Wildlife Ecology Midterm 1

Home > Preview

The flashcards below were created by user Kinazulu808 on FreezingBlue Flashcards.

  1. Biodiversity
    The sum of all lifeforms present in any given location (E.O. Wilson)
  2. Levels of Analysis
    Genes, populations, species, communities, ecosystems, landscapes
  3. Bacteria
    • Produces asexually instead of sexually
    • Liven in environments where carbon is not the basis of life (replaced by sulfar in deep thermal vents)
    • Do not need air
  4. How many species are there?
    • Estimate 5 to 30 million
    • 2 famous estimates
    • - Dr. Terry Erwin: entomologist (1982, Coleopterist's Bulletin)
    • - Dr. Robert May: theoretical ecologist (1992, Scientific American)
  5. Erwin's Estimates
    • S. American rainforest (Luhea seemanni, tree sp's)
    • Method: fogging trees catching dead bugs
    • Found 1100 bettles sp's, 160 specialized to canopy Luhea
    • 40% of all insects are bettles
    • Estimated 400 sp's specialized to L. Seemanii (160 of 40% of 400)
    • 2/3 of insects live in canopy, 600 total specialized in 1 tree (400 is 2/3 of 600)
    • 50,000 tree sp's in tropical forests, 30 mill. insect sp's in tropics(50,000 trees x 600 insects)
    • Insects 75% all known sp's (except 40 mill. sp's of life)
  6. What's needed to verify Erwin's Estimates?
    • Measure tree specificity of insect sp's
    • better sampling of canopy & terrestrial insects
    • Measure tropical tree diversity thoroughly
    • Lose about 300 tropical tree sp's/yr
    • Erwin: 300 x 600 = 180,000 arthropods lost/yr; 500/day
  7. Bob May Mathematics
    • Estimate diversity by looking at distributions of sizes of organisms (don't need to know identity of sp's)
    • Ecological principles limit the diversity of organisms as they get bigger (ex generation time)
    • Plot sp's # on log. scale on y-axis against log of orgnism size
  8. Genetic studies of Legionella penumophila
    • Organims sharing 50% of DNA considered same sp's
    • Equivalent to difference btwn fishes & mammals
    • Humans & chimps share 99% of DNA
  9. Any hope for cataloging biodiversity?
    • Taxonomists (7 % decline in U.S. & U.K. btwn 1980 & 1990)
    • Ageing pop. of systematics (63% over 46 yrs. old; only 8% younger than 35)
    • Mismatch btwn location of diversity & location of taxonomists
    • 80% scientists in N.AM./Europe, no latin Am. & tropical Africa/Asia
  10. Sp's distributed on earth?
    Depends on spatial scale of analsis & taxonomic group, but some major patterns apparent
  11. Spatial levels of analysis
    • Point Richness (single pt. in space)
    • Alpha Diversity (single habitat type/community)
    • Beta Diversity (multiple habitats/communities)
    • Gamma Diversity (entire regions/collections of ecosystems)
  12. Point Richness
    • Number of sp's at a single pt in space
    • Ex. Bird pt count
    • Problem: unknown area of habitat
  13. Alpha Diversity
    • Number of sp's in an individual community/ small "homogeneous" area
    • Some incorporate measures of abundance
    • Problem: detected w/in a single habitat
  14. Evenness
    • When all sp's have relatively same abundance: very even
    • All have extremely dissimilar abundances: very uneven
  15. Alpha Diversity
    • Low alpha diversity: few sp's, highly uneven
    • High alpha diversity: many sp's, even
  16. Distribution of biodiversity at the 'alpha diversity level'
    • Key correlations w/ increasing sp's richness
    • structural complexity of habitat
    • primary productivity
    • altitude
    • latitude
    • area
  17. Structural complexity of habitat
    • Positive correlation of sp's richness w/increasing complexity of habitat (in a certain region)
    • Ex. Bird Sp's (Grassland << shrubby fields << forests)
  18. Foilage Height Diversity Profiles
    • MacArthur
    • Habitats w/ greater complexity support more bird sp's
  19. Primary Productivity
    • Assimilation of energy & production of organic matter by photosynthesis
    • Greater primary porduction means more energy is available to support mroe sp's . . . up to a pt.
  20. Hump-shaped diversity curve
    Richness versus productivity
    • Produtivity - diversity paradox
  21. Paradox of Enrichment
    • Fertilizing sites w/ high sp's richness causes a decrease in richness
    • Salt Marshes, Hot Springs, Seasgrass beds highly productive; have few sp's.
  22. Altitudinal Diveristy Pattern
    • Fewer sp's w/ increasing elevation
  23. Latitudinal Diversity Gradients
    • Richness decreases w/ increasing latitude
    • Tropics have more species than temperate areas
    • Ex:
    • Ants 10 @ 60 degrees N; 2000 @ equator
    • Birds: handful at poles; 2500 @ equator
    • Exceptions: Marine
    • Marine Algae (peak 20-40 N)
    • Salamanders & Ichneumonid Wasps (Appalachian Mts)
    • Conifers (Boreal Zone)
    • Penguins (Antarctica)
    • Waterfowl (N. Temperate Zones)
  24. Islands
    • Fewer sp's than comparable area on mainland
    • General island patterns
    • - Richness Increases w/ (size, topographic (habitat) complexity)
    • - Decreases w/ isolation
  25. Beta Diversity
    • Degree of change in sp's composition across habitats
    • Cumulative number of sp's detected as move from one habitat to the next
  26. Species Accumulation Curves
    • Effort Curve
    • Plot number of sp's found versus measure of effect
  27. Beta Diversity Influenced By
    • Habitat specificity (degree of specialization)
    • Thought to be higher specialization in tropics
    • - geographic range sizes
    • - smaller in tropics (poorly known)
    • - altitudinal ranges smaller in tropics
  28. Gamma Diversity
    Overall richness across entire regions or landscapes (regional sp's pool)
  29. Diversity Measures
    • 2 components
    • Richness is # of sp's
    • Diversity is richness & pattern of abundance
  30. Measuring S (richness)
    • Sp's Accumulation Curve
    • Cumulative # of sp's found as a function of effort spent searching
    • - Time Spent Searching
    • - # of individuals identified
  31. Chao's Estimator
    S* = Sobs + (a2/2b)

    • S*: estimated # of sp's
    • Sobs: # actually found & identified
    • a: # of sp's where we saw only one individual (singleton sp's)
    • b: # of sp's where we saw 2 individuals (doubleton sp's)
  32. Chao's Variance
    • VarianceChao = b[{c4/4) + c3 + (c2/2)
    • C= a/b
  33. Confidence Interval
    • Approximate a confidence interval w/ 2 times standard deviation
    • Explains if our observed S fall w/ in 2 standard deviation of our estimated S*
    • Square root of variance is equal to the standard deviation
    • 1 S.D. above & below a mean = 64% all possible estimates
    • 2 S.D. = 96 %
    • Calculate by:
    • S.D. = square root variance
    • S* = S* +/- 2(S.D.)
  34. Simpson's Diversity Index
    • D = 1/SUMpi2
    • Calculate proportion of all individuals represented by each sp's
    • pi: fraction of individuals out of the whole sample of organisms that are of a certain sp's
    • Steps:
    • Square each proportion
    • Add them together
    • Diveide # into 1
  35. Shannon- Eaver Index
    • H' = -SUM [pi*ln(pi)]
    • Calculate fraction of all individuals represented by each sp's
    • Take natural log (loge) of each pi value
    • Multiply pi times ln(pi) for each sp's
    • Sum all those products
    • Take the negative to get H'
  36. Species area relationship
    • Space increases in site, # of sp's in space increase
    • Bases for wildlife ecology:
    • - biogeography theory: bigger islands have more sp's than smaller islands
    • - conservation strategies: big reserves will preserve more sp's than small reserves
    • - predictions of how habitat loss will affect species richness
  37. Sp's Area & Power Curve
    • S = cAz
    • logS = (log c) + z (log a)
    • S = # of sp's
    • C = constant measuring # of sp's per unit area
    • A = area of island
    • Z = Constant measuring slope of line relating to S and A
  38. Use relationship to protect sp's losses
    • Inventory plots of various sizes
    • construct sp's area graphs
    • predict effects of habitat loss
  39. Area Sensitive Sp's
    sp's occuring only in habitats/ islands/ reserves of a certain size or larger
  40. Incidence Functions
    • Best Studied in Vertebrates
    • shows the frequency of occurence of a sp's w/ respect to habitat patch area
  41. Incidence function calculations
    • survey many sites for a sp's
    • sites need to range in sizes
    • need method for ensuring detection of sp's of interest
    • generate graph of occupancy vs. size of area surveyed
    • look at shapes of incidence functions to determine area sensitivity
  42. Who's the most vulnerable to fragmentation?
    • Wide ranging sp's (mt. lion: food occur sparsley/ hard to catch)
    • Naturally rare sp's (ivory-billed woodpecker: old growth swamps & trees)
  43. Sp's of limited mobility
    • immigration btwn patches might be eliminated, therefore reducing persistence
    • dung beetle (beetles), amphibians (salamanders), some tropical birds
  44. Sp's with low fecundity
    inability to adjust to different levels of predation in fragments; can't reproduce frequency enough to offset higher predation
  45. Ground nesters
    • if populations of terrestrial predators increase in fragments, ground nesters decline
    • ex. racoons
  46. Sp's vulnerable to human exploitation / persecution
    • fargmentation allows easier human access, increase negative encounters (road kill)
    • ex. parrots (tree cavities, low pop. densities)
    • - breed in small fragments = high chance person locate nests
  47. Sp's with short life cycles
    failure to reproduce in successive yrs. might doom popoulation; longer lifespan increases chances of success
  48. Sp's dependent on patchy resoruces
    patchy resources may not be plentiful in smaller fragments; may occur irregularly in time
  49. Interior Sp's
    some sp's require resource found only deep w/in patches (microclimate conditions, food, etc)
  50. Why does fragmentation affect soem sp's
    • Reduction in total areas of habitat
    • Edge effects
    • Ecological Traps
  51. Edge Effects
    • Edges are transition zones btwn habitat types (ecotones: boundaries btwn natural communities)
    • some predators sp's proliferate in disturbed habitats
    • Microclimatic changes alter habitat (more sunlight, drier, more wind exposure)
    • Structural changes in habitat (increased veg. density, more weedy sp's, more treefalls)
    • Parasites increase in abundance
  52. Brood Parasitism
    • Parasitize the parental care of hosts
    • Female find the nests of songbirds & lay their eggs & leave them
    • Go find another nest to do same (up to 40 or more)
    • Find nest w/ eggs same size or smaller
    • Ex: Cowbirds
  53. Reduce RS of hosts
    • Often remove host egg(s) when laying cowbird egg
    • Cowbirds eggs hatch first
    • Young get most of food
    • Sometimes eject host eggs or young
    • Some hosts do not recognize that cowbird is not thier own, so don't breed again that yr.
  54. History of cowbirds
    • Native to great plains
    • Followed bison (nomadic, lay egg & leave)
    • Not a forest sp's, so parasitized grassland sp's
    • Grassland sp's adapted to tolerate parasitism and/or recognize cowbird eggs & eject them
    • Forest clearing allowed range expansion to east & west
    • Continental build up in #'s
    • Access to native host sp's not able to compensate for brood parasitism
    • Now parasitize over 100 sp's of songbirds
    • Max commuting range 7-10 km (Large forest provide habitat for songbirds)
  55. Corea Area
    • Portion of a fragment that is not influenced by edge effects
    • Dependent on shape
  56. Ecological Traps
    • Situations where habitat structure attracts individuals, but biotic alterations reduce reproductive success
  57. Habitat Loss
    • Area has been reduced & expect decline in sp's richness to occur becasue of reduction in habitat
    • - primary factor causing sp's to become rare & endangered
    • Happens for all habitats, but we'll focus on forests
    • Examples
    • - USA: 1620 - Pilgrims 1st, forest extensive (a lot)
    • - Costa Rica: Lost 70% of forests in 45 yrs
  58. Predictable sequence of forests loss
    • Cadiz Township in Wisconsin
    • -1831: area covered by forests (farmers colonized area & began to cut trees, forest became distributed as isolated patches)
    • -1902: few larger patches were left
    • - 1950: dominated by agriculture & only few small isoated patches
  59. Perforation
    • Forman's Categories
    • Initial stage of fragmentation
    • - clear cuts, developement of homestead, slash & burn
  60. Dissection
    • Forman's Categories
    • Creation of linear strip of deforested habitats
    • - Creation of roads /powerline corridors
  61. Fragmentation
    • Forman's Categories
    • Isolated patches of habitat by removing some forest from landscape
  62. Shrinkage
    • Forman's Categories
    • Loss of area from habitat patches
  63. Attrition
    • Forman's Categories
    • total loss of patches
  64. Faunal Relaxation
    Loss of sp's through time after isolation
  65. Super Saturation
    • Fragment during spike, has more sp's than expected given its area
  66. Biological Dynamics of Forest Fragments Project
    • Manaus, Brazil
    • - Cut trees to isolate several 1, 10, 100 ha fragments
    • Found faunal relaxation
  67. Extinction Debt
    • Expected # of sp's losses based on sp' area equation
  68. Sp's isolation relationships
  69. Why sp's disappear from fragments
    • Sp's area effects: habitat is lost, area declines
    • Sp's isolation effects: poor dispersers don't recolonize after extinctions
    • Sp's environment effects: changes in abiotic conditions after habitat quality
    • Sp's interaction effects: changes in food web organization

Card Set Information

Wildlife Ecology Midterm 1
2010-07-19 02:13:36
FW Wildlife Ecology

Midterm 1
Show Answers:

What would you like to do?

Home > Flashcards > Print Preview