Transcript Flow of Energy Through an Ecosystem

Ecology
What is Ecology?
• Ecology is the study of interactions among
organisms and their environments, or
surroundings
– also includes the study of human interactions
and the impact of human activities on the
environment
The Biosphere
The combined portion of the planet where life exists
-land, water, atmosphere ect…
-extends 8 kilometers above Earth’s surface
and 11 kilometers
Levels of Organization within
the Biosphere
• Species- group of organisms so similar they can interbreed
and produce fertile offspring
• Population- group of organisms of the same species living
in the same area
• Community- collection of all species populations living in
the same area
• Ecosystem- living community + nonliving physical
environment
– Abiotic- nonliving factors
• Climate, sunlight, soil composition, nutrients ect…
– Biotic- living organisms
• community
• Biome- group of similar ecosystems with similar climate
and similar communities
– Usually cover a large geographic area
Energy with Ecosystems
• Producers (autotrophs)- organisms capable of making their
own energy supply
– Plants on land and algae in water (photosynthesis)
• Consumers (heterotrophs)- organisms that rely on other
organisms for food supply (must consume other organisms
to obtain energy supplies
– Herbivores, carnivores, omnivores, detritivores ect…
– Primary, secondary, tertiary ect…
• Decomposers- obtain energy by breaking down organic
matter
– Bacteria & Fungi
– Very important- return nutrients to abiotic environment (soil)
Relative Importance
• Which class of organisms do you feel are most
important and why?
– Producers- most vital (important) make energy for
themselves all other organisms in their ecosystems.
• WITHOUT PRODUCERS there is NO OTHER LIFE!
– Decomposers- very important because they break
down organic matter
• Return nutrients to soil/abiotic environment
– Consumers- complete the “balance of life” yet are
least important
The Food Chain
• Series of steps that show feeding relationships
and flow of energy through an ecosystem
– Each STEP IN FOOD CHAIN = TROPHIC LEVEL
– Starts with producer
• Convert energy from sunlight
Food Webs
• Show all the feeding relationships or
interconnected food chains within an
ecosystem
Flow of Energy Through an Ecosystem
• http://www.youtube.com/watch?feature=play
er_detailpage&v=De_53QflEXQ
Flow of Energy Through an Ecosystem
• Energy Flows Through an ecosystem in ONE
DIRECTION.
– It is not recycled!
• Organisms use approximately 90% of the energy they
take in for metabolic activity (life processes)
– Most of this energy is lost to the environment as heat.
• Only about 10% of the energy that an organism takes
in is stored in its structures and available for organisms
at the next trophic level (step of the food chain)
• This relationship can be shown in an energy pyramid
The ENERGY Pyramid
Matter vs Energy
• Unlike Energy, MATTER is RECYCLED in nature
– Matter Cycles between abiotic (nonliving
environment) and community (living things)
• Common Substances Cycle in Nature.
– Water
– Carbon
– Nitrogen
– Phosphorus
The Water Cycle
• Evaporation, Transpiration, Condensation,
Precipitation, Water Runoff
The Carbon Cycle
• In Atmosphere (CO2), Photosynthesis, Food
Chain (sugars), Respiration, 3D’s (Death, Dung,
and Decay) Burning of Fossil Fuels
The Nitrogen Cycle
• In Atmosphere (N2), Nitrogen Fixation, Plant
Uptake, Food Chain, 3 D’s (Death, Dung, and
Decay), Denitrification
The Phosphorus Cycle
• In Soil, Rocks, and Bodies of Water
• Plant Uptake, Food Chain
• Death, Dung and Decay
Weather vs Climate
• Weather- day to day condition @ a particular
time and place
• Climate- average yr after yr conditions at a
particular place
– Average temperatures (fall,winter, spring,
summer)
– Precipitation- amount of rainfall, snow, hail ect..
Effect of Climate on Ecosystems
• Climate shapes Ecosystems!
– Climate is the #1 Abiotic Factor that determines
what type of community that will be found in a
particular area.
– Temperatures and rainfall determine what type of
plants (plant life) can be found in an area
• This also determines the type of animals and # of
animals that can be found in an area
• Solar Radiation Heats Earth
• Earth Heats Atmosphere
• Some Heat Trapped in Atmosphere by Greenhouse Gases
•
CO2, CH4, and N2O
• Without greenhouse effect Earth would be VERY COLD!
Effect of Latitude on Climate
• Near equator the angle of solar radiation is more direct
• More solar radiation will penetrate the atmosphere
near equator
– Warmer an d wetter as a result
• 3 distinct zones created (tropical,temperate, and polar)
Biomes of the World
The Niche
• An organism’s “role” within the ecosystem
– Feeding Relationships
• Where does it belong in food chain
– Physical requirements (temperature, shelter, ect…)
– Other relationships with other species
Community Interactions
• Competition- organisms of the same or different
species trying to use the same resource at the
same time
– Water, nutrients, light, food, space ect…
• Predation-one organism captures and feeds upon
another organism
– Ex: Deer and wolf
• Predator-Wolf
• Prey-Deer
Community Interactions Cont…
• Symbiosis-when two organisms live close to one
another and have some sort of Relationship
– Mutualism- a relationship in which both species
benefit
• Ex: Oxpecker and cattle
– Commensalism- a relationship in which one species
benefits and the other is neither helped not harmed
• Ex: Tree and bird
– Parasitism- a relationship in which one species
benefits and the species is harmed
• Parasite vs Host
• Ex: Tapeworm (parasite) and Animals (Host)
Ecological Succession
• Ecological Succession- changes in a
community after human or natural
disturbances
– Usually changes are predictable
– Simple to complex
– Can be Primary or Secondary
Primary Succession
• Primary succession- no soil present
– Follows volcanic lava flows or eruptions
– Pioneer species- 1st species to populate the area
• Lichens, bacteria
• Other species follow as rock is weathered to create soil
that is suitable
– Lichens  grasses  small shrubs  trees ect…
– This process is SLOW
– Eventually Reaches Climax Community
• Climax Community- steady community with lots of
diversity and many community interactions
Secondary Succession
• Secondary Succession- Soil is already present
– Follows Forest Fires, Floods, Changes in Abiotic
Environment, Human Disturbances ect..
– Occurs much, much faster than primary
succession
• Soil is already present
IF YOU STUDY ALL 1-30 SLIDES
HARD…YOU ARE AN EXCELLENT
STUDENT  AND WILL BE PREPARED
Population Growth
• 4 Factors that influence the growth of a
population
– Immigration- individuals moving Into a population
– Emigration- individuals leaving or Exiting the
population
– Birth Rate- Individuals being born per year
– Death Rate- individuals dying per year
Types of Population Growth
• Exponential Growth
– Continuous growth
• Must have unlimited
resources and no limiting
factors restricting a populations size/growth
-not usually realistic in nature
Types of Population Growth
• Logistic Growth
– begins w/ rapid grow
• exponential phase
– Carrying Capacity- max #
of individuals that ecosystem
support
– growth rate slows as
population size nears carrying
capacity. WHY?
• Limiting Factors- limit pop. growth
– predation, competition, parasitism & disease
– Natural disasters, unusual weather and/or climate change, and
human activity
Logistic Growth (cont.)
• Slight fluctuation near carrying capacity is
normal
• Population could “crash” and reenter
exponential phase
Biodiversity
• All the different species living on Earth
– Human activity has significantly lowered the
amount of biodiversity on Earth.
– Are we currently causing a mass extinction?
– Extinction is a natural process but…
• It is estimated that human activity has increased the
rate of extinction by 1,000 to 10,000 times the natural
rate
• 30-50% of all species will be extinct by mid century
(2050)
Who Cares?
• Human survival is tied to biodiversity
– Humans are dependent upon living things for:
• Natural resources
• Food and goods
• Pharmaceuticals (medicines)
Human Actions
• Habitat Destruction/Alteration- This is the leading cause of
extinction.
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Urban development
Industrial development
Dams/Alteration of Aquatic Environments
Agricultural Development
• Deforestation
• Habitat Fragmentation- splitting of ecosystems into pieces
(islands)
– many organisms such as GRIZZLIES need a large area to survive.
• Fragmentation can equal extinction
Overfishing/Overhunting/Poaching
INVASIVE (nonnative) SPECIES
• Introduction of Invasive (nonnative) species
has a negative impact on ecosystems
– Invasive species can outcompete native species
and disrupt balance or relationships within a
natural ecosystem
Pollution
– Acid Rain
• Chemicals within smog combine with water from rain
to form nitric and sulfuric acid
– Changes acidity of marine systems and terrestial systems
– Toxic Waste
– Biological Magnification- build up of toxins as they
pass through food chain
• Some toxins do not degrade
• These toxins reach lethal level as they reach upper
levels of a food chain
• Example- DDT
OZONE DEPLETION
• CFC’s and other Air Pollutants destroy the
ozone layer
– Ozone (O3) is in the upper layer of the atmosphere
and deflect much solar and UV radiation
• CANCER KILLS
• ALSO Contributes to global warming
GLOBAL WARMING
• Burning of Fossil Fuel INCREASES CO2 levels in
the atmosphere
– CO2 is a greenhouse gas and traps heat
– Excess CO2 is causing global climate change is
taking place
Conservation Efforts
• Today, focus is on saving entire ecosystems in
addition to single species
– Ecological Reserves
– National Parks Ect…
– Doing so preserves relationships in nature and
provides an increased chance of saving many
species.
What have you done lately?
• Interested in more?
– AP Environmental Science