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# Lec. 22: Ecology **Ecology:** Study of an organism & its environment * **Population ecology:** factors that effect populations (same species) * **Community ecology:** Species interactions & effects on pops./commun. * **Ecosystem ecology:** energy & chemical flaw btwn organisms & environment * **...

# Lec. 22: Ecology **Ecology:** Study of an organism & its environment * **Population ecology:** factors that effect populations (same species) * **Community ecology:** Species interactions & effects on pops./commun. * **Ecosystem ecology:** energy & chemical flaw btwn organisms & environment * **Climate:** depends on: temp., precipitation, wind, & sunlight. (global-solar energy. Local-Seasons) * Radiation at the equator causes changes in global air circulation * Seasonal cydes experienced when earth tilts → seasons → impact wind & oceans * Oceans warm/cool air mass. Mountains cool/dry air travelling over windward side * Rain Shower effect on leeward side; air warms/absorbs moisture and Nud * More forest = absorb more solar radiation + H₂O returns to atm, cools surface **Microclimates:** Shade, wind patterns, evaporative patterns **Abiotic (nonliving):** PH. temp. H₂O, wind, light, nutrients **Biotic (living):** animals, plants, insects **Ecological change:** * Alters outcome of ecological interactions * Alters selective pressures → Evolutionary change **Global Climate Change:** Caused by burning fossil fuels (extreme weather/temp.) **Terrestrial biome:** Species → convergent evolution. Dessert, Savanna, Chaparral, Trop forests **Ecotones:** borders between biomes. Grassland, Tundra → hight precipitation → lowest **Aquatic biomes:** marine (3% salt). fresh H₂O (0.1% salt). divided into zones * **Pelagic:** photic (light reaches) → aphotic (no light) * Abyssal: below aphotic (2,000-6,000 m below Surface) * Benthic: Sediment & organic matter below H₂O (Coral reefs, lakes, Oceans, wetlands H₂O, Streams/river) **Thermocline:** layer of rapid temperature change * Winter - cold * Spring → 0 * Summer , fall → warm upper H₂O & Cold lower H₂O **Hypoxia:** State of low oxygen in freshwater. **Edemic species:** found in only one geographical area (Kangaroo, Saguaro cactus) **Higher elevations:** high temps, low O₂, dry conditions,** high UV radiation **Example of an observed ecological change (median guppies):** * Evolved under low predators conditions → (reduce algae pops) * Evolved under high predators conditions → (increase algae pops)