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Fig. 52.18 PowerPoint Presentation

Fig. 52.18

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Fig. 52.18

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  1. Fig. 52.18

  2. Ecology • Biotic Factors • Competition • Predation • Disease • Parasitism

  3. Fig. 52.20

  4. Ecology • Abiotic Factors • Temperature • Temperature and temperature variation extremely important • Cells may rupture at very cold temperatures • Why don’t trees freeze and explode? • Proteins denature at sustained high temperatures (usually >45 oC) • Some bacteria can survive at >90 oC • Water • Essential to life • Availability varies • Terrestrial organisms always fighting desiccation • Aquatic organisms struggling with osmotic stress

  5. Ecology • Abiotic Factors • Sunlight • Provides vast majority of energy for living systems • Affects distributions of terrestrial organisms • Affects depth distributions and sensory systems of aquatic organisms • Intensity and spectrum change with depth • May affect behavior • Ex: DVM, activity patterns • Wind • Amplifies temperature variation through evaporation and convection • Ex: Wind chill factor • Affects rates of water loss, growth forms of plants • Rocks and Soil • Physical structure, pH, mineral composition, organic content • Aquatic sediments affect water chemistry • First four factors (temperature, water, light, wind) are major components of climate (long-term patterns)

  6. Ecology • Climate Effects • Affects geographic distribution (range) of species • Affects survival, reproduction, dispersal

  7. Silver-Washed Fritillary (Argynnis paphia) Fig. 52.8

  8. Population Ecology • Density and Dispersion • Density • Number of individuals + size of habitat • May be influenced by resource availability, disturbance • May vary over time • How do we measure organismal densities? • Complete census • Subsample (quadrats, transects, single taxon) • Indicators of density (tracks, scat) • Mark-recapture • Not static over time