What we did, how we did it, and what we learned!

    Our project was the collection of soil biota for the week 8 lab of the Soil 205 class. We began our journey at the entomology lab on the 4th floor of Cordley Hall. As we stood in utter confusion, our valiant coordinator stepped into the hallway to rescue us all! Kim Townsend was her name, and bugs were her game. We first learned that she had already collected the six samples we would be using and set up eight Berlese Funnels with six samples that were to be used the labs.

 

Berlese Funnels with lights on and mason jars secured

 

Attaching the mason jars to the Berlese Funnels, these funnels are the catch system for the soil biota.

   If you didn't know, a Berlese Funnel is a curious contraption that you place a sample of soil into, and place a heat lamp over the top to drive the bugs down into a container of observation. either they went into an ethanol bath to quickly, humanely die or a moist environment to keep them thriving for live observation. It takes at least forty-eight hours to drive the majority of biota down into the holding containers, though some come out very fast.

Inside the Berlese Funnel, a mesh cover prevents the litter from falling into the biota samples collected in mason jars

Lauren and Briana fill the Berlese Funnels with the soil samples

   We initially sorted the bugs under a stereoscope, trying to classify the bugs by their phyla, and observe their physical characteristics. We quickly realized that it would be more effective not to classify, but to provide diverse samples for each lab. One really interesting way that we learned to classify the biota is by identifying their purpose in the ecosystem of the Oi horizon. For example, by looking at the physical characteristics of millipedes and centipedes we found out that centipedes are the predators because they are fast like soil sharks and millipedes are decomposers because they move more slowly and break down litter like a sloth on a hot day. Other attributes include; the millipedes have a defense mechanism where they release a chemical compound (cyanide) when touched by a perceived predator. Here is a picture to further show their differences.

    Another interesting fact that we learned during our project was that during the last ice age, most of the native earthworms were wiped out and were no longer around in american soils. The earthworms that exist in our soils today are mostly not native and were brought in from Europe unintentionally in soils used for ship ballast on cargo ships. They quickly moved across the new world and are the most common earth worms today. 

Katie fills the Berlese Funnels with soil