Download presentation
Presentation is loading. Please wait.
Published byBertha Rose Modified over 8 years ago
1
Environmental Science Chapter 8 1
2
Section 8.1 2
3
A population is all the members of a species living in the same place at the same time. The three main properties of a population are size, density, and dispersion. 3
4
Population Density Density is the number of individuals per unit area or volume. Dispersion is the relative distribution or arrangement of its individuals within a given amount of space. 4
5
Even Clumped Random 5
6
Births and immigration increase a population Deaths and emigration decrease a population Growth rate is the birth rate minus the death rate. 6
7
Positive: more births than deaths Negative: more deaths than births Zero: the average number of births equals the average number of deaths 7
8
Biotic potential is the fastest rate at which its population can grow. Reproductive potential is the maximum number of offspring that each member of the population can produce. 8
9
Individuals produce more offspring at a time Reproduce more often Reproduce earlier in life 9
10
When a population grows exponentially because there are plenty of resources available and little or no predators. 10
11
Carrying capacity: the maximum population that the ecosystem can support indefinitely. Resource limits: consuming natural resources at the same rate they are being produced. Competition: members of the population fighting over available resources. 11
12
Density dependent means it depends on population size Examples: competition and predator-prey Density independent means it does not depend on the size of the population Examples: severe weather and natural disasters 12
13
Time for a reading quiz 13
14
Section 8.2 14
15
HabitatNiche Habitat is an organism’s location. Think of it as your address. Niche is the role of a species within its habitat. Physical home, environmental factors, and interactions. 15
16
Niche overlapNiche division Niche overlap Insects feeding on same plant or same feeder but at different times of day. Niche division or restriction Birds feeding on different parts of the tree. 16
17
Is when an organism feeds on another organism Predator is the one feeding. Prey is the one being fed upon. 17
18
Is when one organism lives in or on another organism. The one that benefits is the parasite. The host is harmed. 18
19
Is when both species benefit from the relationship. 19
20
Is when one organism benefits and the other organism is not affected at all. 20
21
symbiosis coevolution A relationship in which two different species live in close association with each other. Three types: mutualism, commensalism, and parasitism When two species evolve adaptations that reduce the harm or improve the benefit of the relationship. 21
22
Time for reading quiz 22
Similar presentations
© 2024 SlidePlayer.com Inc.
All rights reserved.