Community Ecology

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Community Ecology
2013-09-24 20:02:58
Biology GRE

Biology GRE
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  1. Evolution
    Change in frequency of different alleles in population and time

    Individuals do not evolve, populations evolve
  2. Hardy Weinberg Theorm (idea)
    • "ideal" gene pool
    • came up with five requirements that a population needs to meet in order to remain in non evolving state
    • **no population actually meets all of these
  3. Hardy Weinburg Five Conditions
    • No emigration/immigration, no genes enter or leave
    • Large population, few mutations are effectively diluted not so in small populations 
    • No net mutations, many copies of the same gene mean that change few alleles do not effect net
    • No natural selection, certain alleles with survival advantage and therefore frequency in subsequent generations if natural selection is occurring
    • Random mating
  4. Biomes
    named for type of vegetation that grow there
  5. Taiga
    • Confierous forest, dense conifers, cone bearing trees 
    • Little to no undergrowth
    • Poorly fertilized soil
    • Get a lot of sunlight, so grow tall quickly
  6. Taiga Expected Fauna and adaptation
    • Bears wolves small cats
    • Thick coats fur tress thin point seed
  7. Desert
    • Driest of all biomes
    • Decrease amount of rain, limit vegetation that can live there
    • Must be able to store water in their stems or varnish like coating to conserve water
    • Need to produce seeds and fruits quickly so they can grow and mature during rainy season
  8. Desert Animals and Adaptations
    • Seed eaters, reptiles, snakes, large variety of insects beetle
    • Appendages designed for burying in sand, water retention (solid urine), scales, develop from eggs, large ears
  9. Tundra
    • Frozen desert
    • Dark for up to 10 months of the year
    • Biodiversity low
    • Plant are usually short to ground and have short growing season and need little water
    • Lichen moss predominate
  10. Tundra Animals and adaptations
    • need winter camoflague, and dark for short summer months
    • oxen, caribou, wolves
    • Large compact bodies, thick fur, plumage, thick fat
  11. Permafrost
    • Layer of subsoil that never thaws even in warmer summer months
    • Prevents plants from anchoring themselves with deeper roots and from absorbing lots of water. Therefore, they are short and compact
  12. Charparral
    Found in coastal areas with long hot summers, short rainy winters
  13. Fire Resistant plants
    Abundant is savanna, short dense shrubs whose seeds sprout quickly and vigorously after fires that frequently sweep chaparral
  14. Chaparral animals and adaptaions
    • Scavengers, seed eating birds, coytoes
    • Live in prolonged dry periods, varied diet characteristics
  15. Savanna
    • Sparse short trees lots of shrubs, mainly grassland season similar to chaparral  hot and dry and warm and wet
    • Fire adapted flora most of earths largest mammals
  16. Savanna animals and adaptations
    • Large plant eaters, buffalo, large cats, giraffe, zebra
    • Burrowing abilities for small
    • Migratory social group interaction
    • Long periods of dryness
    • Speed in larger animals
  17. Temperate Grasslands
    • Similar to seasons in charparral and savanna
    • Hot and dry then warm and wet
    • Periodic fires which allow fast growing fire resistant plants to recollinize
    • Large grazing mammals prevent plants, growing very tall
    • Praires across midwestern U/S/ Fertile N rich oil small animals eat dead and decaying matter and contribute to N rich soil
  18. Temperate Grasslands animals and adaptations
    • Horses, buffalo, raccoon
    • Digestive systems for grass plant consumptions
    • Second stomach, longer intestines fur, head behavior/ migration in larger animals
  19. Tropical Forest
    • Temperate fairly stable throughout the year, ex tropical rain forests
    • Soil is very low in nutrients but so much can grow because so much living and dying soil does not hold for long time get used up night away
    • Tall trees usually prevent small trees from popping up
  20. Evapotransiration
    Evaporation of water from surface of leaves
  21. Tropical dry forest
    Grow in warm tropical regions that do not experience the rainfall of tropical rain forests

    ~dene chaparral
  22. Tropical Deciduous
    • Populated with taller deciduous trees, which loose eave until next rainy seasons
    • Moderate rainfall but experience dry season
    • *all three aboave essential watershed areas, basin lie area land abundant sources clean water
  23. Tropical forest animals
    • Lots of species insects apes mammals rodent amphibans birds
    • climbing ability, claws, gripping appendages, jumping
  24. Temperature deciduous Forest
    Experience all four seasons, tree have growing cycles where loose their leaves
  25. Temperate Deciduous Animals and adaptations
    • Rodents, birds, mammals
    • Thick fur coats, hibernation
  26. Primary Succesion
    • Communities of organisms are completely restructured
    • Gradual change of new and lifeless areas into thriving ecosystems
    • Lichens mosses, then insects, small birds, and eventually larger organisms
  27. Secondary Succession
    • Rebuilding of community organisms that have been destroyed by natural disaster or human interference 
    • Forest Fire Volcano
    • Smaller grasses , shrubs provide foundation for growth of large conifers and deciduous trees
  28. Interspecific competition
    • Competition for sparse resources between populations of different species
    • Two species eat grass
  29. Pioneer Organism
    • Those who first take hold in barren habitat
    • Many facilitate the growth of other species
    • Ex: plant species improve the quality of soil so other plants can come in
    • Mycorhizea
  30. Symboisis: 4 Types
    • Living together
    • Does not necessarily imply +/+
    • Competition
    • Parasitism
    • Commensilism
    • Mutualism
  31. Competition
    Two of more species in one habitat
  32. Interference Competition
    Fight physically to gain resources, usually space
  33. Exploitative Competition
    Compete by comsuming same resources
  34. Competitive exclusion principle
    When two species compete for same limited resources one will be driven to extinction
  35. Niche
    • Physical area in which organism lives and ha resources needed to survive
    • Organisms role in ecosystem (i.e. where it is in the food web)
  36. Dinural vs Nocturanal
    Awake at day vs night
  37. Fundamental Niche
    Comprised of all potential resources that species can use
  38. Realized Niche
    • Comprised of the resources the species actually uses
    • Competition with other species limits the actual resources available
  39. Parasitism
    One organism lives on or within another host organism to give enters and nutrition to ones self
  40. Ectoparasite/Endoparasite
    Lives outside host, lives inside host
  41. Brood parasite
    • Not actually feeding but rather fooling a host organism into caring for the parasites offsprings
    • ex: birds lay eggs in other nests and have them keep them warm
  42. Conmensalism
    • Benefit from relationship but doesnt harm or help the other
    • Hitchhikers or protection
    • Remoras and sharks
  43. Mutualism
    • Typical symbiosis
    • Both benefit
    • Zooxanthelle and corals
  44. Species Richness
    • how many types of species of organisms
    • All species
  45. Relative abundance
    how many of a particular species
  46. Biodiversity
    Species richness and relative abundance
  47. Resilience
    Ability of community to survive through various environmental changes
  48. Stability
    Ability of community to regain ORIGINAL biodiversity after stressor
  49. Keystone Species
    • Species which if removed can cause widespread destruction
    • Habitats change dramatically
    • Are more important than their relative abundance
  50. Three Ecosystem Roles
    • Produces-Use light or chemical energy and turn into sugars
    • Consumers
    • Decomposers-Respire for breaking down bodes of cells of dead organism
  51. Hetertrophs
    • Get energy from other oganisms
    • Herbivores-eat plants, have flat teeth, long digestive tract to digest cellulose 
    • carnivores- Meat eaters, have pointed teeth, shorter digestive tract
    • Omnivores-eat both
  52. Primary, Secondary, Teritary Consumers EX:
    Herbivores, Carnivore, Bigger Carnivore
  53. Decomposers
    • Saprphytes/detrivores
    • heterotrophs that get energy from others even if they are dead
    • Scavengers play a similar role
  54. Trophic Levels
    • Level of the food chain
    • Each contains different quantities of stored chemical energy
  55. Organisms that eat at higher trophic levels must
    • consume more volume of food to get same nutrients/E value
    • Eating farther away from the sun, loose energy to respiration and metabolic processes
    • Only 10% is carried on to the next level
  56. Gross PP
    Total chemical energy generated by producers in a given area
  57. Net PP
    Total-Losses fro respiration and other E uses by plants
  58. Biomass
    • Number of individuals in community
    • Each trophic level contains 10% of biomass in level beneath it
    • Aquatic is usually upside down because phyto have such a fast turn over but can support large communities