1. Introduction to Ecology Chapter 52

2. Climate ► …is the average long-term weather of an area; varies with differing amounts of solar energy received by different places on Earth. ► Solar energy input determines temperature, precipitation, and air and ocean circulation patterns which leads to different climates and vegetation patterns.

3. Uneven Heating ► Regions near equator are hot due to more direct sun rays, concentrating energy in a smaller area. ► Regions near poles are cold due to the acute angle of rays. ► Regions in between have intermediate temps.

4. Seasonal Changes ► The 23.5 degree axis tilt causes regions to receive more direct rays during certain times of the year. ► Our winter = northern hemisphere tilted away from sun. ► Our summer = northern hemisphere tilted toward sun.

5. Hadley Cells ► …vertical convection cells that distribute heat and moisture over earth’s surface. ► Warm moist air rises, dropping precip. ► Air moves N or S, then falls as cool dry air.

6. Global air circulation ► Most precip tends to fall at equator (rainforests), tapering off towards 30 degrees latitude. ► Dry air descends at 30 degrees (deserts). ► Precip falls again at 60 degrees (decid. and conif. forests). ► Dry air descends at poles.

7. Coriolis Effect and Winds ► Due to the rotation of the earth, air masses don’t just move N and S. ► Air masses (winds) in northern hemisphere are deflected to the right. ► Winds in southern hemisphere deflected to the left.

8. Microclimates ► …local climates that differ from the general climate of a region due to local topography. ► …formed by:  Rain shadow effect: more arid conditions on leeward sides of mountain ranges.  Cities: buildings block wind, absorb and emit heat.  Land breezes/Sea breezes: day to night differences in coastal areas.  Altitude: climate colder as elevation increases.

9. Rain Shadow Effect

10. Aquatic Biomes ► Saltwater (marine):  Oceans  Estuaries – semi-enclosed area; saltwater mixes with freshwater.  Coastal wetlands – land areas covered with water at least part-time. ► Freshwater:  Standing (lentic) – lakes, ponds, inland wetlands.  Flowing (lotic) – stream and river systems.

12. Areas of Concern ► Coral reefs: ► High diversity and productivity. ► Grow slowly, disrupted easily, need certain temp and nutrients. ► Problems: warming trends, destruction. ► Inland wetlands: ► Marshes, swamps, prairie potholes, floodplains. ► Vital breeding grounds. ► Water purification. ► Flood control.

13. Terrestrial Biomes ► Have characteristic climate and plant life. ► Here is an incomplete list of biomes: ► Temperate ForestConiferous Forest Taiga Tundra Temperate Grassland Savannas Chaparral/Mediterranean Scrub Desert Tropical Rain Forest