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