Background

When students think about a beach, one of the last habitats they would think of is a desert because of all the "water, water everywhere". However, in many ways, the dune and upper beach habitats are very similar to a desert. The stresses of high temperatures on the sand, intense sunlight, wind, salt spray, and dry soils demand special adaptations.  

White Sands National Park

    Plants on the dunes share some of the typical desert plant adaptations. Many of the plants have reduced leaves, waxy coatings over the leaves, succulent stems and leaves, or tiny hairs or spines covering the leaf surfaces. The plants also have specialized root systems, often running deep and wide to collect water from the porous sand. These adaptations are most noticeable among the primary dune plants, such as sea rocket, Russian thistle, and sand bur. Even the shrubs of the dunes, bayberry and wax myrtle, have waxy leaves. Occasionally, prickly pear cactus and yucca plants growing in the dunes are obvious reminders of the desert habitat.

    Animals living among the dunes must also cope with the desert-like environment. One of the best ways to get away from the intense sun and heat is to dig into the sand. The ant lion digs in the sand without reinforcing the sides of its hole, which becomes a funnel. Prey then slide down the sides of the funnel into the waiting jaws of the ant lion. Other digging animals do reinforce their holes: the ghosty crab with special secretions and the wolf spider with a modified web. Blow gently across the surface of one of these holes to see the web.

    Some dune animals, like ghost crabs, have light body color which serves as camouflage and reduces absorption of heat from sun. Some have hairs, which, in addition to acting as sensory adaptations, help reflect the suns's rays. Many dune animals are crepuscular (active at dawn and dusk) or nocturnal (active at night), and thereby avoid the heat of the day.

    Anyone who has walked across the hot sand barefoot during the summer realizes the great effect the temperature might have on beach and dune inhabitants. By measuring differences in temperature along the beach and dunes and by observing plants and animals living there, students can gain a better appreciation for the environmental stresses and the special adaptations which allow these organisms to survive in their habitat.

------------------------------------------------------------------------

Photo contributions courtesy of Gloria M. of http://members.tripod.com/~GloryM/index-3.html

 

Tell the class that this animal might like sand.  Ask them why?  Ask will it be found in the desert sand or the ocean beach sand habitat?

Ask them if they have ever seen or felt the fur of a tortoise.

This is a bunny.  Is it a desert or an ocean sand dweller?

Ask them why or why not a rattlesnake likes sand?

Ask the pupils if this lizard lives in the desert sand or the ocean beach sand habitat.

These photos can be found at http://www.desertgold.com/park/parklife.html

This is a picture of a cactus plant known as the "Old Man."  Ask pupils why it might have such a name.

This is a picture of a cactus plant known as the "Hedgehog Cactus."  Ask pupils why it might have such a name.

________________________________________________________________________________________