1. ECOSYSTEMS CHAPTER 10

2. WHAT IS AN ECOSYSTEM? An ecosystem is all the living things and nonliving things in a given area Examples of ecosystems: ◦ Forests, deserts, grasslands, rivers, beaches, and coral reefs

3. Abiotic Vs. Biotic Factors Abiotic factors: the nonliving parts of an ecosystem ◦ Ex. Sunlight, temperature, air, water, soil Biotic factors: the living OR once-living things in an ecosystem ◦ Ex. Bacterium, dead organisms(fallen leaves), decayed plant matter in soil, people, animals, plants, etc

4. Parts of an Ecosystem Habitat: the place within an ecosystem that provides food, water, shelter, and other biotic and abiotic factors that an organism needs to survive and reproduce Population: All the organisms of the same species that live in the same area at the same time Community: ALL of the populations living in the SAME area at the SAME time DRAW UPSIDE DOWN PYRAMID TO SHOW CONNECTION!

5. Too Many Fish in the Sea? Most populations change over time. ◦ Increase = production of offspring ◦ Decrease = death of individuals ◦ Move = changes in abiotic/biotic factors How can you determine if an area contains too much of something? You could calculate the population density! Population Density: the size of a population compared to the amount of space available PD = number of individuals unit area or volume of space

6. Relationships Within Ecosystems How does a niche differ from a habitat? A habitat is a PLACE within an ecosystem that provides abiotic and biotic factors that an organism needs to survive and reproduce. A niche is the WAY a species interacts with abiotic and biotic factors to obtain the needs to survive ◦ Example: different food source

7. Relationships within an ecosystem continued…. Competition: describes the demand for resources such as food, water, and shelter, in short supply in a community. ** Competition limits population size Overpopulation: occurs when a population becomes so large that it causes damage to the environment

8. Relationships within Ecosystems Predation: the act of one organism, a predator, feeding on another organism, its prey.  Ex. Dragonfly capturing a fly-Dragonfly is the ???? And Fly is the???? Symbiosis: a close, long term relationship between two species that usually involves an exchange

9. 3 Types of Symbiosis Mutualism: a relationship in which both organisms benefit Commensalism: a relationship in which ONE organism benefits but NEITHER is harmed Parasitism: relationship in which ONE organism benefits and the other is harmed