Desert Biome & Species Diversity

Desert Biome & Species Diversity

Desert...
Dumont Sand Dunes, Death Valley

Desert Biome

  •  Occur between 15 & 20° North & South laBtude
  •  Generally occur in interior of the continents
  •  Air currents descending, usually diminishing formation of rain

Deserts of the World

Deserts....

  •  Occupy about 20% of all landmass
  •  Rainfall less than 20 inches (50 cm) per year

Deserts...Alluvial Fans & Bajadas

Desert....Inselbergs

Desert Sands...

  •  Soils usually have abundant nutrients but lack organic matter
  •  Soils consist of sand & closely packed bounders
  •  Little humus in the soil profile

Desert Plants....

1

Desert Succulents

  •  Store Water,have waxy leaves to minimize transpiraBon
  •  Have small surface areas exposed to light, open their stomata at night
  •  Shallow roots to collect water during rainfalls
  •  Store biomass in seeds

Succulents

  •  VerBcal orientaBon minimizes exposure to sun
  •  Sharp spines reflect sunlight, create shade & discourage herbivores
  •  CacB secrete toxins into soil to prevent interspecific compeBBon

Desert Plants...Root Systems

  •  Note the root systems for geZng water!
  •  Succulents--shallow for short rainfalls
  •  Mesquite & creosote--deep for tapping into water table
  •  Remember--succulents are allelopathic!

Desert Wildflowers...Annuals

Short-lived wildflowers!

Desert Animals

  •  Animals are small w/ small surface areas
  •  O`en nocturnal
  •  Some animals metabolize (eat) dry seeds

Kangaroo Rats....

  •  Get all the water they need from plants & seeds they eat
  •  Secrete concentrated urine
  •  Are prey for animals as both food & water source
  •  Move ~6 m/second
  •  Freak you out when they

run over you while youre camping in the desert!

Desert Rats...

© lbranch 2013