Learning the Lessons of Powerful Storms

by Max McCormack

     "I’ve never seen so many trees blown over. We’ve been without power since Sunday morning."

     "Have you noticed the broken, ripped out root systems?"

      That was the talk on a sidewalk in Bangor on Tuesday, Nov. 4. Yes, the parks, roadsides, and views across wooded landscapes displayed a pandemonium reminiscent of a game of jackstraws or dominoes lined up in rows knocked over in sequence one-by-one. This was the scene in parts of Waldo and across southern Penobscot, Hancock, and Washington Counties. There was little consolation in recognizing that it was nature taking its course. 

     The storm on Sunday, Nov. 2, came as a blast of early, wet, heavy snow with winds packing the snow into tree crowns and triggering a pendulum action that rocked the spindly stems. Many root systems not yet frozen into the ground by winter temperatures were pried loose and torn asunder (See photo). Where root systems held their anchorage, the rocking, snow-burdened crowns shattered stems at their weakest points. The mayhem was aggravated by the pulsing winds and poorly developed trees with low live crown ratios that were especially vulnerable to the storm’s fury. 

     It was a unique combination of circumstances that would have resulted in serious damage even in stands that had been culturally tended. In 1972 I witnessed severe wind damage from a storm off the North Sea that devastated well-managed forests in northern Germany. Forest managers, with tears in their eyes, gazed across tangles of broken, horizontal trees representing an estimated volume equivalent of 15 years of annual harvests that had been knocked to the ground overnight. 

     The flood of wood posed challenges for effective marketing and storage of roundwood subject to decay and insect damage. Similar, smaller scale events occurring over subsequent decades dictated that large proportions of planned annual harvests be comprised of salvaged storm wood. Fortunately, their well-established trail systems made salvage harvests feasible.

     In Maine, there has been a long-standing expectation that commercial thinnings, and other partial cut harvests, would likely be followed by wind damage that could result in wood volume losses. Salvage has been impractical. Disorderly, downed stems have impeded access and deterred management of regeneration.

      Remedial action in such damaged stands is difficult if not fruitless. Solutions are best found in planning and preparing to avoid wind vulnerability during regeneration and early stand development, complemented by timely intermediate silviculture treatments. Crop trees should have generous spacing for continuous, robust growth that produces healthy crowns and root systems. This should be done with a focus on maintaining positive momentum. 

     Landowners can conduct management activities with anticipation of forceful prevailing winds, and establish long-term, convenient access for operational treatments and salvage of damaged, high-value stems. They can vary stand structure patterns and species composition with incorporation of wind-firm components (oaks, pines, and red spruce). As always, efforts should be focused on areas of best site quality. Don’t waste resources on poor sites that are inherently vulnerable to wind damage.