New River Gorge National River, WV: A hike along the rim of the New River Gorge offers spectacular vistas of steep walls, rushing water, and lush green trees. This environment hosts large groves of Hemlock trees, which have stood for centuries. Since early 2005 these groves have been under attack from an unassuming visitor, the deadly Hemlock Woolly Adelgid.
Native to Asia, the Hemlock Woolly Adelgid has found sanctuary in the abundance of hemlock groves found on the eastern coast of North America. Without a native predator the Woolly Adelgid has the ability to reproduce quickly. So quickly in fact, the United States Department of Agriculture found that a single Hemlock Woolly Adelgid lays 300 eggs in a year, yielding an average of 90,000 new adelgids!
The hungry offspring feast at the base hemlock needles. As the adelgid consumes sap, it subsequently cuts off the flow of stored starches from the boughs. Once this connection is made nutrients will not reach the needles, causing them to darken in color, eventually turning brown and falling off. In 3-5 years the tree will die from this exposure to the invasive species.
(Photo provided by the New River Gorge National Park Service)
The hemlock groves of the New River Gorge National River provide a habitat for trout, salamanders, and birds such as the wood thrush. Hemlock trees cool mountain streams in the summer and retain moderate temperatures to prevent freezing during the winter months. Without hemlocks this area will see a dramatic shift in the ecosystem, a fact that should not be underestimated.
The National Park Service alongside the United States Forest Service is combating the Hemlock Woolly Adelgid using three techniques. Systemic pesticide injections and insecticidal oils and soaps are proven ways for temporarily disturbing the effect of the adelgid in single or small stands of trees. In vast forests of hemlocks biological control is implemented. Pt and Lari beetles are the only predator of the Hemlock Woolly Adelgids. Dispersing the small black beetles significantly decreases the population of woolly adelgids.
So what can you do?! Controlling any invasive species requires preventing the spread of the species itself. Here are some tips and tricks to minimize the spread of invasive species, including the Hemlock Woolly Adelgid.
· Plan ahead and prepare about invasive species in your area
· Clean your clothes or gear before changing locations
· Brush down the soles of your boots or trail shoes
· Leave natural objects as you find them to avoid picking up hitchhikers
· After hiking with your pet be sure to brush their coat
· Use firewood from local sources only
· Wash your car tire or bike tread before traveling long distances
Let’s work together to stop the spread of invasive species, and to save our Hemlock trees on the east coast!
Steph & Andy
Leave No Trace’s Stephanie Whatton and Andy Mossey are part of the 2015 Subaru/Leave No Trace Traveling Trainer Program that provides free, mobile education to communities across the country. Proud partners of this program include Subaru of America, Deuter, Hi-Cone, REI, Smartwool, The North Face, and Yakima.