As I wandered through the Shamokin Springs Nature Preserve at the peak of fall foliage, I noticed that the vast majority of trees in the preserve had dropped their leaves a bit too early. Other locations around the mountain showed similar behavior signaling an abrupt end to the growing season. The forest at Wintergreen is in a time of great stress and this Nine Minute Naturalist will be focused on some of the causes and solutions to a stressed-out forest.

Black ash

The Shamokin Springs Nature Preserve (SSNP) is a microcosm of the greater forest at Wintergreen. It has many acute and universal factors causing decline throughout the preserve. A major problem is introduced forest problems. The preserve is laden with ash (white and black varieties) and American beech. The emerald ash borer, an invasive brought in via packing materials from China, has devastated all ash from Colorado to Massachusetts. The insect attacked the black ash first and has since moved on to killing the white ash in the preserve and throughout Wintergreen. The beech is being killed by beech bark disease, a disease complex featuring a non-native scale insect which bores into the bark and causes cracks that the native nectria fungus enters and deforms the stem. The monoculture of beech in the nature preserve are slowly breaking and ending on the forest floor.

Emerald Ash Borer

A few acute stressors not caused by introduced species include ice, flood and drought damage. These factors are problematic not only in the SSNP but throughout the Wintergreen landscape. A simple glance to the treetops in the SSNP or any exposed ridge will reveal a mass of broken off tops as a result of ice and wind damage. This damage rarely results in instant mortality but instead is a stepping stone on the path to the trees demise. Flooding has been a constant problem the past few years and the 10, 50, and 100-year storms seem to be happening at shortening intervals. Root damage and exposure is common during flash floods that seem to be common at Wintergreen lately. Before our period of flooding in the past 3 or 4 years, drought was the stress point trees were dealing with. This combination of stress factors is not generally lethal by itself but when combined they shorten the lifespan of many trees.

Another overall factor that is particular to high elevation forests such as Wintergreen is climate change. The SSNP is a case study for this change. This preserve is unique because it offers a slightly lower surface temperatures due to the volume of water running through this location. This has allowed species common in New England and Canada to find a foothold in Virginia. Species such as black ash or speckled alder are living at their southern range. Any change in temperature will weaken these northern forest species and they won’t be able to deal with additional health factors. The Nature Foundation is partnering with VCU professor Catherine Hulshof to study the effects of climate change on our forest at multiple sites at Wintergreen.

The solution to constant forest stress is resilience. The way to achieve this goal is diversity in the forest. New species-specific pests or diseases will arise and the key to withstanding the loss of one species is having many that will fill the gap. What this means for the Wintergreen homeowner is when you have planting opportunities, attempt to increase the diversity of your forest by planting a variety of native trees that will excel in our changing landscape. Another recommendation is be proactive in your decision-making on how to treat individual trees. If an insect or disease descends on your location don’t wait to act but chose quickly whether the tree is worth the expense of treatment. This will ensure the tree retains its vigor to fight the other myriad of stressors coming its way.

If you have a question on particular trees in your forest feel free to send me images at forestmanage@tnfw.org or call me at 434-325-8169 and set up a time for me to look at your forest to provide recommendations.