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Invasive Species in Our Backyards and Forests

WESTFIELD – Any species, regardless of how insignificant it may seem, is the product of thousands or millions of years of evolution, and more importantly, plays an irreplaceable role in the complex web of Earth’s ecosystems. Scientists estimate of the current total number of different species in the world is anywhere between one and twenty million, yet we have only identified a small portion of those twenty million. They also estimate the number of species that go extinct every day is between fifty and several hundred. Some of those species will never be identified before they go extinct. The current rate is significantly higher than “normal” extinction rates in nature of one species every twenty years. The top two causes for species extinction across the globe are directly related to human activity: habitat loss and invasive species.

In the past, many of these invasive species were brought into the United States as ornamentals for gardens or because the plant was useful in some way such as to stabilize stream banks. However, since then they have “escaped” and they are causing havoc to our native wetlands and woodlands.

What makes a species invasive?

Invasive species are non-native insects, plants and animals that when introduced, disrupt and/or destroy native ecosystems. They have reproductive mechanisms that allow them to grow and spread rapidly. They have no “local” diseases or predators to decrease or keep their numbers in check. Some invasive plants can have thousands or even millions of seeds on a single plant. Water, wind, birds and animals then disperse seeds and plant parts, thereby allowing them to colonize new areas. Many times invasive plants establish themselves in disturbed areas such as utility corridors or new construction. They easily adapt to variable environmental surroundings, as some plants can thrive in wetlands, as well as uplands. Invasive species are typically heartier than native species, and can survive extreme environmental changes, such as changes in temperature or available water.

Adaptable and fast growing, they easily take over native habitats. By crowding out and taking habitats from various native species, they decrease biodiversity and can alter ecosystem processes, such as hydrology and soil chemistry. One invasive, garlic mustard, releases a chemical compound into the surrounding soil that prohibits native plants from absorbing essential nutrients from the soils. Invasive plants can even be noxious to humans such as the giant hogweed plant that produces large painful lesions on the skin if exposed to the sap.

Invasive species cause economic problems

Invasive species can also be economic disasters. Some invasive plants, such as Japanese knotweed, have rhizomes, or underground roots and stems that invade new areas. Knotweed can have roots that extend 10 feet down and 25 feet outward in all directions. The rhizomes are strong enough to penetrate brick, concrete and even volcanic rock. I recently attended a discussion where an environmental consultant from England was a guest speaker. You can check out his website at: www.jksl.com. He spoke of the knotweed problem in the United Kingdom. It’s estimated that 40 percent of all properties in the UK have Japanese knotweed present. Because knotweed is so destructive to buildings, mortgage companies in the UK are refusing to give mortgage loans on properties where this invasive is present or is found within 100 feet of the property line. Can you imagine being turned down for a mortgage because of a plant that’s not even on the property you want to buy? We have not seen this occurring in the US as yet, but if left unaddressed, this issue will eventually cause us similar economic hardship.

What can be done?

Many environmental, as well as governmental, groups are working on the problem. The Massachusetts Natural Heritage and Endangered Species Program (NHESP) recently issued an updated guide listing 66 species identified in Massachusetts as either invasive, likely invasive or potentially invasive. In 2005, the Massachusetts Department of Agriculture Resources established regulations involving the banning or phase-out of importation, propagation or sale of more than 140 plants in Massachusetts.

You may check the Department of Agriculture’s website for a current list of prohibited plants at www.mass.gov/agr. Other helpful sources include NHESP at www.nhesp.org, or the New England Wildflower Society at www.newfs.org, or the Invasive Plant Atlas of New England (IPANE) at www.eddmaps.org/ipane, or the Nature Conservancy at www.tnc.org. If you need further information or would like to report invasive species, feel free to contact the coordinator for the Westfield River Watershed Invasive Species Partnership (WISP) Hannah Beach at 413-628-4485, ext 3 or you can email WISP at [email protected]

Do you have Norway maple, oriental bittersweet, autumn olive, garlic mustard, buckthorn, Japanese honeysuckle, multi-flora rose, Phragmites, purple loosestrife, tree-of-heaven, Japanese knotweed, burning bush or Japanese barberry in your yard? These are just a few of the more common invasive plants, and chances are you have at least one of them on your property. If you have identified invasive species on your property and would like to remove them, please be mindful of their location in relation to wetlands, as any work in or near wetlands may require a permit from the conservation commission. However, the commission does not want to over burden residents with paperwork, and will work with you to improve your property and protect the wetlands at the same time. If you have these concerns, feel free to contact me, Karen Leigh, at 572-6281.

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