Why Calibrate? - Landscape Toolbox
Transcript of Why Calibrate? - Landscape Toolbox
Why Calibrate?
• Your data are being used by land managers and researchers to make
decisions.
• To ensure the accuracy and technique of all crew members• Quality Assurance is an integral part of your responsibilities as a data
collector
• Your name is on the data. You are representing yourself.
???
?
When ?
● A significant change in vegetative community
● A new data collector joins the team
● If a month has passed since the last calibration
*Vegetative communities can be significantly different in
stratum, it is up to the discretion of the Project Lead or Crew
lead to decide whether that difference is great enough to call for
a calibration.
Allow for time in the field
“What Am I Expected to Do in the Field?”1. Set up a standard length transect (e.g. 25 m) in a place representative of where
AIM data will be collected. Then set up an equal length transect 120 degrees tangent,
on the RIGHT SIDE to the first T in order to create a wedge for the species walk
1. Each person will complete LPI, Gap intercept, Species inventory, Vegetation
height
1. Be mindful: Don’t trample the area along the transect as you go through or move
the tape.
1. Run an indicator report in DIMA (on paper) to see if you are within 10 2 2
• LPI & Gap intercept: Indicator absolute difference ≤ 10%
• Height: Absolute difference of heights records in each category
≤ 2
• Absolute difference of # of species present in the area ≤ 2 species
• You don’t calibrate with soil stability or texturing but verify that all crew members are collecting uniform peds
• Soil textures can be calibrated against a known lab sample
• REMEMBER: 10 2 2
DIMA
calculates for
you… BUT
YOU MUST
SET UP THE
DIMA
PROPERLY
⮚You can use
paper calibration
sheets.
⮚You will need to
do the math
yourself in the
field…
OR
Overview of DIMA
Calibration Set Up⮚ Set up a new plot in DIMA for each calibration
exercise with a stratum name followed by an
underscore and the date
⮚ C_LOAMY_20190123_1
⮚ NC_LOAMY_20190123_1
⮚ A LINE is made for each crew member, in the
SAME PLOT, who then will complete LPI, Gap
intercept, Species inventory, and Vegetation height
⮚ A report can be generated to compare indicators
(you won’t have to do the math in the field)!
Please fill out the state and county information as well as any
other details you would like to include in the Plot Description
What Should My DIMA Look Like?
Site ID
Plot ID
Site NameSite ID
Plot ID
THE SAME PLOT
Naming
lines
after the
data
collector
How Do I Run The Report In DIMA?
Choose your calibration site
1
2
3Selecting your 1. Site, 2. Plot, & 3. Method
Has each crew member completed LPI, Gap?
Is this the plot data we want? Are there any lines missing?
Paper Sheet
DIMA
We need 5 indicators for the L.P.I. report
Data Sheet
Gap Report
Vegetation Heights
Data Sheet
OR check the DIMA Data Entry
Calculations Tab
Excel Report for Height under the lines tab.
Select the Species Richness Report
12
3
Species Richness per Observer. Do I have a difference of sp. count ≤ 2?
“What if we don’t calibrate?”
Where can
we improve?Bare
ground!
I’ll set
up our
DIMA!
What if we don’t calibrate? Cont’d..
⮚ Identify the methods and indicators that exceeded the acceptable
range of variation
⮚ Discuss possible reasons with one another and compare technique
and definitions
⮚ Remember that an outlier value may be the most correct one
⮚ Consider equipment used (e.g. Did all of the collectors use the
same pin?)
⮚ Repeat the calibration exercise on a new transect until each
method is completely calibrated.
IMPORTANT EXAMPLE:
If Jack collects a litter cover of 10%, Pablo collects a litter cover of
22%, and Jane collects a litter cover of 12% then the range of values
is 12% (22 - 10 = 12) which is greater than the maximum permitted
range of 10% and the crew must repeat the LPI calibration for all
indicators.
If an indicator does not meet calibration criteria, the whole
method for all indicators must be redone.
If a crew passes one method but fails another, they only need to
redo the method that didn’t meet calibration criteria.
❑Has the ecosystem the is being sampled in
changed to something significantly different
than the last sample area?
❑When using DIMA, is there a line for each
person, in the same plot ?
❑Have all indicators been checked for
calibration criteria?
❑Have all reports been run in DIMA?
Questions?
⮚Consult the Manual
⮚Visit www.aim.landscapetoolbox.org