As Earth Day approaches (April 22 this year) I am reminded, as I have been every year over the past couple decades, of how poorly managed our City’s urban forests are, especially in the most central neighborhoods, such as Queen Anne Hill, Capitol Hill, and Beacon Hill. Living on Queen Anne Hill, I have frequent occasion to walk, bike or drive by the various segments of “greenbelt” that have been purchased by the City over the yaears with parks levy dollars. Case in point is the “Northeast Queen Anne Greenbelt” – a compendium of disaggregated full and half-blocks of forested hillside that in some cases stretch for a few blocks and in others are simply single-block in-holdings. In this area in particular the “urban forest” – for want of a better term – is in such poor condition that one wonders if a controlled burn or some other scorched-earth approach might not be in order to start over.
While there’s no denying that undeveloped swaths of green space offer a welcome respite from the dense development in our central urban neighborhoods, when they are choked with vines and other intrusive vegetation, harbor rats and other vermin, and are essentially inaccessible for a casual urban hike, are they really serving the purpose they were likely intended to do – at taxpayer expense?
Not so many years ago it seemed the universally feared vegetative invaders were English ivy (Hedera helix) and Himalayan blackberry (Rubus armeniacus). That’s not to say that they have ceased fulfilling this invidious role, but over the past 15 years or so, especially in the most central urban forests, the dreaded wild oriental clematis (Clematis orientalis) has taken a foothold and is on the rampage.
This rapacious vine leaves the other two behind by leaps and bounds – literally. This plant’s vines thrust upward onto tree canopies and literally engulf an entire tree. I’ve seen greenbelt acreage in my neighborhood that formerly sported a variety of individual trees now resemble a Dr. Seuss-like living carpet of vines with indistinguishable hillocks of vine mass where the trees once stood. What’s more, these vines so aggressively pull on their victims that branches and even small trees literally fall over under their weight. I witnessed a large branch of a big-leaf maple come tumbling down into the sidewalk and one of the southbound travel lanes of Aurora Avenue North.
Perhaps the worst effect of all of these invasives in our greenbelt lands, even if individual trees find a way to survive their onslaught, is that the potential for a new generation of tree canopy is all but lost across these pockets of greenbelt. With the understory almost entirely engulfed in vines of one sort or another, new saplings or seedlings have no chance of survival. And as our mostly deciduous urban forests reach their maturity (most big-leaf maples and alders have a lifespan of only 75 years or so), what will we be left with to grace our hillsides? Tangled masses of vines clinging to dead snags?
I know that municipal budgets are tight and our City’s pressing needs are many, but it may be time to consider appropriating some even modest amounts to fund incremental rescue efforts in our taxpayer-purchased greenbelt areas. Volunteers do help, and I have a long-standing tradition of going out, heavy-duty clippers in hand, on every Earth Day weekend to do my small part, but volunteers alone cannot take it all on. I hope the City will see the wisdom in helping to stem this insidious tide.