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Protocol Test - Graminoid BioMass
Task with Student Directions

GLOBE Assessment
Grade 9-12

Graminoid Biomass Protocol Test

The Graminoid Biomass protocol test assesses students' ability to take accurate graminoid biomass measurements.

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Graminoid Biomass Protocol Test




Student activity & Level of Performance

+ appropriate student performance

- inappropriate student performance

n.a. not appropriate or not observed

Collecting Graminoid Biomass                                  
Blindfolded partner throws beanbag within site                                  
Mark 1-meter square around beanbag                                  
Clip all vegetation within square to ground level                                  
Collect clippings (avoid unattached leaves / litter)                                  
Sort clippings into green/brown; put in labeled bags                                  
Repeat two more times; do not combine clippings                                  
Calculating Biomass                                  
Set temperature of drying oven (50° - 70° C)                                  
Put labeled bags in drying oven                                  
Mass each bag once a day; record (g); continue until mass is same two days in a row                                  
Shake out contents of bag; mass empty bag; record                                  
Calculate, & record Graminoid Mass:

Mass of vegetation = total mass - mass of empty bag

Calculate average Green graminoid mass                                  
Calculate average Brown graminoid mass                                  


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