Ecology

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Anonymous
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17703
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Ecology
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2010-05-04 00:24:37
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Ecology
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midterm 1
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  1. Define Ecology
    The science by which we study how organisms interact in and with the natural world.
  2. Define Ecological System
    A collection of living and non-living components that are tied together by regular interactions
  3. What are the 3 levels of organization in an Ecological System
    • 1) Organism with its surroundings
    • 2) Populations within a habitat
    • 3) Community with abiotic environment
  4. What are the 3 principles of an Ecological System?
    • 1) Ecological systems are physical entities
    • 2) Ecological systems exchange materials and energy with their surroundings
    • 3) Ecological systems undergo evolutionary change
  5. Can biological systems alter physical or chemical properties?
    No
  6. Do ecological systems exist in steady or un-steady states?
    Steady states
  7. Who is the founding father of ecology as a science?
    Ernst Haeckal
  8. What does Macroecology do?
    Characterizes and explains the statistical patterns of Abundance, Distribution, and Diversity
  9. Define Optimal Range
    The range in an environmental gradient in which a species is best suited for growth or reproduction
  10. What does it mean when sheep sorrel get pushed out of the soil pH where they grow the best and grow in acidic soils?
    They have been restricted to one end of it's tolerance range in nature
  11. Define the Law of Minimum
    When a process depends on many different factors, then the process will be limited by the factor in the Lowest Relative Abundance
  12. What is Diatom growth regulated by?
    Silicate or Phospahate limitation
  13. What is Synergy?
    Interaction greater than sum
  14. Define Acclimation
    A reversible physiological or structural change in response to a changing environment
  15. Define Adaptation
    A genetically determined charactersistic that enhances the ability of an organism to cope with it's environment
  16. Define the Law of Trade-Offs
    Adaptatioin to one environment makes it difficult or impossible to live in a different environment
  17. Define Ecotypes
    Different populations of a species that have genetic differences of ecological significance (color, size, physiology)
  18. What rank is Oregon in species diversity?
    4th
  19. What are the Biotic regions in Oregon?
    • 1) Forested Regions
    • 2) Interior Valleys
    • 3) Steppe Region
    • 4) Coastal Strand
  20. Do Assimilatory processes consume or release energy?
    Consume - Inorganic--> Organic
  21. Do Dissimilatory processes consume or release energy?
    Release- Organic--> Inorganic
  22. Define Compartment Models
    Organization of ecosystem into functional units that exchange materials and energy
  23. What are some examples of compartment models?
    • -Living Organisms
    • -Inorganic pool
    • -Organic pool
    • -Unavailable pools
  24. What can use atmospheric supply directly?
    Nitrogen Fixing organisms (prokaryotes)
  25. Define Rates of Decomposition
    Rate at which nutrients are made available to primary producers is determined largely by rate of mineralization
  26. Gallardo and Merino found
    Differences in mass loss by the target species reflected differences in the physical and chemical characteristics of their leaves
  27. Melillo used
    Litter bags to study decomposition in temperate forests
  28. Gessner and Chauvet found that
    Leaves with a higher lignin content decomposed at a slower rate
  29. Suberkropp and Chauvet found that
    Leaves degraded faster in streams with higher nitrate concentrations
  30. Webster found that
    Nutrients in streams are subject to downstream transport
  31. MacNaughton found
    A positive relationship between grazing intensity and rate of turnover in plant biomass in Serengeti Plain
  32. Witkowski compared
    Nutrient dynamics under canopy of native shrub and introduced acacia
  33. Vitousek and Walker found
    Invading N-fixing tree Myrica faya is altering N dynamics of Hawaiian ecosystems
  34. Define Ecological Community
    A group of populations that occur together, interact, and whose ecological function and dynamics are in some way interdependent
  35. Ecological communities can be characterized by
    • -Dominant species
    • -Major growth habit
    • -Geographic location
    • -Climate type
    • -Major taxon
    • -Trophic level
  36. Define Stratification
    The organization of the community in vertical space
  37. Define Zonation
    Horizontal changes in the physical environment reflect zonational changes in plant and animal components of ecological communities
  38. Define Guild
    A group of species thatexploit the same environmental resources in a similar way
  39. In what ways could an organism be dominant in the ecological community?
    • -Most numerous
    • -Greatest biomass
    • -Preempt the most space
    • -Largest contribution to energy or nutrient flow
    • -Behavior
  40. What are the two fundamentally different models for why certain species occur together?
    • -Open/Individualistic Communities
    • -Closed/Organismal Communities
  41. Who was the main proponent of Open communities?
    Henry Gleason
  42. Describe characteristics of an Open community
    • -Species are individualistic
    • -Occurrence of one species is independent of other species
    • -Each species has a characteristic environmental tolerance or optimal range
    • -Species occur together where environmental tolerance coincide
    • -Overlapping species populations intergrade
    • -Communities are a gradient or continuum of species associations accross a changing physical environment
  43. Describe characteristics of a closed community
    • -Main proponent was Frederic Clements
    • -Communities are discrete, discontinuous, predictable entities
    • -Community types are compared to "super organisms"
    • -Certain clusters of species reach their optima in the same environmental conditions
    • -Dominant members of one group do not occur as important or dominant members of any other group
    • -Only minor overlap between communities
  44. What is the Intermediate Disturbance Hypothesis?
    • -Species diversity is low when frequency or intensity of disturbance is high
    • -Species diversity is low when frequency or intensity of disturbance is low
    • Greatest species diversity occurs when frequency or intensity of disturbance is intermediate
  45. Define Species Diversity
    The total number of species in a community or region
  46. What are the 2 components of diversity?
    • 1) Species richness
    • 2) Relative abundance (species evenness)
  47. Define Diversity Index
    A quantitative measure of relative diversity
  48. What is the simplest and most common measure of diversity?
    Species Richness
  49. Define Rarefaction
    Statistical method to compare species richness for unequal sample sizes
  50. What should be known about rarefaction
    • -Can be used to compare species richness for unequal sample sizes
    • -Uses number of species and relative abundance to estimate expected number of species in a standard sample size
    • -Some information is lost, number of species and relative abundance is converted to expected number of species only
  51. Describe Lognormal Distribution
    The majority of communities studied by ecologists display a log normal pattern of species abundance
  52. Describe Simpson's Index
    • -Based on dominance of species
    • -Emphasizes evenness
  53. What are the disadvantages of Simpson's Index?
    • -Rare species are mostly ignored
    • -Influenced by sample size
  54. Define Simpson's Index
    The probability that any two individuals drawn randomly from a population belong to different species
  55. What do Rank Abundance Curves do?
    Portray relative abundance and species diversity within a community by plotting relative abundance of species against their rank in abundance
  56. What are the 3 terms used to divide spatial scale continuum?
    • 1) Alpha local
    • 2) Beta regional
    • 3) Gamma biogeographical
  57. Define Alpha diversity
    Diversity of small areas of relatively homogeneous habitat; number of species per unit area
  58. What is the principal goal of Alpha diversity?
    Describe local community structure
  59. Define Beta Diversity
    Change in species composition over relatively small distances; often between distinct adjacent habitats along an environmental gradient
  60. What is the principal goal of Beta Diversity?
    Describe species turnover
  61. Define Gamma Diversity
    Diversity of similar habitat type separated by wide geographic distances
  62. What is the principal goal of Gamma Diversity?
    Address the relative roles that history and ecology have played in species assemblages, distribution
  63. In latitudinal diversity gradients, species diversity (Increases/Decreases) with decreasing lattitude
    Increases
  64. In elevational diversity gradients, diversity (Increases/Decreases) with increasing elevation
    Decreases
  65. In Aridity diversity gradiants, diversity (Increases/Decreases) with increasing aridity
    Decreases
  66. What are the 2 factors controlling diversity?
    • 1) Environmental Heterogeneity
    • 2) Area
    • 3) Climatic Stability
    • 4) Biotic factors
    • 5) Evolutionary speed

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