1. Chapter 1.2
Biodiversity in
Ecosystems

2. 1.2: Learning Outcomes
Explain various relationships with respect to food chains, food
webs, and food pyramids, including:
producer
consumer (herbivore, carnivore, omnivore)
predation (predator‐prey cycle)
decomposers
symbiosis (mutualism, commensalism, parasitism)
2. Describe the relationships between abiotic and biotic elements within an ecosystem, including air, water, soil, light, temperature (abiotic) and bacteria, plants, animals (biotic)
3. Design and analyse experiments on the effects of altering biotic or abiotic factors (e.g., nutrients in soil: compare two plant types with the same nutrients, compare one plant type with different nutrients)

3. 1.2: VOCABULARY Ecosystem Habitat Community Species Population
Symbiosis
Mutualism
Commensalism
Parasitism
Predation
Niche
Competition
Predator
Prey
Biodiversity

4. ECOSYSTEMS
By studying past and present ecosystems, we can better understand what may happen in the future.
Historical ecology is the study of natural and written materials to better understand the ecology of a certain area.
Many First Nations sources provide detailed knowledge of plants, animals, and natural occurrences of an area.

5. PARTS OF ECOSYSTEMS An ecosystem is made up of many parts.
Abiotic (non-living) factors include air, water, soil, nutrients, and light.
Biotic (living) factors include plants, animals, and micro-organisms.
Ecosystems can take up many hectares of land or can be small, such as a tide pool or a rotting log.
A habitat is where an organism lives.
The habitat of the red fox often includes the edges of forests or marshlands.

6. EXAMPLES OF HABITATS

7. HABITATS

8. There are all sorts of different ‘habitats’ that different species occupy:
The Blind Flatworm
& the eyeless shrimp
Live in dark caves. They are called “troglobites” (cave-dwellers). They have adapted to darkness - do not require eyes...

9. White-Spotted Puffer Fish
Lives in coral reefs (in tropical waters)
Second most poisonous vertebrate in the world...
It’s muscles, skin, liver and ovaries contain toxin 3x deadlier than cyanide.

10. The Rattle Snake
Occupies different habitats depending on the time of year... SUMMER WINTER
Open grassland (areas with high rodent density)
Hibernating dens (rock fissures or caves)

11. EXAMPLES OF HABITATS

12. Abiotic interactions In ecosystems
The abiotic components are what allow the biotic components to survive in an ecosystem
Abiotic factors include oxygen, water, nutrients, light and soil.
Oxygen is produced by the green plants and certain micro-organisms and is used by animals and most other micro-organisms.
An example of a micro-organism that
produces oxygen is cyanobacteria. They
are found in oceans, rivers, bare rocks, and
soil. “Blue-green algae”

13. Abiotic interactions In ecosystems
Water is necessary for all life.
Nutrients often enter the food chain with plants and are very important for growth.
Light is required for photosynthesis, which is the process in plants that converts and stores the Sun’s energy into starches and sugars.
Soil not only contains water and nutrients
but also is home to many plants and animals.
Earthworms in soil

14. biotic interactions In ecosystems
A community = all the organisms that interact within an ecosystem.
A species refers to all of the organisms within an ecosystem that have the same structure and that can reproduce with each other.
A population refers to all of the members of a certain species within an ecosystem.

15. biotic interactions In ecosystems
Symbiotic relationships are the interactions between members of two different species that live together in a close association.
Commensalism – one species benefits, one is not affected
Example: the barnacles on a whale
Mutualism – both species benefit
Example: a bee gathering nectar from a flower
Parasitism – one species benefits, the other is harmed
Example: hookworm living in dogs
Mutualism Video

16. COMMENSALISM

17. COMMENSALISM (Biological hitch-hiking)
The Imperial shrimp hitches a ride
on a large sea cucumber. It rides
along through areas of potential
food, at no cost to the other
organism.
Anyone home?
The pearlfish is a small fish (5-10cm) that lives
inside a seacumber in the day and at night, exits
through the anus of the seacumber to feed.

18. MUTUALISM

19. MUTALISM Leaf Cutter Ants Cut the leaf..
These ants cultivate (grow) a fungus. They feed the fungus and the fungus serves as their food!
Chew into a pulp
Store the pulp with ant feces and fungus spores
Teachers' Domain: Ancient Farmers of the Amazon
Fungus begins to grow...

20. MUTALISM LICHEN = algae + fungus
Fungus provides a place for the algae to live. It also provides moisture that the algae needs.
The algae provides food (glucose) for the fungus through photosynthesis.

21. PARASITISM

22. PARASITISM
MOUTH
HOOK WORMS The common way for hook worms to enter is through the skin (walking barefoot)...
A parasitic worm that lives inside the intestines of its host (mammal). These worms such blood from the host’s intestinal walls ...this leads to anemia (iron deficiency).

23. PARASITISM The Pine Beetle
The pine beetle has infested lodgepole pine trees in BC’s Central Interior.
Burrows in the tree, feeds on trees phloem (nutrients) and lays its eggs.

24. The Pine Beetle’s Legacy....
In B.C., the provincial government estimates the beetle's spread will have economic implications for 30 communities and will impact 25,000 families whose livelihood depends on the pulp and paper industry.
The environment is also affected: trees normally capture CO2 (greenhouse gas) – but the death of more trees has instead released carbon into the atmosphere, according to a study published in April 2008 in the journal Nature.

25. NICHES
A niche refers to the role an organism has within an ecosystem, physically, chemically and biologically.
Within the niche, an organism interacts with other individuals of the same species or with individuals of other species

26. COMPETITION Competition occurs when a resource is
needed by two or more individuals.
Competition usually means resources are limited.
This limits the size and health of that individual
and perhaps that population.
Examples of resources that organisms compete over include food, water, and mates

27. PREDATION
Predation is the relationship between the “eaters” and the “eaten”.
Predators have adaptations to help them catch their prey.
Prey have adaptations to help avoid predators.
Examples of adaptations include spines and shells, camouflage and mimicry.
The numbers of predators and prey influence each other.

28. EXAMPLES OF PREDATOR-PREY MODELS

29. EXAMPLES OF PREDATOR-PREY MODELS

30. Biodiversity in ecosystems
Biodiversity refers to the variety and number of different individuals and species in an ecosystem.
Healthy ecosystems generally have high biodiversity.
Most biodiversity losses occur from the loss of habitat.

31. Biodiversity in ecosystems
Humans often have a negative impact on biodiversity.
Many efforts are now made to lessen this impact in order to maintain biodiversity.
Ecological management programs try to balance human progress with maintaining biodiversity.