Chihuahuan Desert Abiotic Study

Introduction

The Chihuahuan Desert is the easternmost, southernmost, and largest North American desert. Today you will be studying living conditions in the Chihuahuan Desert. This activity will help you understand the non-living environment of the desert.

Materials

Each group will need the following materials:

• 10 m rope
• meter stick
• Chihuahuan Desert Sampling Log
• clipboard, paper and pencils
• weather bag:
  • cloud chart
  • Beauford wind scale
  • thermometer
  • compass
  • engineer's tape
• soil bag:
  • trowel
  • spade
  • calibrated soil thermometer
  • sandwich bag
  • permanent marker for labelling
• percolation bag:
  • 2 soup cans
  • water container
  • measuring cup

Procedures

1. Form groups of four or five students.
2. Decide where to lay down the transect.
   TIP: The transect must be by a Creosote bush as this is an indicator plant of the Chihuahuan Desert.
3. Laying out the transect:
   a) place one stake at one point, measure out 10 meters, and place another stake;
   b) connect the 2 stakes with the rope;
4. Collecting weather data (at one of the stakes):
   a) take air temperature by placing or holding the thermometer, facing North, for at least 2 minutes;
   b) tie a long piece of engineering tape to the stake to see the wind direction:
   c) use the Beauford wind scale to estimate wind speed;
   d) determine cloud cover and type;
   e) record this data on the Chihuahuan Desert Sampling Log.
5. Collecting soil sample (at the middle of the transect):
   a) fill up a plastic sandwich bag with a soil sample (to be analyzed later);
   b) record the time of day;
   c) record the soil temperature at the soil surface and at 5cm., 10cm.,15cm. and 20cm;
   d) record the air surface temperature.
6. Collecting Percolation Rate (at the middle of the transect):
   a) work each can into the ground 2 cm;
   b) pour a measured amount of water into each can;
   c) measure the time required for all the water to enter the soil;
   d) record amount of water and time for each can and average the results.

Questions

Working in your small groups, get ready to present to the larger group. Once all the groups have reported to the larger group, contrast and compare the information. Here are some questions to get you started. Come up with some of your own.

• Which transect had the highest soil temperature?
• Which transect absorbed the water most rapidly?
• What are the advantages/disadvantages of fast infiltration of water?
• Did the amount of shade affect the temperature at all levels of soil?

Online Resources

• The Chihuahuan Desert
• An Introduction to the Chihuahuan Desert
• Chihuahuan Desert Resources on the Web
• El Paso Online Bio Project
• The Chihuahuan Desert through time

Extension

Do this activity along with a biotic study.
Do this activity along with a journaling activity.

Publish

Keep very good notes and illustrations. Collect your findings in a spreadsheet for the class.