sulfuric or nitric acid
(caused by pollution );
damages forests and
lakes
Ozone Layer
 Ozone (O3) layer –
protects life from UV
rays; damaged by
chlorofluorocarbons
(CFC’s) in spray cans
and refrigerator
coolant
GLOBAL WARMING/CLIMATE
CHANGE
 Greenhouse effect – warming of the surface and lower
atmosphere of Earth when CO2 and water vapor absorb
and reradiate heat
 Greenhouse effect – necessary to keep Earth’s
temperatures stable
 Global temperatures rising steadily
 Cause believed to be increase in CO2 (air pollution)
 May have serious environmental problems – polar ice
caps, melting loss of polar species habitat , rise in
sea levels, destruction of coastal ecosystems and
homes, more common hurricanes, typhoons, droughts
Climate Change Video (7 min)
WATER POLLUTION
 Due to fertilizers , pesticides ,
livestock farms, industrial
waste, oil runoff, septic tanks,
unlined landfills
 Polluted surface water
percolates through soil to
groundwater
 Pollutants run off land into rivers – both aquatic
habitats and public water are contaminated ie: DDT
(pesticide) harmed bald eagle, endangered
 Alga blooms because of fertilizer runoff – deplete
dissolved O2 in water, organisms die
SOIL DAMAGE
Soil Erosion
World needs fertile soil for food – agriculture
• Soil erosion – materials of Earth’s surface are worn
away and transported from one place to another by
wind, gravity or water
• Destroys fertile soil
• Roots help hold soil together protecting from erosion
• Removal of vegetation; soil erodes
• Farming may lead to soil erosion – plowing
Soil Conservation
 Sustainable agricultural practices
help conserve fertile soil
 Terracing – change steep field into
flat steps (stops gravity erosion)
 Cover crop – restores nutrients
in soil
 Crop rotation – plant different crop
every year, slows depletion of
nutrients
 Contour plowing – rows plowed
in curves along hills instead of
straight lines – act as dams to
prevent water erosion
Terracing
Cover Crop
Contour Plowing
ECOSYSTEM DISRUPTION
 Population size increasing – effecting every
ecosystem, diversity of life suffering
 Results in loss of biodiversity , food supplies,
potential cures for diseases, balance of
ecosystems that supports all life on Earth
Habitat Destruction
 Deforestation – over last 50 years, half of world’s
tropical rain forests cut down or burned for timber,
pastureland, farmland
 Rain forest disappears – loss of biodiversity, possible
extinction
Loss of Biodiversity
• Disappearance of species food affects webs
• Keystone species disappearance may cause
other species to disappear
• Biodiversity affects stability of organisms and
sustainability of populations
Invasive Species
• Introducing nonnative species into an environment
• Ie: Zebra mussel – introduced to Great Lakes –
disrupted ecosystem (no native predators ), too many
mussels now – native species suffering, also causing
clogs in pipes of water treatment facilities
Extinction
• Death of every member of a species
• Caused by disruption to ecosystems
• Ie: red panda, 2 anticancer drugs developed
from rosy periwinkle (flower in Madagscar)
threatened by deforestation
ENVIORONMENTAL
SOLUTIONS
Protecting the environment is
critical to human well-being. With
new technologies and the effort of
individuals and governments,
many environmental problems
can be solved.
CONSERVATION AND
RESTORATION
• Conservation – protects existing natural
habitats
• Restoration – clean up and restore damaged
habitats
• Prevents problems from happening!
REDUCE RESOURCE USE
• Reduce use of resources (water, fossil fuels)
and wastes produced (use ceramic plates
instead of paper plates)
• Reuse goods ie: plastic bags and utensils
• Recycle – process of reusing things instead of
taking more resources from the environment
ie: cans, paper, plastics
TECHNOLOGY
• Advances led to production of cars and industry
– pollution
• Advances can lead to due to solutions
scientific research
• Protect environment – cleaner energy sources
( renewable resources vs. non-renewable
resources), waste management, clean pollution
Non-renewable Resources
Non-renewable resource
: natural
resource, cannot be re-made, re-grown or
regenerated on a scale comparative to its
consumption; exists in a fixed amount;
being consumed faster than made by
nature
Oil
Natural
gas
NON - Renewable Resources used for power
Coal
Renewable Resources
• Renewable resource : replenished by
natural processes at a rate comparable or
faster than its rate of consumption by
humans or other users
Wind
Solar
Renewable Resources used for power
Lumber
Corn
Water
Technology Advances
• Hybrid cars, hydrogen fuel cells, solar,
wind, water power
ENVIRONMENTAL AWARENESS
• Addressing environmental issues – conservation
groups, individuals and governments work together
• Education – people aware of environmental issues and
how to help address issues
• Helping to solve the issues, support efforts to protect
environment – advocacy
PLANNING FOR THE FUTURE
• In order for populations to thrive, sustain quality
of life and keep resources – must plan for the
future
• Planning – avoid damaging the environment
and solve issues at hand
• Governments must help plan - enforce laws
and limitations on developers and protect
resources ( renewable and non-renewable )
Global Warming
What causes the
change?
Implications of the
change.
What can we do
about it?
Ozone Depletion
Acid Rain