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Biology Lab: Field Exercise #1 - Establishing a Baseline Survey

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Lab Exercise

Remember that field labs must be done in order....on time if possible.

Biology Lab: Field Lab #1

This lab is similar to Illustrated Guide to Home Biology Experiments Procedure V-1-1 (Select Survey Area), V-1-2 (Survey Plant Community), and V-1-3 (Population Count). Please read through those procedures for additional information and suggestions, then adapt the procedure below to your observing site.

Goal: To identify and inventory a specific area for field study throughout the year, and to plan a scientific observation.


Review the principles of designing a good experiment. An experiment should test a hypothesis or prediction about the behavior of specific objects by gathering data on what happens to identified and measurable characteristics (dependent variables) of the objects when conditions affecting them (independent variables) are varied in a controlled way. If possible, conditions are controlled so that only one independent variable is manipulated at a time. The experimental procedure is replicated, either by running the experiment repeatedly or by running it several times simultaneously under the same conditions. The results are then compared to the predictions.



You will need to find an outdoor area at least 20 x 20 feet, which you can have access to at most times of the day for most of the year. It should have a wide variety of plant and animal life. The ideal area for this kind of observation is one which is still natural and open to different kinds of animals. A nature trail or greenbelt, undeveloped area of a park, farm field, or meadow are all good choices and will provide a variety of plants and animals to observe. Your backyard or local park are also possibilities, although they may not contain as many different types of organisms as an open area.

After you have identified the area, begin to inventory all plants and animals that you see. Keep your observations in a spiral or loose leaf notebook you can take with you into the field.

  1. Always record the date and time of your observations, the weather conditions, and the temperature, if possible (use an outdoor thermometer if you can; otherwise, check the weather report for your area). Since you will be coming back to this area, it would be a good idea to determine what standard information you will collect each time to help you compare conditions in the area.
  2. Make a map of each large plant or plant group. Estimate the overall size of the plant or group. I use a 30-foot string knotted at 1-foot intervals; this lets me estimate diameters, lengths, and (with a little trigonometry) heights.
  3. Describe the plants and draw them (do this carefully and take your time). What kinds of characteristics do you note about the plant? Which characteristics will help you identify the type of plant? Which characteristics help you determine its health, age, or other aspects unique to the individual plant?
    • Are the plant stems green and supple like vines, or woody like tree branches?
    • What shape are the plant's leaves?
    • Are the veins in the leaves parallel or netted?
    • Are there flowers, berries, or seeds?
    • What colors are they?
  4. Listen as well: how many different animal sounds do you hear? Can you hear birds, mammals, insects?
  5. Are there signs of animal life? Look for nests in trees or on the ground; look for holes in the dirt where snakes, gophers, or small rodents may live. [NEVER STICK YOUR HAND OR ANY OTHER ITEM DOWN A HOLE! You may be bitten or you may injure the inhabitant.] If the dirt is soft or wet, look for tracks.
  6. Sit quietly, so that any animals in the area become used to your presence. Note any that you see (birds and insects are the most likely; but you may see small animals like snakes, lizards, frogs, mice, or squirrels as well).
  7. If there is a lake, pond, or stream in your sample area, observe the surface: are there any insects which can walk on the water? Can you see fish or amphibians at or near the surface? If possible, pull up a handful of plants growing in the water, or a rock or tree limb, and check for aquatic life which may be clinging to it.
  8. Check plant and animal identification books (you may need to go to the library for these), and identify as many of the organisms you found as possible.
  9. On the basis of your observations, determine a question or hypothesis that you wish to test by observation over the coming year. Identify
    • what will be measured (the dependent variable) and how
    • what variable factors you will observe (the independent variables) and how you will measure them
    • what control group you will use, if possible
    • what replication (duplication of observations) will be used
    • what your expectations are (predict the results if your hypothesis is correct)
    • take your first set of measurements


Prepare a summary of your observations in a format that you can use for subsequent observations. This will make comparisons easier. Remember that the goal of any scientific report should be to include enough information that a similarly-equipped peer can duplicate your observations and check his own results against yours. You may want to review mycroft's report below before writing your own.

  1. Remember to include all pertinent data about the location and conditions (weather, time of day, season of year) affecting your observations.
  2. Identify at least three different areas which intrigue you and write one or more questions for each one. Then choose one area, write a well-defined, narrow question, an hypothesis based on the question, and propose a way to test the question.

Example Report

Turn in a report similar to mycroft's. It should include the date, time, weather conditions, and temperature; a description of the area, general observations, and a table with the organisms observed and their identification.

mycroft's report

Field notebook entry August 7, 2000. Late afternoon and early evening 5pm-6:30pm PDT.

Weather is sunny and dry, approx. 70 deg F.

Location: Jogging trail along 161st Avenue SE, Bellevue, between 28th Place and Eastgate Way. Trail area is 50-70 feet wide by one mile long with less than 20 foot change in elevation; most of trail is between street and parking area, so animals are disturbed by passing traffic.

General notes: Plants are native to area but not entirely wild, since the trail is maintained by city and corporate groundskeepers. Plants range from primarily conifers at northern end through mixed forest to primarily deciduous at southern end.

Organisms observed:

Tree: dark grey-green needles, stiff, 1/2" long distributed evenly around stem. Limbs primarily horizontal near bottom of tree, rising upward near top. Bark grey with ridges. Tree height 50-60 feet.

Noble fir


Tree missing limbs on lower south side, possible due to lack of sunlight.

Tree: dark green needles, tips of branches with lighter green needles 1/2" long, distributed evenly around stem. Bark smoother than noble fir.

Douglas fir


Tree has many broken branches.

Tree: Maple-shaped leaves over 10" across; many stems or trunks

Vine Maple


Growing on street side, gets direct sun at least 1/2 day

Tree: Maple-shaped leaves mostly 8" or less across; many stems or trunks

Vine Maple


Growing under cedar in shade

Snake: approx. 3 feet long, black with green stripes

Garter snake


Coiled in the sun

Bird: black with redwings

Redwing blackbird


In cedar tree

Hypothesis for further study: Vine maples grow better in direct sunlight than in shade.

Dependent variable: Number and size of leaves on plant; length of time on plant (when do they drop off in the fall?); date of appearance in the spring.

Independent variables: Amount of sunlight. Note: soil type is likely to be more acidic under conifers; elevation and drainage may contribute to differences in water available. Observed trees should be close together.

Control group: No specific control group can be determined. A range would help in establishing the tendency (trees in full, partial, and no sunlight).

Replication: Two vine maples in each type of location (full, partial, no sun) will be selected. Differences in drainage will be noted.

Expectation: Vine maples receiving direct sun will be larger, have larger leaves in greater numbers, develop their leaves sooner and lose their leaves later, than those growing in shade

Measurements should be added at this point, and conclusions....but that should be enough to give you an idea of the information to collect.