Fwd: Invertebrates in your soil
Orion Kriegman
From: Carly Becker <19cb...@gannacademy.org>
Date: Thu, May 31, 2018 at 9:43 PM
Subject: Invertebrates in your soil
To: "or...@bostonfoodforest.org" <or...@bostonfoodforest.org>
Hi Orion,
Sorry I'm sending this so late after our oven building week. I've been very busy with final projects from school, but now I am finally sending you my report. A disclaimer: I am not an expert on invertebrates or soil quality, but I am avidly interested in invertebrates and fairly familiar with the species in our state of Massachusetts.
Isopods
Also known as woodlice or pill-bugs, isopods are a type of crustacean that consume tough organic matter, like dead leaves and wood, converting it into soil. They live best in soil layered with organic debris and they are very beneficial to soil quality.
There are at least three species of isopod thriving at the Eggleston site: Armadillium vulgare (which has the ability to roll up into a ball), Oniscus asellus (which cannot roll into a ball), and an unidentified species that is light colored. The native isopod species in New England are not well documented, but A. vulgare and O. asellus are both introduced from the British Isles and are now widespread, making up some of the most common species in this area. Their numbers were healthy and seemed concentrated around the area near the entrance.
While digging up the birdbath, we also noticed a spider with a bright red thorax and tan abdomen, which I later identified as a species in Dysdera, probably Dysdera erythrina but I am not 100% sure. The genus Dysdera is adapted specifically to prey on isopods, millipedes, and other hard bodied detritivores, and the presence of this species in your soil is a sign that your shelled invertebrate populations are healthy enough to support a specialized predator.
Molluscs
I found four species of molluscs in the garden.
Slugs: various Arion species. Arion sp. slugs can grow to be three inches long and they feed on living organic matter. They are introduced from Europe but have become widespread in the Northeastern US. I also noticed a Deroceras species. I believe this species is also introduced, but there is not a lot of documentation. The diversity of slugs on your plot is about the same as I have observed on minimally disturbed forest sites.
Snails: I found small, obscure brown snails with a flat, grooved shell hiding underneath leaf rubble. I have seen this species before in other places, I believe it's in the genus Trochulus. There are also plenty of grove snails, Cepaea nemoralis.
Other:
Small unidentified millipedes, centipedes, ants, and worms.
Something I didn't notice that could be improved:
An organism that I couldn't find anywhere, but is characteristic of healthy, rich, solid woodland ground, are springtails. Springtails are tiny, hopping, proto-insects that feed on a variety of things, most notably on fungi. They are a strong asset of healthy soil. It's possible I wasn't looking hard enough, but I did not encounter any springtails when I was looking around. A good way to provide better habitat for springtails would be to set up undisturbed refugia in wet, shaded areas, like a pile of woodchips or leaves.
Thank you for letting me check out these bugs! If you still want to send along the soil testing results that you had, I would appreciate that a ton.
Sincerely,
Kira
We have it within our power to create merciful acts."
-- Terry Tempest Williams
We have it within our power to create merciful acts."
-- Terry Tempest Williams