Tuesday, April 15, 2014

Stinging Nettle Sprouts

The Stinging Nettle (Urtica dioica) doesn't seem to care that it's cold out, it's still going to sprout.  And in case you're wondering, it can still deliver a very irritating sting even at this early stage.  I know I was wondering . . .

Thursday, April 10, 2014

An Illustrated Life List: European Starlings

Don't take this as a defense of starlings; I do understand their negative impact on other cavity nesting birds (but really, who's to blame for this), but I enjoy watching starlings.  I especially enjoy listening to them for other bird sounds that they are imitating.  I frequently see them in my neighborhood on the mess of utility lines that run through the alleys and along the streets.  I envisioned these lines as the lines on a sonogram graph, with the starling's call taking the shape of the bird they are imitating; the blips on the sonogram.

Saturday, April 5, 2014

Last Year's Last Mushroom With This Year's First Mushroom



A couple of weeks ago I noticed a large clump of well-aged Sulfur Shelf (Laetiporus sulphureus) mushrooms on a large, fallen tree.  On the same tree further down the trunk now log were a few orange freshly sprouted mushrooms that appeared to be Galerina marginata.  It struck me that a number of  cycles were intertwined and represented on this log.  There was the end of the tree's life cycle, very possibly caused by parasitism of the Sulfur Shelf mushroom.  Then there was the cycling of the tree's nutrients back into the soil, aided by the saprobic G. marginata.  And also the seasonal cycle of mushroom fruiting, with the Sulfur Shelf most likely being one of the last fungi to fruit last fall, and G. marginata being one of the first of this year's spring.

Sunday, March 30, 2014

Red-stained Box Elder Wood




It was recently pointed out to me that the wood of Box Elder trees (Acer negundo) often exhibits a reddish stain.  I was curious to find out what caused it.  After some research, I learned that typically, the stain has been attributed to the fungus Fusarium reticulatum, but that research done at the U of MN has shown that the stain is not associated with any particular species of fungus.  Instead the stain is likely a result of some compound produced by the tree to protect tissue after it is compromised in some fashion.
What actually causes the stain was undetermined by the study; the compound is broken down quickly after it is produced (the authors of the study speculate that it is a phenol that oxidizes to produce the stain, but that detail will be left to the distracted chemist to explain further).

The above picture shows a box elder stump with the red stain along with a network of black lines.  This is know as spalting, and is attributed to fungal decay, though as far as I know, not any particular species.

Box Elder wood is not widely used since it is a relatively weak and rot-prone wood.  But wood with  the red stain is used by wood workers to make smaller, ornamental objects.

Tuesday, March 18, 2014

Life In A Sap Bucket - Springtails

The Sugar Maple sap started running today, not a lot, but enough to attract these minute Spingtails (class Collembola) to the buckets.  I almost overlooked them; they initially registered in my brain as woody junk that fell into the bucket from the tree.

I was surprised to learn after observing these today that springtails are not insects, they are in their own taxonomic class.  They share some similarities with insects: three body parts, six legs, two antenna.  But they don't have compound eyes, but instead feature a cluster of eye spots on their head.  And two notable structures that are unique to springtails is the furcula, an appendage on the end of their abdomen that allows them to "spring" when flexed.  And the collophore, a tube located at the front of their abdomen that aids in moisture uptake and excretion.  And please note, that this description is very simplistic, and probably contains some inaccuracies due to it's brevity.

Springtails are usually found in damp places, and are omnivorous, feeding on a wide range of organic matter.  Though mostly unknown to the majority of us, it seems they can be found anywhere there's moisture and organic matter, often in large numbers.  In MN, you can sometimes observe springtails on the snow during warmer weather.  They are commonly called snow fleas - but of course aren't fleas at all, because fleas are insects.

And oddly enough, this my second run in with springtails within a week.  I toured the Cave of the Mounds in WI with my family this weekend, and it was mentioned on the tour that the only creature living in the cave were springtails.