Snow and Wind Bring a Load of Hurt to Landscapes
I yelled and screamed until I almost lost my voice. I clapped and stamped trying to get their attention to the impending doom. Things were dropping and drooping all over the place. It felt like January, but the calendar said October 29. But no matter what I did, the outcome was the same, and all across the field there were winners and losers. It would become known as ‘The Nightmare before Halloween.’
I was at the Rutgers v.West Virginiagame last Saturday while the ‘great pumpkin’ nor’easter came for an early season visit last Saturday evening. With all the dropped passes and branches, I could have been talking about either one. Just like the leadRutgershad, the nor’easter was fairly short lived as far as storms go. But the storm’s impact will be felt for months if not years into the future.
As we saw this past weekend, a heavy load of snow, not just measured in inches but also in its quality, can easily bend tree limbs into arches and eventually cause branches to snap. Many of us have enjoyed those glistening winter mornings in our neighborhoods or ski slopes where birches are bent over by ice or snow, creating a gorgeous arched glade. But what happens when the load is just too much for the tree to bear? What many of us experienced – snapped limbs and trees, power outages, property damage, and personal injury or worse.
Crown snow-load, which refers to the snow which clings fast to the trees, requires special conditions to develop. The ordinary, light, and fluffy snow that we’re all accustomed to will fall from the trees in a slight wind, but ‘wetter’ snow as we saw this past weekend, stays put. That is, until the branch breaks or tree topples over.
But just how much weight are we talking about? Research conducted inFinland, where they know snow for sure, has shown that a single 60-foot tall spruce tree has a snow load limit of just over 7,000 pounds. Every branch and needle that collects that sticky wet snow adds to the weight of the tree’s branches, and some of them quickly fail and break. Since leaves are so much larger than needles on evergreens, imagine the weight load as each catches more than a handful of heavy wet snow.
And as we just saw, it’s not just the weight itself but how rapidly the load builds on tree branches and how any bit of wind can bring the whole thing crashing down on us.
Closer to home,RutgersUrban Forestry Professor Dr. Jason Grabosky has teamed up with Dr. Ed Gliman of Florida, a Rutgers alum, to look at how even young trees respond to certain loads, specifically when the wind howls.
They went so far as to build a wind machine with a propeller capable of generating hurricane force winds (75 mph) to determine the influence of nursery practices, planting, and pruning on trunk movement of oaks at various wind speeds. As you might imagine, increasing wind speed increased trunk movement, but they found that thinning the trees to seemingly allow the passage of wind through the canopy was one of the least effective pruning types for reducing trunk movement in wind.
These and other research findings were presented at the recently held conference of the NJ Shade Tree Federation inCherry Hill,NJ. All the presenters underscored the need to properly manage not only the large stately trees in our neighborhoods, but even the very young to middle aged trees that are just coming into their own to beautify our communities, alleviate pollution’s health effects, and mitigate storm water runoff.
The New Jersey Shade Tree Federation (www.njstf.org) is a non-profit organization that has been assisting those individuals and agencies entrusted with the selection, planting and care of trees, since 1926. Their motto, “Trees turn cities into hometowns” is attributed to their former Executive Director William Porter. The Federation strives to provide their members and municipal and county officials with the latest information and techniques in municipal tree care.
“A properly selected tree, given a suitable location and proper care, will outlive the person who plants it, and will continue to benefit people for generations to come,” stated current Executive Director Donna Massa. “Trees create green spaces in communities. Placing the right trees in the right places benefits you, your home and your community now and in the future.”
Hopefully your town has a Shade Tree Commission, or at the very least a knowledgeable Department of Public Works that cares for your town’s trees, because their workload has now increased several fold. Crews were in my neighborhood Sunday afternoon clearing roads of fallen trees and limbs, and they have yet to scratch the surface.
A trained eye would know to look up and inspect the trees from the top down, looking for cracked or hanging branches that haven’t fallen to the ground yet. But they will, and hopefully after reading this article you’ll go out and look up, maybe even with binoculars. Most people are used to seeing things from their eye height down, and never even think about what’s above until it droops too low or somehow gets in their way.
Shade tree commission members and tree care advocates take a higher and longer view of our landscapes, cleaning up the debris from fallen trees and also inspecting younger trees for cracked or split branches that were bent just a bit too far by the storm. Granted, the limbs may be nearly back up where they were, but they may have incurred enough damage that even smaller healthier looking trees may have to be replaced.
Just as Irene flooded homes and businesses and drained municipal and county budgets, this pre-Halloween snow storm will do the same, but over a much longer time frame. As we look to repair and replant out hometowns, we’ll see that this ‘trick or treater’ took much more than just trees last weekend.
Nicholas Polanin
Associate Professor, Agricultural Agent II
RutgersNew JerseyAgricultural Experiment Station
Cooperative Extension ofSomersetCounty