National Sampling Protocol 3 – Quantitative Hand-Sorting for Short and Long-Term Monitoring
Equipment you will need
- clothes and shoes that can get dirty
- a partner(s)
- a spade or shovel (square ended works best)
- soil thermometer* (optional)
- 2 plastic sheets or large garbage bags
- 2 well rinsed plastic containers (yogurt, margarine or cottage cheese containers work best)
- data sheets
- pencil/pens and a 30 cm ruler
- the taxonomic key to adult earthworms (downloadable Taxonomic Key)
- a camera (optional)
*Note: do not use glass thermometers because they will break when you push them into soil.
Quantified Hand-Sort Protocol
- Dig a hole of known volume.
- Measure the width of the blade of your spade. If your spade is 15 cm across then note that you will dig a 15 cm wide by 15 cm long by 20 cm deep hole. Place the plastic sheet on the ground in a convenient place near where you are digging and get your containers out. If there is a lot of litter (dead leaves, old plant parts, or twigs) on the surface then trace an outline of the square hole with the spade on the soil surface and then remove and sort through the surface material. Carefully look under the bark on dead twigs, and through the leaves because you might find surface or litter dwelling earthworms. Often these earthworms deposit their egg capsules or cocoons in the plant litter, so look for them too. Put the earthworms and cocoons you find in the container and record how many earthworms and cocoons you found in the litter layer (layer 1) on the Observation Form and that you found them in the litter layer.
- Now dig down to 10 cm, you can make a mark on you spade or measure down with your measuring stick beside your spade. Cut the hole to 10 cm on all sides with the spade then scoop the soil out with the spade from one side onto one of the plastic sheets or bags (away from the plant litter). Try as best you can to make a square hole i.e. if you are digging a 15 cm wide hole then it should measure 15 cm wide at the bottom after your have removed 10 cm of soil. Now cut along the edges of the hole down another 10 cm to 20 cm and scoop the soil out onto the other plastic bag. Measure the hole you made and record the size on your data sheet. Check to make sure it is the same size at the bottom as it is at the top and record any differences.
Note: You may only be able to dig to 10cm, which is fine just make sure that you consistently only dig to 10cm at all your sites and that you indicate the depth of the hole on the data sheet.
- Hand-sort the soil from the bottom half of the hole first. As you go through the soil, put any earthworms or cocoons into the container.
- To hand-sort, grab a handful of soil and gently but firmly break-up any clumps. As you are breaking the clumps look for earthworms and cocoons. Sometimes inside clumps of soil, you will find earthworms that are coiled into what looks like a ball of wool. These earthworms are aestivating, which means they are in a resting state until the soil conditions are more favourable. Aestivating earthworms are smaller and pinker than regular active earthworms. Put the aestivating earthworms into your container to count – they cannot be identified.
- Count the earthworms and cocoons in each container and record the numbers on Observation form. Count the earthworms and cocoons from each layer, one layer at a time starting with the deepest layer. (You should have already counted everything from the litter layer and recorded it on your data sheet). Put the juveniles, cocoons and aestivating earthworms back in the soil. Keep your adults to identify by using the key provided and following the instructions provided on the web site. Try to make sure you do not mix the soil layers you have carefully dug.
- Record the number of adult earthworms along with each species for each soil layer on your Observation Form. If you don’t find any earthworms, that’s important information too!
- After you have identified your adults from each soil layer and the litter layer, return all the earthworms to the soil layer in which they were found and put the 20 cm soil layer back into the hole first, then the 10cm layer, pat the soil down lightly with your foot and then replace the litter layer. Now, please take a picture of your sites. These pictures help us become familiar with the area you sampled in.
- If you have found an earthworm that you cannot identify, take a picture of the specimen and follow the instructions for earthworm identification verification found on this website.