Ecology. Ecology - the study of interactions between organisms and the living and nonliving components of their environment.

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1 Ecology Ecology - the study of interactions between organisms and the living and nonliving components of their environment.

2 Interdependence a key theme in ecology Everything is connected even if we do not always see the connection. So, any change in the environment can affect things far away. For example, What is the connection between a huge crop of acorns and an increase in Lyme disease in people?

3 More acorns feed more deer and deer mice More deer & deer mice provide more homes for deer ticks More ticks can bite people & spread Lyme Disease

4 Levels of Organization Ecologists subdivide the environment into smaller units to make it easier to study. 1. Biosphere - This is the most inclusive level of organization - it is the thin outer portion of the earth and the surrounding atmosphere that supports life (~20 km thick) - includes all living things

5 Levels of Organization cont. 2. Ecosystems - all organisms & non-living components in a particular place - some examples of ecosystems are: * ponds * sandy beaches * tide pools *desert

6 What are some of the differences in the non-living components of these ecosystems?

7 - Name some of the living and non-living components of a pond ecosystem Living (Biotic) Non-living (Abiotic)

8 Levels of Organization cont. 3. Communities - all of the interacting organisms in an area - there can still be hundreds of species living in a community but this level does not include the abiotic factors 4. Populations - all the members of a single species that live in the same place at the same time (can interbreed)

9 Ecosystem Components Ecosystems can be broken down into smaller habitats. Habitats are the places where an organism lives. Why do certain organisms (for example, a trout) live where they do? They need the correct habitat which depends on what else is living there (biotic factors) and what the physical & chemical characteristics of the area are (abiotic factors)

10 Ecosystem Components cont.. Because the environment is constantly changing, organisms must be able to survive in a range of conditions. How well it survives in different conditions (like temperature or ph) can be shown on a graph called a tolerance curve.

11 Tolerance Curve for Cutthroat Trout Shows they can tolerate temps between 5 and 23 C)

12 Acclimation some organisms can change their tolerance to abiotic factors by becoming acclimated to the new condition - for example, if you raised the temperature of a goldfish bowl a degree every week, your fish might be able to tolerate higher temperatures than other goldfish This is not the same as adaptation! Adaptation is a change in a species over time. Acclimation occurs in the lifetime of the individual organism.

13 How do organisms deal with change in their physical environment? Strategy 1 Conformers - these organisms do not control their internal conditions and change as their external environment changes example: reptiles are temperature conformers Strategy 2 Regulators - these organisms do control their internal conditions and maintain within their optimum range in spite of external conditions ex. Mammals maintain constant body temp

14 What if conditions change too drastically? How does an organism survive? Some species become dormant (a state of reduced activity) when the environmental conditions aren't suitable (like too cold, not enough food, too dry) Some species migrate (move to a more favorable habitat) when conditions become unbearable

15 The Niche (or what am I doing here?) - a niche is a role or way of life of a species in its environment examples include: food choices, how it gets resources, number of offspring it has

16 Some species are generalists & tolerate a wide variety of conditions. An example of this is the rat which can feed on almost anything. Some species are specialists. They have a narrow niche (ie: they are picky). Example: Koala bear that only feeds on certain kinds of Eucalyptus leaves