Biogeography lecture 5

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Biogeography lecture 5

• Animal distribution and limits to distribution

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1.  Compare Good's and Wallaces Areal Scales
showing global boundries. 

• Good
• http//geo.arizona.edu/Antevs/ecol438/goodregn.htm
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• Wallace
• http//geo.arizona.edu/Antevs/ecol438/walcregn.htm
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2.  How does plant distribution vary among the US
southwest's great deserts?  Name each desert,
give 2 identifying characteristics and give
example of a typical plants.

• http//geo.arizona.edu/Antevs/ecol438/namdesrt.htm
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• Great Basin Desert .Cold Desert (Steppe,
  Grassland)Winter rainfall Sagebrush (Artemisia
  tridentata) Shadscale (Atriplex convertifolia)
• Mojave DesertWarm Desert Winter RainfallJoshua
  tree (Yucca brevifolia), blackbrush (Coleogyne
  ramosissima), Creosotebush (Larrea tridentata)
  white bursage (Ambrosia dumosa)
• Sonoran DesertHot Desert Summer
  RainfallSaguaro (Cereus gigantea), paloverde
  (Cercidium microphyllum)Creosote Bush (Larrea
  tridentata), cholla (Opuntia spp.)
• Chihuahuan DesertHot Desert Summer
  RainfallCreosote Bush (Larrea tridentata), agave
  (Agave spp.)Tarbush (Flourensia cernua)

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Southwest
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Overcoming Barriers - Disturbance

• Resistance to Invasion
• Successful alien invaders a fraction of total
  introductions
• Successful invaders depend on lower species
  diversity human-made habitats

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Overcoming barriers - climate

• Palm tree distribution limited by cold climate.
• Pine trees cosmopolitan (found almost
  everywhere)

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Overcoming barriers inhospitable environments

• Deserts
• Adaptation Camel hump, feet that flatten
• Behavior nocturnal fennec fox
• Tundra
• Migrate waterfowl, caribou

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How do limiting factors influence distribution?

• Tolerant species with a wide optimal range expand
  into a greater range of habitats
• Ex. Carp, insects, weeds, pest species

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Types of limiting factors that influence animal
distribution.

• Limiting Factors anything that makes difficult
  survival, growth, or reproduction
• moisture
• CO2
• light
• nutrients (aquatic)
• Oxygen
• pressure

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5. How does competition influence animal
distribution? Ex 1

• barnacles (Chthamalus stellatus)
• rare in subtidal Balanus balanoides
  competesThais lapillus eats
• low in supertidal (upper limit set by drying)

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5. How does competition influence animal
distribution? Ex 2

• starlings (Sturnus vulgaris) 'urban' bird in
  North America
• nesting space available (cities)
• food scarce (countryside)
• Outcompete native birds due to group behavior

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6.  Briefly describe each of the following ways
animals can overcome barriers.  Ex 1.

• Corridors favorable habitat connecting larger
  ones
• Tethyan Sea (Pangean coastal faunas)
• Bering Land Bridge map
• Panama Isthmus map

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6.  Briefly describe each of the following ways
animals can overcome barriers.  Ex 3.

• Filters blocks or slows passage of some
  organisms
• Arabian desert allows movement of animals between
  Africa and Asia
• Panama Canal freshwater separates Caribbean from
  Pacific

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6.  Briefly describe each of the following ways
animals can overcome barriers.  Ex 3
Green iguana central America Galapagos iquana

• Sweepstakes Routes severe barrier that permits
  rare dispersals
• Asian snails in the South Pacific
• South American animals in the Galapagos

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7.  What is the most important corridor in the
US?  Why is it so important? 

• The majority of North American land birds,
  seeking winter homes in the tropics, that come
  south through the Mississippi Flyway

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8.  Why might birds, reptiles and mammals migrate
south from North America?

• Animals that have moved north killer bees, red
  ants- additional resources in N. America
• What should limit spread of both further north?
• Animals moving south many reptiles amphibians
  temp better in s. America

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9.  What factors may have led fish and amphibians
to migrate north from S. America?

• Hint how many amphibian and fish species exist
  in S. and Central America?

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12.  Define and give an example of each of the
following

•         evolutionary relic
•         evolutionary disjunction
•         climatic relic
•         endemic
•         cosmopolitan
•         Provincialism

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Disjunct Distributions - Evolutionary relicts

• Linnaeus, Gray - deciduous forest disjuncts
• Magnolia was widespread during late Cretaceous
• Range reduced during Pleistocene

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      climatic relic

• Ferns persist throughout time, but limited
  distribution based on climate (warm temps
  required).

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Endemic

• Endemism - isolation and stability
• occurring nowhere else, unique to a particular
  area
• example Sarcobatus Great Basin only
  pictureTaxonomic effect Lower taxonomic ranks
  tend to be more narrowly distributed

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References

• Maps and diagrams from Davis -
• Educational use only
• http//geo.arizona.edu/Antevs/ecol438/lect04.htm