Chapter 3.3 – Studying Organisms in Ecosystems (pages 93 – 108) Chapter 3.3 – Studying Organisms in Ecosystems

3.3 Studying Organisms in Ecosystems In this section you will: Identify abiotic and biotic characteristics, and explain how they affect ecosystems Explain how ecosystems support a diversity of organisms because of a variety of niches and habitats Explain how limiting factors can affect the distribution and size of a population of organisms Design an investigation to study a local ecosystem Research the impacts of an introduced species in western Canada Investigate and study a local ecosystem

Life on Earth is not evenly distributed What conditions affect biodiversity of organisms that will be found in a given area? The abiotic factors that dictate the productivity of an ecosystem often have major effects on the distribution.

Climate and Biomes Climate- Average weather conditions in a particular region over a period of time. Temperature and rainfall are the main determining factors in he climate of an area.

Why are there different climates on Earth?

Earth heats unevenly because it is a sphere This affects movement of ocean and wind currents that interact with physical features to produce patterns of rainfall. Patterns of precipitation influence soil type.

Altitude has a similar effect as latitude, but on a local scale Q #3

Biomes Biomes are large ecosystems or groups of ecosystems. Biomes have distinct biotic life due to distinct abiotic conditions How could you use this graph to predict the distributions of Earth’s biomes?

Question 1. Which biome do you expect to find the greatest diversity of life in, which biome has the least diversity of life? How did you make this prediction?

Question 2. Although the same biome may be found on different continents, what similarity do biomes often share?

Altitude/Latitude Both altitude and altitude effect population distribution as well Altitude- Height of an object or point in relation to sea level or ground level Latitude- Angular distance of a place north or south of the earth's equator, usually expressed in degrees and minutes.

Effects of Latitude and Altitude

The biosphere is divided into smaller geographic regions that allow us to study organisms at different levels of inclusion: biosphere  biome  range  habitat  niche

Question 3. Latitude effects the distribution of biomes on a global scale. What has the same effect on the distribution of biomes on a local scale?

Habitats Within a biome there can be a tremendous amount of variation. A biome may be broken down further into a vegetation zone, which may be further divided into different habitats.

Habitats Each habitat has its own set of organisms and abiotic conditions.

Question 4. What biome does the majority of Alberta occupy?

Habitat Habitat- area with particular characteristics, both biotic and abiotic. Each species has its own habitat which meets all of its needs for survival and reproduction.

Habitat Each species is in the specific habitat that its physical, physiological and behavioral adaptations equip it to survive and reproduce in.

Range A range is an area where an organism is generally found. Within its range, an organism is only found where its habitat requirements are met.

Question 5. Distinguish between a species habitat and range Question 5. Distinguish between a species habitat and range. Will a species be found everywhere throughout a range? Why or why not?

However, not all places within a range will have a suitable habitat for those organisms Therefore, organisms do not live throughout their range, but rather in habitat within range Range may change as humans interfere or modify the environment

As you can see, the range of the bear has greatly decreased since 1850 This map shows the historical and current range of the Grizzly bear in the western United States and Canada. As you can see, the range of the bear has greatly decreased since 1850 www.greateryellowstone.org

Habitats and Niches within Ecosystems An ecological niche is the role an organism plays within its community; the total range of biotic and abiotic requirements. How can so many warbler species inhabit the same tree?

Question 6. How might an organism having an very narrow niche (eats 2 varies of plants for food source) put it at a higher risk of becoming endangered than an organism that eats a wide variety of vegetation?

Question 8. How is it possible for two species to successfully share the same habitat; for example, different species of warblers are known to occupy the same spruce tree. Question 9. What would happen to the different species of warblers is they all tried to occupy the same area of the same tree?

Niches in Aquatic Environments In aquatic environments- amount of available light is often the main determining factor Each zone of a lake will have distinct groups of organisms