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....
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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 you’re camping in the desert!
Desert Rats...
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