The Biosphere Flashcards
Ecology
Interactions of organisms and environment in order to understand distributions and abundances.
Levels of Organisation in the biosphere
Organism-population-group of conspecific individuals living in same geographical area
Community-All populations of all species living in same geographical area (biotic factors)
Ecosystems-all populations of all species in same area/similar areas, including abiotic factors affecting them. (different species have different habitats within an ecosystem).
Chemoautotrphy
No sunlight needed for energy, depends on presence of chemoautotrophic prokaryotes (deep sea vents)-sulfides
Sources of Energy: Temperature
Heat ultimately arises from solar radiation, except for in ecosystems with geothermal sources-determines productivity of ecosystem-photosynthesis highly reduced or absent below 0 degrees Celsius and above 40 degrees Celsius.
Sources of Energy: Water
Organisms must maintain certain level of solute concentration in their extracellular fluid pools-homeostasis. Terrestrial organisms must keep from loosing too much water, fresh water organisms must control influx of water from environment (osmosis). Salt water organisms must control loss of water to environment (osmosis).
Axial Tilt
Earth is canted relative to its orbital plane. Hemispheres receive more indirect insolation at different points in orbit (seasons).
Eliptical orbit
Earth varies within a year in distance from the sun
Rotation
Earth is rotating more quickly than the atmosphere, resulting in atmosphere being “dragged”.
Coriolis force
Winds trend from east to west due to lag of earths atmosphere as it rotates.
Atmospheric Circulation Patterns
Differences in insolation due to movements, shape and tilt of earth responsible for large-scale circulation cells-form basis of terrestrial climate patterns. Highly complicated by disposition and topography of land masses.
Oceanic Circulation-Currents
Produced by prevailing winds and differences in insolation-strongly affected by distribution of land masses.
Oceanic Circulation-Redistribute Heat
Water has high specific heat, can store large quantities of heat and affect climate of nearby land.
Landforms
Changes in elevation affects air tempterature (+ or - 6 degrees per 1000 metres). Works in combination with prevailing wind to determine precipitation patterns on land. Land more distant from water tends to have extreme climate.
What does the global water cycle do?
Links all the biomes. Temperature differences across earths surface cause water to move from oceans into atmosphere, out of atmosphere, across earth’s surface, and back into oceans.
What are Biomes?
Major ecological associations determined by abiotic factors (tundra, desert, tropical forest). Determined mainly by temperature, precipitation, and elevation.
