Title: Topic 6: Ecology
1Topic 6 Ecology
- I. Parts of an EcosystemII. Population Dynamics
2What is it?
ECOLOGY
- Study of how organisms INTERACT with living and
non-living things
3What will we be looking at?
- Parts of an ecosystem
- Things that affect popn size
- Roles and relationships in an ecosystem
- Energy flow in an ecosystem
- Importance of biodiversity
- Succession
- Human impacts on the environment
4Ecosystem describes any portion of the
environment (ie. Decaying log, a pond, fish
tank, field of corn)
5The environment is every living and nonliving
thing that surrounds an organism
6Ecosystems Brainpop (139))
7What makes up an ecosystem?
Abiotic Factors
Biotic Factors
ECOSYSTEM
ECOSYSTEM
8- 1. BIOTIC FACTORS
- Bio means living
- LIVING things in an ecosystem
- ie.Plants, animals,
- bacteria
- Can you list the living things that could live in
this ecosystem? - Frogs, insects, fish, hawks, grasses, bacteria,
amoeba etc..
9- 2. ABIOTIC FACTORS
- When you put a in front of a word it negates it
- Means NON-LIVING factors
- Can you list some non-living factors that affect
the pond ecosystem? - WATER, LIGHT, TEMP, acidity, oxygen and nitrogen
levels
10Ecological Levels of the Organization of Life
11Collectively all of the Earths ecosystems make
up the biosphere
12The specific environment in which organisms live
is their habitat
13Ecosystem - populations in a community and the
abiotic factors with which they interact (ex.
Biomes)
14All the different populations are combined to
form a community
15All the organisms of a species that live in the
same area, produce fertile offspring, and compete
with each other for resources (food, mates,
shelter, etc.) make up a population
16- Organism - any unicellular or multicellular form
exhibiting all of the characteristics of life, an
individual. - The lowest level of organization
17Ecological Levels of the Organization of Life
- BIOSPHERE
- HABITAT (BIOME)
- ECOSYSTEM
- COMMUNITY
- POPULATION
- ORGANISM
Decreasing amount of biotic and abiotic factors
18Population Growth Brain Pop Video (227)
19What affects population sizes in an ecosystem?
- COMPETITION!
- Struggle for resources among organisms
- If no competition, populations would grow
INFINITELY (no limit!) - Competition maintains FINITE (limited) popn
sizes - Finite populations limited by LIMITING FACTORS
- CAN BE ABIOTIC OR BIOTIC
20Lets look.Comparing Finite and Infinite
Populations
INFINTITE GROWTH
FINITE GROWTH
21What affects population sizes in an ecosystem?
- A) ABIOTIC LIMITING FACTORS
- Amount and intensity of sunlight
- Amount of water
- Amount of dissolved oxygen (lakes, rivers, etc)
- Acid level
- Temperature range
- Minerals available
22What affects population sizes in an ecosystem?
- B) BIOTIC LIMITING FACTORS
- Predator/Prey relationships
- Predators limit prey population sizes by eating
them - Prey limit predator population sizes by
dying/being killed - If too many killed, predators starve
- Adapting (survival of the best adapted)
23Lets take a look. Effects of Predator/Prey
Relationship
As you can see, AS PREY POPULATION DECREASES, THE
PREDATORS POPULATION DECREASES (Direct
relationship)
24What do we call it when a species reaches its
limit?
- EVERY population in an ecosystem has a CARRYING
CAPACITY (K) - THE OF ORGANISMS OF A SINGLE SPECIES AN
ECOSYSTEM CAN SUPPORT - Determined by BIOTIC and ABIOTIC factors
- EX a fox population is affected by how much it
has to eat (biotic) and also temperature
(abiotic) - Once K is reached, population will remain stable
unless major changes in biotic and abiotic factors
Carrying Capacity (K) of a Stable Population
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26Part 2 POPULATION INTERACTIONS
- How organisms interact in an ecosystem!
- What role are you up for?
27Competitive Exclusion Principle
- If two different species compete for the same
food source or reproductive sites, one species
may be eliminated. - This establishes one species per niche in a
community.
28A. What does it mean to have a role in an
ecosystem?
- NICHE
- THE ROLE (NOT SPACE!!!!!) AN ORGANISM PLAYS IN
ITS ECOSYSTEM - ONLY ONE SPECIES CAN OCCUPY A NICHE AT A TIME
- LEADS TO COMPETITION IF MORE THAN ONE SPECIES
WANTS ROLE - SIMILAR SPECIES CAN COEXIST AS LONG AS THEY HAVE
DIFFERENT NICHES! - EX p102 in RB WARBLERS
29HOW CAN I REMEMBER THAT NICHE MEANS ROLE AND
NOT SPACE?
- THINK OF A PLAY!
- EVERY ROLE NEEDS TO BE FILLED IN ORDER FOR THE
PLAY TO WORK! - IF MORE THAN TWO FOLKS (SPECIES) WANT A ROLE,
THERE IS COMPETITION AND THE BEST WINS!
30What are the relationships in an ecosystem?
- Food chain Food web
- (1 path of energy) (all possible energy
paths)
31B. What are the relationships in an ecosystem?
- 1. FOOD CHAINS
- Illustrate NUTRITIONAL RELATIONSHIPS between
predators and prey - 1 path of energy
- Specific organisms are included
- Lets take a look!
32FOOD CHAINS
33Feeding Relationships
- A. Autotrophs (Producers)
- Make own food (grass)
- B. Heterotrophs (Consumers)
- Herbivores Eat plants (grasshopper)
- Carnivores Eat animals (snake)
- Omnivores Eat plants and animals (humans)
- Scavengers Eat dead things lifes clean-up
crew! (vultures) - Decomposers lifes recyclers (bacteria and fungi)
34- 2. SYMBIOTIC RELATIONSHIPS
- When organisms live in REALLY close quarters
- Parasitism Live off other orgs but dont kill
them (some worms, ticks, fleas) - Mutualism Orgs that both benefit (Clownfish and
sea anemone) - Commensalism One org benefits the other -
neither harmed or benefitted (Whale and barnacles)
PARASITISM MUTALISM
COMMENSALISM
35- 3. FOOD WEBS
- All food chains in an ecosystem are illustrated
in a food web - INVOLVES all possible energy paths
36Food Webs are diagrams that show more complex
feeding relationships
37A simplified food web at a pond
38Lets talk energy! The fuel of life!
- Ask yourself Where does our ultimate source of
energy come from? - The sun of course!
- Ask yourself Which orgs can harness suns
energy and make food? - Plants of course!
- Ask yourself What happens to the plants energy
when a herbivore eats it? -
- Ask yourself What happens to the herbivores
energy when a carnivore eats it? - Ask yourself What happens to the carnivores
energy when another carnivore eats it?
Decreases
Decreases
Decreases
391. What happens to ENERGY in an ecosystem?
- Every organism uses energy to carry out life
processes - If an organism is eaten, it will give less energy
to the predator - THEREFORE, ENERGY DECREASES AS YOU MOVE UP A FOOD
CHAIN!
40- WE USE AN ENERGY PYRAMID TO SHOW THIS
- see fig 6-7 and 6-8 on page 107 in your review
book!
Carnivores - BIRD
Herbivores - CATERPILLAR
Producers(Autotrophs) OAK TREE
41As energy is transferred, much of it is lost to
the environmentLets watch http//www.brainpop
.com/science/energy/energypyramid
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47D. RECYCLING NUTRIENTS
- DECOMPOSERS extract what little nutrients are
left - They return raw materials (nitrogen) back to soil
- Other orgs continually recycling CARBON DIOXIDE,
OXYGEN, AND NITROGEN - ENERGY IS NEVER RECYCLED!
- involves the processes of RESPIRATION and
PHOTOSYNTHESIS.
48Lets look at pg 108 in RB RECYCLING OF
MATERIALS IN ECOSYSTEMS
- Lets Watch brain pop carbon CYCLE VIDEO (232)