Robotic ecological mapping: Habitats and the search for life in the Atacama Desert
Desert Life
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Transcript of Desert Life
Desert Life
Desert ecology
Desert ecology• Why are deserts dry?• What adaptations to animals and
plants need to live there?
Desert ecology
Deserts• Definition of a desert: less than 10
inches of rain per year, more evaporation than precipitation
• This is caused either by dry winds (air heating up as it gets warmer), a mountain “rainshadow”, or lack of water in the middle of a continent
Desert ecology
Why are deserts dry?• Rainshadow of mountain / middle of
continent• Falling air / cool air holds little
moisture – and at this latitude, air often falls
from having risen at the equator
Desert ecology
Deserts
Desert ecology
North American Deserts• Sonoran
Desert• Mojave Desert• Chihuahuan
Desert• Great Basin
Desert
Desert ecology
North American DesertsCharacteristic plants:• Sonoran Desert: Saguaro, cacti• Mojave Desert: Joshua tree• Chihuahuan Desert: yuccas• Great Basin Desert: sagebush
The abiotic environment
Why does any organism live where it lives?
Usually three kinds of explanations:• Abiotic environment (the right
climate, nesting sites, etc.)• Biotic interactions (prey is there)• History (it evolved there and did not
migrate somewhere else)
The abiotic environment
Why are most cacti only found in the American deserts?
• Abiotic environment (dry with periodic rain; not too cold)
• Biotic interactions (can defend themselves against desert herbivores and compete with other desert plants)
• History (evolved in the Americas, and cannot migrate to Africa, for example)
Desert ecology
North American DesertsCharacteristic plants because of
characteristic climate:• Sonoran Desert: winter and summer rains
(monsoon), very hot• Mojave Desert: winter rains, hot• Chihuahuan Desert: summer rains, warm• Great Basin Desert: winter rains, high
elevation, colder (especially in winter)
Desert ecology
Desert adaptations• Animals and plants that live in the
desert are adapted to the hot, dry climate.
• Three basic methods:– Evade– Endure– Expire
Desert ecology
Evade Endure Expire
• Migrate away in summer
• Only be active at night
• Minimize water loss
• Maximize heat loss
• Store water
• Adults may die before it gets too hot
• Durable eggs or seeds survive to next wet season
Desert ecology
Endure: ways to cope with hot & dry climate• Store water• Conserve water• Tolerate dehydration• Reduce heat input• Dissipate heat• Tolerate hypothermia
Desert ecology
Endure: ways to cope with hot & dry climate• Store water• Conserve water• Tolerate dehydration• Reduce heat input• Dissipate heat• Tolerate hypothermia
Desert ecology
Endure: ways to cope with hot & dry climate• Store water• Conserve water• Tolerate dehydration• Reduce heat input• Dissipate heat• Tolerate hypothermia
Desert ecology
Endure: ways to cope with hot & dry climate• Store water• Conserve water• Tolerate dehydration• Reduce heat input• Dissipate heat• Tolerate hypothermia vertical leaves, insulation
with hairs
Desert ecology
Endure: ways to cope with hot & dry climate• Store water• Conserve water• Tolerate dehydration• Reduce heat input• Dissipate heat• Tolerate hypothermia
Desert ecology
Endure: ways to cope with hot & dry climate• Store water• Conserve water• Tolerate dehydration• Reduce heat input• Dissipate heat• Tolerate hypothermia
Summary
Deserts• Deserts are drier than other places• But there are different kinds of deserts
depending on the temperature, seasons, and when & how much rain
• Animals and plants are adapted to a particular “niche”, which includes climate and other species
• Where an animal/plant lives also has historic reasons