And who do we have to thank for turning dead trees into soil? If you answered fungi and decomposers, you’re right – but there’s more to the story. Though I could have titled this post “decomposers”, I didn’t for a reason. All the tiny critters – millipedes, pillbugs, earthworms, nematodes, bacteria and so on – they do an incredible job of eating dead stuff and breaking it down. But there’s one thing they can’t digest: lignin, the toughest part of wood. Only some bacteria, and fungal deconstructors in the class Basidiomycetes have evolved to do this specialized task.
Here is a typical job site for the “Polypores”, as many of the lignin-deconstructing fungi are called. This group includes most of the bracket or shelf fungi; two different species can be seen in the lower right and left corners of the pic. The huge old Hackberry tree they’re working on crashed down a few years ago, and is typical of what’s happening all over our forest.
A close-up shows that Polypores have pores instead of gills.
One Polypore many of us are familiar with is the aptly named Turkey Tail Mushroom, Trametes versicolor. “Versicolor” means variegated in color; the one in the pic is a particularly colorful Turkeytail. The beautiful bands are annual growth rings.
Though fungal reproduction is complicated, it’s safe to say the visible parts are usually the result of sexual reproduction, and are called “fruiting bodies”. They produce the dustlike spores, often in unbelievably huge numbers. But they’re just the tip of the fungus – most of it, the “mycelium”, lives and feeds deep within dead wood or soil. The lignin-breakers are part of a special group referred to as “white rot” fungi, since their mycelial activity creates a bleached look in dead wood. See this link for more: http://www.mykoweb.com/articles/DeconstructingDecomposing.html
The wood rotters also help other decomposers get access to nutrients, as explained in this good article: http://theconversation.com/wood-beetles-are-natures-recyclers-with-a-little-help-from-fungi-76029
The related Corticoid Crust fungi also degrade lignin; and as their name implies, they form a spreading “crust” on the surface of dead wood. If you’re not familiar with crust fungi, don’t feel bad – they seem to receive a lesser amount of attention from mycologists and field guide writers alike.
It’s been a nice surprise to learn that several species of crust fungus prefer to grow on the dead stumps of Bush Honeysuckle, as in the pics below.
Turkey Tails are particularly happy on Honeysuckle stumps
Other fungal groups in the Basidiomycetes include Stinkhorns and Puffballs, both of which have erupted with fruiting bodies recently.
The Giant Puffball is found world-wide in temperate climates; no surprise since a fruiting body can produce up to five trillion spores!
Conrad’s hard hat won’t fit on this one.
This spongy looking brown mass is the Puffball’s ripe fruiting body – kick it and some of those trillions of spores will explode out like smoke.
All of the fungi in this post are still visible in our forest – even more so as the leaves fall off. Fungi seeking makes a a good excuse for a walk in the forest, if you really need one!