Ecology Professor Andrea Garrison Biology 3A Illustrations 2014 Cengage Learning unless otherwise noted
Ecology Ecology (oikos = house) is the study of where an organism lives and all the interactions occurring there Much of ecology is descriptive Forms basis for hypotheses about interrelationships that can be tested Ecology 2
Ecology Organismal ecology = study all aspects of relationships of a species of organisms to their environment (genetic, physiological, anatomical, etc.) Population = all individuals of a species within given geographical area Population ecology = study of how size and other characteristics of a population change over time and space Community = all the different populations occurring in a given area Community ecology = study of how different populations of a community interact with each other; including how predation, competition and environmental disturbance affect a community Ecosystem = the community + non-living aspects of environment Ecosystem = biotic + abiotic environments Ecosystem ecology is study of nutrient cycling and energy flow between biotic and abiotic components of ecosystem Ecology 3
Ecology Biosphere = all aspects of the earth that sustain life; earth s crust, water, atmosphere Environmental issues affect ecosystems and biosphere Ecology of an organism/population/community heavily impacted by environmental factors Ecology 4
Environmental Diversity of Biosphere Biosphere heavily influenced by climate Climate varies around the world Factors influencing climate on global, regional and local scale Sunlight Temperature Clouds Rainfall Humidity Wind speed Ecology 5
Global Climate Variations Minimum and maximum monthly temps vary with latitude Solar radiation more intense near equator than near poles Ecology 6
Global Climate Variations Earth s tilt causes seasonal variation in hours and intensity of light Ecology 7
Global Climate Variations Uneven heating creates air circulation and rain patterns Ecology 8
An idealized pattern of air circulation. Air warms, absorbs moisture, ascends, cools, and releases moisture. Cool, dry air descends at 30. Warm air at the equator absorbs moisture. It cools as it rises and releases moisture as precipitation. Rotation of Earth on its axis Cool, dry air descends. Polar circulation cell Middle latitude circulation cell Low latitude circulation cell Air flow near Earth s surface is deflected by the Coriolis Effect. Easterlies (winds from the east) Westerlies (winds from the west) Northeast tradewinds Southeast tradewinds Cool, dry air descends at 30. Air warms, absorbs moisture, ascends, cools, and releases moisture. Cool, dry air descends. Westerlies Easterlies Ecology 9
Global Climate Variations Uneven heating by solar radiation also warms ocean waters unevenly. Expansion of warmer equatorial waters causes 8cm higher sea level at equator Water runs downhill Prevailing winds blow this water in their direction Coriolis Effect and position of landmasses create circular current patterns Water is warm after spending time at equator Water is cold after spending time at poles Temperature of water impacts coastal climates Coasts on western edge of ocean are warmer than coasts on eastern edge of ocean Ecology 10
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Regional Climate Variations Ocean moderates climate Absorbs heat in summer Releases heat in winter Coastal regions more moderate climate than inland regions Ecology 12
Regional Climate Variations Monsoons (Arizona, New Mexico, Africa, Asia, So. America) Wind reversals due to heating of land Hot air rises in summer Air moves in due to low P Air coming from ocean brings moisture As air warms it rises, causing cooling and release of rain Cold air sinks in winter Air moves out due to hi P here and low P over ocean Winter air dry Ecology 13
Regional & Local Climate Variations Mountains, valleys, etc., affect regional and local climates In No. Hemisphere, south facing hillsides get more sun; warmer and drier than north facing hillsides Mountains create rain shadows Ecology; photo by A. Garrison: westbound Hwy 58 east of Bakersfield 14
Regional & Local Climate Variations 1 Winds carry moisture inland from Pacific Ocean. 2 Clouds form and rain falls on windward side of mountain range. 1 3 3 Rain shadow forms on leeward side of mountain range. Moist habitats 4000/75 3000/85 2000/50 1800/125 1000/85 1300/30 15/25 White numbers indicate altitude in meters followed by mean annual precipitation in centimeters for the Sierra Nevada of California. Ecology 15
Variations in Precipitation Ecology 16
Local Climate Variations Abiotic conditions immediately surrounding an organism have greatest impact Microclimate EX: Fallen log creates moist, cool climate underneath EX: Large tree decreases temp and increases humidity EX: Crevice in rock protects from sun, wind, waves Ecology 17
Terrestrial Biomes Worldwide region of life described by type of vegetation and the other organisms associated with it. Usually characterized by annual rainfall and temperatures Vegetation is superficially similar to other locations with same biome due to similar climate, however, the species are often different Ecology 18
Terrestrial Biomes Know these biomes and their general characteristics Tropical rainforests Tropical deciduous forests Tropical montane forests Savanna Deserts Chaparral Temperate grasslands Temperate deciduous forests Temperate rainforests Boreal forest (taiga) Arctic tundra Alpine tundra Ecology 19
Aquatic Habitats Know these biomes and their general characteristics Freshwater environments Streams Rivers Wetlands Lakes Littoral, limnetic, profundal zones Marine environments Photic and aphotic zones Pelagic zone Neritic and oceanic zones Benthic zone Intertidal and abyssal zones Estuaries Be sure to understand where phytoplankton can survive and the impact of this on the community Ecology 20