Arthropod and Earthworm Data and Procedures 2015-2017

In an attempt to research arthropod and earthworms using a less invasive technique, ESSRE interns utilized different protocols during the years 2015, 2016, and 2017 than had been previously used in the program. Unfortunately, while less invasive, these techniques were also less accurate. On this page you will find the data we collected during those years as well as the protocols used.

Survey Data

2015 Arthropod and Earthworm Survey Data                      2016 Arthropod and Earthworm Survey Data                   2017 Arthropod and Earthworm Survey Data                   

Statistical Summaries

2015 Arthropod and Earthworm Statistical Summaries                           2016 Arthropod and Earthworm Statistical Summaries                       2017 Arthropod and Earthworm Statistical Summaries       

Protocols

Estimating Arthropod Density and Diversity

Method used in 2015

  1. In an area with lots of plant coverage, select a 10 cm diameter area in which your extraction will be performed
  2. Clear the surface while manually counting visible arthropods, record any arthropods found and discard onto nearby ground
  3. Hammer the tube into the cleared area using a mallet until the dirt inside the tube reaches the brim of the tube
  4. Manually pull out the tube (this might involve twisting and wiggling the tube slightly) and directly transfer the dirt inside the tube into a gallon sized plastic bag. If any dirt falls out during the extraction process, be sure to manually gather the spilled dirt and place it into the gallon bag.
  5. When back inside, fill a transparent tub with two liters of the MgSO4 solution
  6. With gloves on, carefully crumble the dirt directly from the gallon sized bag into the transparent tub with the solution in it
    1. Be sure not to crumble the dirt hard enough that the arthropods are crushed
    2. Make sure all major dirt clumps are crumbled to release the arthropods so they can float
    3. If larger invertebrates are found during the crumbling process, record their species and return them to the wild (i.e. earthworms, large spiders)
  7. Stir the soil in the solution with the stirring rod to distribute the soil evenly on the bottom of the container
  8. Let the solution and dirt sit still in the tub for 24 hours
  9. Gently use the large wire mesh to glide across the surface of the solution to extract the plant matter floating on the surface. Place this matter next to the tub.
  10.  With tweezers and a magnifying glass, sift through the plant matter and record any arthropods found. Place the counted arthropods aside to avoid double counting.
  11.  Also with a magnifying glass and tweezers, examine the matter and organisms floating on top of the solution. Record any arthropods found, and put aside to avoid double counting.

Method used from 2016 to 2017

  1. Select a soft plot of land approximately 10 cm wide in any of the four quadrants. This is where the extraction will be performed.
  2. Place the 16 cm PVC pipe over the chosen location and hammer the tube into the ground
  3. Take out the surface layer of the soil (about 2 cm) inside the pipe and place in the bucket.
  4. Continue hammering until the soil covers 15 cm inside the pipe.
  5. Manually pull out the tube (this might involve twisting and wiggling the tube slightly) and directly transfer the dirt inside the tube into a bucket. If any dirt falls out during the extraction process, be sure to gather the spilled dirt and place it into the bucket along with the previously collected 2 cm of soil (in step 3).
  6. Examine the soil for any arthropods and earthworms and record. Once the soil is inspected, continuously place back in the 15 cm hole.
  7. Repeat steps 1 through 6 once more in the same quadrant for a total of two extractions in each quadrant.
  8. Repeat steps 1 through 7 three more times in each of the four quadrants.
  9. Multiply all recorded values by 31.8 to estimate the number of arthropods per square meter.

 

Estimating Annelid Density:

Method used in 2015

  1. In an area with lots of plant coverage, select a 10 cm diameter area in which your extraction will be performed
  2. Clear the surface while manually counting visible arthropods, record any arthropods found and discard onto nearby ground
  3. Hammer the tube into the cleared area using a mallet until the dirt inside the tube reaches the brim of the tube
  4. Manually pull out the tube (this might involve twisting and wiggling the tube slightly) and directly transfer the dirt inside the tube into a gallon sized plastic bag. If any dirt falls out during the extraction process, be sure to manually gather the spilled dirt and place it into the gallon bag.
  5. When back inside, fill a transparent tub with two liters of the MgSO4 solution
  6. With gloves on, carefully crumble the dirt directly from the gallon sized bag into the transparent tub with the solution in it
    1. Be sure not to crumble the dirt hard enough that the arthropods are crushed
    2. Make sure all major dirt clumps are crumbled to release the arthropods so they can float
    3. If larger invertebrates are found during the crumbling process, record their species and return them to the wild (i.e. earthworms, large spiders)
  7. Stir the soil in the solution with the stirring rod to distribute the soil evenly on the bottom of the container
  8. Let the solution and dirt sit still in the tub for 24 hours
  9. Gently use the large wire mesh to glide across the surface of the solution to extract the plant matter floating on the surface. Place this matter next to the tub.
  10.  With tweezers and a magnifying glass, sift through the plant matter and record any arthropods found. Place the counted arthropods aside to avoid double counting.
  11.  Also with a magnifying glass and tweezers, examine the matter and organisms floating on top of the solution. Record any annelid found, and put aside to avoid double counting.

Method used from 2016 to 2017

  1. Select a soft plot of land approximately 10 cm wide in any of the four quadrants. This is where the extraction will be performed.
  2. Place the 16 cm PVC pipe over the chosen location and hammer the tube into the ground
  3. Take out the surface layer of the soil (about 2 cm) inside the pipe and place in the bucket.
  4. Continue hammering until the soil covers 15 cm inside the pipe.
  5. Manually pull out the tube (this might involve twisting and wiggling the tube slightly) and directly transfer the dirt inside the tube into a bucket. If any dirt falls out during the extraction process, be sure to gather the spilled dirt and place it into the bucket along with the previously collected 2 cm of soil (in step 3).
  6. Examine the soil for any arthropods and earthworms and record. Once the soil is inspected, continuously place back in the 15 cm hole.
  7. Repeat steps 1 through 6 once more in the same quadrant for a total of two extractions in each quadrant.
  8. Repeat steps 1 through 7 three more times in each of the four quadrants.
  9. Multiply all recorded values by 31.8 to estimate the number of annelid per square meter.