Chapter 40 - Population Ecology and Distribution of Organisms

1. Chapter 40 - Population Ecology and Distribution of Organisms

2. Earth from the moon - A “Humbling View”Does our Environment Have Limits?What is Our Role?

3. “The ‘Control of Nature’ is a phrase conceived in arrogance, born of the Neanderthal age of biology and philosophy, when it was supposed that nature exists for the convenience of man.”Rachel Carson in her 1962 book Silent Spring.”

4. Ecology – The scientific study of the interactions between organisms and their environments.(from the Greek “Oikos” home -“logos” study)Ecology vs. Environmental ConcernDistribution (Geographic Range)Abundance (# of Particular Organism in Range)Factors Affecting Distribution and Abundance:Abiotic Factors (Non-Living Chemical and Physical Factors like Temperature, water, light and nutrients.)Biotic Factors (Living Factors – All of the organisms that are part of an individual’s environment. They may compete with, prey on or change its physical or chemical environment.)

5. Distribution and Abundance of the red kangaroo in Australia, based on aerial surveys

6. Organismal Ecology Population Ecology Community Ecology Ecosystem Ecology Four Basic Levels of Ecology

7. Ecological Time (Minutes, Months, Years) Evolutionary Time (Decades, Centuries, Millenia, or Longer!) Example: Hawk Feeding on Field Mice Four Basic Levels of Ecology Organismal Ecology (Individual) Population Ecology (#’s) Community Ecology (Interaction) Ecosystem Ecology (Energy Flow) Other Types of Ecology Landscape Ecology (Arrays of ecosystems and how they are arranged in a geographic region) Biosphere “Global Ecosystem” – Sum of all Planet’s Ecosystems – includes atmosphere, sub-terranium, land, lakes, caves, oceans.

8. Biogeographic realms

9. Distribution of OrganismsFlowchart of factors limiting geographic distribution

10. Species Dispersal Dispersal: The distribution of individuals within geographic boundaries. - Geographic isolation in evolution. - Broad patterns of current geographic distributions

11. Transplant Successful: Distribution Limited because the area is inaccessible, time has been too short to reach the area, or the species fails to recognize the area as suitable living space Transplant Unsuccessful: Distribution limited either by other species or by physical and chemical factors. Control: A transplant done within existing range provides a baseline on handling and transporting. Rarely Done : Most observation done on natural and human caused transplant. Example: Zebra Mussels Species TransplantSet of transplant experiments for a hypothetical species

12. Spread of the African honeybee in the Americas since 1956

13. Biomes and Biosphere • Biosphere - the sum of all the planet’s ecosystems • Biome - areas of predominant flora and fauna • Affect of Temperature and Precipitation on Defining Biomes Ecotone: biome grading areas

14. Terrestrial biomes • Tropical forests- equator; most complex; constant temperature and rainfall; canopy • Savanna- tropical grassland with scattered trees; occasional fire and drought; large herbivores • Desert- sparse rainfall (<30cm/yr) • Chaparral- spiny evergreens at midlatitudes along coasts • Temperate grassland- all grasses; seasonal drought, occasional fires; large mammals • Temperate deciduous forest- midlatitude regions; broad-leaf deciduous trees • Coniferous forest- cone-bearing trees • Tundra- permafrost; very little precipitation

15. Global climate •Precipitation & Winds • Seasons

16. Lake stratification & turnover • Thermal stratification - vertical temperature layering • Biannual mixing - spring and autumn • Turnover - changing water temperature profiles; brings oxygenated water from the surface to the bottom and nutrient rich water form the bottom to the surface

17. Aquatic biomes Vertical stratification: • photic zone - photosynthetic light • aphotic zone - little light • Thermocline - narrow stratum of rapid temperature change • benthic zone - bottom substrate • Benthos - community of organisms • Detritus - dead organic matter; food for benthic organisms

18. Freshwater biomes • Littoral zone - shallow, well-lit waters close to shore • Limnetic zone - well-lit, open water farther from shore • Profundal zone - deep, aphotic waters Lake classification: • oligotrophic - deep, nutrient poor • eutrophic - shallow, high nutrient content • mesotrophic – moderate productivity • Wetland - area covered with water • Estuary - area where freshwater merges with ocean

19. Marine biomes • Intertidal zone- area where land meets water • Neritic zone- shallow regions over continental shelves • Oceanic zone- very deep water past the continental shelves • Pelagic zone- open water of any depth • Benthic zone- seafloor bottom • Abyssal zone- benthic region in deep oceans