Download presentation
Presentation is loading. Please wait.
1
Populations
2
A Population group of organisms of the same species living in the same place at the same time
3
Different populations are all connected!
When one population decreases or increases in an ecosystem, another population can be affected! Example: The story of the sea otters!
5
Figure 1.15 page 18
6
When the sea otters are absent…
7
Carrying Capacity The maximum population that an environment can sustain or support. Seychelles Paradise Flycatcher needs one acre of mixed forest per breeding pair. They live on the little island of Madagascar
8
Carrying Capacity a population remains at its carrying capacity when in balance (number of individuals added and the number of individuals that leave or die are the same)
9
Factors Determining Carrying Capacity
materials & energy: energy, water, carbon, and other essential nutrients (Abiotic Factors)
10
Factors Determining Carrying Capacity
2. Food chains: the population size is limited by the size of the populations at lower trophic levels
11
Factors Determining Carrying Capacity
3. Competition: each organism has the same need as any other; they compete for resources such as food, water, mates and space
12
3. A closer look at Competition: Two types of competition:
Intraspecific competition: among members of the same species ex: two wolves compete for a rabbit Interspecific competition: between different species ex: cheetah and lion compete for zebra
13
4. Population Density: depending on their size, environment and way of life, different species have different needs for space
14
Density Dependent Factors
Occur when the density has gone beyond an appropriate level Over-population can: Increase stress & lead to easier spread of diseases and parasites Increases aggression & causes parents to neglect offspring This causes the population to decrease
15
Density Independent Factors
Limits the population- no matter what the density is. Forest fires Earthquakes Volcanic Eruptions Tornadoes Floods
16
To Do: Vocabulary Words and questions at the end of your sheet of notes Sheet - Population Terms
17
Video - Populations Ecology - Crash Course
18
Population Growth Curves
19
Population Growth if unlimited resources are present, growth will be exponential the curve will always be a “J” curve or an exponential growth curve
21
resources are never unlimited
as population rises, resources decline if the growth is too rapid, resources are rapidly depleted and a population crash can occur this pattern occurs often with many populations (including humans)
22
Elk
23
Video - The Importance of Predators
24
more often what happens is that the resources slowly decrease, the growth rate slowly increases, and they meet this point that they oscillate around is the carrying capacity of the environment for that particular organism this is called an s-shaped or logistic curve
25
To do: Notes: Population Growth Curves/
Practice Sheet: Carrying Capacity Practice Sheet: Fruit Flies and population growth
26
Human Population Growth
What are the causes of this huge increase in the human population? What are some possible consequences for us? Our future? (Think: the elk)
27
To Do: Video: 7 Billion Current World Population
Activity: Human Population Growth
28
Video – How many people can live on planet Earth? (45 min)
Video – How Many People Can Earth Support (10 min) Movie – Future Earth (45 min)
29
Movie - World Population to hit 11 Billion in 2100 (45 minutes)
Movie – Overpopulated (1 hour) Video – The Science of Overpopulation (crash course) – 10 minutes
Similar presentations
© 2024 SlidePlayer.com Inc.
All rights reserved.