They come to us in many innocuous ways, from packages from overseas, to clinging onto the bottom of our fishing boats. They are the invaders that cause so much trouble when they go unchecked. I am talking about invasive species. From the long-horned asian beetle to the goby, from giant hogweed to feral swine. These non-native, introduced species of fish, plants, mammals, and insects have come from overseas and without any natural checks to keep them from populating our waters and woods at a very fast rate, causing alarming damage. Most of which goes unchecked and unseen until it is at the point where the invasives are out of control.
While there are thousands of invasive species in the United States, I am just going to cover the most common and destructive found here in our area of New York, including some in my own backyard. Here, I will introduce you to the critters and alert you to the damage they have done and will continue to do if they are left to populate without our intervention. I will give you a brief history of how they got here, what they look like, what damage they have done and what is being done or what you can do to eradicate them from our area.
In this first of a series, I will start out with the terrestrial plants. One invasive that can be found in most woodlots throughout the county is the garlic mustard plant. Garlic mustard is an invasive herb that has spread throughout much of the United States over the past 150 years, becoming one of the worst invaders of forests in the Northeast. Garlic mustard originated in Europe and parts of Asia. It is believed that it was purposely introduced into our country for medicinal purposes and food. The earliest known report of it growing in the United States dates back to 1868 on Long Island, NY. These three foot tall plants are biennials. The first year they form a low growing rosette that most probably overlook. The second year the plant forms a three foot stalk that contains the seed pods that help it spread. Each pod contains up to 28 seeds, with 22 pods present in most plants...Thus easy math will show you that one plant can produce about 600 seeds and obviously spread quite rapidly.
Garlic mustard has the potential to form dense stands that choke out native plants in the understory by controlling light, water, and nutrients. Garlic mustard is one of the plants able to dominate the understory in forests. Altering plant diversity can cause a change in leaf litter on the forest floor, potentially impacting salamanders and snails. Insects, including some butterflies, may be affected through the lost diversity in plants. Garlic mustard may also affect the tree composition by creating a selective barrier that some seedlings may not be able to overcome.