Measuring Submerged Aquatic Macrophytes (SAMs)



Reading the Graph

1. How many times did the researcher collect data? On what approximate dates?

She collected data four times, approximately June 2, July 15, August 31 and September 15

2. How many different species of submerged aquatic macrophytes (SAMs) did the researcher collect?

She collected three species, Elodea, Ranunculus, Potamogeton.

Interpreting the Graph

3. Based on the information presented in the graph, to what do you attribute the decrease in biomass between mid summer (approx. June 15) and late summer (approx. Sept 1)? Be sure to account for both the fire and the monsoon flood events.

Because the researcher did not collect data after the fire and before the floods, it is hard to attribute the decrease to a specific cause. However, since the plants are "submerged," they probably didn't get burned by the fire. It is most likely that they were scoured away by the floods.

4.Using the graph and what you know about NM’s climate, predict what the biomass would be for each species of SAM if the researcher had collected data on November 15.

The biomass for each species would be near zero. On average, the river is iced over by November and by December is covered by a thick blanket of snow. Without light, the SAMs can't photosynthesize and the vast majority of the plants die back, float downstream and are consumed by insects, fungi and microbes.

Digging Deeper

5. Write a hypothetical email message to the researcher suggesting a plan for future data collection. Include the question you would like answered, the species to be sampled, and the date for data collection.

Answers will vary. Complete answers will include a question, the species to be sampled, and the date for data collection.

Click here to go back to the lesson.