Ecology Test 4 vocab

  1. 1
  2. coevolution 
      The evolution of two interacting species, each in response to selection pressure imposed by the other.
  3. ectoparasite   
    A parasite that lives on the surface of another organism. Compare endoparasite.
  4. endoparasite   
    A parasite that lives inside the body of its host organism. Compare ectoparasite.
  5. gene-for-gene interaction  
    A specific defensive response that makes particular plant genotypes resistant to particular parasite genotypes.
  6. host   
    An organism on or within which a parasite or other symbiont lives.
  7. macroparasites   
    Relatively large parasite species, such as arthropods and worms. Compare microparasites.
  8. microparasites   
    Parasite species too small to be seen with the naked eye, such as bacteria, protists, and fungi. Compare macroparasites.
  9. parasite   
    An organism that lives in or on a host organism and feeds on its tissues or body fluids.
  10. pathogen   
    A parasite that causes disease.
  11. symbiont   
    An organism that lives in or on an organism of another species, referred to as its host; a symbiont is the smaller member of a symbiosis. See also host, symbiosis.
  12. threshold density   
    The minimum number of individuals susceptible to a disease that must be present in a population for the disease to become established and spread.
  13. arbuscular mycorrhizae   
    Mycorrhizae in which the fungal partner grows into the soil, extending some distance away from the plant root, and also grows between some root cells while penetrating others. Compare ectomycorrhizae
  14. cheater   
    In a mutualism, an individual that increases its production of offspring by overexploiting its mutualistic partner.
  15. commensalisms   
    An interaction between two species in which individuals of one species benefit while individuals of the other species do not benefit and are not harmed.
  16. ectomycorrhizae   
    Mycorrhizae in which the fungal partner typically grows between plant root cells and forms a mantle around the exterior of the root. Compare arbuscular mycorrhizae.
  17. habitat mutualism  
    A mutualism in which one partner provides the other with shelter, a place to live, or favorable habitat.
  18. mutualism   
    A mutually beneficial interaction between individuals of two species (a +/+ relationship).
  19. mycorrhizae   
    Symbiotic associations between plant roots and various types of fungi that are usually mutualistic.
  20. positive interactions   
    Interactions between species in which one or both species benefit and neither is harmed.
  21. service mutualism   
    A mutualism in which one partner performs an ecological service for the other.
  22. symbiosis  
    A relationship in which two species live in close physiological contact with each other. See also host, symbiont.
  23. trophic mutualism   
    A mutualism in which one or both of the mutualists receives energy or nutrients from its partner.
  24. biodiversity   
    The diversity of important ecological entities that span multiple spatial scales, from genes to species to communities.
  25. community structure   
    The set of characteristics that shape a community, including the number, composition, and abundance of species.
  26. community   
    A group of interacting species that occur together at the same place and time.
  27. competitive networks   
    Sets of competitive interactions involving multiple species in which every species negatively interacts with every other species thus promoting species coexistence.
  28. direct interactions   
    Interactions between two species, including competition, exploitation, and positive interactions. Compare indirect interactions.
  29. dominant species   
    A species that has large, community-wide effects by virtue of its size or abundance, its strong competitive ability, or its provision of habitat or food for other species, also called a foundation species.
  30. ecosystem engineer   
    A species that influences its community by creating, modifying, or maintaining physical habitat for itself and other species.
  31. foundation species 
      See dominant species.
  32. functional group   
    A subset of a community that includes species that function in similar ways, but do not necessarily use the same resources. Compare guild.
  33. guild   
    A subset of a community that includes species that use the same resources, whether or not they are taxonomically related. Compare functional group.
  34. horizontal interactions   
    Non-trophic interactions, such as competition and some positive interactions, that occur within a trophic level.
  35. indirect interactions   
    Interactions in which the relationship between two species is mediated by a third (or more) species. Compare direct interactions.
  36. interaction strength  
    A measure of the effect of one species (the interactor) on the abundance of another species (the target species).
  37. interaction web   
    A concept that describes both the trophic (vertical) and non-trophic (horizontal) interactions among the species in a traditional food web.
  38. keystone species   
    A strong interactor that has an effect on energy flow and community structure that is disproportionate to its abundance or biomass.
  39. omnivore   
    (1) In trophic studies, an organism that feeds on more than one trophic level. (2) An organism that feeds on both plants and animals."
  40. rank abundance curve   
    A graph that plots the proportional abundance of each species in a community relative to the others in rank order, from most abundant to least abundant.
  41. Shannon index   
    The index most commonly used to describe species diversity quantitatively.
  42. species accumulation curve   
    A graph that plots species richness as a function of the total number of individuals that have accumulated with each additional sample.
  43. species composition   
    The identity of the species present in a community.
  44. species diversity   
    A measure that combines the number of species (species richness) in a community and their relative abundances compared with one another (species evenness).
  45. species evenness   
    The relative abundances of species in a community compared with one another.
  46. species richness   
    The number of species in a community.
  47. trophic cascade   
    A change in the rate of consumption at one trophic level that results in a series of changes in species abundance or composition at lower trophic levels.
  48. trophic facilitation   
    An interaction in which a consumer is indirectly facilitated by a positive interaction between its prey or food plant and another species.
  49. trophic level   
    A group of species that obtain energy in similar ways, classified by the number of feeding steps by which the group is removed from primary producers, which are the first trophic level.
  50. alpha diversity   
    Species diversity at the local or community scale. Compare beta diversity, gamma diversity.
  51. beta diversity   
    The change in species number and composition, or turnover of species, as one moves from one community to another. Compare alpha diversity, gamma diversity.
  52. biogeographic region   
    A portion of Earth containing a distinct biota that differs markedly from the biotas of other biogeographic regions in its species composition and diversity.
  53. biogeography   
    The study of variation in species composition and diversity among geographic locations.
  54. continental drift   
    The slow movement of tectonic plates (sections of Earth's crust) across Earth's surface.
  55. endemic   
    Occurring in a particular geographic location and nowhere else on Earth.
  56. equilibrium theory of island biogeography   
    A theory proposing that the number of species on an island or in an island-like habitat results from a dynamic balance between immigration rates and extinction rates.
  57. gamma diversity   
    Species diversity at the regional scale; the regional species pool. Compare alpha diversity, beta diversity.
  58. local scale   
    A spatial scale that is essentially equivalent to a community.
  59. regional scale   
    A spatial scale that encompasses a geographic area where the climate is roughly uniform and the species contained therein are often restricted to that region by dispersal limitation.
  60. regional species pool   
    All the species contained within a region; sometimes called gamma diversity.
  61. species–area relationship   
    The relationship between species richness and area sampled.
  62. turnover   
    (1) The mixing of the entire water column in a stratified lake when all the layers of water reach the same temperature and density. (2) The replacement of one species with another over time or space.
  63. vicariance   
    The evolutionary separation of species due to a barrier such as continental drift that result in the geographic isolation of species that once were connected to one another.
  64. biofuel   
    A liquid or gas fuel made from plant material (biomass).
  65. biotic resistance   
    Interactions of the native species in a community with non-native species that exclude or slow the growth of those non-native species.
  66. carbon neutral   
    Of or relating to fuels that produce an amount of CO2 when burned that is equal to or less than the amount taken up by the plants from which they are made.
  67. complementarity hypothesis   
    A hypothesis proposing that as the species richness of a community increases, there is a linear increase in the positive effects of those species on community function. Compare redundancy hypothesis.
  68. driver and passenger hypothesis   
    A hypothesis proposing that the strengths of the effects of species' ecological functions on their communities vary dramatically, such that "driver" species have a large effect on community function, while "passenger" species have a minimal effect.
  69. dynamic equilibrium model   
    An elaboration of the intermediate disturbance hypothesis proposing that species diversity is maximized when the level of disturbance and the rate of competitive displacement are roughly equivalent.
  70. intermediate disturbance hypothesis   
    A hypothesis proposing that species diversity in communities should be greatest at intermediate levels of disturbance (or stress or predation) because competitive exclusion at low levels of disturbance and mortality at high levels of disturbance should reduce species diversity.
  71. lottery model   
    A hypothesis proposing that species diversity in communities is maintained by a "lottery" in which resources made available by the effects of disturbance, stress, or predation are captured at random by recruits from a larger pool of potential colonists.
  72. redundancy hypothesis 
    A hypothesis that assumes an upper limit on the positive effect of species richness on community function because once species richness reaches some threshold, the functions of species in the community will overlap. Compare complimentary hypothesis.
  73. resistance   
    (1) Any force that impedes the movement of compounds such as water or CO2 across an energy or concentration gradient; its opposite is conductance. (2) The ability of a community to resist change from outside influences such as disturbance.
  74. resource partitioning   
    The use of limiting resources by different species in a community in different ways.
  75. resource ratio hypothesis   
    A hypothesis proposing that species can coexist in a community by using the same resources, but in differing proportions.
  76. stability   
    The tendency of a community to remain the same in structure and function.
Card Set
Ecology Test 4 vocab
Ecology Test 4 vocab