As I write this column, I am sitting in a sixth floor room of a hotel in Plymouth Meeting. When I was a child, Plymouth Meeting was still something of a strange crossroads between the two legs of the Pennsylvania Turnpike and the still-future Blue Route. Since the infrastructure was not completely filled out, commercial development had not yet reached its zenith. So there were open areas, and the area still had evidence of the time when the two miles from the Philadelphia border might have been 200.
Now that the infrastructure is complete, and commercial development has followed, Plymouth Meeting is something of a storefront, parking lot and highway paradise, if anyone can call asphalt and concrete paradise.
But in its development, thankfully, even though every square inch of space is managed, green has not been forgotten. As far as the eye can see, there are parking lot islands planted with trees that not only soften the scene, they intercept rainwater, screen pollution, cool both the air around them and the pavement beneath, and soften the ceaseless drone of traffic. This is the urban forest hard at work. But is it the urban forest at its best?
To find out what could be the urban forest at its best, we have to look at its natural counterpart. Here, the unmanaged forest comprises not just every square inch but every cubic inch as well. In other words, here in Plymouth Meeting, there is a “forest” floor, built of lawn or ornamented mulch. There is also a uniform canopy, which includes the crowns of the trees planted in the islands reserved from the reaches of the asphalt sea. But the cubic inches between the top of the grass or mulch and the bottom of the tree canopy are forgotten.
Now let’s dream about replacing the forest in these islands. In forest ecology, the area beneath the shade trees is called the understory. Because it is shaded by the taller trees, its plants bud earlier, and its leaves drop later than the canopy. And it is a crowded, sometimes impenetrable thicket full of plant and animal species.
Think of the maintenance requirements of this reestablished forest: no grass to mow, curbs to edge, mulch to replace annually. Instead, the leaves must still be raked, but only on the pavement, because the rest will recycle on the “forest” floor. Periodically, litter must be removed, and the reach of the shrubbery must be restrained annually with loppers.
Otherwise, this reestablished ecosystem that filters light, water, wind, noise, traffic and sights will be inexpensively self-sustaining and perpetually variable.
Could such a “wonder” be brought home to the right-of-way in our front yards from the corporate park and hotel? Perhaps with discretion, and the genius of being the planet’s cultivators is that we get to choose.
Joshua Arp is an ISA-certified municipal specialist, Clarks Summit’s municipal arborist and an operator of an organic lawn and landscape maintenance business. Reach him at firstname.lastname@example.org.