Getting Down and Dirty with Lumbricus terrestris


Figure 4. Retrieved from by signing up for and downloading at Kuhn Photos. 2013/12/08
The Lumbricus terrsteris, a species of earth worm, is primarily found in the soil of a non-acidic ecosystem. They are located in both temperate and terrestrial locations. Because they are detritivores, they tend to live in areas were leaf litter is plentiful, so that they can decompose the vegetative matter. They tend to move in soil with high carbon concentrations as well. They are key ecological engineers, in the fact that they essentially mix soil (Griffith et. al 2013). According to Bey et. al, 2013, earthworms are constantly effecting their terrestrial ecosystems by, aiding in diffrent chemical, biological and physical soil processes. Some of the physical processes include making casts and burrows,  which in turn the will make up the key soil properties in the area by transfering  water and other elements. This is also known ass aggregation. What this means is that earthworms themselves contribute to the health and makeup of the soil in their environments, which in turn effects the plant life around the Lumbricus terrestris. (Bey et. al 2013).

Earthworms move through the soil and consume carbon rich soil and plant matter and then egest (or expel as waste) these processed materials, plant and soil residues, as they push through the soil. This is known as a cast and leads to the formation of an aggregate. An aggregate is, according to Yasemin Kavdir, 2011, in the book Biology of Earthworms, made by combining bits of clay, silt, and sand with organic and inorganic substances found in the soil. Soil aggregates in turn can make up the soil structure in a particular area by binding with various chemicals produced by plants and other chemicals found naturally in the soil. Worms carry decaying matter to the burrows, their permanent residence. They excrete much of the soil and plant residue around their home, making the burrow area a spot with a high concentration of plant nutrients. This makes a good spot for plants to place their roots. Worms can also effect the soil physically, by creating large pores to decrease the soil density. This allows the soil to have gasses, air, and water flow. All these factors together are the environment that the earth worm lives in, and that the earthworm contributes to (Karaca 2011).
Figure 6. Earth Worm bringing back live plant to burrow. Retrieved from signing up for and downloading at Kuhn Photo.Accessed on 2013/12/08While Earthworms have been shown to have some benefits to the ecosystem, there is evidence that they may be doing harm as well. According to a study done by Brad Griffith, 2013, L. terrestris, has recently been showing evidence of herbivore activity in this species. There is video evidence of the earthworm not only attacking the seeds and seedlings of plants, but also evidence of the worms attacking the leaves of the plants as well. It is not exactly known if the worms are directly digesting the leaves or if they are bringing the leaf bits back to their burrows to decompose the plant there. The conclusion of this experiment is that the herbivore activity, Depends on the amount of leaf litter available and the time of the year. This means that when the litter availability is low, the earthworms resort more to these respective activities (Griffith et al 2013).Figure 5. Earth Worm Enviornment. Retrieved from signing up for and downloading at Kuhn Photo.Accessed on 2013/12/08

Another study by Jean-David Moore, 2013, suggests that through tests, the Lumbricus terrestris has proven the capability of being able to invade “limed forests". These would include “limed sugar maple stands in southern Quebec and those on richer soils in Ontario”, and the northern hardwood forests of the USA and Canda, where the studies where done. This is linked with human activity. The more humans disrupt forests, the more lime the soil will contain, making these areas susceptible to the invasion of this species of earthworms. Earthworms also have shown evidence of being able to tolerate the cold in the northern hardwood forests, making them better adapted to this area, and more likely to live there, if an invasion were to occur. The earthworms moving to these areas, would change the ecosystems in both positive and negative manners. They would change the soil composition for the better, allowing plants to grow, but would also possibly display their herbivore manner, and destroy some of the plant life in this area (Moore et al. 2013).

Learn a little more about the soil they live in by moving onto our Soil Structure page!

Check out where we gathered our information from on our Reference page