Tracking fall’s progress in a patch of Manhattan forest in Inwood Hill Park.
On Tuesday morning, the woods are sparse and still, reduced to their most basic elements: trees, rocks, terrain. The scene is a frugal study in browns and grays against a big blue sky.
The low-angled sun casts sharp light and extended shadows. It feels like December. My fingers are cold, despite my leather gloves. I make a mental note to wear thicker socks next time.
There are no leaves underfoot. This season’s have been wind-swept into the hollows, some of which are knee-deep with leaves. The bare ground showcases a mosaic of once-hidden flotsam: broken glass, bottle caps, flinty rocks, small twigs, discarded cigarettes.
The leafless mounds are covered by moss. Mosses creep up the trunks of trees. Mosses spread along the surface of stones. Mosses blanket the flat distance in between. These primal plants have been here all along — the park has the largest expanse of mosses in Manhattan — but we were busy charting changes in more recently evolved flora.
Emerald carpets of fire moss roll out in all directions. A dislodged clump pushed into the soil will root and grow, one reason why it is the most common species here. Silver ball moss grows in a velvety pincushion at the base of a rock. When dried, it develops a whitish cast. Callicladium moss on the lower trunk of a white oak looks like an old shaggy rug. Haircap mosses resemble miniature conifer trees. The beds support seedlings of larger woody species, especially blueberry and black cherry, that will eventually overshadow and outcompete the moss.
The same environments that harbor moss also support lichens. Lichens are two organisms in one, a shared existence between algae and fungus. These work in unison to survive in exposed environments like the sides of trees and surfaces of rocks. Lichens are sensitive to air pollution, especially sulfur and nitrogen. Their presence signifies clean air.
Lichens parade in an array of curious shapes and colors. The crustose types appear as a skin on a rock or tree. The edges of foliose lichen rise up from the surfaces they grow on like the margins of curling paper. There are sea foam green swirls, chalky gray dust and cubed, saltlike deposits. Lichens do not harm the trees that support them. In fact, they return the favor by transforming atmospheric nitrogen into a form that plants can use.
More color is provided by large swathes of paint on trees and rocks to mask graffiti. One trunk is scripted in a minty green that I first mistake for lichen. But nothing grows on these painted strips.
At the edge of our woods, a dark-eyed junco jumps out of view. A blue jay flaps away, the tips of its wings resembling spread fingers. Schoolchildren are visiting the park below.
The sun’s glare is relentless. At the bottom of the stairs I stand in the intense light for a minute to warm up. The cold should be a fixture now. Winter begins on Thursday. Marielle Anzelone