Biodiversity Study -- A Unit Study

Jeb Schenck
Hot Springs County HS
Thermopolis, Wyoming
AEJSchenck@aol.com

The activity is used to introduce students to biology in general and the significance of environmental studies. The focus of the terrestrial biodiversity survey is to examine the impact of humans upon the environment. Through a series of investigations students develop their own hypothesis about human impact and then test this on a site not previously examined. Final analysis and discussion of the results allows the students to develop a theory about the impact of humans upon the biodiversity.

Students also are introduced to experimental design, use of statistics to determine whether to accept or reject a hypothesis, and the significance of taxonomy.


Target Audience


Background Information


TIME
Approximately 12-14 class days. This works extremely well if following a block schedule. Students are more focused and discussions more powerful.

TEACHER NOTES
Sites for the surveys need to be checked out prior to class and should pose few or no obstacles. Try to have a plant taxonomist help check your sites because you will sample the plants and you don't wish to remove rare species. You might be surprised at what you have locally. Students on crutches and in wheel chairs can do many of the activities if site is well selected. The teacher should actually run their own biodiversity survey in two other sites first just to gain the feel of what the students will run into.

STUDENTS
Students need to practice (dry lab) the procedures for counting the biodiversity in the classroom. Review these with the student teams at the end of the practice. Students will be crawling on the ground collecting samples.


PREP TIME 1 Hr = 1 class period
equipment organization (teacher time): 3/4 Hr.
student survey sampling & instruction: 1 Hr. (class time)
CLASS TIME Performing Survey, post lab discussion
Surveying 3 terrestrial sites 3 Hrs
Data analysis 2 Hrs
Hypothesis development
Experimental design 1-2 Hrs.
Survey of final terrestrial site 1 Hr.
Data analysis and discussion of
acceptance or rejection 3 Hrs.
TOTAL STUDENT TIME: 14 Hrs. (approx)
MATERIALS 1 plant press per class
1 note book per team
3-4 10 m tapes
Arthropod/insect ID book or taxonomy key
Plant/shrub ID book or taxonomy key
Animal tracks/scat ID book


Opening exercise - Setting the stage

Engage students in a cooperative learning exercise on whether their own environment is important or not. Move onto the concept of diversity. Model diversity within the classroom, and repeat until the students can tell each other or in written form, what diversity is. Expand this to biodiversity. Each person should predict what they think biodiversity means and why it is or isn't significant. Discuss how biodiversity might be measured. Demonstrate on the board, floor or field how to run a line survey (there are other names for the same procedure).


Sampling With Line Surveys

*Student teams of 5 (1 recorder, 2 animal surveyors, 2 plant samplers)

Three to Four sites will be needed for the survey in order to see patterns. One site should have little or low human impact. A second site should have moderate human impact and a third should have high human impact. (This can be run in the parking lot or football field). A four site is where the students will check their predictions. It can be have any level of impact you wish.

A site is selected and a base point selected (see drawing) from which a straight line will be measured. Several line surveys may be run per site.


1 Site = 4 Surveys

  1. Students first OBSERVE over the site any organisms that cross an imaginary straight line. Organisms may fly, crawl or move across the line. Do for 5 minutes and record all observations and time of day (some animals are active only at particular times of day).

  2. Shoulder to shoulder the two animal surveyors crawl the 10 meter line and call out every single SIGN or type of animal... as long as they can tell they are different. This might be foot prints, scat, pop cans (sign of humans), animal burrows, trails, the different insects, rodents, birds, other arthropods. Lift up all leaves, branches, rocks...everything.

    Recorder notes the data. We want the number of different TYPES. You can expand the study to include the number of each type as well.

  3. After the animal survey, the plant samplers go in and collect one of each type of plant. All they need to do is be able to tell one plant is different from another. Collect the plants properly, by including the root system. Place properly in plant press. These may be used for later plant taxonomy. Again, we're trying to survey the number of different types, but you may wish to know many of each type.



Analysis Of Data

Chart the data for each site, and how many types of organisms (be sure to keep a record of the different categories organisms). You may also chart how many of each species as well.

Compare the data from each site. Note and discuss trends.



Hypothesis Development And Experiment Design

Based upon the data, have students individually or in teams develop a hypothesis. The hypothesis must be measurable. Keep it simple if possible! Have students design their procedure for testing their hypothesis and other students are used to check to make certain it is understandable.

Review and discuss as needed. Be encouraging, this may be the first time they've ever designed their own experiment.

Discuss how will they know if their hypothesis should be accepted or rejected. Avoid use of "we prove", "We don't prove", "WE SUGGEST". Use your math teachers to help introduce the ideas of sample sizes, significance and how math is used to decide what we accept or reject. This could easily launch into other discussions about how "good or poor" a theory is.



Run Their Experiment

Have the student run their experiment and analyze the data. Present the data in a lab report and chart and display for class discussion. Did they support their hypothesis? How can we check it mathematically?



Evaluation

Evaluation of the lab is accomplished by a series of reflection and conclusion activities that are performed individually, collaboratively and cooperatively. These are usually finalized in a written form although they may be extensively discussed. The procedures of inquiry, reflection and the biological principles found in biodiversity are repeatedly used throughout the remainder of the year with all other organisms. Reinforcement is frequent.



Reflections And Conclusions

Typical Questions to be answered individually, collaboratively, cooperatively.



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