DATA COLLECTION STRATEGIES
by Dick Walton
CONDUCTING AN
INVENTORY
There are several ways to characterize the plants and animals
that occur at your site. A good way to begin is to make an inventory
of the most obvious and abundant forms of plant and animal life.
Once you have this basic inventory you can choose specific organisms
to look at in more detail.
Inventories are lists
of organisms (trees, ferns, birds, mammals etc.) found at a particular
site over time. Observations should be recorded in a systematic
way (using a data sheet or standard journal entry form) and include
such data as organism observed, observer, date, and site location.
You may also want to include a space for observer comments.
A. Plants
Plants can be classified as falling into one of four simple categories.
-Canopy: the tallest trees
-Understory: the smaller and younger trees and taller shrubs
-Shrub Layer: the lower shrubs
-Herb Layer: ferns and wildflowers
PalmOS work: Graphic representations of plant layers provide a way for students to compare their site "architecture" with the model. [You could make a pull-down menu of types in the site description.]
Interesting data about plants include:
Correlation with light (canopy, through seasons), temperature, moisture (using probes)
Density and spacing patterns
Biodiversity measures (baseline and after development)
B. Animals
-Vertebrates: mammals, birds, amphibians & reptiles,fish
-Invertebrates: insects (see Arthropods)
SAMPLING/CENSUSING
An inventory is one way to establish an index of biodiversity
for your site. Sampling and censusing provide a different set
of techniques to characterize your site's animal and plant populations.
If you went to your site on a regular basis and counted all the
birds (or alternately all the Blue Jays) you observed in a particular
area in a set amount of time, your numbers would represent a
sample. If you continued to sample the birds over a year you
might begin to see seasonal changes in bird populations. If you
carried out this sampling over a number of years, your data might
suggest increases or decreases in bird populations.
Here are some guidelines for establishing a sampling project.
1) choose an animal or plant (or groups of animals or plants) that is (are) well represented on your site
2) define the methodology precisely enough for others to follow
3) create a data sheet to record your observations
When you design your sampling research project it is critical to define your methodology in a way that your work can be understood by and/or continued by future researchers. Sampling methods may be simple but they need to be consistant. Typical sampling methodologies include:
1) Point Samples (for example, counting all the ants crossing a path at a specified point)
2) Area Samples (for example, counting all the milkweeds in a defined area)
3) Transect Samples (for example, counting all the birds heard or seen at points along a given route). Useful if you have a large area to cover.
An EXAMPLE: Monarch Butterflies
Here's an example for sampling monarch butterflies.
Monarch butterflies will be sampled during September and October as they are migrating south. A 5 mile transect is defined along local roads covering varied habitat. The census will be conducted 3 times a day at 9:00, 12:00, and 3:00 (EST).
Road Census General Methodology: drive your route at a leisurely pace recording monarchs as you go. Do not stop to count groups of monarchs but rather get the most accurate count possible as you pass along the route. Do not estimate numbers but record only butterflies actually observed and counted.
Include the following
elements in the data sheet:
Title Monarch Monitoring Project
Road Census - Data Sheet
Obs: observer's name
Date: record month, day, and year as 10/5/01 (October 5, 2001) for each census
ST:EST: record start time for each census; convert all times to Eastern Standard Time (Daylight Savings minus 1 hour)
FT:EST: record finish time for each census; convert all times to Eastern Standard Time (Daylight Savings minus 1 hour)
MO: total minutes of observation
Dps: total Monarchs (Danaus plexippus) observed
O'sF: set thermometer in shade 3 feet above ground level
Sun: visibility of sun:
use these codes:
0 = sun not visible
1/4 = sun's position can just be located
1/2 = sun's position visible but not with full force
3/4 = sun's position clearly visible with almost full force
4/4 = full sun
WD: wind direction - use one, two, or three capital letters (for exam ple NNE for north-northeast) to indicate the direction the wind is coming from
WS: wind speed: use these
codes:
0= less than 1 mi/h; smoke rises vertically
1= 1-3 mi/h; smoke drift indicates wind direction
2= 4-7 mi/h; leaves rustle; wind is felt on face
3= 8-12 mi/h; leaves in constant motion; small flag extended
4= 13-18 mi/h; raises dust and loose paper; small branches in
motion
5= 19-24 mi/h; small trees in leaf sway
6= 25-31 mi/h; larger branches in motion; whistling heard in
wires
To find out more about the actual Monarch census that uses this sampling methodology see:
http://www.concord.org/~dick/mon.html
PROBEWARE
Several probeware systems exist at this time that make the handheld computer into even more of a portable laboratory. ImagiWorks (http://www.imagiworks.com) has a snap-on interface box for the handheld computer to read most analog sensors including pH, light, temperature, dissolved oxygen, etc. The Concord Consortium, through the NSF-funded project Technology Enhanced Elementary and Middle School Science (TEEMSS), is developing a set of sensors that connect to the handheld computer so that students can investigate a wide range of environmental concerns. For example, the Fast Response Temperature probe can detect changes in air temperature as a cloud passes over head, or the Current/Voltage probe could be used to register a motorized paddle wheel output in a stream to monitor water flow. The robust software allows the students to view activities and respond in notes or drawings in a LabBook on their hand computer. The LabBook, written in WABA, and portable to all types of handheld computers, also allows the importing of other applications to facilitate a coordinated location for students to oversee their projects.
PalmOS work: data sheet templates,
transect and area maps, databases; sampling strategies
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