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2011-12-06 17:17:17

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  1. In predator-prey dynamics, the product of attack rate (a) and size of prey population (N) is known as the ____________
    Functional response
  2. Formula for the functional response in predator-prey interactions
  3. In predator-prey interactions, the product of attack rate (a), conversion efficiency (e), and size of the prey population (N) is known as the _____________ of the ______ population
    Numerical response, predator
  4. When the growth rate of the prey population (r) is high, there tend to be ______ predators in an environment
  5. When the attack rate (a) of predation is high, there tend to be ______ predators in an environment, and _______ prey
    • Fewer
    • Fewer
  6. When does the predator-prey model NOT generate cycles? (2) How?
    • Initial numbers of predator-prey are at the joint equilibrium -- cycle won't occur
    • OR
    • If initial conditions are too extreme (too far from the equilibrium) -- one population will crash/go extinct
  7. Assumptions of the Lotka-Volterra predator-prey models (6)
    • 1) No age structure
    • 2) No immigration
    • 3) Prey population is only limited by predation
    • 4) Predators are specialists that eat only the focal prey
    • species
    • 5) Individual predators can consume an infinite number
    • of prey (type 1)
    • 6) Predator and prey contact each other randomly, no
    • prey refuges
  8. Stabilizing factors of predator-prey cycles? (3)
    • Reduced time delays/lagged density dependence
    • Prey phenotypic plasticity (ie behaving to reduce attack rate, like hiding)
    • Low predator attack rate
  9. How can predators respond numerically to changes in prey populations? (2)
    • Immigration/tracking prey
    • Local population growth (less mobile species)
  10. The idea that fertilizing a food chain makes it less stable, increases growth rate of plants, causes them to overshoot carrying capacity (i.e. algae+nutrients experiment)
    Paradox of enrichment
  11. In the algae + nutrients experiment, adding warmth results in ______ stability
  12. Limiting resource other than food for sessile organism
  13. Limiting resource other than food for mobile organisms
  14. Limiting resources most common in exploitative competition (2)
    Nutrients and/or energy
  15. In models of competition, if alpha = 0, then _____________
    There is NO interspecific competition
  16. In models of competition, if alpha = 1, then _________________
    Species 1 and Species 2 are interchangeable
  17. In competition models, if alpha < 1, then _______________
    INTRASPECIFIC competition is higher than interspecific competition
  18. In competition models, if alpha is > 1, then __________________
    INTERSPECIFIC competition is higher than intraspecific competition
  19. In competition models, the higher K-value has ________ intraspecific competition, and the lower has _________ intraspecific competition
    Weaker, Stronger
  20. In competition models, the higher alpha value has ___________ interspecific competition
  21. In the competition equilibrium model, as the population size of species 2 (N2) goes up, the population size of species 1 (N1) ________, at some rate defined by _____
    Goes down; Alpha
  22. Combination of densities of two species where growth rates are zero
  23. To have coexistence at equilibrium, _________________
    Two species' isoclines have to cross
  24. Isoclines are made by setting equations to ______ and solving one species' _______ for the other
    • Zero
    • Density
  25. What circumstances must be in place for coexistence to occur in the competition models?
    Lower alpha values (gives a larger range of Ks)
  26. Assumptions of the Lotka-Volterra competition model (4)
    • Resources are always limiting
    • Competition coefficients and carrying capacities are constants
    • Linear density dependence
    • Populations are at equilibrium
  27. How do we tell how important inter-specific competition is in nature? (3)
    • Removal experiments
    • Natural distribution patterns
    • Species invasions and extinctions
  28. In competition experiments of California native vs annual perennials, the invasive plants took over because ________________
    The invaders do better under mowing conditions
  29. In the rocky intertidal competition experiments, the upper limit of space distribution is set by ___________, while the lower boundary is set by _____________

    Example of ___________ competition
    • Physical stress
    • Competition
    • Asymmetrical
  30. Conclusions from experiments and observations on inter-specific competition:
    --Competition is _______-dependent
    --Modified by _________ (3)
    • Condition (i.e. barnacles)
    • Physiological stress, disturbance, predation
  31. Two effects of interactions between competition and predation
    • Keystone predation
    • Apparent competition
  32. Regarding evolutionary effects of competition, species should evolve either to:
    Increase their _________ on other species (ie ________)
    Decrease _______________ on themselves (ie ______)
    • Alphas; become more effective resource exploiters
    • Other species' competitive effects; resource partitioning
  33. Evolutionary result of resource partitioning that reduces competition
    Character displacement
  34. Evidence for strong environmental control in species diversity is clear in the small amount of diversity in _____________
    Places with low productivity, i.e. far north, very dry deserts
  35. Issues when measuring diversity (3)
    • Species vary in abundance
    • Many kinds of diversity
    • No one universal correct measure of diversity
  36. Two ways to compare species-abundance sampling curves
    • Rarefaction sub-samples (drawn at random)
    • Curve-fitting (estimate total # of species from a sample)
  37. How the number of species you find varies as a function of the number of individuals you examine, on a graph, is known as the ______________
    Sampling curve
  38. Species richness refers to ___________
    The number of species in a community
  39. Problems of species relative abundance measures (2)
    • Total number of species in a sample depends on sample size
    • Individual species may not contribute equally to diversity
  40. In the Simpson's index equation, "pi" refers to ______________________
    The proportional abundance of each species in the total sample
  41. In the Simpson's index equation, gamma refers to ________________________, and its formula is _____
    The probability that any two species drawn randomly from the sample will be the same species

    gamma = E (sum of) pi2
  42. Formula for Simpson's index
    Si = 1/gamma
  43. Simpson's index is a measure of __________ that takes ___________ into account
    • Diversity
    • Abundance
  44. Maximum number of S in Simpson's index is equal to ________
    The number of species in the sample
  45. Larger values of Si indicate ______________
    Greater diversity/species more evenly distributed
  46. In Simpson's index, when Si = S, _____________
    All species have equal abundances
  47. In Simpson's index, when Si < S, _____________
    Species have unequal abundances
  48. In Simpson's index, S refers to ___________
    Species richness (# of sps in a sample)
  49. Types of diversity/explanations (4)
    • Genetic (how many different genotypes)
    • Species (how many/abundance)
    • Phylogenetic (how much evol history represented by a community)
    • Functional trait (how different are species in their ecology)
  50. Equilibrium theories of diversity maintenance work to ______________
    Minimize alphas/competition
  51. Non-equilibrium theories of diversity maintenance work to ______________
    Prevent equilibrium from being reached
  52. Equilibrium theories (4)
    • Resource partitioning
    • Energy input and resource availability
    • Keystone predation
    • Janzen-Connell hypothesis
  53. Non-equilibrium theories
    • Intermediate Disturbance Hypothesis
    • Dynamic Equilibrium Theory
    • Lottery Model
  54. Two ways that resource partitioning can maintain diversity:
    • If there is a broader resource spectrum/environmental variability
    • More generalized species (wider niches of species) and/or more densely packed/more overlapped
  55. Example of resource partitioning
    Warblers (birds) use different parts of the same tree
  56. In resource partitioning experiments, stable coexistence tends to only occur when the resources are _________________
    Relatively even, otherwise competitive exclusion occurs
  57. How does energy input impact local diversity?
    Higher NPP/energy input = higher diversity
  58. Two mechanisms/explanations for high diversity in areas of high productivity:
    • More individuals, less extinction @ low population size
    • More resource variability, greater potential for partitioning
  59. Factor of local diversity that selectively removes competitive dominants (equilibrium theory)
    Keystone predation, ie sea stars, prevents competitive exclusion
  60. Janzen-Connell hypothesis is a(n) ____________ theory that suggests forest diversity is promoted by avoidance of __________, whereby juvenile seedlings _______________

    Also happens in __________ because of __________
    • Equilibrium
    • Pathogens
    • Fall far away from their parents
    • Coral reefs, bacteria
  61. What is the intermediate disturbance hypothesis, and what conditions are needed for it?
    Peak diversity occurs are medium levels of disturbance, because at low disturbance, competitive exclusion occurs, and at high disturbance, species excluded by the disturbance itself
  62. Example of intermediate disturbance hypothesis
    Rocks in the intertidal zone
  63. According to the dynamic equilibrium model, the highest diversity occurs at ____ levels of ________, and _____ levels of ___________
    • Intermediate, productivity
    • Intermediate, disturbance
  64. Example of the dynamic equilibrium model
    Plant diversity peaks at intermediate productivity and disturbance in Alaskan wetlands
  65. What is the Lottery Model, and when does it apply?
    The idea that whoever gets to a territory first and defends it "wins," caused by random factors that are totally out beyond the organisms' control, ie ocean currents, upwelling, etc.

    Applies to species where juveniles are broadly dispersed, but adults maintain territories
  66. Local diversity refers to _________

    Also called _________
    The number of species in a small area of homogeneous habitat

    Alpha diversity
  67. Beta diversity measures _____________
    Turnover in species composition from one habitat to the next within a region
  68. Regional diversity is ______________________

    Also called _________
    The total number of species observed in all habitats within a barrier-free geographic area

    Gamma diversity; regional species pool
  69. Beta diversity is measured by
    Regional diversity / Local diversity
  70. A beta value of 1 indicates _________
    Local diversity and regional diversity are the same, habitat is homogenous
  71. Beta value above 1 indicates ___________
    Higher regional diversity than local diversity
  72. Beta value below 1 indicates ____________
    Higher local diversity than regional diversity
  73. How has beta diversity changed over time? Why?
    Beta diversity has gone down, due to biological globalization
  74. Two aspects of function in diversity
    • Productivity
    • Stability
  75. How does diversity affect productivity? Why? Example?
    Higher diversity = higher resistance to drought and faster recorvery rate

    Because increased diversity increases the chance that at least some species can withstand periods of environmental stress

    Shown in Cedar Creek plots
  76. Four mechanisms/hypotheses suggested for the species richness effect on ecosystem function
    • Complementarity
    • Redundancy
    • Driver-passenger
    • Driver-passenger + overlap
  77. How do the hypotheses of species diversity's effects on function differ? (2)
    • Degree of overlap
    • How much they vary in function
  78. According to the complementary hypothesis, ________
    • As species richness increases, community function increases linearly
    • Each species added has an equal effect on community function
  79. According to the redundancy hypothesis, _____________

    Indicates that _________ richness may matter more than __________ richness
    As species richness increases, there is an increase in ecosystem function until a threshold is reached, at which point there is functional overlap and species are redundant

    Functional, species
  80. According to the Driver-Passenger hypothesis, ____________________
    Some species (Driver species) have larger effect on community function than others (Passenger species),
  81. Adding "Drivers" will increase community function, while adding "Passengers" will not change anything
  82. According to the modified Driver-Passenger hypothesis, __________________
    There is variation in productivity of species (Drivers > Passengers), PLUS a lot of niche overlap, which combines to make a curvilinear staircase graph that reaches a threshold @ high richness
  83. In the Cedar Creek grassland experiments, the effect of adding species depends on how many species are present, suggesting support for the ______________ hypothesis
  84. The diversity/production experiments in grasslands' production of biofuels found that
    Native communities with higher diversity are better for the environment and require less maintenance than introduced communities, that are more productive but require too much maintenance
  85. Algal diversity experiments have found that _________________
    Higher diversity of algae = higher productivity and more efficient communities
  86. 2 mechanisms by which diversity may enhance stability
    • Portfolio effect
    • Compensatory dynamics
  87. According to the portfolio effect, ___________

    Occurs if species abundances are varying ____________
    The more species there are, the more stable (less variable) the total biomass/production will be

  88. According to compensatory dynamics, _____________
    Out-of-phase fluctuations of species will dampen out the changes in abundance/stabilize them and reduce their variability due to compensation
  89. 2 components of ecosystem function stability
    • Resistance
    • Resilience
  90. Example of diversity/function stability
    Mt St Helens' vegetation response to eruption, plants with greatest resistance also had greatest resilience
  91. Wallace came up with ___________
    Theory of biogeography based on observations of similarities and differences between species globally
  92. 2 important global patterns that Wallace discovered
    • Earth's land mass can be divided into 6 biogeographic regions
    • There is a gradient of species diversity with latitude
  93. Vicariance refers to __________
    Evolutionary separation of species due to a barrier such as continental drift
  94. Examples of vicariance (2)
    • Ratites
    • Polar bears and penguins
  95. Why might the Indo-west Pacific mangroves have greater regional diversity relative to the Caribbean mangroves? (3 possible explanations)
    • More plant taxa invaded mangroves more frequently in the Pacific
    • Fewer extinctions in the Pacific
    • Fragmentation (i.e. more islands) of Indo-West Pacific habitats may have isolated populations and fostered speciation/diversity
  96. In experiments to see if a regional species pool is what limits local species diversity, three types of relationships between them may occur:
    1) Slope is 1, regional and local diversity are the same (uncommon)

    2) Linear positive relationship -- community species diversity is largely determined by the species pool

    3) Local species saturate/do not increase after a certain threshold, thus having nothing to do with regional species pool, limited by local factors
  97. Experiment of local vs regional species diversity in marine invertebrates indicates that __________ species richness explains ____ of variation in local species richness
    Regional, 75%
  98. Most studies of local vs regional species richness have found Type ____ relationships (i.e. ______ and ________), which may indicate that _________ limits local richness more than ______
    • 2
    • Positive, linear
    • Dispersal, local interactions
  99. Shurin's lake experiments of regional vs local richness found Type ____ relationship

    His experimental species introductions test found that __________
    • 2
    • Local species interactions have an impact on community diversity, and are NOT dispersal limited (regionally controlled)
  100. According to the equilibrium theory of island biogeography, addition of species results from ________, and the rate of arrival of new species is a(n) ________ function of _________________________.
    • Colonization
    • Declining
    • The number of species already on the island
  101. According to the equilibrium theory of island biogeography, removal of species results from __________, and the rate of loss of species is a(n) _____________ function of _______________
    • Extinction
    • Increasing
    • The number of species already on the island
  102. According to the equilibrium theory of island biogeography, maximum colonization rate occurs when ________, and colonization rate is 0 when __________
    • S (number of species on the island) = 0
    • S = P (mainland species pool)
  103. In the colonization rate formula, C - (C/P)S ,
    C refers to ___________
    P refers to ___________
    S refers to ___________
    • Maximum colonization rate
    • Mainland species pool
    • Number of species on the island
  104. In island biogeography, the extinction rate formula (E/P)S,
    E refers to __________
    P refers to __________
    S refers to __________
    • Maximum extinction rate
    • Mainland species pool
    • Number of species on island
  105. According to the equilibrium theory of island biogeography, maximum extinction rate occurs when ____________
    S = P
  106. In the equilibrium theory of island biogeography, the rate of change in species richness (dS/dt) = ______, and the formula for Species equilibrium is _______
    • 0
    • Sequil = CP/(C + E)
  107. Assumptions of the equilibrium theory of island biogeography (2)
    • Species don't differ in their colonization and extinction rates regardless of S
    • Islands don't differ in their C and E rates
  108. Relaxing the assumptions of island biogeo, how should C and E depend on S? (3)
    • Species differ in dispersal capability and susceptibility to extinction:
    • --Good dispersers arrive soon, poor dispersers arrive later (C curve, negative)
    • --Competition is low with low S, high with high S (E curve, positive)
  109. Relaxing the assumptions of island biogeography, extinction curves should be _______ for small islands than for large ones, because ____________________

    Additionally, colonization rates may be ________ for small islands
    • Higher, smaller islands tend to have smaller populations
    • Lower
  110. Relaxing the assumptions of island biogeography, colonization curves should be __________ for far islands than for near ones

    Additionally, extinction curves may be ______ for far islands than for near ones
    • Lower
    • Higher
  111. According to the island biogeography graph, the most species will be found on ______, ______ islands
    Large, nearby
  112. Limitations of the equilibrium theory of island biogeography (6)
    • Rate curves of extinction and colonization not known
    • Islands may not be in equilibrium
    • Probabilities of extinction and colonization vary among species
    • Extinction and colonization are not independent
    • Multiple mainlands = multiple immigration routes
    • Assumes no speciation
  113. Species-area curve refers to ______________
    Most of the time, represents a ______ slope
    • The relationship between the size of an area and the number of species present in the area
    • Positive
  114. Formula for species-area curve
    • S = c * Az
  115. In the species-area curve formula, a bigger z-value (steeper slope) means _________ turnover, ________ beta diversity
    • High
    • High
  116. In the species-area curve formula,
    S refers to _______
    c refers to _______
    A refers to _______
    z refers to ________
    • Species richness
    • Scaling constant
    • Area
    • Slope, Measure of species turnover in space
  117. In experimental tests of species-area curve relationships, z-values are _________ for continental areas than for islands, suggests that ________ have greater beta diversity
    • Lower
    • Islands
  118. In species-area curve relationships, z-values are ________ for big organisms (e.g. plants) than for small organisms (e.g. bacteria), which means their accumulation of __________ occurs ________
    • Higher
    • Diversity, faster
  119. Globarlly, terrestrial species diversity is richest __________, and marine diversity is richest _________
    • Near the equator
    • Along the equatorial coastlines
  120. What types of functional responses may be destabilizing? Why?
    Type II and Type III, if predators can't keep up with prey populations and maintain top-down control
  121. Exploitative competition refers to ________ competition, mediated by __________, in which one species ___________ to the other

    Example: ___________
    • Indirect
    • Abundance of resources
    • Decreases the supply of resources available
    • Mussels dominating space in intertidal zones
  122. Interference competition refers to ________ competition through ____________, common when ___________

    Example: _________
    • Direct
    • Antagonistic behaviors
    • Resources can be profitably defended
    • Allelopathy in plants
  123. Numerical responses in predator-prey models refer to changes in _____________ as a function of __________
    • Number of predator individuals
    • Number of prey
  124. Functional responses in predator-prey models refer to changes in _________ as a function of ____________
    • Number of prey eaten by predators
    • Number of prey
  125. Measures of diversity (2)
    • Species richness
    • Evenness
  126. An ecosystem with low diversity will be _______________________ than will one with high diversity
    More susceptible to environmental stress
  127. A large value of Si indicates that the sample has __________________ with ________________
    Greater divrsity species more evenly distributed
  128. Equilibrium theories are those that ______________
    Maintain local diversity
  129. Hypotheses for diversity-function
    A) No overlap, No variation
    B) Yes overlap, No variation
    C) No overlap, Yes variation
    D) Yes overlap, Yes variation
    • A = Complementarity
    • B = Redundancy
    • C = Driver-Passenger
    • D = Driver-Passenger + overlap
  130. In island biogeo, increasing the size of the mainland species pool (P) will ______ the number of colonizations and _______ the number of extinctions
    • Increase
    • Decrease
  131. In the prey equilibrium, an increase in r, growth rate of prey, causes ____________ in predators, and ________ in prey
    • Increase
    • No change (prey are at equilibrium)