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  Food web in hot desert hot biome

   The food web in the hot desert biome is a simple one. Life in this hot, dry environment is challenging, requiring adaptations from both animals and plants. The soil is often dry, and desert winds carry fine dust particles away, leaving a stony landscape. Plants that live in the desert year round have evolved special adaptations for capturing and storing water. Adaptations include secreting a waxy substance to protect their leaves from drying out, thorns and spines to keep hungry animals at bay, and body shapes that can expand rapidly when water becomes available. Plants have large networks of roots that lie near the surface and can capture rain when it falls. One bush, the creosote bush, actually secretes a substance in its roots that keep other roots out of its feeding area.

     Many desert plants no longer have leaves, or grow only very small ones.  They have chlorphyll in their stems.  Many cacti do not have leaves at all. Their rounded bodies have a low surface to volume ratio, and the spines that protect them also cast a little precious shade on their green bodies.  Annual desert plants germinate, grow, and flower quickly when there is a rainy year. They make small, hard seeds that may not sprout for ten years or longer. Some perennial plants store moisture in underground tubers or bulbs.

     Desert plants are the primary producers.  Animals that live in the desert feed on the plants' seeds, flowers, and juicy bodies and leaves.

     The plant-eating animals are the primary consumers. These animals are small, and can get by on very little food. Some desert dwellers are insects, and some, such as snakes and lizards, are reptiles.  Reptiles are "cold blooded" and they can survive on only a little food. The warmth of the desert sun heats their bodies so that they can move quickly.  A few small warm-blooded animals, such as kangaroo also live here. They hide from the heat in burrows, and come out at night to feed.

     The secondary consumers eat the plant eaters. Lizards eat insects: snakes eat lizards, insects, and little desert rodents such as deer mice and kangaroo rats.  Scorpions and tarrantulas also eat insects. They have exoskeletons, which help them to conserve moisture.

    All animals need protection from the sun during the heat of the day. There is no shade in the desert, but there are little crannies in the rocks where a small animal can find shelter. Some of the animals go into underground burrows, where the air is a little cooler.

     Not all land classified as desert is equally arid. The driest parts may look very stony, but where there is more moisture there will be more plants, such as sage brush, seasonal grasses, and small shrubs. There may tree sized cacti, palo verde, and Joshua trees. These greener deserts may be home to quail, pygmy owls, and even desert foxes and hawks. A few tertiary consumers may be able to survive in these richer environments.

     An interesting desert "extra" is the oasis, a place where springs of water flow to the surface, providing an environment where palm trees and shrubs may grow. Though rare, oases gladden the hearts of travelers, and provide a refreshing micro-world with its own ecology.


 The Hot Desert

 Introduction to Desert Biomes

 The Cold Desert

 

A Food Pyramid in the Hot Desert Biome

© Elizabeth Anne Viau, 1999. This material may be used freely for instructional purposes but not sold for a price beyond the cost of reproduction. Please inform the author if you use it at
eviau@earthlink.net.