Have you read the headlines about emerald ash borer? Didymo? Spiny waterflea? Asian clam? These non-native pests, plants and aquatic invaders are on the move, and our forests, rivers and lakes are seemingly under an endless siege. With many species, it can be hard to keep track of every one as well as to keep the big picture in mind and the solutions in sight. Here is a snapshot of the top threats to the Adirondack region, and what is at stake.
If left unchecked, invasive forest pests will kill trees, reduce timber harvests and weaken the wood products industry. Every landowner should know these two non-natives: emerald ash borer and Asian longhorn beetle. Actually, it is the trees that they attack that one should know. Why? Because landowners are often the first detectors of dead or dying trees resulting from a forest pest infestation. And, if detected early enough, opportunities for eradication exist.
Emerald ash borer is in at least 15 states and two provinces. It is a small, green beetle from Asia no bigger than a penny that kills its host trees - green, white or black ash - in just a few years. Seven percent of the trees in New York state are ash. Though not yet detected in the Adirondacks, EAB is reported just north of the U.S.-Canadian border, to the west in the Finger Lakes and to the south in the Catskills.
Asian longhorn beetle, on the other hand, is in isolated infestations in only 4 states and has yet to be detected in New York north of Manhattan. The reality is, however, that ALB has the possibility of spreading across much of the country causing widespread damage to hardwood forests. Its primary food source is maples, birch, poplar and other hardwoods. Unlike EAB, ALB is not a strong flier, is in only a few locations and can be eradicated, if enough resources are invested in its control. Also, clamping down on the transport of infected firewood, the main pathway of long distance spread of these forest pests, will slow their spread.
What about terrestrial invasive plants? If left to spread, terrestrial plants clog drainages, obscure visibility along roadways, cause erosion, reduce tree regeneration, push out native plants and degrade habitat for wildlife. The main points of introduction of terrestrial invaders are ornamental plantings of invasive species, often by uninformed gardeners or landscapers, and roadside disturbance.
Which ones are on the move? Japanese knotweed plagues communities across the park with its thick stands and dense canopies, threatening to spread for miles along rivers and streams. Phragmites, or common reed grass, is increasing its numbers in wetlands, notably along state Route 3 from Tupper Lake west to the Park's edge. Surveys show epicenters of garlic mustard in the southwestern Adirondacks and throughout campgrounds in the region. In late summer, purple loosestrife signals its continued march along state Routes 30 and 73, I-87 and other right-of-ways and wetlands.
Newer on the scene is yellow iris, which unfortunately is growing in popularity as plantings in gardens and along shorelines. Another popular ornamental, Asiatic bittersweet, is creeping along the forest edge up the Northway. Swallow-wort is staking its claim along Lake Champlain. Infestations were known along the fringe of the northwestern border of the Park, but this year new reports surfaced in Willsboro and Ticonderoga.
What's happening in the water? Fishing, boating, swimming, property values, water quality, water flows and native plants and fish - these are all at risk from aquatic invasives. At least 74 waters are invaded by one of eight aquatic invasive plants. The two most widespread species are Eurasian milfoil (in more than 50 waters) and variable leaf milfoil (in more than 20) but others such as water chestnut and curlyleaf pondweed should not be overlooked. Contaminated recreational watercraft and trailers are the main culprits here.
Non-plant invaders are dangers, too. These are largely introduced via bilge water, bait buckets or gear. Spiny waterflea is in four waters in the southern Adirondacks, and Asian clam came on the scene in August in Lake George. Zebra mussels remain in only two waters in the Park, Lake George and Lake Champlain. Another season passed with no didymo sightings in renowned Adirondack trout streams, like the Ausable River. And, luckily, the fish killing disease, VHS (viral hemorrhagic septicemia), was also kept at bay.
So, what does all of this mean? What should we do, now? Well, we have to know what we are up against in order to be able to fight it. And now we do know. And we are fighting it, but we need your help. Learn how in the next, and last, Eye on Invasives column of this season.
Eye on Invasives is a biweekly column that spotlights a top invader when it is easiest to identify. Hilary Smith directs the Adirondack Park Invasive Plant Program, a partnership program housed at the Adirondack Chapter of The Nature Conservancy in Keene Valley. Find out more about this award-winning program online at www.adkinvasives.com.