On Saturday I took a canoe trip down the little stream with the big name (West Fork of the Moose Horn River) that passes through my property to visit the western section. This area is approximately 56 acres and forested. Most of it is upland aspen and spruce forest but there is a large hardwood swamp near the southern property line.

The ground was still snow covered but it was melting fast in the warm sun. I spent most of my time in a portion of a hardwood swamp looking at tree trunks for lichens and fungi. I found several lichen species previously documented from here and possibly one new species for the list. There are also a number of unknown lichen specimens to figure out.

Shadow Lichen (Phaeophyscia orbicularis?) on a sapling black ash tree.

Shadow Lichen (Phaeophyscia sp.) with an unknown gray foliose species on a small but old red maple.

Shadow Lichen (Phaeophyscia sp.) on a sapling black ash tree.

Lung Lichen (Lobaria pulmonaria) on a small but old red maple

Appalachian Punctelia (Punctelia appalachensis) on a black ash tree.

Appalachian Punctelia (Punctelia appalachensis) on a black ash tree.

Powdered Fringe Lichen (Heterodermia speciosa) on a black ash tree.

Frost Lichen (Physconia sp.) on a black ash tree

Frost Lichen (Physconia sp.) on a black ash tree

Saucer Lichen (Ochrolechia trochophora) on a black ash tree.

Four lichens: Script Lichen (Graphis scripta in upper right) and three unknowns.

There were two fungi that interested me. One is Phellinus igniarius, a polypore bracket fungus, that was growing on the trunk of an old quaking aspen. This fungus decays the lignin in the wood leaving behind the lighter colored cellulose and is one of the causes of white-rot in hardwood trees. The other fungus looks like P. igniarius and like it causes decay in living hardwoods. This one seems to only grow on black ash trees. It is a polypore but the pore surface looks shaggy rather than smooth. So far no luck in figuring it out.

Phellinus igniarius on quaking aspen.

Phellinus igniarius on quaking aspen.

Unknown bracket fungus on black ash.

Unknown bracket fungus on black ash.

Most of the trees in the hardwood swamp are black ash (Fraxinus nigra) with some green ash (F. pensylvanica), yellow birch (Betula allegheniensis), paper birch (B. papyrifera), American elm (Ulmus americana), quaking aspen (Populus tremuloides), and red maple (Acer rubrum). A year ago I measured the trees in the lower two-thirds of the swamp to get a population count by species and to calculate basal area. Some of the black ash trees are huge (for this part of Minnesota anyway). Of the 64 black ash measured 14 were between 28 cm and 44 cm in diameter. There were also 12 yellow birch in this size range. Black ash and yellow birch are slow growing trees even on good sites like this one so it is possible that the largest trees are at the century mark.

Large diameter black ash tree.

Large diameter black ash tree.