PASCO Probes Aid Salamander Study

From Patty McGinnis
Science Teacher -- Arcola Intermediate School, Norristown, PA

NORRISTOWN, Pennsylvania -- Patty McGinnis, a science teacher at Arcola Intermediate School in Norristown, Penn., recently applied for and received a Toyota Tapestry grant. The grant enabled McGinnis and her students to conduct a study on the effect of habitat fragmentation on Plethodon cinereus, more commonly known as the red-backed salamander.

McGinnis chose the red-backed salamander because it was easy to find in her area, relatively large and easy to handle. She then used the grant money to purchase probeware from PASCO scientific to allow her seventh grade students to quickly and accurately assess environmental data to determine the salamander's preferred habitat.

McGinnis chose two locations to examine: an undisturbed forest site and a fragmented woodlot. She took students to both locations every day for a week to conduct the study. The students ran 50-meter line transects, stopping every five meters to sample their assigned site. They collected population data and used the PASCO Xplorers and probes to assess soil temperature, humidity and light at ground level at each place where P. cinereus were found. Leaf litter depth, dominant tree species and soil pH were also recorded. The data was then compiled into a database to enable the students to generate graphs using DataStudio and to conduct a comparative analysis of the sites. The students also used DataStudio to manipulate the data to determine if there were any relationships between salamander size and humidity, or any other factors.

"Students found out the salamanders preferred darker areas that were more humid. The temperature didn't really seem to matter," said McGinnis. "And we actually found more salamanders in the fragmented wood lot than at the edge of the forest, which was surprising. I think that was because there weren't a lot of people walking around in the woodlot, whereas there is a picnic area at the edge of the forest. If we looked further into the woods we found more."

In addition to gathering real-time data quickly and accurately, McGinnis said the students also learned how to run transects and follow scientific protocol during the study. "They wanted to run through the woods and flip rocks over, but they had to follow a specific protocol. If a salamander was in your quadrant, you could count it. If it wasn't, you couldn't count it," she said. "Getting students to understand that as scientists we try to do things systematically was a difficult concept for some of them to handle."

Students also learned more about the red-backed salamander and its place in the food chain. "Surprisingly, a lot of kids didn't even know there was such an animal," McGinnis said. "This salamander is also very important in the food web."

This is the third time McGinnis has used a grant to purchase PASCO probeware. She also uses the sensors, software and dataloggers to conduct water quality monitoring with her students. "The kids really like using them," she said.

McGinnis recently gave one group of her students PASCO CO2 probes and encouraged them to conduct an independent investigation. One student placed a CO2 meter in her classroom for a 24-hour period to examine how CO2 levels fluctuated during the day. Another student examined what affect different amounts of sugar had on the CO2 production of yeast. The students then printed their graphs and interpreted them during a presentation to the school's assistant superintendent.

"There is no way I could show CO2 or humidity levels in the classroom that easily without the probes," McGinnis said.

McGinnis said she plans to duplicate the red-back salamander study with her students in the spring.