1. Chapter 15- How Ecosystems Change
Section 1 – Interactions within Ecosystems
Section 2 – Ecosystem Development and Change

2. Sec 1 – Interactions within Ecosystems
Species change in response to the challenges posed by their environments.
Therefore, animals, plants and other organisms function within their ecosystem because of specialized characteristics:
Plants in deserts have thick, waxy coating on leaves
Desert animals often hide underground during the hottest part of the day
The interactions between living members of the ecosystem can determine the organism’s ability to survive and reproduce.
Many plant leaves are tough to protect them from being eaten by herbivores.
Herbivores have developed flatter, larger teeth.

3. Coevolution – the response that causes change when two or more species interact
This coevolution interaction creates a complex web among the members of the community.
Insects and flowers depend on each other for food and reproduction
Plants defend themselves by the use of thorns, tough leaves, chemical poisons (which can kill or just taste bade)
Some herbivores have ways to overcome the chemical defenses of plants and feed exclusively on a particular kind of plant. Most insects avoid plants of the mustard family, but cabbage butterfly caterpillars eat these plants voraciously.l

4. Symbiosis is a close, long-term association between two or more species. The three symbiotic relationships are:
Parasitism - obtain nutrition by feeding on the host. A parasite usually does not kill its host, but it eventually can make it very sick.
Mutualism – a relationship where all parties benefit. Each gets something it needs. Example: Lichen is a relationship between a fungus and green algae.
Commensalism – the relationship where one organism benefits and the other is not obviously affected. Example: the barnacles growing on a whale.

5. Sec 2 – Ecosystem Development and Change
Every animal in an ecosystem plays a role in that ecosystem.
An organism may be a prey of one animal and the predator to another animal.
The niche is the sum of the organism’s interactions with its physical environment and with other organisms. The niche defines the movement of energy through the ecosystem.
The niche of the grass is a producer, the niche of the deer that eats grass is that of an herbivore.
The fundamental niche is the total niche that an organism could potentially exist within.