1. Ecosystems

2. Questions for Today: What are the major components of an Ecosystem? How do abiotic factors affect Ecosystems? How do biotic factors affect Ecosystems? Describe the Energy flow and nutrient cycling in Ecosystems.

3. Ecosystems have Living and Nonliving Components An Ecosystem is a community of different species interacting with one another and with their nonliving environment of matter and energy. Two components: –Abiotic – nonliving components –Biotic – Living components

5. Ecosystems have Living and Nonliving Components Each population in an ecosystem has a range of tolerance to variations in its physical and chemical environments.

6. How do Abiotic Factors affect Ecosystems? Abiotic Factors affect Ecosystem through limiting factors. –Limiting factors are any abiotic factor that affects the number of organisms in a population. Limiting Factor Principle states: “Too much or too little of any abiotic factor can limit or prevent growth of a population, even if all other factors are at or near the optimal range of toletance.”

7. Limiting Factors On land, the major limiting factors are: –Precipitation –Soil Nutrients –Temperature In aquatic life zones, the major limiting factors are: –Temperature –Nutrient Availability –Sunlight –Dissolved Oxygen –Salinity –pH

8. Living Components of an Ecosystem All living organisms are assigned a trophic level or feeding level. The first trophic level are the producers. Producers are autotrophs that make their own food through the use of photosynthesis or chemosynthesis On land, producers are usually green land plants that capture 1% of the sun’s energy.

9. Living Components of Ecosystems In aquatic lifezones, the major producers are algae and phytoplankton. Photosynthesis uses light to make glucose Chemosynthesis may use inorganic compounds to create organic compounds. –Found near hydrothermal vents.

10. Living Components of Ecosystems Consumers eat producers and other consumers. Consumers are heterotrophs Several types of consumers: –Primary Consumers (Herbivores) –Secondary Consumers (Carnivores) –Tertiary and Higher Consumers (Large Carnivores) –Omnivores –Decomposers –Detritus Feeders

12. Living Components of Ecosystems In order to obtain the energy from the sun, consumers breakdown the bonds in organic compounds using cellular respiration. Two types: –Aerobic and anaerobic. All organisms, plant and animal, carry out respiration. Only plants carry out photosynthesis.

13. Energy Flow and Nutrient Cycling Ecosystems are sustained through a combination of one-way energy flow, nutrient cycling. Decomposers and Detritus Feeders are essential in environments because they can cycle nutrients back into the soil and help producers to grow.