Smedes review

• Ecosystem


  The interaction of the living & non-living things in a specific area
• Environment


  The entire natural world
• Habitat


  The specific environmental conditions that a given species needs
• Symbiosis

  Two species living in close proximity
• Mutualism

  A symbiotic relationship where both species benefit from the interaction (Bees & plants)
• Biome


  An area that shares an average yearly temperature and precipitation pattern, defined by annual precipitation & temperature
• Aquatic Biomes

  •influenced by salinity, depth, and flow
• Aquatic Biomes


  • Influenced by Salinity, flow, & depth
• Law of Conservation of Matter


  Matter is never created or destroyed, it only changes form
• Reservoirs

  Things that temporarily store matter
• Sources


  Processes that move matter around between reservoirs
• Sinks


  Reservoirs that store more matter than they give off
• Carbon Cycle


  1. Carbon sources return carbon to atmosphere

  2. Sinks remove carbon from atmosphere

  3. The amount of time carbon spends in different reservoirs significantly varies

  4. Extraction & Combustion are biggest contributors for carbon dioxide
• Nitrogen Cycle


  1. Nitrogen cycles pretty quickly through reservoirs

  2. Atmosphere is biggest nitrogen reservoir

  3. Nitrogen exists in a form that's biologically unavailable to plants or animals

  4. Nitrogen fixation converts biologically unavailable nitrogen gas (N) into biologically available forms like ammonia (NH3) & nitrate (NO3) (bacteria fix nitrogen)

  5. Rhizo bacteria - Symbiotic bacteria living in root nodules of plants fixing Nitrogen
• Phosphorus Cycle


  1. Rocks and sediments are largest reservoirs

  2. Phosphorus can only be released by weathering

  3. Phosphate released in small rocks

  4. Phosphate ions carried in runoff to new ecosystems
• Water Cycle


  1. Driven by sun's energy

  2. Evaporation happens when the sun has given enough energy for the water to change from liquid to gas

  3. Precipitation happens when moisture in air has reached a condensation point based on temperature of atmosphere

  4. Infiltration - water seeping through soil & recharging groundwater reservoirs

  5. Transpiration - water evaporating from the leaves of plants
• Fresh water reservoirs


  • Ice caps/glaciers
  • Groundwater
  • Rivers/lakes
• Primary Productivity

  The rate at which plants in an area convert sunlight into glucose or plant tissue
• Respiration loss


  The energy plants use up for their own cellular respiration
• Gross Primary Productivity (GPP)


  Total primary productivity
• Net Primary Productivity (NPP)

  Total amount plants can store after cellular respiration
• NPP = GPP - Respiration loss
• GPP = 1000 Kcal/m²/year, Respiration loss = 250 Kcal/m²/year, therefore NPP = 1000 - 250 = 750 Kcal/m²/year
• Food chains

  Arrows show the movement of both energy & matter
• Trophic cascades

  Top predators control herbivore populations, leading to larger primary producer populations
• Age Structure Diagrams


  • If pre-reproductive age cohort is higher, high growth rate
  • If reproductive age cohort is larger, growth rate has slowed
  • If pre and reproductive age became more equal, population growth is slow, nearing stable population size
  • If pre-reproductive age is lower, negative birth rate, increased life expectancy with widespread access to healthcare
• Total Fertility rate


  Average number of babies a woman in a population will give birth to in her lifetime
• The earlier a woman has children


  The more likely she will be to have more in her lifetime
• Crude Birth rate / Crude Death rate

  Births & deaths per 1000 people in a population
• Rule of 70= 70/growth rate % = doubling time in years
• Infant Mortality rate


  Deaths of children under 1 per 1000 live births
• Infant Mortality rate


  Can be affected by access to clean drinking water, can increase Total Fertility Rate
• Replacement Level Fertility


  Average children born per woman that a population would need to remain constant
• Gross Domestic Product


  Total market value of all finished goods & services produced in a country divided by all the people living there
• Theory of Demographic Transition


  Over time, countries undergo industrialization which decreases death rate & birth rate while increasing population growth & affluence
• Specialist species


  • Species that rely on a highly narrow, specific niche
• Generalist species


  • Species that have a broad ecological niche or range of food & habitat tolerance
• 1. R selected species

  • Capable of a rapidly high population growth rate, advantaged in constantly changing ecosystems, reach sexual maturity quickly, little to no parental care, produce large number of offspring
• 1. K selected species

  • Typically live in populations that are at or near carrying capacity, slow to reach sexual maturity, few offspring at a time, longer life spans, high level of parental care, advantaged in ecosystems with high competition
• Biotic Potential


  Maximum number of offspring a species can produce