The Scope of Ecology Chapter 34

Oikos- greek for “house” What is ecology? Ecology- the scientific study of interactions between organisms and their environments, focusing on energy transfer It is a science of relationships. Oikos- greek for “house” What do you think about when I say ecology? Recycling? Acid rain?

#16 http://www.youtube.com/watch?v=izRvPaAWgyw #16#14 (ecology rules of life CC)

Ecology is primarily a descriptive science but is becoming more experimental

1.  very difficult to control experiments 2.  some research done in laboratories 3.  most done in the field

What do you mean by environment? The environment is made up of two factors: Biotic factors- all living organisms inhabiting the Earth Abiotic factors- nonliving parts of the environment (i.e. temperature, soil, light, moisture, air currents) When I say environment you think what—weather. Well Ok but it it much more than that

Interaction interaction includes how the environment affects the organism and how the organism can alter the environment

Interaction 1.        photosynthetic organisms use sunlight (abiotic factor) and produce oxygen as a bi-product which is used by organisms for cellular respiration

Interaction 2.        shading of the forest floor by trees can make the environment less suitable for their offspring to grow, yet more suitable for other organisms

Levels of Ecology ecological research ranges from studying adaptations of organisms to the dynamics of ecosystems

Organism- any unicellular or multicellular form exhibiting all of the characteristics of life, an individual. The lowest level of organization

1.  organismal ecology – study of the way organisms meet the challenges of abiotic environmental factors e.g., reptiles retreat to shaded areas to maintain body temperature

Population-a group of organisms of one species living in the same place at the same time that interbreed and compete with each other for resources (ex. food, mates, shelter)

2.        population ecology – study of populations and interaction with environment e.g., what environmental factors affect population size and composition?

Community- several interacting populations that inhabit a common environment and are interdependent.

3.        community ecology – study of all organisms that inhabit an area e.g., study of predator – prey relationships, competition, disease

4.        ecosystem ecology – study of all abiotic factors as well as all organisms in an area e.g., study of energy flow and chemical cycling among the biotic and abiotic components

Biosphere- life supporting portions of Earth composed of air, land, fresh water, and salt water. The highest level of organization

5. Biosphere ecology – studying the global system of living things e.g. humans effect on the ozone layer or climate change

Biosphere Ecosystem Community Population Organism Just like with classification, ecology is hierarchal. Each level builds on itself and they fit together like nesting boxes. Population Organism

Abiotic factors   temperature 1.        most organisms are NOT able to regulate their body temperature; i.e., they’re ectothermic as apposed to endothermic 2.        temperature has a tremendous affect on metabolism 3.        even endotherms function best within a temperature range

Abiotic factors   water 1. essential for life 2. poses osmotic challenges for organisms

Abiotic factors   wind amplifies the effects of temperature by increasing heat loss and evaporation

Abiotic factors  

Climate Weather over a long period of time most important components Precipitation Temperature Wind

Convection Heat transfer in a fluid (liquid or gas) Heat rises The current formed is a Convection Cell

http://www.youtube.com/watch?v=5QOVwX-6g-Q #81Video #76 (Global winds)

Desert Latitude 30 degrees N or S Cool dry falling air limits precipitation

Rain-Shadow Effect

Rain Shadow Effect Air flowing over mountain ranges rises and cools, losing moisture Climate is much dryer on the backside of the mountain range

Coriolis Effect Coriolis effect is the apparent curvature of global winds, ocean currents, and everything else that moves freely across the Earth's surface.

Videos##77,78,79 Coriolis effect, Force, CC http://www.youtube.com/watch?v=i2mec3vgeaI # http://www.youtube.com/watch?v=aeY9tY9vKgs #83 http://www.youtube.com/watch?v=rdGtcZSFRLk

"The tendency of a circulation in a fluid to develop in a clockwise direction in the Northern Hemisphere and a counterclockwise direction in the Southern Hemisphere can be traced to the earth's rotation. Imagine a cannon fired southward from any latitude above the equator. Its initial eastward motion is the same as that at a point on the spinning earth. This initial eastward velocity is less than that at a point later in its trajectory, because points closer to the equator travel in a bigger circle as the earth rotates. Therefore, the cannon shell is deflected westward (to the right), from the perspective of a person standing on the earth. A gunner firing a cannon northward would find that the shell is also deflected toward the right. These sideways deflections are attributed to the Coriolis force, although there really is no force involved--it is just an effect of being in a rotating reference frame."

The Coriolis force accounts for why cyclones are counterclockwise-rotating storms in the Northern Hemisphere, but rotate clockwise in the Southern Hemisphere. The circulation directions result from interactions between moving masses of air and air masses moving with the rotating earth. The effects of the rotation of the earth are, of course, much more pronounced when the circulation covers a larger area than would occur inside your bathtub.

Northern Hemisphere- everything turns right causing counterclockwise rotation of weather systems

Polar Easterlies Westerlies Northeast Tradewinds

Seasons Seasons are caused by the Earth’s tilt on its axis

Terrestrial Biomes

#80 (Biomes Biology) http://www.youtube.com/watch?v=RFEV-hiP2gQ

Terrestrial Biomes Biome- geographic areas that have similar climates and ecosystems

Terrestrial Biomes The most common biomes are: Tundra Taiga Temperate Deciduous Forest Tropical Rain Forest Grassland Savanna Desert

Terrestrial biomes Tundra is located in areas where temperatures minimize plant growth but not covered completely with ice

Tundra Found in parts of Canada, Alaska, and Siberia

http://www.youtube.com/watch?v=3pp4hIg4JjQ #15 (Arctic Tundra)

Tundra – “The Cold Desert” Found at latitudes around the North Pole Less than 25 cm precipitation yearly Very cold year round (-40ºC in winter) Cold, dry, treeless region

Tundra – “The Land of the Midnight Sun” Winter lasts 6 to 9 months with no daylight Summer is short and cold with 24 hours of sunlight a day

Tundra- Soil is poor Permafrost Layer of permanently frozen soil

Plants of the Tundra Tundra plants are resistant to drought and cold

Plants of the Tundra Reindeer moss – It’s a lichen!

Plants of the Tundra Lichens

Plants of the Tundra Lichen

Plants of the Tundra True Mosses

Plants of the Tundra Small shrubs and flowers

Plants of the Tundra Small shrubs and flowers

Plants of the Tundra Small shrubs and flowers

Plants of the Tundra Grasses

Animals of the Tundra Many animals of the tundra migrate there during the short summer

Animals of the Tundra Biting insects Mosquito Blackfly

Animals of the Tundra Snowy owl

Animals of the Tundra Arctic hare

Animals of the Tundra Caribou – “Reindeer”

Animals of the Tundra Musk oxen

Animals of the Tundra Lemmings

Animals of the Tundra Lemmings