The old maple is dying.
It faded slowly at first, but last summer it began to go fast, its lichen-covered limbs snapping and falling to the ground, the gray bark covered with dark green moss. It has far fewer leaves. A crack runs up the middle. More plants grow in the tree’s crevices: purple blackberry canes, spiky grasses and red-tinged euonymus. For the first time, I see three woodpecker holes, so beautifully aligned they look like Orion’s belt.
I do not know why the tree is dying, so I do some research. Maples are prone to many diseases, such as anthracnose, verticillium wilt, and powdery mildew, but I am still confused, so I call Brian Crooks, a forester with the Western Pennsylvania Conservancy. The giveaway, he says, are the small honey-colored mushrooms at the tree’s base, which indicate the maple has a fungus: Armillaria root rot.
The Armillaria fungus affects many hardwoods and conifers, especially maples, oaks, and elms. Black, stringy rhizomorphs grow through the soil into the roots and trunk of the tree and attack the wood. If I remove the bark, I might see bright, white mycelial fans. But none of that is visible yet. I learn that the Armillaria fungus is the world’s largest known organism, bigger than the 200-ton blue whale. A patch of Armillaria was discovered in Oregon in 1998 covering 2384 acres.
I don’t know how large ours is, but I do worry about it encroaching on a nearby tree, a large red oak that is a favorite of my husband’s.
I wonder if the maple doesn’t like our new western Pennsylvania weather: the extreme heat, the drought, then the microbursts of rain and wind and the flash floods. When our floods come now, the water runs down the hill so fast that the maple sits in the middle of a pond, a stream running through it. I do know from maple sugaring with my friend and his 89-year-old uncle that changing climatic conditions are making sugaring more difficult. For the sap to run in February or March, the days must be warm and the nights cold. The timing is less predictable now. But I am not a scientist, so I ask Crooks.
Source: The New York Times