Unit 3: Biodiversity and Management

Question 1

Biodiversity

Answer 1

Variety of life within an area

Question 2

Diversity is defined on which 4 fronts?

Answer 2

1. Landscapes
2. Ecosystems/habitats
3. Species and (evenness, richness, and dominance)
4. Gene pool

Question 3

What is biodiversity linked to?

Answer 3

The goods and services we rely on to fulfill our requirements

Question 4

What 3 hierarchal categories can biodiversity be divided into?

Answer 4

1. Genes
2. Species
3. Ecosystems

Question 4

How many species are there?

Answer 4

3.6 to 100 million species
-world

160 000 in Canada

Question 4

Why is biodiversity important?

Answer 4

1. Economic well being
2. Ecosystem services - benefits from the natural world (pollenating, clean water)
3. Cultural value (artists)
4. Recreational value (going for walks, birdwatching)
5. Scientific value

Question 4

What factors contribute to variations in species diversity?

Answer 4

1. Geographic isolation
   - reduces biodiversity by limiting gene dispersal (islands, ecological island, hydro dam, inbreeding)
2. Latitudinal gradient
   -biodiversity is strongest at the equator, declines with latitude, and is associated with temperature stability and precipitation
3. Age of the ecosystem
   -tropical regions are “older” because they didn’t undergo glaciation
   -tropical regions are more diverse
4. Structural complexity of the ecosystem
   -Forests offer more ecological niches than grasslands because they offer lots of habitats

Question 4

How do scientists evaluate biodiversity?

Answer 4

1. Species Richness: # of species
2. Species Evenness: # distribution of species
3. Dominance: is there more of any one species?

Question 5

Ecological Niche

Answer 5

A multi-dimensional view of everything an organism does

-where they live and find resources, interactions with other organisms, lifestyle, adaptations

Question 5

What is a keystone species?

Answer 5

A species/group that has a huge impact on the ecosystem if they were to be taken away/decreased

ex. prairie dogs
-bring nutrients from deep in the ground to the surface
-Cut down the tall grasses
-Increase nitrogen in the soil

Wolves
-When they were introduced, the population of deer went down, valleys grew, birds moved in, beavers built dams, changed the behaviour of the rivers/physical geography, less soil erosion

Question 5

Resource partitioning

Answer 5

To minimize competition between species, organisms will alter aspects of their ecological niche

ex. eating during the day vs at night

Question 5

What are the 3 types of Symbiosis?

Answer 5

1. Mutualism
   -sharing benefit (bees feed on necture then spread pollen to help the plant reproduce)
2. Commensalism
   -One species benefits, one is not affected (squirrel in a tree)
3. Parasitism
   -Parasite benefits, the host is harmed (ticks)

Question 5

Population ecology

Answer 5

The number of individuals of a species found in an area, and why those numbers increase and decrease

1. Exponential growth
2. Logistic growth

Question 5

What is predation?

Answer 5

The consumption of one species by another

Prey develops strategies of defence:
-Nocturnal behaviour
-Living in groups
-Mechanical/chemical defenses
-Camouflage

Question 6

Exponential growth

Answer 6

Increases by a fixed rate over time

-J-shaped
-slow at the start (lag), then a dramatic increase in population size
-bacteria/fungi

Question 6

Carrying capacity

Answer 6

The largest population that can be sustained without degrading resources or jeopardizing availability for future generations

Question 6

Logistic growth

Answer 6

Population starts off exponential, but then slows as one or several environmental factors become limiting

-Lag phase, exponential, then stabilizes due to the carrying capacity

Question 7

Population crash

Answer 7

Exceeding the carrying capacity

-mountain