The Dessert By Stefano Pacifici

Dessert Locations  Major locations include: Sahara Africa, South Africa, Australia, and The Arabian Peninsula.

Dessert Vegetations  Palm Tress  Desert Sage  Barrel Cactus  Palm Tress  Desert Sage  Barrel Cactus

Average Rainfall  In Sahara, there is less than 1.5cm a year.  In the USA, there is about 25cm a year.  On average, there is no more than 10 inches of rainfall in any desert.  In Sahara, there is less than 1.5cm a year.  In the USA, there is about 25cm a year.  On average, there is no more than 10 inches of rainfall in any desert.

Desert Sunlight  On average, most deserts receive immense amount of sunlight throughout the day.

Desert Temperatures  Desert temperatures get very high during the day, around a 100 degrees.  Yet, get very low at night.  This is because they are bare and have no protection to keep them from heating up in the sun and cooling off when the sun disappears at night.  Desert temperatures get very high during the day, around a 100 degrees.  Yet, get very low at night.  This is because they are bare and have no protection to keep them from heating up in the sun and cooling off when the sun disappears at night.

Soil Fertility  Deserts have a low soil fertility because of their arid (little rain) soil that contains little to no nutrients.

Seasonal Changes  At specific times of year, nights can drop below freezing.  Also, amount of precipitation can fluctuate drastically and can come and go sporadically.  At specific times of year, nights can drop below freezing.  Also, amount of precipitation can fluctuate drastically and can come and go sporadically.

Limiting Factors  Low amounts of rain and high temperatures are limiting factors.  Because of the low amounts of rain, deserts have arid soil without many nutrients so not much vegetation can occur.  Low amounts of rain and high temperatures are limiting factors.  Because of the low amounts of rain, deserts have arid soil without many nutrients so not much vegetation can occur.

Animal Adaptations to Limiting Factors  A lot of desert animals stay deep underground in burrows where it is much cooler.  A lot of desert animals don’t need to drink, they get a lot of their water from plants.  Many animals are nocturnal, sleeping during the hot day and only coming out at night to eat and hunt.  To retain water, a lot of rodents have extra microscopic tubules to retain most of their water from urine.  Several desert animals have extra long appendages to release heat into their environment; a more effective way of evaporative cooling.  A lot of desert animals stay deep underground in burrows where it is much cooler.  A lot of desert animals don’t need to drink, they get a lot of their water from plants.  Many animals are nocturnal, sleeping during the hot day and only coming out at night to eat and hunt.  To retain water, a lot of rodents have extra microscopic tubules to retain most of their water from urine.  Several desert animals have extra long appendages to release heat into their environment; a more effective way of evaporative cooling.

Desert Animals  Cheetah  Naked Mole Rat  Sand Cat  Mexican Milk Snake  Coyote  Lizards  Ostrich  Llama  Cheetah  Naked Mole Rat  Sand Cat  Mexican Milk Snake  Coyote  Lizards  Ostrich  Llama

Plant Adaptations to Limiting Factors  Desert plants, such as cacti can activate their xerophytes, which have special abilities in retaining water.  Other plants, called Phreatophytes, have developed extremely long roots to allow them to acquire moisture better.  Dessert perennial plants often survive my remaining dormant during dry periods, then coming to lift when water becomes available.  Annual desert plants germinate right after a period of heavy rain, then complete their reproductive cycle very quickly.  Some desert plants have developed spines to prevent animals from eating plants for water.  Desert plants, such as cacti can activate their xerophytes, which have special abilities in retaining water.  Other plants, called Phreatophytes, have developed extremely long roots to allow them to acquire moisture better.  Dessert perennial plants often survive my remaining dormant during dry periods, then coming to lift when water becomes available.  Annual desert plants germinate right after a period of heavy rain, then complete their reproductive cycle very quickly.  Some desert plants have developed spines to prevent animals from eating plants for water.

Desert Plants  Creosote Bush  Saguaro  Desert Wildflower  Desert Marigold  Desert Lily  Orange Pipe Cactus  Elephant Tree  Desert Willow  Creosote Bush  Saguaro  Desert Wildflower  Desert Marigold  Desert Lily  Orange Pipe Cactus  Elephant Tree  Desert Willow

Desert Food web

Human Activities Affecting Deserts  Over the past century, humans have found more and more efficient ways to make the desert livable for more people.  The formation of dams, miles of water canals, and millions of air-conditioning units have resulted in the deserts becoming a comfortable environment for cities, as well as agriculture and grazing industries.  Over the past century, humans have found more and more efficient ways to make the desert livable for more people.  The formation of dams, miles of water canals, and millions of air-conditioning units have resulted in the deserts becoming a comfortable environment for cities, as well as agriculture and grazing industries.

Colorado River and Hoover Dam on the border of Arizona and Nevada

Desert Changes  Increased grazing has altered the desert plant community and agriculture.  Irrigation has altered streams, rivers, and canyons.  Invasive species have been able to come and dominate some of the landscape.  Last, the growth of cities in replacing the once desert landscape with concrete, lawns, and homes.  These have all caused nutrient availability in the soil to decrease, and moisture retention of the soil is to decrease.  Increased grazing has altered the desert plant community and agriculture.  Irrigation has altered streams, rivers, and canyons.  Invasive species have been able to come and dominate some of the landscape.  Last, the growth of cities in replacing the once desert landscape with concrete, lawns, and homes.  These have all caused nutrient availability in the soil to decrease, and moisture retention of the soil is to decrease.

Desert Conservation  The Salt River Project is a plan that could restore the Salt River, north of Phoenix, to its natural state. The plan involves reintroducing a small, flowing stream and desert habitat to the currently dry riverbed.